forked from mirrors/gecko-dev
		
	
		
			
				
	
	
		
			5330 lines
		
	
	
	
		
			219 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			5330 lines
		
	
	
	
		
			219 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 | ||
| /* vim: set ts=8 sts=2 et sw=2 tw=80: */
 | ||
| /* This Source Code Form is subject to the terms of the Mozilla Public
 | ||
|  * License, v. 2.0. If a copy of the MPL was not distributed with this
 | ||
|  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 | ||
| 
 | ||
| /* rendering object for CSS "display: flex" */
 | ||
| 
 | ||
| #include "nsFlexContainerFrame.h"
 | ||
| #include "nsContentUtils.h"
 | ||
| #include "nsCSSAnonBoxes.h"
 | ||
| #include "nsDisplayList.h"
 | ||
| #include "nsIFrameInlines.h"
 | ||
| #include "nsLayoutUtils.h"
 | ||
| #include "nsPlaceholderFrame.h"
 | ||
| #include "nsPresContext.h"
 | ||
| #include "mozilla/ComputedStyle.h"
 | ||
| #include "mozilla/CSSOrderAwareFrameIterator.h"
 | ||
| #include "mozilla/Logging.h"
 | ||
| #include <algorithm>
 | ||
| #include "gfxContext.h"
 | ||
| #include "mozilla/LinkedList.h"
 | ||
| #include "mozilla/FloatingPoint.h"
 | ||
| #include "mozilla/UniquePtr.h"
 | ||
| #include "WritingModes.h"
 | ||
| 
 | ||
| using namespace mozilla;
 | ||
| using namespace mozilla::layout;
 | ||
| 
 | ||
| // Convenience typedefs for helper classes that we forward-declare in .h file
 | ||
| // (so that nsFlexContainerFrame methods can use them as parameters):
 | ||
| typedef nsFlexContainerFrame::FlexItem FlexItem;
 | ||
| typedef nsFlexContainerFrame::FlexLine FlexLine;
 | ||
| typedef nsFlexContainerFrame::FlexboxAxisTracker FlexboxAxisTracker;
 | ||
| typedef nsFlexContainerFrame::StrutInfo StrutInfo;
 | ||
| typedef nsFlexContainerFrame::CachedMeasuringReflowResult
 | ||
|           CachedMeasuringReflowResult;
 | ||
| typedef nsLayoutUtils::IntrinsicISizeType IntrinsicISizeType;
 | ||
| 
 | ||
| static mozilla::LazyLogModule gFlexContainerLog("nsFlexContainerFrame");
 | ||
| 
 | ||
| // XXXdholbert Some of this helper-stuff should be separated out into a general
 | ||
| // "main/cross-axis utils" header, shared by grid & flexbox?
 | ||
| // (Particularly when grid gets support for align-*/justify-* properties.)
 | ||
| 
 | ||
| // Helper enums
 | ||
| // ============
 | ||
| 
 | ||
| // Represents a physical orientation for an axis.
 | ||
| // The directional suffix indicates the direction in which the axis *grows*.
 | ||
| // So e.g. eAxis_LR means a horizontal left-to-right axis, whereas eAxis_BT
 | ||
| // means a vertical bottom-to-top axis.
 | ||
| // NOTE: The order here is important -- these values are used as indices into
 | ||
| // the static array 'kAxisOrientationToSidesMap', defined below.
 | ||
| enum AxisOrientationType {
 | ||
|   eAxis_LR,
 | ||
|   eAxis_RL,
 | ||
|   eAxis_TB,
 | ||
|   eAxis_BT,
 | ||
|   eNumAxisOrientationTypes // For sizing arrays that use these values as indices
 | ||
| };
 | ||
| 
 | ||
| // Represents one or the other extreme of an axis (e.g. for the main axis, the
 | ||
| // main-start vs. main-end edge.
 | ||
| // NOTE: The order here is important -- these values are used as indices into
 | ||
| // the sub-arrays in 'kAxisOrientationToSidesMap', defined below.
 | ||
| enum AxisEdgeType {
 | ||
|   eAxisEdge_Start,
 | ||
|   eAxisEdge_End,
 | ||
|   eNumAxisEdges // For sizing arrays that use these values as indices
 | ||
| };
 | ||
| 
 | ||
| // This array maps each axis orientation to a pair of corresponding
 | ||
| // [start, end] physical mozilla::Side values.
 | ||
| static const mozilla::Side
 | ||
| kAxisOrientationToSidesMap[eNumAxisOrientationTypes][eNumAxisEdges] = {
 | ||
|   { eSideLeft,   eSideRight  },  // eAxis_LR
 | ||
|   { eSideRight,  eSideLeft   },  // eAxis_RL
 | ||
|   { eSideTop,    eSideBottom },  // eAxis_TB
 | ||
|   { eSideBottom, eSideTop }      // eAxis_BT
 | ||
| };
 | ||
| 
 | ||
| // Helper structs / classes / methods
 | ||
| // ==================================
 | ||
| // Returns true iff the given nsStyleDisplay has display:-webkit-{inline-}box
 | ||
| // or display:-moz-{inline-}box.
 | ||
| static inline bool
 | ||
| IsDisplayValueLegacyBox(const nsStyleDisplay* aStyleDisp)
 | ||
| {
 | ||
|   return aStyleDisp->mDisplay == mozilla::StyleDisplay::WebkitBox ||
 | ||
|     aStyleDisp->mDisplay == mozilla::StyleDisplay::WebkitInlineBox ||
 | ||
|     aStyleDisp->mDisplay == mozilla::StyleDisplay::MozBox ||
 | ||
|     aStyleDisp->mDisplay == mozilla::StyleDisplay::MozInlineBox;
 | ||
| }
 | ||
| 
 | ||
| // Returns true if aFlexContainer is a frame for some element that has
 | ||
| // display:-webkit-{inline-}box (or -moz-{inline-}box). aFlexContainer is
 | ||
| // expected to be an instance of nsFlexContainerFrame (enforced with an assert);
 | ||
| // otherwise, this function's state-bit-check here is bogus.
 | ||
| static bool
 | ||
| IsLegacyBox(const nsIFrame* aFlexContainer)
 | ||
| {
 | ||
|   MOZ_ASSERT(aFlexContainer->IsFlexContainerFrame(),
 | ||
|              "only flex containers may be passed to this function");
 | ||
|   return aFlexContainer->HasAnyStateBits(NS_STATE_FLEX_IS_EMULATING_LEGACY_BOX);
 | ||
| }
 | ||
| 
 | ||
| // Returns the OrderingProperty enum that we should pass to
 | ||
| // CSSOrderAwareFrameIterator (depending on whether it's a legacy box).
 | ||
| static CSSOrderAwareFrameIterator::OrderingProperty
 | ||
| OrderingPropertyForIter(const nsFlexContainerFrame* aFlexContainer)
 | ||
| {
 | ||
|   return IsLegacyBox(aFlexContainer)
 | ||
|     ? CSSOrderAwareFrameIterator::OrderingProperty::eUseBoxOrdinalGroup
 | ||
|     : CSSOrderAwareFrameIterator::OrderingProperty::eUseOrder;
 | ||
| }
 | ||
| 
 | ||
| // Returns the "align-items" value that's equivalent to the legacy "box-align"
 | ||
| // value in the given style struct.
 | ||
| static uint8_t
 | ||
| ConvertLegacyStyleToAlignItems(const nsStyleXUL* aStyleXUL)
 | ||
| {
 | ||
|   // -[moz|webkit]-box-align corresponds to modern "align-items"
 | ||
|   switch (aStyleXUL->mBoxAlign) {
 | ||
|     case StyleBoxAlign::Stretch:
 | ||
|       return NS_STYLE_ALIGN_STRETCH;
 | ||
|     case StyleBoxAlign::Start:
 | ||
|       return NS_STYLE_ALIGN_FLEX_START;
 | ||
|     case StyleBoxAlign::Center:
 | ||
|       return NS_STYLE_ALIGN_CENTER;
 | ||
|     case StyleBoxAlign::Baseline:
 | ||
|       return NS_STYLE_ALIGN_BASELINE;
 | ||
|     case StyleBoxAlign::End:
 | ||
|       return NS_STYLE_ALIGN_FLEX_END;
 | ||
|   }
 | ||
| 
 | ||
|   MOZ_ASSERT_UNREACHABLE("Unrecognized mBoxAlign enum value");
 | ||
|   // Fall back to default value of "align-items" property:
 | ||
|   return NS_STYLE_ALIGN_STRETCH;
 | ||
| }
 | ||
| 
 | ||
| // Returns the "justify-content" value that's equivalent to the legacy
 | ||
| // "box-pack" value in the given style struct.
 | ||
| static uint8_t
 | ||
| ConvertLegacyStyleToJustifyContent(const nsStyleXUL* aStyleXUL)
 | ||
| {
 | ||
|   // -[moz|webkit]-box-pack corresponds to modern "justify-content"
 | ||
|   switch (aStyleXUL->mBoxPack) {
 | ||
|     case StyleBoxPack::Start:
 | ||
|       return NS_STYLE_ALIGN_FLEX_START;
 | ||
|     case StyleBoxPack::Center:
 | ||
|       return NS_STYLE_ALIGN_CENTER;
 | ||
|     case StyleBoxPack::End:
 | ||
|       return NS_STYLE_ALIGN_FLEX_END;
 | ||
|     case StyleBoxPack::Justify:
 | ||
|       return NS_STYLE_ALIGN_SPACE_BETWEEN;
 | ||
|   }
 | ||
| 
 | ||
|   MOZ_ASSERT_UNREACHABLE("Unrecognized mBoxPack enum value");
 | ||
|   // Fall back to default value of "justify-content" property:
 | ||
|   return NS_STYLE_ALIGN_FLEX_START;
 | ||
| }
 | ||
| 
 | ||
| // Helper-function to find the first non-anonymous-box descendent of aFrame.
 | ||
| static nsIFrame*
 | ||
| GetFirstNonAnonBoxDescendant(nsIFrame* aFrame)
 | ||
| {
 | ||
|   while (aFrame) {
 | ||
|     nsAtom* pseudoTag = aFrame->Style()->GetPseudo();
 | ||
| 
 | ||
|     // If aFrame isn't an anonymous container, then it'll do.
 | ||
|     if (!pseudoTag ||                                 // No pseudotag.
 | ||
|         !nsCSSAnonBoxes::IsAnonBox(pseudoTag) ||      // Pseudotag isn't anon.
 | ||
|         nsCSSAnonBoxes::IsNonElement(pseudoTag)) {    // Text, not a container.
 | ||
|       break;
 | ||
|     }
 | ||
| 
 | ||
|     // Otherwise, descend to its first child and repeat.
 | ||
| 
 | ||
|     // SPECIAL CASE: if we're dealing with an anonymous table, then it might
 | ||
|     // be wrapping something non-anonymous in its caption or col-group lists
 | ||
|     // (instead of its principal child list), so we have to look there.
 | ||
|     // (Note: For anonymous tables that have a non-anon cell *and* a non-anon
 | ||
|     // column, we'll always return the column. This is fine; we're really just
 | ||
|     // looking for a handle to *anything* with a meaningful content node inside
 | ||
|     // the table, for use in DOM comparisons to things outside of the table.)
 | ||
|     if (MOZ_UNLIKELY(aFrame->IsTableWrapperFrame())) {
 | ||
|       nsIFrame* captionDescendant =
 | ||
|         GetFirstNonAnonBoxDescendant(aFrame->GetChildList(kCaptionList).FirstChild());
 | ||
|       if (captionDescendant) {
 | ||
|         return captionDescendant;
 | ||
|       }
 | ||
|     } else if (MOZ_UNLIKELY(aFrame->IsTableFrame())) {
 | ||
|       nsIFrame* colgroupDescendant =
 | ||
|         GetFirstNonAnonBoxDescendant(aFrame->GetChildList(kColGroupList).FirstChild());
 | ||
|       if (colgroupDescendant) {
 | ||
|         return colgroupDescendant;
 | ||
|       }
 | ||
|     }
 | ||
| 
 | ||
|     // USUAL CASE: Descend to the first child in principal list.
 | ||
|     aFrame = aFrame->PrincipalChildList().FirstChild();
 | ||
|   }
 | ||
|   return aFrame;
 | ||
| }
 | ||
| 
 | ||
| // Indicates whether advancing along the given axis is equivalent to
 | ||
| // increasing our X or Y position (as opposed to decreasing it).
 | ||
| static inline bool
 | ||
| AxisGrowsInPositiveDirection(AxisOrientationType aAxis)
 | ||
| {
 | ||
|   return eAxis_LR == aAxis || eAxis_TB == aAxis;
 | ||
| }
 | ||
| 
 | ||
| // Given an AxisOrientationType, returns the "reverse" AxisOrientationType
 | ||
| // (in the same dimension, but the opposite direction)
 | ||
| static inline AxisOrientationType
 | ||
| GetReverseAxis(AxisOrientationType aAxis)
 | ||
| {
 | ||
|   AxisOrientationType reversedAxis;
 | ||
| 
 | ||
|   if (aAxis % 2 == 0) {
 | ||
|     // even enum value. Add 1 to reverse.
 | ||
|     reversedAxis = AxisOrientationType(aAxis + 1);
 | ||
|   } else {
 | ||
|     // odd enum value. Subtract 1 to reverse.
 | ||
|     reversedAxis = AxisOrientationType(aAxis - 1);
 | ||
|   }
 | ||
| 
 | ||
|   // Check that we're still in the enum's valid range
 | ||
|   MOZ_ASSERT(reversedAxis >= eAxis_LR &&
 | ||
|              reversedAxis <= eAxis_BT);
 | ||
| 
 | ||
|   return reversedAxis;
 | ||
| }
 | ||
| 
 | ||
| /**
 | ||
|  * Converts a "flex-relative" coordinate in a single axis (a main- or cross-axis
 | ||
|  * coordinate) into a coordinate in the corresponding physical (x or y) axis. If
 | ||
|  * the flex-relative axis in question already maps *directly* to a physical
 | ||
|  * axis (i.e. if it's LTR or TTB), then the physical coordinate has the same
 | ||
|  * numeric value as the provided flex-relative coordinate. Otherwise, we have to
 | ||
|  * subtract the flex-relative coordinate from the flex container's size in that
 | ||
|  * axis, to flip the polarity. (So e.g. a main-axis position of 2px in a RTL
 | ||
|  * 20px-wide container would correspond to a physical coordinate (x-value) of
 | ||
|  * 18px.)
 | ||
|  */
 | ||
| static nscoord
 | ||
| PhysicalCoordFromFlexRelativeCoord(nscoord aFlexRelativeCoord,
 | ||
|                                    nscoord aContainerSize,
 | ||
|                                    AxisOrientationType aAxis) {
 | ||
|   if (AxisGrowsInPositiveDirection(aAxis)) {
 | ||
|     return aFlexRelativeCoord;
 | ||
|   }
 | ||
|   return aContainerSize - aFlexRelativeCoord;
 | ||
| }
 | ||
| 
 | ||
| // Add two nscoord values, using CheckedInt to handle integer overflow.
 | ||
| // This function returns the sum of its two args -- but if we trigger integer
 | ||
| // overflow while adding them, then this function returns nscoord_MAX instead.
 | ||
| static nscoord
 | ||
| AddChecked(nscoord aFirst, nscoord aSecond)
 | ||
| {
 | ||
|   CheckedInt<nscoord> checkedResult = CheckedInt<nscoord>(aFirst) + aSecond;
 | ||
|   return checkedResult.isValid() ? checkedResult.value() : nscoord_MAX;
 | ||
| }
 | ||
| 
 | ||
| // Helper-macros to let us pick one of two expressions to evaluate
 | ||
| // (an inline-axis expression vs. a block-axis expression), to get a
 | ||
| // main-axis or cross-axis component.
 | ||
| // For code that has e.g. a LogicalSize object, the methods
 | ||
| // FlexboxAxisTracker::GetMainComponent and GetCrossComponent are cleaner
 | ||
| // than these macros. But in cases where we simply have two separate
 | ||
| // expressions for ISize and BSize (which may be expensive to evaluate),
 | ||
| // these macros can be used to ensure that only the needed expression is
 | ||
| // evaluated.
 | ||
| #define GET_MAIN_COMPONENT_LOGICAL(axisTracker_, wm_, isize_, bsize_)  \
 | ||
|   wm_.IsOrthogonalTo(axisTracker_.GetWritingMode()) != \
 | ||
|     (axisTracker_).IsRowOriented() ? (isize_) : (bsize_)
 | ||
| 
 | ||
| #define GET_CROSS_COMPONENT_LOGICAL(axisTracker_, wm_, isize_, bsize_)  \
 | ||
|   wm_.IsOrthogonalTo(axisTracker_.GetWritingMode()) != \
 | ||
|     (axisTracker_).IsRowOriented() ? (bsize_) : (isize_)
 | ||
| 
 | ||
| // Flags to customize behavior of the FlexboxAxisTracker constructor:
 | ||
| enum AxisTrackerFlags {
 | ||
|   eNoFlags = 0x0,
 | ||
| 
 | ||
|   // Normally, FlexboxAxisTracker may attempt to reverse axes & iteration order
 | ||
|   // to avoid bottom-to-top child ordering, for saner pagination. This flag
 | ||
|   // suppresses that behavior (so that we allow bottom-to-top child ordering).
 | ||
|   // (This may be helpful e.g. when we're only dealing with a single child.)
 | ||
|   eAllowBottomToTopChildOrdering = 0x1
 | ||
| };
 | ||
| MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(AxisTrackerFlags)
 | ||
| 
 | ||
| // Encapsulates our flex container's main & cross axes.
 | ||
| class MOZ_STACK_CLASS nsFlexContainerFrame::FlexboxAxisTracker {
 | ||
| public:
 | ||
|   FlexboxAxisTracker(const nsFlexContainerFrame* aFlexContainer,
 | ||
|                      const WritingMode& aWM,
 | ||
|                      AxisTrackerFlags aFlags = eNoFlags);
 | ||
| 
 | ||
|   // Accessors:
 | ||
|   // XXXdholbert [BEGIN DEPRECATED]
 | ||
|   AxisOrientationType GetMainAxis() const  { return mMainAxis;  }
 | ||
|   AxisOrientationType GetCrossAxis() const { return mCrossAxis; }
 | ||
|   // XXXdholbert [END DEPRECATED]
 | ||
| 
 | ||
|   // Returns the flex container's writing mode.
 | ||
|   WritingMode GetWritingMode() const { return mWM; }
 | ||
| 
 | ||
|   // Returns true if our main axis is in the reverse direction of our
 | ||
|   // writing mode's corresponding axis. (From 'flex-direction: *-reverse')
 | ||
|   bool IsMainAxisReversed() const {
 | ||
|     return mIsMainAxisReversed;
 | ||
|   }
 | ||
|   // Returns true if our cross axis is in the reverse direction of our
 | ||
|   // writing mode's corresponding axis. (From 'flex-wrap: *-reverse')
 | ||
|   bool IsCrossAxisReversed() const {
 | ||
|     return mIsCrossAxisReversed;
 | ||
|   }
 | ||
| 
 | ||
|   bool IsRowOriented() const { return mIsRowOriented; }
 | ||
|   bool IsColumnOriented() const { return !mIsRowOriented; }
 | ||
| 
 | ||
|   // aSize is expected to match the flex container's WritingMode.
 | ||
|   nscoord GetMainComponent(const LogicalSize& aSize) const {
 | ||
|     return IsRowOriented() ? aSize.ISize(mWM) : aSize.BSize(mWM);
 | ||
|   }
 | ||
|   int32_t GetMainComponent(const LayoutDeviceIntSize& aIntSize) const {
 | ||
|     return IsMainAxisHorizontal() ? aIntSize.width : aIntSize.height;
 | ||
|   }
 | ||
| 
 | ||
|   // aSize is expected to match the flex container's WritingMode.
 | ||
|   nscoord GetCrossComponent(const LogicalSize& aSize) const {
 | ||
|     return IsRowOriented() ? aSize.BSize(mWM) : aSize.ISize(mWM);
 | ||
|   }
 | ||
|   int32_t GetCrossComponent(const LayoutDeviceIntSize& aIntSize) const {
 | ||
|     return IsMainAxisHorizontal() ? aIntSize.height : aIntSize.width;
 | ||
|   }
 | ||
| 
 | ||
|   // NOTE: aMargin is expected to use the flex container's WritingMode.
 | ||
|   nscoord GetMarginSizeInMainAxis(const LogicalMargin& aMargin) const {
 | ||
|     // If we're row-oriented, our main axis is the inline axis.
 | ||
|     return IsRowOriented()
 | ||
|       ? aMargin.IStartEnd(mWM)
 | ||
|       : aMargin.BStartEnd(mWM);
 | ||
|   }
 | ||
|   nscoord GetMarginSizeInCrossAxis(const LogicalMargin& aMargin) const {
 | ||
|     // If we're row-oriented, our cross axis is the block axis.
 | ||
|     return IsRowOriented()
 | ||
|       ? aMargin.BStartEnd(mWM)
 | ||
|       : aMargin.IStartEnd(mWM);
 | ||
|   }
 | ||
| 
 | ||
|   /**
 | ||
|    * Converts a "flex-relative" point (a main-axis & cross-axis coordinate)
 | ||
|    * into a LogicalPoint, using the flex container's writing mode.
 | ||
|    *
 | ||
|    *  @arg aMainCoord  The main-axis coordinate -- i.e an offset from the
 | ||
|    *                   main-start edge of the flex container's content box.
 | ||
|    *  @arg aCrossCoord The cross-axis coordinate -- i.e an offset from the
 | ||
|    *                   cross-start edge of the flex container's content box.
 | ||
|    *  @arg aContainerMainSize  The main size of flex container's content box.
 | ||
|    *  @arg aContainerCrossSize The cross size of flex container's content box.
 | ||
|    *  @return A LogicalPoint, with the flex container's writing mode, that
 | ||
|    *          represents the same position. The logical coordinates are
 | ||
|    *          relative to the flex container's content box.
 | ||
|    */
 | ||
|   LogicalPoint
 | ||
|   LogicalPointFromFlexRelativePoint(nscoord aMainCoord,
 | ||
|                                     nscoord aCrossCoord,
 | ||
|                                     nscoord aContainerMainSize,
 | ||
|                                     nscoord aContainerCrossSize) const {
 | ||
|     nscoord logicalCoordInMainAxis = mIsMainAxisReversed ?
 | ||
|       aContainerMainSize - aMainCoord : aMainCoord;
 | ||
|     nscoord logicalCoordInCrossAxis = mIsCrossAxisReversed ?
 | ||
|       aContainerCrossSize - aCrossCoord : aCrossCoord;
 | ||
| 
 | ||
|     return mIsRowOriented ?
 | ||
|       LogicalPoint(mWM, logicalCoordInMainAxis, logicalCoordInCrossAxis) :
 | ||
|       LogicalPoint(mWM, logicalCoordInCrossAxis, logicalCoordInMainAxis);
 | ||
|   }
 | ||
| 
 | ||
|   /**
 | ||
|    * Converts a "flex-relative" size (a main-axis & cross-axis size)
 | ||
|    * into a LogicalSize, using the flex container's writing mode.
 | ||
|    *
 | ||
|    *  @arg aMainSize  The main-axis size.
 | ||
|    *  @arg aCrossSize The cross-axis size.
 | ||
|    *  @return A LogicalSize, with the flex container's writing mode, that
 | ||
|    *          represents the same size.
 | ||
|    */
 | ||
|   LogicalSize LogicalSizeFromFlexRelativeSizes(nscoord aMainSize,
 | ||
|                                                nscoord aCrossSize) const {
 | ||
|     return mIsRowOriented ?
 | ||
|       LogicalSize(mWM, aMainSize, aCrossSize) :
 | ||
|       LogicalSize(mWM, aCrossSize, aMainSize);
 | ||
|   }
 | ||
| 
 | ||
|   // Are my axes reversed with respect to what the author asked for?
 | ||
|   // (We may reverse the axes in the FlexboxAxisTracker constructor and set
 | ||
|   // this flag, to avoid reflowing our children in bottom-to-top order.)
 | ||
|   bool AreAxesInternallyReversed() const
 | ||
|   {
 | ||
|     return mAreAxesInternallyReversed;
 | ||
|   }
 | ||
| 
 | ||
| private:
 | ||
|   // Delete copy-constructor & reassignment operator, to prevent accidental
 | ||
|   // (unnecessary) copying.
 | ||
|   FlexboxAxisTracker(const FlexboxAxisTracker&) = delete;
 | ||
|   FlexboxAxisTracker& operator=(const FlexboxAxisTracker&) = delete;
 | ||
| 
 | ||
|   // Private because callers shouldn't need to care about physical axes
 | ||
|   // (but we do internally, to provide one API).
 | ||
|   bool IsMainAxisHorizontal() const {
 | ||
|     // If we're row-oriented, and our writing mode is NOT vertical,
 | ||
|     // or we're column-oriented and our writing mode IS vertical,
 | ||
|     // then our main axis is horizontal. This handles all cases:
 | ||
|     return mIsRowOriented != mWM.IsVertical();
 | ||
|   }
 | ||
| 
 | ||
|   // Helpers for constructor which determine the orientation of our axes, based
 | ||
|   // on legacy box properties (-webkit-box-orient, -webkit-box-direction) or
 | ||
|   // modern flexbox properties (flex-direction, flex-wrap) depending on whether
 | ||
|   // the flex container is a "legacy box" (as determined by IsLegacyBox).
 | ||
|   void InitAxesFromLegacyProps(const nsFlexContainerFrame* aFlexContainer);
 | ||
|   void InitAxesFromModernProps(const nsFlexContainerFrame* aFlexContainer);
 | ||
| 
 | ||
|   // XXXdholbert [BEGIN DEPRECATED]
 | ||
|   AxisOrientationType mMainAxis;
 | ||
|   AxisOrientationType mCrossAxis;
 | ||
|   // XXXdholbert [END DEPRECATED]
 | ||
| 
 | ||
|   const WritingMode mWM; // The flex container's writing mode.
 | ||
| 
 | ||
|   bool mIsRowOriented; // Is our main axis the inline axis?
 | ||
|                        // (Are we 'flex-direction:row[-reverse]'?)
 | ||
| 
 | ||
|   bool mIsMainAxisReversed; // Is our main axis in the opposite direction
 | ||
|                             // as mWM's corresponding axis? (e.g. RTL vs LTR)
 | ||
|   bool mIsCrossAxisReversed; // Is our cross axis in the opposite direction
 | ||
|                              // as mWM's corresponding axis? (e.g. BTT vs TTB)
 | ||
| 
 | ||
|   // Implementation detail -- this indicates whether we've decided to
 | ||
|   // transparently reverse our axes & our child ordering, to avoid having
 | ||
|   // frames flow from bottom to top in either axis (& to make pagination saner).
 | ||
|   bool mAreAxesInternallyReversed;
 | ||
| };
 | ||
| 
 | ||
| /**
 | ||
|  * Represents a flex item.
 | ||
|  * Includes the various pieces of input that the Flexbox Layout Algorithm uses
 | ||
|  * to resolve a flexible width.
 | ||
|  */
 | ||
| class nsFlexContainerFrame::FlexItem : public LinkedListElement<FlexItem>
 | ||
| {
 | ||
| public:
 | ||
|   // Normal constructor:
 | ||
|   FlexItem(ReflowInput& aFlexItemReflowInput,
 | ||
|            float aFlexGrow, float aFlexShrink, nscoord aMainBaseSize,
 | ||
|            nscoord aMainMinSize, nscoord aMainMaxSize,
 | ||
|            nscoord aTentativeCrossSize,
 | ||
|            nscoord aCrossMinSize, nscoord aCrossMaxSize,
 | ||
|            const FlexboxAxisTracker& aAxisTracker);
 | ||
| 
 | ||
|   // Simplified constructor, to be used only for generating "struts":
 | ||
|   // (NOTE: This "strut" constructor uses the *container's* writing mode, which
 | ||
|   // we'll use on this FlexItem instead of the child frame's real writing mode.
 | ||
|   // This is fine - it doesn't matter what writing mode we use for a
 | ||
|   // strut, since it won't render any content and we already know its size.)
 | ||
|   FlexItem(nsIFrame* aChildFrame, nscoord aCrossSize, WritingMode aContainerWM);
 | ||
| 
 | ||
|   // Accessors
 | ||
|   nsIFrame* Frame() const          { return mFrame; }
 | ||
|   nscoord GetFlexBaseSize() const  { return mFlexBaseSize; }
 | ||
| 
 | ||
|   nscoord GetMainMinSize() const   {
 | ||
|     MOZ_ASSERT(!mNeedsMinSizeAutoResolution,
 | ||
|                "Someone's using an unresolved 'auto' main min-size");
 | ||
|     return mMainMinSize;
 | ||
|   }
 | ||
|   nscoord GetMainMaxSize() const   { return mMainMaxSize; }
 | ||
| 
 | ||
|   // Note: These return the main-axis position and size of our *content box*.
 | ||
|   nscoord GetMainSize() const      { return mMainSize; }
 | ||
|   nscoord GetMainPosition() const  { return mMainPosn; }
 | ||
| 
 | ||
|   nscoord GetCrossMinSize() const  { return mCrossMinSize; }
 | ||
|   nscoord GetCrossMaxSize() const  { return mCrossMaxSize; }
 | ||
| 
 | ||
|   // Note: These return the cross-axis position and size of our *content box*.
 | ||
|   nscoord GetCrossSize() const     { return mCrossSize;  }
 | ||
|   nscoord GetCrossPosition() const { return mCrossPosn; }
 | ||
| 
 | ||
|   nscoord ResolvedAscent(bool aUseFirstBaseline) const {
 | ||
|     if (mAscent == ReflowOutput::ASK_FOR_BASELINE) {
 | ||
|       // XXXdholbert We should probably be using the *container's* writing-mode
 | ||
|       // here, instead of the item's -- though it doesn't much matter right
 | ||
|       // now, because all of the baseline-handling code here essentially
 | ||
|       // assumes that the container & items have the same writing-mode. This
 | ||
|       // will matter more (& can be expanded/tested) once we officially support
 | ||
|       // logical directions & vertical writing-modes in flexbox, in bug 1079155
 | ||
|       // or a dependency.
 | ||
|       // Use GetFirstLineBaseline() or GetLastLineBaseline() as appropriate,
 | ||
|       // or just GetLogicalBaseline() if that fails.
 | ||
|       bool found = aUseFirstBaseline ?
 | ||
|         nsLayoutUtils::GetFirstLineBaseline(mWM, mFrame, &mAscent) :
 | ||
|         nsLayoutUtils::GetLastLineBaseline(mWM, mFrame, &mAscent);
 | ||
| 
 | ||
|       if (!found) {
 | ||
|         mAscent = mFrame->SynthesizeBaselineBOffsetFromBorderBox(mWM,
 | ||
|                             BaselineSharingGroup::eFirst);
 | ||
|       }
 | ||
|     }
 | ||
|     return mAscent;
 | ||
|   }
 | ||
| 
 | ||
|   // Convenience methods to compute the main & cross size of our *margin-box*.
 | ||
|   // The caller is responsible for telling us the right axis, so that we can
 | ||
|   // pull out the appropriate components of our margin/border/padding structs.
 | ||
|   nscoord GetOuterMainSize(AxisOrientationType aMainAxis) const
 | ||
|   {
 | ||
|     return mMainSize + GetMarginBorderPaddingSizeInAxis(aMainAxis);
 | ||
|   }
 | ||
| 
 | ||
|   nscoord GetOuterCrossSize(AxisOrientationType aCrossAxis) const
 | ||
|   {
 | ||
|     return mCrossSize + GetMarginBorderPaddingSizeInAxis(aCrossAxis);
 | ||
|   }
 | ||
| 
 | ||
|   // Returns the distance between this FlexItem's baseline and the cross-start
 | ||
|   // edge of its margin-box. Used in baseline alignment.
 | ||
|   // (This function needs to be told which edge we're measuring the baseline
 | ||
|   // from, so that it can look up the appropriate components from mMargin.)
 | ||
|   nscoord GetBaselineOffsetFromOuterCrossEdge(
 | ||
|     AxisEdgeType aEdge,
 | ||
|     const FlexboxAxisTracker& aAxisTracker,
 | ||
|     bool aUseFirstLineBaseline) const;
 | ||
| 
 | ||
|   float GetShareOfWeightSoFar() const { return mShareOfWeightSoFar; }
 | ||
| 
 | ||
|   bool IsFrozen() const            { return mIsFrozen; }
 | ||
| 
 | ||
|   bool HadMinViolation() const     { return mHadMinViolation; }
 | ||
|   bool HadMaxViolation() const     { return mHadMaxViolation; }
 | ||
| 
 | ||
|   // Indicates whether this item received a preliminary "measuring" reflow
 | ||
|   // before its actual reflow.
 | ||
|   bool HadMeasuringReflow() const  { return mHadMeasuringReflow; }
 | ||
| 
 | ||
|   // Indicates whether this item's computed cross-size property is 'auto'.
 | ||
|   bool IsCrossSizeAuto() const;
 | ||
| 
 | ||
|   // Indicates whether this item's cross-size has been stretched (from having
 | ||
|   // "align-self: stretch" with an auto cross-size and no auto margins in the
 | ||
|   // cross axis).
 | ||
|   bool IsStretched() const         { return mIsStretched; }
 | ||
| 
 | ||
|   // Indicates whether we need to resolve an 'auto' value for the main-axis
 | ||
|   // min-[width|height] property.
 | ||
|   bool NeedsMinSizeAutoResolution() const
 | ||
|     { return mNeedsMinSizeAutoResolution; }
 | ||
| 
 | ||
|   bool HasAnyAutoMargin() const
 | ||
|     { return mHasAnyAutoMargin; }
 | ||
| 
 | ||
|   // Indicates whether this item is a "strut" left behind by an element with
 | ||
|   // visibility:collapse.
 | ||
|   bool IsStrut() const             { return mIsStrut; }
 | ||
| 
 | ||
|   // IsInlineAxisMainAxis() returns true if this item's inline axis is parallel
 | ||
|   // (or antiparallel) to the container's main axis. Otherwise (i.e. if this
 | ||
|   // item's inline axis is orthogonal to the container's main axis), this
 | ||
|   // function returns false. The next 3 methods are all other ways of asking
 | ||
|   // the same question, and only exist for readability at callsites (depending
 | ||
|   // on which axes those callsites are reasoning about).
 | ||
|   bool IsInlineAxisMainAxis() const  { return mIsInlineAxisMainAxis;  }
 | ||
|   bool IsInlineAxisCrossAxis() const { return !mIsInlineAxisMainAxis; }
 | ||
|   bool IsBlockAxisMainAxis() const   { return !mIsInlineAxisMainAxis; }
 | ||
|   bool IsBlockAxisCrossAxis() const  { return mIsInlineAxisMainAxis;  }
 | ||
| 
 | ||
| 
 | ||
|   WritingMode GetWritingMode() const { return mWM; }
 | ||
|   uint8_t GetAlignSelf() const     { return mAlignSelf; }
 | ||
| 
 | ||
|   // Returns the flex factor (flex-grow or flex-shrink), depending on
 | ||
|   // 'aIsUsingFlexGrow'.
 | ||
|   //
 | ||
|   // Asserts fatally if called on a frozen item (since frozen items are not
 | ||
|   // flexible).
 | ||
|   float GetFlexFactor(bool aIsUsingFlexGrow)
 | ||
|   {
 | ||
|     MOZ_ASSERT(!IsFrozen(), "shouldn't need flex factor after item is frozen");
 | ||
| 
 | ||
|     return aIsUsingFlexGrow ? mFlexGrow : mFlexShrink;
 | ||
|   }
 | ||
| 
 | ||
|   // Returns the weight that we should use in the "resolving flexible lengths"
 | ||
|   // algorithm.  If we're using the flex grow factor, we just return that;
 | ||
|   // otherwise, we return the "scaled flex shrink factor" (scaled by our flex
 | ||
|   // base size, so that when both large and small items are shrinking, the large
 | ||
|   // items shrink more).
 | ||
|   //
 | ||
|   // I'm calling this a "weight" instead of a "[scaled] flex-[grow|shrink]
 | ||
|   // factor", to more clearly distinguish it from the actual flex-grow &
 | ||
|   // flex-shrink factors.
 | ||
|   //
 | ||
|   // Asserts fatally if called on a frozen item (since frozen items are not
 | ||
|   // flexible).
 | ||
|   float GetWeight(bool aIsUsingFlexGrow)
 | ||
|   {
 | ||
|     MOZ_ASSERT(!IsFrozen(), "shouldn't need weight after item is frozen");
 | ||
| 
 | ||
|     if (aIsUsingFlexGrow) {
 | ||
|       return mFlexGrow;
 | ||
|     }
 | ||
| 
 | ||
|     // We're using flex-shrink --> return mFlexShrink * mFlexBaseSize
 | ||
|     if (mFlexBaseSize == 0) {
 | ||
|       // Special-case for mFlexBaseSize == 0 -- we have no room to shrink, so
 | ||
|       // regardless of mFlexShrink, we should just return 0.
 | ||
|       // (This is really a special-case for when mFlexShrink is infinity, to
 | ||
|       // avoid performing mFlexShrink * mFlexBaseSize = inf * 0 = undefined.)
 | ||
|       return 0.0f;
 | ||
|     }
 | ||
|     return mFlexShrink * mFlexBaseSize;
 | ||
|   }
 | ||
| 
 | ||
|   // Returns a LogicalSize representing the flex item's logical intrinsic ratio
 | ||
|   // (ISize:BSize), as expressed in the *flex container's* writing mode.
 | ||
|   const LogicalSize& IntrinsicRatio() const { return mIntrinsicRatio; }
 | ||
|   bool HasIntrinsicRatio() const { return !mIntrinsicRatio.IsAllZero(); }
 | ||
| 
 | ||
|   // Getters for margin:
 | ||
|   // ===================
 | ||
|   const nsMargin& GetMargin() const { return mMargin; }
 | ||
| 
 | ||
|   // Returns the margin component for a given mozilla::Side
 | ||
|   nscoord GetMarginComponentForSide(mozilla::Side aSide) const
 | ||
|   { return mMargin.Side(aSide); }
 | ||
| 
 | ||
|   // Returns the total space occupied by this item's margins in the given axis
 | ||
|   nscoord GetMarginSizeInAxis(AxisOrientationType aAxis) const
 | ||
|   {
 | ||
|     mozilla::Side startSide = kAxisOrientationToSidesMap[aAxis][eAxisEdge_Start];
 | ||
|     mozilla::Side endSide = kAxisOrientationToSidesMap[aAxis][eAxisEdge_End];
 | ||
|     return GetMarginComponentForSide(startSide) +
 | ||
|       GetMarginComponentForSide(endSide);
 | ||
|   }
 | ||
| 
 | ||
|   // Getters for border/padding
 | ||
|   // ==========================
 | ||
|   const nsMargin& GetBorderPadding() const { return mBorderPadding; }
 | ||
| 
 | ||
|   // Returns the border+padding component for a given mozilla::Side
 | ||
|   nscoord GetBorderPaddingComponentForSide(mozilla::Side aSide) const
 | ||
|   { return mBorderPadding.Side(aSide); }
 | ||
| 
 | ||
|   // Returns the total space occupied by this item's borders and padding in
 | ||
|   // the given axis
 | ||
|   nscoord GetBorderPaddingSizeInAxis(AxisOrientationType aAxis) const
 | ||
|   {
 | ||
|     mozilla::Side startSide = kAxisOrientationToSidesMap[aAxis][eAxisEdge_Start];
 | ||
|     mozilla::Side endSide = kAxisOrientationToSidesMap[aAxis][eAxisEdge_End];
 | ||
|     return GetBorderPaddingComponentForSide(startSide) +
 | ||
|       GetBorderPaddingComponentForSide(endSide);
 | ||
|   }
 | ||
| 
 | ||
|   // Getter for combined margin/border/padding
 | ||
|   // =========================================
 | ||
|   // Returns the total space occupied by this item's margins, borders and
 | ||
|   // padding in the given axis
 | ||
|   nscoord GetMarginBorderPaddingSizeInAxis(AxisOrientationType aAxis) const
 | ||
|   {
 | ||
|     return GetMarginSizeInAxis(aAxis) + GetBorderPaddingSizeInAxis(aAxis);
 | ||
|   }
 | ||
| 
 | ||
|   // Setters
 | ||
|   // =======
 | ||
|   // Helper to set the resolved value of min-[width|height]:auto for the main
 | ||
|   // axis. (Should only be used if NeedsMinSizeAutoResolution() returns true.)
 | ||
|   void UpdateMainMinSize(nscoord aNewMinSize)
 | ||
|   {
 | ||
|     NS_ASSERTION(aNewMinSize >= 0,
 | ||
|                  "How did we end up with a negative min-size?");
 | ||
|     MOZ_ASSERT(mMainMaxSize >= aNewMinSize,
 | ||
|                "Should only use this function for resolving min-size:auto, "
 | ||
|                "and main max-size should be an upper-bound for resolved val");
 | ||
|     MOZ_ASSERT(mNeedsMinSizeAutoResolution &&
 | ||
|                (mMainMinSize == 0 || mFrame->IsThemed(mFrame->StyleDisplay())),
 | ||
|                "Should only use this function for resolving min-size:auto, "
 | ||
|                "so we shouldn't already have a nonzero min-size established "
 | ||
|                "(unless it's a themed-widget-imposed minimum size)");
 | ||
| 
 | ||
|     if (aNewMinSize > mMainMinSize) {
 | ||
|       mMainMinSize = aNewMinSize;
 | ||
|       // Also clamp main-size to be >= new min-size:
 | ||
|       mMainSize = std::max(mMainSize, aNewMinSize);
 | ||
|     }
 | ||
|     mNeedsMinSizeAutoResolution = false;
 | ||
|   }
 | ||
| 
 | ||
|   // This sets our flex base size, and then sets our main size to the
 | ||
|   // resulting "hypothetical main size" (the base size clamped to our
 | ||
|   // main-axis [min,max] sizing constraints).
 | ||
|   void SetFlexBaseSizeAndMainSize(nscoord aNewFlexBaseSize)
 | ||
|   {
 | ||
|     MOZ_ASSERT(!mIsFrozen || mFlexBaseSize == NS_INTRINSICSIZE,
 | ||
|                "flex base size shouldn't change after we're frozen "
 | ||
|                "(unless we're just resolving an intrinsic size)");
 | ||
|     mFlexBaseSize = aNewFlexBaseSize;
 | ||
| 
 | ||
|     // Before we've resolved flexible lengths, we keep mMainSize set to
 | ||
|     // the 'hypothetical main size', which is the flex base size, clamped
 | ||
|     // to the [min,max] range:
 | ||
|     mMainSize = NS_CSS_MINMAX(mFlexBaseSize, mMainMinSize, mMainMaxSize);
 | ||
|   }
 | ||
| 
 | ||
|   // Setters used while we're resolving flexible lengths
 | ||
|   // ---------------------------------------------------
 | ||
| 
 | ||
|   // Sets the main-size of our flex item's content-box.
 | ||
|   void SetMainSize(nscoord aNewMainSize)
 | ||
|   {
 | ||
|     MOZ_ASSERT(!mIsFrozen, "main size shouldn't change after we're frozen");
 | ||
|     mMainSize = aNewMainSize;
 | ||
|   }
 | ||
| 
 | ||
|   void SetShareOfWeightSoFar(float aNewShare)
 | ||
|   {
 | ||
|     MOZ_ASSERT(!mIsFrozen || aNewShare == 0.0f,
 | ||
|                "shouldn't be giving this item any share of the weight "
 | ||
|                "after it's frozen");
 | ||
|     mShareOfWeightSoFar = aNewShare;
 | ||
|   }
 | ||
| 
 | ||
|   void Freeze() { mIsFrozen = true; }
 | ||
| 
 | ||
|   void SetHadMinViolation()
 | ||
|   {
 | ||
|     MOZ_ASSERT(!mIsFrozen,
 | ||
|                "shouldn't be changing main size & having violations "
 | ||
|                "after we're frozen");
 | ||
|     mHadMinViolation = true;
 | ||
|   }
 | ||
|   void SetHadMaxViolation()
 | ||
|   {
 | ||
|     MOZ_ASSERT(!mIsFrozen,
 | ||
|                "shouldn't be changing main size & having violations "
 | ||
|                "after we're frozen");
 | ||
|     mHadMaxViolation = true;
 | ||
|   }
 | ||
|   void ClearViolationFlags()
 | ||
|   { mHadMinViolation = mHadMaxViolation = false; }
 | ||
| 
 | ||
|   // Setters for values that are determined after we've resolved our main size
 | ||
|   // -------------------------------------------------------------------------
 | ||
| 
 | ||
|   // Sets the main-axis position of our flex item's content-box.
 | ||
|   // (This is the distance between the main-start edge of the flex container
 | ||
|   // and the main-start edge of the flex item's content-box.)
 | ||
|   void SetMainPosition(nscoord aPosn) {
 | ||
|     MOZ_ASSERT(mIsFrozen, "main size should be resolved before this");
 | ||
|     mMainPosn  = aPosn;
 | ||
|   }
 | ||
| 
 | ||
|   // Sets the cross-size of our flex item's content-box.
 | ||
|   void SetCrossSize(nscoord aCrossSize) {
 | ||
|     MOZ_ASSERT(!mIsStretched,
 | ||
|                "Cross size shouldn't be modified after it's been stretched");
 | ||
|     mCrossSize = aCrossSize;
 | ||
|   }
 | ||
| 
 | ||
|   // Sets the cross-axis position of our flex item's content-box.
 | ||
|   // (This is the distance between the cross-start edge of the flex container
 | ||
|   // and the cross-start edge of the flex item.)
 | ||
|   void SetCrossPosition(nscoord aPosn) {
 | ||
|     MOZ_ASSERT(mIsFrozen, "main size should be resolved before this");
 | ||
|     mCrossPosn = aPosn;
 | ||
|   }
 | ||
| 
 | ||
|   // After a FlexItem has had a reflow, this method can be used to cache its
 | ||
|   // (possibly-unresolved) ascent, in case it's needed later for
 | ||
|   // baseline-alignment or to establish the container's baseline.
 | ||
|   // (NOTE: This can be marked 'const' even though it's modifying mAscent,
 | ||
|   // because mAscent is mutable. It's nice for this to be 'const', because it
 | ||
|   // means our final reflow can iterate over const FlexItem pointers, and we
 | ||
|   // can be sure it's not modifying those FlexItems, except via this method.)
 | ||
|   void SetAscent(nscoord aAscent) const {
 | ||
|     mAscent = aAscent; // NOTE: this may be ASK_FOR_BASELINE
 | ||
|   }
 | ||
| 
 | ||
|   void SetHadMeasuringReflow() {
 | ||
|     mHadMeasuringReflow = true;
 | ||
|   }
 | ||
| 
 | ||
|   void SetIsStretched() {
 | ||
|     MOZ_ASSERT(mIsFrozen, "main size should be resolved before this");
 | ||
|     mIsStretched = true;
 | ||
|   }
 | ||
| 
 | ||
|   // Setter for margin components (for resolving "auto" margins)
 | ||
|   void SetMarginComponentForSide(mozilla::Side aSide, nscoord aLength)
 | ||
|   {
 | ||
|     MOZ_ASSERT(mIsFrozen, "main size should be resolved before this");
 | ||
|     mMargin.Side(aSide) = aLength;
 | ||
|   }
 | ||
| 
 | ||
|   void ResolveStretchedCrossSize(nscoord aLineCrossSize,
 | ||
|                                  const FlexboxAxisTracker& aAxisTracker);
 | ||
| 
 | ||
|   uint32_t GetNumAutoMarginsInAxis(AxisOrientationType aAxis) const;
 | ||
| 
 | ||
|   // Once the main size has been resolved, should we bother doing layout to
 | ||
|   // establish the cross size?
 | ||
|   bool CanMainSizeInfluenceCrossSize(const FlexboxAxisTracker& aAxisTracker) const;
 | ||
| 
 | ||
| protected:
 | ||
|   // Helper called by the constructor, to set mNeedsMinSizeAutoResolution:
 | ||
|   void CheckForMinSizeAuto(const ReflowInput& aFlexItemReflowInput,
 | ||
|                            const FlexboxAxisTracker& aAxisTracker);
 | ||
| 
 | ||
|   // Values that we already know in constructor (and are hence mostly 'const'):
 | ||
|   nsIFrame* const mFrame; // The flex item's frame.
 | ||
|   const float mFlexGrow;
 | ||
|   const float mFlexShrink;
 | ||
|   const LogicalSize mIntrinsicRatio;
 | ||
|   const nsMargin mBorderPadding;
 | ||
|   nsMargin mMargin; // non-const because we need to resolve auto margins
 | ||
| 
 | ||
|   // These are non-const so that we can lazily update them with the item's
 | ||
|   // intrinsic size (obtained via a "measuring" reflow), when necessary.
 | ||
|   // (e.g. for "flex-basis:auto;height:auto" & "min-height:auto")
 | ||
|   nscoord mFlexBaseSize;
 | ||
|   nscoord mMainMinSize;
 | ||
|   nscoord mMainMaxSize;
 | ||
| 
 | ||
|   const nscoord mCrossMinSize;
 | ||
|   const nscoord mCrossMaxSize;
 | ||
| 
 | ||
|   // Values that we compute after constructor:
 | ||
|   nscoord mMainSize;
 | ||
|   nscoord mMainPosn;
 | ||
|   nscoord mCrossSize;
 | ||
|   nscoord mCrossPosn;
 | ||
|   mutable nscoord mAscent; // Mutable b/c it's set & resolved lazily, sometimes
 | ||
|                            // via const pointer. See comment above SetAscent().
 | ||
| 
 | ||
|   // Temporary state, while we're resolving flexible widths (for our main size)
 | ||
|   // XXXdholbert To save space, we could use a union to make these variables
 | ||
|   // overlay the same memory as some other member vars that aren't touched
 | ||
|   // until after main-size has been resolved. In particular, these could share
 | ||
|   // memory with mMainPosn through mAscent, and mIsStretched.
 | ||
|   float mShareOfWeightSoFar;
 | ||
| 
 | ||
|   const WritingMode mWM; // The flex item's writing mode.
 | ||
|   bool mIsFrozen;
 | ||
|   bool mHadMinViolation;
 | ||
|   bool mHadMaxViolation;
 | ||
| 
 | ||
|   // Misc:
 | ||
|   bool mHadMeasuringReflow; // Did this item get a preliminary reflow,
 | ||
|                             // to measure its desired height?
 | ||
|   bool mIsStretched; // See IsStretched() documentation
 | ||
|   bool mIsStrut;     // Is this item a "strut" left behind by an element
 | ||
|                      // with visibility:collapse?
 | ||
|   const bool mIsInlineAxisMainAxis; // See IsInlineAxisMainAxis() documentation
 | ||
| 
 | ||
|   // Does this item need to resolve a min-[width|height]:auto (in main-axis).
 | ||
|   bool mNeedsMinSizeAutoResolution;
 | ||
| 
 | ||
|   // Does this item have an auto margin in either main or cross axis?
 | ||
|   bool mHasAnyAutoMargin;
 | ||
| 
 | ||
|   uint8_t mAlignSelf; // My "align-self" computed value (with "auto"
 | ||
|                       // swapped out for parent"s "align-items" value,
 | ||
|                       // in our constructor).
 | ||
| };
 | ||
| 
 | ||
| /**
 | ||
|  * Represents a single flex line in a flex container.
 | ||
|  * Manages a linked list of the FlexItems that are in the line.
 | ||
|  */
 | ||
| class nsFlexContainerFrame::FlexLine : public LinkedListElement<FlexLine>
 | ||
| {
 | ||
| public:
 | ||
|   explicit FlexLine(nscoord aMainGapSize)
 | ||
|   : mNumItems(0),
 | ||
|     mNumFrozenItems(0),
 | ||
|     mTotalItemMBP(0),
 | ||
|     mTotalOuterHypotheticalMainSize(0),
 | ||
|     mLineCrossSize(0),
 | ||
|     mFirstBaselineOffset(nscoord_MIN),
 | ||
|     mLastBaselineOffset(nscoord_MIN),
 | ||
|     mMainGapSize(aMainGapSize)
 | ||
|   {}
 | ||
| 
 | ||
|   nscoord GetSumOfGaps() const {
 | ||
|     return mNumItems > 0 ? (mNumItems - 1) * mMainGapSize : 0;
 | ||
|   }
 | ||
| 
 | ||
|   // Returns the sum of our FlexItems' outer hypothetical main sizes plus the
 | ||
|   // sum of main axis {row,column}-gaps between items.
 | ||
|   // ("outer" = margin-box, and "hypothetical" = before flexing)
 | ||
|   nscoord GetTotalOuterHypotheticalMainSize() const {
 | ||
|     return mTotalOuterHypotheticalMainSize;
 | ||
|   }
 | ||
| 
 | ||
|   // Accessors for our FlexItems & information about them:
 | ||
|   FlexItem* GetFirstItem()
 | ||
|   {
 | ||
|     MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
 | ||
|                "mNumItems bookkeeping is off");
 | ||
|     return mItems.getFirst();
 | ||
|   }
 | ||
| 
 | ||
|   const FlexItem* GetFirstItem() const
 | ||
|   {
 | ||
|     MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
 | ||
|                "mNumItems bookkeeping is off");
 | ||
|     return mItems.getFirst();
 | ||
|   }
 | ||
| 
 | ||
|   FlexItem* GetLastItem()
 | ||
|   {
 | ||
|     MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
 | ||
|                "mNumItems bookkeeping is off");
 | ||
|     return mItems.getLast();
 | ||
|   }
 | ||
| 
 | ||
|   const FlexItem* GetLastItem() const
 | ||
|   {
 | ||
|     MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
 | ||
|                "mNumItems bookkeeping is off");
 | ||
|     return mItems.getLast();
 | ||
|   }
 | ||
| 
 | ||
|   bool IsEmpty() const
 | ||
|   {
 | ||
|     MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
 | ||
|                "mNumItems bookkeeping is off");
 | ||
|     return mItems.isEmpty();
 | ||
|   }
 | ||
| 
 | ||
|   uint32_t NumItems() const
 | ||
|   {
 | ||
|     MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
 | ||
|                "mNumItems bookkeeping is off");
 | ||
|     return mNumItems;
 | ||
|   }
 | ||
| 
 | ||
|   // Adds the given FlexItem to our list of items (at the front or back
 | ||
|   // depending on aShouldInsertAtFront), and adds its hypothetical
 | ||
|   // outer & inner main sizes to our totals. Use this method instead of
 | ||
|   // directly modifying the item list, so that our bookkeeping remains correct.
 | ||
|   void AddItem(FlexItem* aItem,
 | ||
|                bool aShouldInsertAtFront,
 | ||
|                nscoord aItemInnerHypotheticalMainSize,
 | ||
|                nscoord aItemOuterHypotheticalMainSize)
 | ||
|   {
 | ||
|     if (aShouldInsertAtFront) {
 | ||
|       mItems.insertFront(aItem);
 | ||
|     } else {
 | ||
|       mItems.insertBack(aItem);
 | ||
|     }
 | ||
| 
 | ||
|     // Update our various bookkeeping member-vars:
 | ||
|     mNumItems++;
 | ||
|     if (aItem->IsFrozen()) {
 | ||
|       mNumFrozenItems++;
 | ||
|     }
 | ||
| 
 | ||
|     nscoord itemMBP =
 | ||
|       aItemOuterHypotheticalMainSize - aItemInnerHypotheticalMainSize;
 | ||
| 
 | ||
|     // Note: If our flex item is (or contains) a table with
 | ||
|     // "table-layout:fixed", it may have a value near nscoord_MAX as its
 | ||
|     // hypothetical main size. This means we can run into absurdly large sizes
 | ||
|     // here, even when the author didn't explicitly specify anything huge.
 | ||
|     // We'd really rather not allow that to cause integer overflow (e.g. we
 | ||
|     // don't want that to make mTotalOuterHypotheticalMainSize overflow to a
 | ||
|     // negative value), because that'd make us incorrectly think that we should
 | ||
|     // grow our flex items rather than shrink them when it comes time to
 | ||
|     // resolve flexible items. Hence, we sum up the hypothetical sizes using a
 | ||
|     // helper function AddChecked() to avoid overflow.
 | ||
|     mTotalItemMBP = AddChecked(mTotalItemMBP, itemMBP);
 | ||
| 
 | ||
|     mTotalOuterHypotheticalMainSize =
 | ||
|       AddChecked(mTotalOuterHypotheticalMainSize,
 | ||
|                  aItemOuterHypotheticalMainSize);
 | ||
| 
 | ||
|     // If the item added was not the first item in the line, we add in any gap
 | ||
|     // space as needed.
 | ||
|     if (mNumItems >= 2) {
 | ||
|       mTotalOuterHypotheticalMainSize =
 | ||
|         AddChecked(mTotalOuterHypotheticalMainSize, mMainGapSize);
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Computes the cross-size and baseline position of this FlexLine, based on
 | ||
|   // its FlexItems.
 | ||
|   void ComputeCrossSizeAndBaseline(const FlexboxAxisTracker& aAxisTracker);
 | ||
| 
 | ||
|   // Returns the cross-size of this line.
 | ||
|   nscoord GetLineCrossSize() const { return mLineCrossSize; }
 | ||
| 
 | ||
|   // Setter for line cross-size -- needed for cases where the flex container
 | ||
|   // imposes a cross-size on the line. (e.g. for single-line flexbox, or for
 | ||
|   // multi-line flexbox with 'align-content: stretch')
 | ||
|   void SetLineCrossSize(nscoord aLineCrossSize) {
 | ||
|     mLineCrossSize = aLineCrossSize;
 | ||
|   }
 | ||
| 
 | ||
|   /**
 | ||
|    * Returns the offset within this line where any baseline-aligned FlexItems
 | ||
|    * should place their baseline. Usually, this represents a distance from the
 | ||
|    * line's cross-start edge, but if we're internally reversing the axes (see
 | ||
|    * AreAxesInternallyReversed()), this instead represents the distance from
 | ||
|    * its cross-end edge.
 | ||
|    *
 | ||
|    * If there are no baseline-aligned FlexItems, returns nscoord_MIN.
 | ||
|    */
 | ||
|   nscoord GetFirstBaselineOffset() const {
 | ||
|     return mFirstBaselineOffset;
 | ||
|   }
 | ||
| 
 | ||
|   /**
 | ||
|    * Returns the offset within this line where any last baseline-aligned
 | ||
|    * FlexItems should place their baseline. Opposite the case of the first
 | ||
|    * baseline offset, this represents a distance from the line's cross-end
 | ||
|    * edge (since last baseline-aligned items are flush to the cross-end edge).
 | ||
|    * If we're internally reversing the axes, this instead represents the
 | ||
|    * distance from the line's cross-start edge.
 | ||
|    *
 | ||
|    * If there are no last baseline-aligned FlexItems, returns nscoord_MIN.
 | ||
|    */
 | ||
|   nscoord GetLastBaselineOffset() const {
 | ||
|     return mLastBaselineOffset;
 | ||
|   }
 | ||
| 
 | ||
|   /**
 | ||
|    * Returns the number of items held in this line. Used for total gap
 | ||
|    * calculations.
 | ||
|    */
 | ||
|   uint32_t GetNumItems() const {
 | ||
|     return mNumItems;
 | ||
|   }
 | ||
| 
 | ||
|   /**
 | ||
|    * Returns the gap size in the main axis for this line. Used for gap
 | ||
|    * calculations.
 | ||
|    */
 | ||
|   nscoord GetMainGapSize() const {
 | ||
|     return mMainGapSize;
 | ||
|   }
 | ||
| 
 | ||
|   // Runs the "Resolving Flexible Lengths" algorithm from section 9.7 of the
 | ||
|   // CSS flexbox spec to distribute aFlexContainerMainSize among our flex items.
 | ||
|   void ResolveFlexibleLengths(nscoord aFlexContainerMainSize,
 | ||
|                               ComputedFlexLineInfo* aLineInfo);
 | ||
| 
 | ||
|   void PositionItemsInMainAxis(uint8_t aJustifyContent,
 | ||
|                                nscoord aContentBoxMainSize,
 | ||
|                                const FlexboxAxisTracker& aAxisTracker);
 | ||
| 
 | ||
|   void PositionItemsInCrossAxis(nscoord aLineStartPosition,
 | ||
|                                 const FlexboxAxisTracker& aAxisTracker);
 | ||
| 
 | ||
|   friend class AutoFlexLineListClearer; // (needs access to mItems)
 | ||
| 
 | ||
| private:
 | ||
|   // Helpers for ResolveFlexibleLengths():
 | ||
|   void FreezeItemsEarly(bool aIsUsingFlexGrow);
 | ||
| 
 | ||
|   void FreezeOrRestoreEachFlexibleSize(const nscoord aTotalViolation,
 | ||
|                                        bool aIsFinalIteration);
 | ||
| 
 | ||
|   LinkedList<FlexItem> mItems; // Linked list of this line's flex items.
 | ||
| 
 | ||
|   uint32_t mNumItems; // Number of FlexItems in this line (in |mItems|).
 | ||
|                       // (Shouldn't change after GenerateFlexLines finishes
 | ||
|                       // with this line -- at least, not until we add support
 | ||
|                       // for splitting lines across continuations. Then we can
 | ||
|                       // update this count carefully.)
 | ||
| 
 | ||
|   // Number of *frozen* FlexItems in this line, based on FlexItem::IsFrozen().
 | ||
|   // Mostly used for optimization purposes, e.g. to bail out early from loops
 | ||
|   // when we can tell they have nothing left to do.
 | ||
|   uint32_t mNumFrozenItems;
 | ||
| 
 | ||
|   // Sum of margin/border/padding for the FlexItems in this FlexLine.
 | ||
|   nscoord mTotalItemMBP;
 | ||
| 
 | ||
|   // Sum of FlexItems' outer hypothetical main sizes and all main-axis
 | ||
|   // {row,columnm}-gaps between items.
 | ||
|   // (i.e. their flex base sizes, clamped via their min/max-size properties,
 | ||
|   // plus their main-axis margin/border/padding, plus the sum of the gaps.)
 | ||
|   nscoord mTotalOuterHypotheticalMainSize;
 | ||
| 
 | ||
|   nscoord mLineCrossSize;
 | ||
|   nscoord mFirstBaselineOffset;
 | ||
|   nscoord mLastBaselineOffset;
 | ||
| 
 | ||
|   // Maintain size of each {row,column}-gap in the main axis
 | ||
|   const nscoord mMainGapSize;
 | ||
| };
 | ||
| 
 | ||
| // Information about a strut left behind by a FlexItem that's been collapsed
 | ||
| // using "visibility:collapse".
 | ||
| struct nsFlexContainerFrame::StrutInfo {
 | ||
|   StrutInfo(uint32_t aItemIdx, nscoord aStrutCrossSize)
 | ||
|     : mItemIdx(aItemIdx),
 | ||
|       mStrutCrossSize(aStrutCrossSize)
 | ||
|   {
 | ||
|   }
 | ||
| 
 | ||
|   uint32_t mItemIdx;      // Index in the child list.
 | ||
|   nscoord mStrutCrossSize; // The cross-size of this strut.
 | ||
| };
 | ||
| 
 | ||
| static void
 | ||
| BuildStrutInfoFromCollapsedItems(const FlexLine* aFirstLine,
 | ||
|                                  nsTArray<StrutInfo>& aStruts)
 | ||
| {
 | ||
|   MOZ_ASSERT(aFirstLine, "null first line pointer");
 | ||
|   MOZ_ASSERT(aStruts.IsEmpty(),
 | ||
|              "We should only build up StrutInfo once per reflow, so "
 | ||
|              "aStruts should be empty when this is called");
 | ||
| 
 | ||
|   uint32_t itemIdxInContainer = 0;
 | ||
|   for (const FlexLine* line = aFirstLine; line; line = line->getNext()) {
 | ||
|     for (const FlexItem* item = line->GetFirstItem(); item;
 | ||
|          item = item->getNext()) {
 | ||
|       if (NS_STYLE_VISIBILITY_COLLAPSE ==
 | ||
|           item->Frame()->StyleVisibility()->mVisible) {
 | ||
|         // Note the cross size of the line as the item's strut size.
 | ||
|         aStruts.AppendElement(StrutInfo(itemIdxInContainer,
 | ||
|                                         line->GetLineCrossSize()));
 | ||
|       }
 | ||
|       itemIdxInContainer++;
 | ||
|     }
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| static uint8_t
 | ||
| SimplifyAlignOrJustifyContentForOneItem(uint16_t aAlignmentVal,
 | ||
|                                         bool aIsAlign)
 | ||
| {
 | ||
|   // Mask away any explicit fallback, to get the main (non-fallback) part of
 | ||
|   // the specified value:
 | ||
|   uint16_t specified = aAlignmentVal & NS_STYLE_ALIGN_ALL_BITS;
 | ||
| 
 | ||
|   // XXX strip off <overflow-position> bits until we implement it (bug 1311892)
 | ||
|   specified &= ~NS_STYLE_ALIGN_FLAG_BITS;
 | ||
| 
 | ||
|   // FIRST: handle a special-case for "justify-content:stretch" (or equivalent),
 | ||
|   // which requires that we ignore any author-provided explicit fallback value.
 | ||
|   if (specified == NS_STYLE_ALIGN_NORMAL) {
 | ||
|     // In a flex container, *-content: "'normal' behaves as 'stretch'".
 | ||
|     // Do that conversion early, so it benefits from our 'stretch' special-case.
 | ||
|     // https://drafts.csswg.org/css-align-3/#distribution-flex
 | ||
|     specified = NS_STYLE_ALIGN_STRETCH;
 | ||
|   }
 | ||
|   if (!aIsAlign && specified == NS_STYLE_ALIGN_STRETCH) {
 | ||
|     // In a flex container, in "justify-content Axis: [...] 'stretch' behaves
 | ||
|     // as 'flex-start' (ignoring the specified fallback alignment, if any)."
 | ||
|     // https://drafts.csswg.org/css-align-3/#distribution-flex
 | ||
|     // So, we just directly return 'flex-start', & ignore explicit fallback..
 | ||
|     return NS_STYLE_ALIGN_FLEX_START;
 | ||
|   }
 | ||
| 
 | ||
|   // Now check for an explicit fallback value (and if it's present, use it).
 | ||
|   uint16_t explicitFallback = aAlignmentVal >> NS_STYLE_ALIGN_ALL_SHIFT;
 | ||
|   if (explicitFallback) {
 | ||
|     // XXX strip off <overflow-position> bits until we implement it
 | ||
|     // (bug 1311892)
 | ||
|     explicitFallback &= ~NS_STYLE_ALIGN_FLAG_BITS;
 | ||
|     return explicitFallback;
 | ||
|   }
 | ||
| 
 | ||
|   // There's no explicit fallback. Use the implied fallback values for
 | ||
|   // space-{between,around,evenly} (since those values only make sense with
 | ||
|   // multiple alignment subjects), and otherwise just use the specified value:
 | ||
|   switch (specified) {
 | ||
|     case NS_STYLE_ALIGN_SPACE_BETWEEN:
 | ||
|       return NS_STYLE_ALIGN_START;
 | ||
|     case NS_STYLE_ALIGN_SPACE_AROUND:
 | ||
|     case NS_STYLE_ALIGN_SPACE_EVENLY:
 | ||
|       return NS_STYLE_ALIGN_CENTER;
 | ||
|     default:
 | ||
|       return specified;
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| uint16_t
 | ||
| nsFlexContainerFrame::CSSAlignmentForAbsPosChild(
 | ||
|   const ReflowInput& aChildRI,
 | ||
|   LogicalAxis aLogicalAxis) const
 | ||
| {
 | ||
|   WritingMode wm = GetWritingMode();
 | ||
|   const FlexboxAxisTracker
 | ||
|     axisTracker(this, wm, AxisTrackerFlags::eAllowBottomToTopChildOrdering);
 | ||
| 
 | ||
|   // If we're row-oriented and the caller is asking about our inline axis (or
 | ||
|   // alternately, if we're column-oriented and the caller is asking about our
 | ||
|   // block axis), then the caller is really asking about our *main* axis.
 | ||
|   // Otherwise, the caller is asking about our cross axis.
 | ||
|   const bool isMainAxis = (axisTracker.IsRowOriented() ==
 | ||
|                            (aLogicalAxis == eLogicalAxisInline));
 | ||
|   const nsStylePosition* containerStylePos = StylePosition();
 | ||
|   const bool isAxisReversed = isMainAxis ? axisTracker.IsMainAxisReversed()
 | ||
|                                          : axisTracker.IsCrossAxisReversed();
 | ||
| 
 | ||
|   uint8_t alignment;
 | ||
|   if (isMainAxis) {
 | ||
|     alignment = SimplifyAlignOrJustifyContentForOneItem(
 | ||
|                   containerStylePos->mJustifyContent,
 | ||
|                   /*aIsAlign = */false);
 | ||
|   } else {
 | ||
|     const uint8_t alignContent = SimplifyAlignOrJustifyContentForOneItem(
 | ||
|                                    containerStylePos->mAlignContent,
 | ||
|                                    /*aIsAlign = */true);
 | ||
|     if (NS_STYLE_FLEX_WRAP_NOWRAP != containerStylePos->mFlexWrap &&
 | ||
|         alignContent != NS_STYLE_ALIGN_STRETCH) {
 | ||
|       // Multi-line, align-content isn't stretch --> align-content determines
 | ||
|       // this child's alignment in the cross axis.
 | ||
|       alignment = alignContent;
 | ||
|     } else {
 | ||
|       // Single-line, or multi-line but the (one) line stretches to fill
 | ||
|       // container. Respect align-self.
 | ||
|       alignment = aChildRI.mStylePosition->UsedAlignSelf(Style());
 | ||
|       // XXX strip off <overflow-position> bits until we implement it
 | ||
|       // (bug 1311892)
 | ||
|       alignment &= ~NS_STYLE_ALIGN_FLAG_BITS;
 | ||
| 
 | ||
|       if (alignment == NS_STYLE_ALIGN_NORMAL) {
 | ||
|         // "the 'normal' keyword behaves as 'start' on replaced
 | ||
|         // absolutely-positioned boxes, and behaves as 'stretch' on all other
 | ||
|         // absolutely-positioned boxes."
 | ||
|         // https://drafts.csswg.org/css-align/#align-abspos
 | ||
|         alignment = aChildRI.mFrame->IsFrameOfType(nsIFrame::eReplaced) ?
 | ||
|           NS_STYLE_ALIGN_START : NS_STYLE_ALIGN_STRETCH;
 | ||
|       }
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Resolve flex-start, flex-end, auto, left, right, baseline, last baseline;
 | ||
|   if (alignment == NS_STYLE_ALIGN_FLEX_START) {
 | ||
|     alignment = isAxisReversed ? NS_STYLE_ALIGN_END : NS_STYLE_ALIGN_START;
 | ||
|   } else if (alignment == NS_STYLE_ALIGN_FLEX_END) {
 | ||
|     alignment = isAxisReversed ? NS_STYLE_ALIGN_START : NS_STYLE_ALIGN_END;
 | ||
|   } else if (alignment == NS_STYLE_ALIGN_LEFT ||
 | ||
|              alignment == NS_STYLE_ALIGN_RIGHT) {
 | ||
|     if (aLogicalAxis == eLogicalAxisInline) {
 | ||
|       const bool isLeft = (alignment == NS_STYLE_ALIGN_LEFT);
 | ||
|       alignment = (isLeft == wm.IsBidiLTR()) ? NS_STYLE_ALIGN_START
 | ||
|                                              : NS_STYLE_ALIGN_END;
 | ||
|     } else {
 | ||
|       alignment = NS_STYLE_ALIGN_START;
 | ||
|     }
 | ||
|   } else if (alignment == NS_STYLE_ALIGN_BASELINE) {
 | ||
|     alignment = NS_STYLE_ALIGN_START;
 | ||
|   } else if (alignment == NS_STYLE_ALIGN_LAST_BASELINE) {
 | ||
|     alignment = NS_STYLE_ALIGN_END;
 | ||
|   }
 | ||
| 
 | ||
|   return alignment;
 | ||
| }
 | ||
| 
 | ||
| UniquePtr<FlexItem>
 | ||
| nsFlexContainerFrame::GenerateFlexItemForChild(
 | ||
|   nsPresContext* aPresContext,
 | ||
|   nsIFrame*      aChildFrame,
 | ||
|   const ReflowInput& aParentReflowInput,
 | ||
|   const FlexboxAxisTracker& aAxisTracker)
 | ||
| {
 | ||
|   // Create temporary reflow state just for sizing -- to get hypothetical
 | ||
|   // main-size and the computed values of min / max main-size property.
 | ||
|   // (This reflow state will _not_ be used for reflow.)
 | ||
|   ReflowInput
 | ||
|     childRI(aPresContext, aParentReflowInput, aChildFrame,
 | ||
|             aParentReflowInput.ComputedSize(aChildFrame->GetWritingMode()));
 | ||
| 
 | ||
|   // FLEX GROW & SHRINK WEIGHTS
 | ||
|   // --------------------------
 | ||
|   float flexGrow, flexShrink;
 | ||
|   if (IsLegacyBox(this)) {
 | ||
|     flexGrow = flexShrink = aChildFrame->StyleXUL()->mBoxFlex;
 | ||
|   } else {
 | ||
|     const nsStylePosition* stylePos = aChildFrame->StylePosition();
 | ||
|     flexGrow   = stylePos->mFlexGrow;
 | ||
|     flexShrink = stylePos->mFlexShrink;
 | ||
|   }
 | ||
| 
 | ||
|   WritingMode childWM = childRI.GetWritingMode();
 | ||
| 
 | ||
|   // MAIN SIZES (flex base size, min/max size)
 | ||
|   // -----------------------------------------
 | ||
|   nscoord flexBaseSize = GET_MAIN_COMPONENT_LOGICAL(aAxisTracker, childWM,
 | ||
|                                                     childRI.ComputedISize(),
 | ||
|                                                     childRI.ComputedBSize());
 | ||
|   nscoord mainMinSize = GET_MAIN_COMPONENT_LOGICAL(aAxisTracker, childWM,
 | ||
|                                                    childRI.ComputedMinISize(),
 | ||
|                                                    childRI.ComputedMinBSize());
 | ||
|   nscoord mainMaxSize = GET_MAIN_COMPONENT_LOGICAL(aAxisTracker, childWM,
 | ||
|                                                    childRI.ComputedMaxISize(),
 | ||
|                                                    childRI.ComputedMaxBSize());
 | ||
|   // This is enforced by the ReflowInput where these values come from:
 | ||
|   MOZ_ASSERT(mainMinSize <= mainMaxSize, "min size is larger than max size");
 | ||
| 
 | ||
|   // CROSS SIZES (tentative cross size, min/max cross size)
 | ||
|   // ------------------------------------------------------
 | ||
|   // Grab the cross size from the reflow state. This might be the right value,
 | ||
|   // or we might resolve it to something else in SizeItemInCrossAxis(); hence,
 | ||
|   // it's tentative. See comment under "Cross Size Determination" for more.
 | ||
|   nscoord tentativeCrossSize =
 | ||
|     GET_CROSS_COMPONENT_LOGICAL(aAxisTracker, childWM,
 | ||
|                                 childRI.ComputedISize(),
 | ||
|                                 childRI.ComputedBSize());
 | ||
|   nscoord crossMinSize =
 | ||
|     GET_CROSS_COMPONENT_LOGICAL(aAxisTracker, childWM,
 | ||
|                                 childRI.ComputedMinISize(),
 | ||
|                                 childRI.ComputedMinBSize());
 | ||
|   nscoord crossMaxSize =
 | ||
|     GET_CROSS_COMPONENT_LOGICAL(aAxisTracker, childWM,
 | ||
|                                 childRI.ComputedMaxISize(),
 | ||
|                                 childRI.ComputedMaxBSize());
 | ||
| 
 | ||
|   // SPECIAL-CASE FOR WIDGET-IMPOSED SIZES
 | ||
|   // Check if we're a themed widget, in which case we might have a minimum
 | ||
|   // main & cross size imposed by our widget (which we can't go below), or
 | ||
|   // (more severe) our widget might have only a single valid size.
 | ||
|   bool isFixedSizeWidget = false;
 | ||
|   const nsStyleDisplay* disp = aChildFrame->StyleDisplay();
 | ||
|   if (aChildFrame->IsThemed(disp)) {
 | ||
|     LayoutDeviceIntSize widgetMinSize;
 | ||
|     bool canOverride = true;
 | ||
|     aPresContext->GetTheme()->
 | ||
|       GetMinimumWidgetSize(aPresContext, aChildFrame,
 | ||
|                            disp->mAppearance,
 | ||
|                            &widgetMinSize, &canOverride);
 | ||
| 
 | ||
|     nscoord widgetMainMinSize =
 | ||
|       aPresContext->DevPixelsToAppUnits(
 | ||
|         aAxisTracker.GetMainComponent(widgetMinSize));
 | ||
|     nscoord widgetCrossMinSize =
 | ||
|       aPresContext->DevPixelsToAppUnits(
 | ||
|         aAxisTracker.GetCrossComponent(widgetMinSize));
 | ||
| 
 | ||
|     // GetMinimumWidgetSize() returns border-box. We need content-box, so
 | ||
|     // subtract borderPadding.
 | ||
|     const LogicalMargin bpInChildWM = childRI.ComputedLogicalBorderPadding();
 | ||
|     const LogicalMargin bpInFlexWM =
 | ||
|       bpInChildWM.ConvertTo(aAxisTracker.GetWritingMode(), childWM);
 | ||
|     widgetMainMinSize -= aAxisTracker.GetMarginSizeInMainAxis(bpInFlexWM);
 | ||
|     widgetCrossMinSize -= aAxisTracker.GetMarginSizeInCrossAxis(bpInFlexWM);
 | ||
|     // ... (but don't let that push these min sizes below 0).
 | ||
|     widgetMainMinSize = std::max(0, widgetMainMinSize);
 | ||
|     widgetCrossMinSize = std::max(0, widgetCrossMinSize);
 | ||
| 
 | ||
|     if (!canOverride) {
 | ||
|       // Fixed-size widget: freeze our main-size at the widget's mandated size.
 | ||
|       // (Set min and max main-sizes to that size, too, to keep us from
 | ||
|       // clamping to any other size later on.)
 | ||
|       flexBaseSize = mainMinSize = mainMaxSize = widgetMainMinSize;
 | ||
|       tentativeCrossSize = crossMinSize = crossMaxSize = widgetCrossMinSize;
 | ||
|       isFixedSizeWidget = true;
 | ||
|     } else {
 | ||
|       // Variable-size widget: ensure our min/max sizes are at least as large
 | ||
|       // as the widget's mandated minimum size, so we don't flex below that.
 | ||
|       mainMinSize = std::max(mainMinSize, widgetMainMinSize);
 | ||
|       mainMaxSize = std::max(mainMaxSize, widgetMainMinSize);
 | ||
| 
 | ||
|       if (tentativeCrossSize != NS_INTRINSICSIZE) {
 | ||
|         tentativeCrossSize = std::max(tentativeCrossSize, widgetCrossMinSize);
 | ||
|       }
 | ||
|       crossMinSize = std::max(crossMinSize, widgetCrossMinSize);
 | ||
|       crossMaxSize = std::max(crossMaxSize, widgetCrossMinSize);
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Construct the flex item!
 | ||
|   auto item = MakeUnique<FlexItem>(childRI,
 | ||
|                                    flexGrow, flexShrink, flexBaseSize,
 | ||
|                                    mainMinSize, mainMaxSize,
 | ||
|                                    tentativeCrossSize,
 | ||
|                                    crossMinSize, crossMaxSize,
 | ||
|                                    aAxisTracker);
 | ||
| 
 | ||
|   // If we're inflexible, we can just freeze to our hypothetical main-size
 | ||
|   // up-front. Similarly, if we're a fixed-size widget, we only have one
 | ||
|   // valid size, so we freeze to keep ourselves from flexing.
 | ||
|   if (isFixedSizeWidget || (flexGrow == 0.0f && flexShrink == 0.0f)) {
 | ||
|     item->Freeze();
 | ||
|   }
 | ||
| 
 | ||
|   // Resolve "flex-basis:auto" and/or "min-[width|height]:auto" (which might
 | ||
|   // require us to reflow the item to measure content height)
 | ||
|   ResolveAutoFlexBasisAndMinSize(aPresContext, *item,
 | ||
|                                  childRI, aAxisTracker);
 | ||
|   return item;
 | ||
| }
 | ||
| 
 | ||
| // Static helper-functions for ResolveAutoFlexBasisAndMinSize():
 | ||
| // -------------------------------------------------------------
 | ||
| // Indicates whether the cross-size property is set to something definite,
 | ||
| // for the purpose of intrinsic ratio calculations.
 | ||
| // The logic here should be similar to the logic for isAutoISize/isAutoBSize
 | ||
| // in nsFrame::ComputeSizeWithIntrinsicDimensions().
 | ||
| static bool
 | ||
| IsCrossSizeDefinite(const ReflowInput& aItemReflowInput,
 | ||
|                     const FlexboxAxisTracker& aAxisTracker)
 | ||
| {
 | ||
|   const nsStylePosition* pos = aItemReflowInput.mStylePosition;
 | ||
|   const WritingMode containerWM = aAxisTracker.GetWritingMode();
 | ||
| 
 | ||
|   if (aAxisTracker.IsColumnOriented()) {
 | ||
|     // Column-oriented means cross axis is container's inline axis.
 | ||
|     return pos->ISize(containerWM).GetUnit() != eStyleUnit_Auto;
 | ||
|   }
 | ||
|   // Else, we're row-oriented, which means cross axis is container's block
 | ||
|   // axis. We need to use IsAutoBSize() to catch e.g. %-BSize applied to
 | ||
|   // indefinite container BSize, which counts as auto.
 | ||
|   nscoord cbBSize = aItemReflowInput.mCBReflowInput->ComputedBSize();
 | ||
|   return !nsLayoutUtils::IsAutoBSize(pos->BSize(containerWM), cbBSize);
 | ||
| }
 | ||
| 
 | ||
| // If aFlexItem has a definite cross size, this function returns it, for usage
 | ||
| // (in combination with an intrinsic ratio) for resolving the item's main size
 | ||
| // or main min-size.
 | ||
| //
 | ||
| // The parameter "aMinSizeFallback" indicates whether we should fall back to
 | ||
| // returning the cross min-size, when the cross size is indefinite. (This param
 | ||
| // should be set IFF the caller intends to resolve the main min-size.) If this
 | ||
| // param is true, then this function is guaranteed to return a definite value
 | ||
| // (i.e. not NS_AUTOHEIGHT, excluding cases where huge sizes are involved).
 | ||
| //
 | ||
| // XXXdholbert the min-size behavior here is based on my understanding in
 | ||
| //   http://lists.w3.org/Archives/Public/www-style/2014Jul/0053.html
 | ||
| // If my understanding there ends up being wrong, we'll need to update this.
 | ||
| static nscoord
 | ||
| CrossSizeToUseWithRatio(const FlexItem& aFlexItem,
 | ||
|                         const ReflowInput& aItemReflowInput,
 | ||
|                         bool aMinSizeFallback,
 | ||
|                         const FlexboxAxisTracker& aAxisTracker)
 | ||
| {
 | ||
|   if (aFlexItem.IsStretched()) {
 | ||
|     // Definite cross-size, imposed via 'align-self:stretch' & flex container.
 | ||
|     return aFlexItem.GetCrossSize();
 | ||
|   }
 | ||
| 
 | ||
|   if (IsCrossSizeDefinite(aItemReflowInput, aAxisTracker)) {
 | ||
|     // Definite cross size.
 | ||
|     return GET_CROSS_COMPONENT_LOGICAL(aAxisTracker, aFlexItem.GetWritingMode(),
 | ||
|                                        aItemReflowInput.ComputedISize(),
 | ||
|                                        aItemReflowInput.ComputedBSize());
 | ||
|   }
 | ||
| 
 | ||
|   if (aMinSizeFallback) {
 | ||
|     // Indefinite cross-size, and we're resolving main min-size, so we'll fall
 | ||
|     // back to ussing the cross min-size (which should be definite).
 | ||
|     return GET_CROSS_COMPONENT_LOGICAL(aAxisTracker, aFlexItem.GetWritingMode(),
 | ||
|                                        aItemReflowInput.ComputedMinISize(),
 | ||
|                                        aItemReflowInput.ComputedMinBSize());
 | ||
|   }
 | ||
| 
 | ||
|   // Indefinite cross-size.
 | ||
|   return NS_AUTOHEIGHT;
 | ||
| }
 | ||
| 
 | ||
| // Convenience function; returns a main-size, given a cross-size and an
 | ||
| // intrinsic ratio. The caller is responsible for ensuring that the passed-in
 | ||
| // intrinsic ratio must not have 0 in its cross-axis component (or else we'll
 | ||
| // divide by 0).
 | ||
| static nscoord
 | ||
| MainSizeFromAspectRatio(nscoord aCrossSize,
 | ||
|                         const LogicalSize& aIntrinsicRatio,
 | ||
|                         const FlexboxAxisTracker& aAxisTracker)
 | ||
| {
 | ||
|   MOZ_ASSERT(aAxisTracker.GetCrossComponent(aIntrinsicRatio) != 0,
 | ||
|              "Invalid ratio; will divide by 0! Caller should've checked...");
 | ||
|   return NSCoordMulDiv(aCrossSize,
 | ||
|                        aAxisTracker.GetMainComponent(aIntrinsicRatio),
 | ||
|                        aAxisTracker.GetCrossComponent(aIntrinsicRatio));
 | ||
| }
 | ||
| 
 | ||
| // Partially resolves "min-[width|height]:auto" and returns the resulting value.
 | ||
| // By "partially", I mean we don't consider the min-content size (but we do
 | ||
| // consider flex-basis, main max-size, and the intrinsic aspect ratio).
 | ||
| // The caller is responsible for computing & considering the min-content size
 | ||
| // in combination with the partially-resolved value that this function returns.
 | ||
| //
 | ||
| // Spec reference: http://dev.w3.org/csswg/css-flexbox/#min-size-auto
 | ||
| static nscoord
 | ||
| PartiallyResolveAutoMinSize(const FlexItem& aFlexItem,
 | ||
|                             const ReflowInput& aItemReflowInput,
 | ||
|                             const FlexboxAxisTracker& aAxisTracker)
 | ||
| {
 | ||
|   MOZ_ASSERT(aFlexItem.NeedsMinSizeAutoResolution(),
 | ||
|              "only call for FlexItems that need min-size auto resolution");
 | ||
| 
 | ||
|   nscoord minMainSize = nscoord_MAX; // Intentionally huge; we'll shrink it
 | ||
|                                      // from here, w/ std::min().
 | ||
| 
 | ||
|   // We need the smallest of:
 | ||
|   // * the used flex-basis, if the computed flex-basis was 'auto':
 | ||
|   // XXXdholbert ('auto' might be renamed to 'main-size'; see bug 1032922)
 | ||
|   if (eStyleUnit_Auto ==
 | ||
|       aItemReflowInput.mStylePosition->mFlexBasis.GetUnit() &&
 | ||
|       aFlexItem.GetFlexBaseSize() != NS_AUTOHEIGHT) {
 | ||
|     // NOTE: We skip this if the flex base size depends on content & isn't yet
 | ||
|     // resolved. This is OK, because the caller is responsible for computing
 | ||
|     // the min-content height and min()'ing it with the value we return, which
 | ||
|     // is equivalent to what would happen if we min()'d that at this point.
 | ||
|     minMainSize = std::min(minMainSize, aFlexItem.GetFlexBaseSize());
 | ||
|   }
 | ||
| 
 | ||
|   // * the computed max-width (max-height), if that value is definite:
 | ||
|   nscoord maxSize =
 | ||
|     GET_MAIN_COMPONENT_LOGICAL(aAxisTracker, aFlexItem.GetWritingMode(),
 | ||
|                                aItemReflowInput.ComputedMaxISize(),
 | ||
|                                aItemReflowInput.ComputedMaxBSize());
 | ||
|   if (maxSize != NS_UNCONSTRAINEDSIZE) {
 | ||
|     minMainSize = std::min(minMainSize, maxSize);
 | ||
|   }
 | ||
| 
 | ||
|   // * if the item has no intrinsic aspect ratio, its min-content size:
 | ||
|   //  --- SKIPPING THIS IN THIS FUNCTION --- caller's responsibility.
 | ||
| 
 | ||
|   // * if the item has an intrinsic aspect ratio, the width (height) calculated
 | ||
|   //   from the aspect ratio and any definite size constraints in the opposite
 | ||
|   //   dimension.
 | ||
|   if (aAxisTracker.GetCrossComponent(aFlexItem.IntrinsicRatio()) != 0) {
 | ||
|     // We have a usable aspect ratio. (not going to divide by 0)
 | ||
|     const bool useMinSizeIfCrossSizeIsIndefinite = true;
 | ||
|     nscoord crossSizeToUseWithRatio =
 | ||
|       CrossSizeToUseWithRatio(aFlexItem, aItemReflowInput,
 | ||
|                               useMinSizeIfCrossSizeIsIndefinite,
 | ||
|                               aAxisTracker);
 | ||
|     nscoord minMainSizeFromRatio =
 | ||
|       MainSizeFromAspectRatio(crossSizeToUseWithRatio,
 | ||
|                               aFlexItem.IntrinsicRatio(), aAxisTracker);
 | ||
|     minMainSize = std::min(minMainSize, minMainSizeFromRatio);
 | ||
|   }
 | ||
| 
 | ||
|   return minMainSize;
 | ||
| }
 | ||
| 
 | ||
| // Resolves flex-basis:auto, using the given intrinsic ratio and the flex
 | ||
| // item's cross size.  On success, updates the flex item with its resolved
 | ||
| // flex-basis and returns true. On failure (e.g. if the ratio is invalid or
 | ||
| // the cross-size is indefinite), returns false.
 | ||
| static bool
 | ||
| ResolveAutoFlexBasisFromRatio(FlexItem& aFlexItem,
 | ||
|                               const ReflowInput& aItemReflowInput,
 | ||
|                               const FlexboxAxisTracker& aAxisTracker)
 | ||
| {
 | ||
|   MOZ_ASSERT(NS_AUTOHEIGHT == aFlexItem.GetFlexBaseSize(),
 | ||
|              "Should only be called to resolve an 'auto' flex-basis");
 | ||
|   // If the flex item has ...
 | ||
|   //  - an intrinsic aspect ratio,
 | ||
|   //  - a [used] flex-basis of 'main-size' [auto?] [We have this, if we're here.]
 | ||
|   //  - a definite cross size
 | ||
|   // then the flex base size is calculated from its inner cross size and the
 | ||
|   // flex item’s intrinsic aspect ratio.
 | ||
|   if (aAxisTracker.GetCrossComponent(aFlexItem.IntrinsicRatio()) != 0) {
 | ||
|     // We have a usable aspect ratio. (not going to divide by 0)
 | ||
|     const bool useMinSizeIfCrossSizeIsIndefinite = false;
 | ||
|     nscoord crossSizeToUseWithRatio =
 | ||
|       CrossSizeToUseWithRatio(aFlexItem, aItemReflowInput,
 | ||
|                               useMinSizeIfCrossSizeIsIndefinite,
 | ||
|                               aAxisTracker);
 | ||
|     if (crossSizeToUseWithRatio != NS_AUTOHEIGHT) {
 | ||
|       // We have a definite cross-size
 | ||
|       nscoord mainSizeFromRatio =
 | ||
|         MainSizeFromAspectRatio(crossSizeToUseWithRatio,
 | ||
|                                 aFlexItem.IntrinsicRatio(), aAxisTracker);
 | ||
|       aFlexItem.SetFlexBaseSizeAndMainSize(mainSizeFromRatio);
 | ||
|       return true;
 | ||
|     }
 | ||
|   }
 | ||
|   return false;
 | ||
| }
 | ||
| 
 | ||
| // Note: If & when we handle "min-height: min-content" for flex items,
 | ||
| // we may want to resolve that in this function, too.
 | ||
| void
 | ||
| nsFlexContainerFrame::
 | ||
|   ResolveAutoFlexBasisAndMinSize(nsPresContext* aPresContext,
 | ||
|                                  FlexItem& aFlexItem,
 | ||
|                                  const ReflowInput& aItemReflowInput,
 | ||
|                                  const FlexboxAxisTracker& aAxisTracker)
 | ||
| {
 | ||
|   // (Note: We can guarantee that the flex-basis will have already been
 | ||
|   // resolved if the main axis is the same is the same as the item's inline
 | ||
|   // axis. Inline-axis values should always be resolvable without reflow.)
 | ||
|   const bool isMainSizeAuto = (!aFlexItem.IsInlineAxisMainAxis() &&
 | ||
|                                NS_AUTOHEIGHT == aFlexItem.GetFlexBaseSize());
 | ||
| 
 | ||
|   const bool isMainMinSizeAuto = aFlexItem.NeedsMinSizeAutoResolution();
 | ||
| 
 | ||
|   if (!isMainSizeAuto && !isMainMinSizeAuto) {
 | ||
|     // Nothing to do; this function is only needed for flex items
 | ||
|     // with a used flex-basis of "auto" or a min-main-size of "auto".
 | ||
|     return;
 | ||
|   }
 | ||
| 
 | ||
|   // We may be about to do computations based on our item's cross-size
 | ||
|   // (e.g. using it as a contstraint when measuring our content in the
 | ||
|   // main axis, or using it with the intrinsic ratio to obtain a main size).
 | ||
|   // BEFORE WE DO THAT, we need let the item "pre-stretch" its cross size (if
 | ||
|   // it's got 'align-self:stretch'), for a certain case where the spec says
 | ||
|   // the stretched cross size is considered "definite". That case is if we
 | ||
|   // have a single-line (nowrap) flex container which itself has a definite
 | ||
|   // cross-size.  Otherwise, we'll wait to do stretching, since (in other
 | ||
|   // cases) we don't know how much the item should stretch yet.
 | ||
|   const ReflowInput* flexContainerRI = aItemReflowInput.mParentReflowInput;
 | ||
|   MOZ_ASSERT(flexContainerRI,
 | ||
|              "flex item's reflow state should have ptr to container's state");
 | ||
|   if (NS_STYLE_FLEX_WRAP_NOWRAP == flexContainerRI->mStylePosition->mFlexWrap) {
 | ||
|     // XXXdholbert Maybe this should share logic with ComputeCrossSize()...
 | ||
|     // Alternately, maybe tentative container cross size should be passed down.
 | ||
|     nscoord containerCrossSize =
 | ||
|       GET_CROSS_COMPONENT_LOGICAL(aAxisTracker, aAxisTracker.GetWritingMode(),
 | ||
|                                   flexContainerRI->ComputedISize(),
 | ||
|                                   flexContainerRI->ComputedBSize());
 | ||
|     // Is container's cross size "definite"?
 | ||
|     // - If it's column-oriented, then "yes", because its cross size is its
 | ||
|     // inline-size which is always definite from its descendants' perspective.
 | ||
|     // - Otherwise (if it's row-oriented), then we check the actual size
 | ||
|     // and call it definite if it's not NS_AUTOHEIGHT.
 | ||
|     if (aAxisTracker.IsColumnOriented() ||
 | ||
|         containerCrossSize != NS_AUTOHEIGHT) {
 | ||
|       // Container's cross size is "definite", so we can resolve the item's
 | ||
|       // stretched cross size using that.
 | ||
|       aFlexItem.ResolveStretchedCrossSize(containerCrossSize, aAxisTracker);
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   nscoord resolvedMinSize; // (only set/used if isMainMinSizeAuto==true)
 | ||
|   bool minSizeNeedsToMeasureContent = false; // assume the best
 | ||
|   if (isMainMinSizeAuto) {
 | ||
|     // Resolve the min-size, except for considering the min-content size.
 | ||
|     // (We'll consider that later, if we need to.)
 | ||
|     resolvedMinSize = PartiallyResolveAutoMinSize(aFlexItem, aItemReflowInput,
 | ||
|                                                   aAxisTracker);
 | ||
|     if (resolvedMinSize > 0 &&
 | ||
|         aAxisTracker.GetCrossComponent(aFlexItem.IntrinsicRatio()) == 0) {
 | ||
|       // We don't have a usable aspect ratio, so we need to consider our
 | ||
|       // min-content size as another candidate min-size, which we'll have to
 | ||
|       // min() with the current resolvedMinSize.
 | ||
|       // (If resolvedMinSize were already at 0, we could skip this measurement
 | ||
|       // because it can't go any lower. But it's not 0, so we need it.)
 | ||
|       minSizeNeedsToMeasureContent = true;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   bool flexBasisNeedsToMeasureContent = false; // assume the best
 | ||
|   if (isMainSizeAuto) {
 | ||
|     if (!ResolveAutoFlexBasisFromRatio(aFlexItem, aItemReflowInput,
 | ||
|                                        aAxisTracker)) {
 | ||
|       flexBasisNeedsToMeasureContent = true;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Measure content, if needed (w/ intrinsic-width method or a reflow)
 | ||
|   if (minSizeNeedsToMeasureContent || flexBasisNeedsToMeasureContent) {
 | ||
|     if (aFlexItem.IsInlineAxisMainAxis()) {
 | ||
|       if (minSizeNeedsToMeasureContent) {
 | ||
|         nscoord frameMinISize =
 | ||
|           aFlexItem.Frame()->GetMinISize(aItemReflowInput.mRenderingContext);
 | ||
|         resolvedMinSize = std::min(resolvedMinSize, frameMinISize);
 | ||
|       }
 | ||
|       NS_ASSERTION(!flexBasisNeedsToMeasureContent,
 | ||
|                    "flex-basis:auto should have been resolved in the "
 | ||
|                    "reflow state, for horizontal flexbox. It shouldn't need "
 | ||
|                    "special handling here");
 | ||
|     } else {
 | ||
|       // If this item is flexible (in its block axis)...
 | ||
|       // OR if we're measuring its 'auto' min-BSize, with its main-size (in its
 | ||
|       // block axis) being something non-"auto"...
 | ||
|       // THEN: we assume that the computed BSize that we're reflowing with now
 | ||
|       // could be different from the one we'll use for this flex item's
 | ||
|       // "actual" reflow later on.  In that case, we need to be sure the flex
 | ||
|       // item treats this as a block-axis resize (regardless of whether there
 | ||
|       // are actually any ancestors being resized in that axis).
 | ||
|       // (Note: We don't have to do this for the inline axis, because
 | ||
|       // InitResizeFlags will always turn on mIsIResize on when it sees that
 | ||
|       // the computed ISize is different from current ISize, and that's all we
 | ||
|       // need.)
 | ||
|       bool forceBResizeForMeasuringReflow =
 | ||
|         !aFlexItem.IsFrozen() ||         // Is the item flexible?
 | ||
|         !flexBasisNeedsToMeasureContent; // Are we *only* measuring it for
 | ||
|                                          // 'min-block-size:auto'?
 | ||
| 
 | ||
|       nscoord contentBSize =
 | ||
|         MeasureFlexItemContentBSize(aPresContext, aFlexItem,
 | ||
|                                     forceBResizeForMeasuringReflow,
 | ||
|                                     *flexContainerRI);
 | ||
|       if (minSizeNeedsToMeasureContent) {
 | ||
|         resolvedMinSize = std::min(resolvedMinSize, contentBSize);
 | ||
|       }
 | ||
|       if (flexBasisNeedsToMeasureContent) {
 | ||
|         aFlexItem.SetFlexBaseSizeAndMainSize(contentBSize);
 | ||
|       }
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   if (isMainMinSizeAuto) {
 | ||
|     aFlexItem.UpdateMainMinSize(resolvedMinSize);
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| /**
 | ||
|  * A cached result for a measuring reflow.
 | ||
|  *
 | ||
|  * Right now we only need to cache the available size and the computed height
 | ||
|  * for checking that the reflow input is valid, and the height and the ascent
 | ||
|  * to be used. This can be extended later if needed.
 | ||
|  *
 | ||
|  * The assumption here is that a given flex item measurement won't change until
 | ||
|  * either the available size or computed height changes, or the flex container
 | ||
|  * intrinsic size is marked as dirty (due to a style or DOM change).
 | ||
|  *
 | ||
|  * In particular the computed height may change between measuring reflows due to
 | ||
|  * how the mIsFlexContainerMeasuringBSize flag affects size computation (see
 | ||
|  * bug 1336708).
 | ||
|  *
 | ||
|  * Caching it prevents us from doing exponential reflows in cases of deeply
 | ||
|  * nested flex and scroll frames.
 | ||
|  *
 | ||
|  * We store them in the frame property table for simplicity.
 | ||
|  */
 | ||
| class nsFlexContainerFrame::CachedMeasuringReflowResult
 | ||
| {
 | ||
|   struct Key
 | ||
|   {
 | ||
|     const LogicalSize mAvailableSize;
 | ||
|     const nscoord mComputedBSize;
 | ||
|     const nscoord mComputedMinBSize;
 | ||
|     const nscoord mComputedMaxBSize;
 | ||
| 
 | ||
|     explicit Key(const ReflowInput& aRI)
 | ||
|       : mAvailableSize(aRI.AvailableSize())
 | ||
|       , mComputedBSize(aRI.ComputedBSize())
 | ||
|       , mComputedMinBSize(aRI.ComputedMinBSize())
 | ||
|       , mComputedMaxBSize(aRI.ComputedMaxBSize())
 | ||
|     { }
 | ||
| 
 | ||
|     bool operator==(const Key& aOther) const
 | ||
|     {
 | ||
|       return mAvailableSize == aOther.mAvailableSize &&
 | ||
|         mComputedBSize == aOther.mComputedBSize &&
 | ||
|         mComputedMinBSize == aOther.mComputedMinBSize &&
 | ||
|         mComputedMaxBSize == aOther.mComputedMaxBSize;
 | ||
|     }
 | ||
|   };
 | ||
| 
 | ||
|   const Key mKey;
 | ||
| 
 | ||
|   const nscoord mBSize;
 | ||
|   const nscoord mAscent;
 | ||
| 
 | ||
| public:
 | ||
|   CachedMeasuringReflowResult(const ReflowInput& aReflowInput,
 | ||
|                               const ReflowOutput& aDesiredSize)
 | ||
|     : mKey(aReflowInput)
 | ||
|     , mBSize(aDesiredSize.BSize(aReflowInput.GetWritingMode()))
 | ||
|     , mAscent(aDesiredSize.BlockStartAscent())
 | ||
|   { }
 | ||
| 
 | ||
|   bool IsValidFor(const ReflowInput& aReflowInput) const
 | ||
|   {
 | ||
|     return mKey == Key(aReflowInput);
 | ||
|   }
 | ||
| 
 | ||
|   nscoord BSize() const { return mBSize; }
 | ||
| 
 | ||
|   nscoord Ascent() const { return mAscent; }
 | ||
| };
 | ||
| 
 | ||
| NS_DECLARE_FRAME_PROPERTY_DELETABLE(CachedFlexMeasuringReflow,
 | ||
|                                     CachedMeasuringReflowResult);
 | ||
| 
 | ||
| const CachedMeasuringReflowResult&
 | ||
| nsFlexContainerFrame::MeasureAscentAndBSizeForFlexItem(
 | ||
|   FlexItem& aItem,
 | ||
|   nsPresContext* aPresContext,
 | ||
|   ReflowInput& aChildReflowInput)
 | ||
| {
 | ||
|   if (const auto* cachedResult =
 | ||
|         aItem.Frame()->GetProperty(CachedFlexMeasuringReflow())) {
 | ||
|     if (cachedResult->IsValidFor(aChildReflowInput)) {
 | ||
|       return *cachedResult;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   ReflowOutput childDesiredSize(aChildReflowInput);
 | ||
|   nsReflowStatus childReflowStatus;
 | ||
| 
 | ||
|   const uint32_t flags = NS_FRAME_NO_MOVE_FRAME;
 | ||
|   ReflowChild(aItem.Frame(), aPresContext,
 | ||
|               childDesiredSize, aChildReflowInput,
 | ||
|               0, 0, flags, childReflowStatus);
 | ||
|   aItem.SetHadMeasuringReflow();
 | ||
| 
 | ||
|   // XXXdholbert Once we do pagination / splitting, we'll need to actually
 | ||
|   // handle incomplete childReflowStatuses. But for now, we give our kids
 | ||
|   // unconstrained available height, which means they should always complete.
 | ||
|   MOZ_ASSERT(childReflowStatus.IsComplete(),
 | ||
|              "We gave flex item unconstrained available height, so it "
 | ||
|              "should be complete");
 | ||
| 
 | ||
|   // Tell the child we're done with its initial reflow.
 | ||
|   // (Necessary for e.g. GetBaseline() to work below w/out asserting)
 | ||
|   FinishReflowChild(aItem.Frame(), aPresContext,
 | ||
|                     childDesiredSize, &aChildReflowInput, 0, 0, flags);
 | ||
| 
 | ||
|   auto result =
 | ||
|     new CachedMeasuringReflowResult(aChildReflowInput, childDesiredSize);
 | ||
| 
 | ||
|   aItem.Frame()->SetProperty(CachedFlexMeasuringReflow(), result);
 | ||
|   return *result;
 | ||
| }
 | ||
| 
 | ||
| /* virtual */ void
 | ||
| nsFlexContainerFrame::MarkIntrinsicISizesDirty()
 | ||
| {
 | ||
|   mCachedMinISize = NS_INTRINSIC_WIDTH_UNKNOWN;
 | ||
|   mCachedPrefISize = NS_INTRINSIC_WIDTH_UNKNOWN;
 | ||
| 
 | ||
|   for (nsIFrame* childFrame : mFrames) {
 | ||
|     childFrame->DeleteProperty(CachedFlexMeasuringReflow());
 | ||
|   }
 | ||
|   nsContainerFrame::MarkIntrinsicISizesDirty();
 | ||
| }
 | ||
| 
 | ||
| nscoord
 | ||
| nsFlexContainerFrame::
 | ||
|   MeasureFlexItemContentBSize(nsPresContext* aPresContext,
 | ||
|                               FlexItem& aFlexItem,
 | ||
|                               bool aForceBResizeForMeasuringReflow,
 | ||
|                               const ReflowInput& aParentReflowInput)
 | ||
| {
 | ||
|   // Set up a reflow state for measuring the flex item's auto-height:
 | ||
|   WritingMode wm = aFlexItem.Frame()->GetWritingMode();
 | ||
|   LogicalSize availSize = aParentReflowInput.ComputedSize(wm);
 | ||
|   availSize.BSize(wm) = NS_UNCONSTRAINEDSIZE;
 | ||
|   ReflowInput
 | ||
|     childRIForMeasuringBSize(aPresContext, aParentReflowInput,
 | ||
|                              aFlexItem.Frame(), availSize,
 | ||
|                              nullptr, ReflowInput::CALLER_WILL_INIT);
 | ||
|   childRIForMeasuringBSize.mFlags.mIsFlexContainerMeasuringBSize = true;
 | ||
|   childRIForMeasuringBSize.Init(aPresContext);
 | ||
| 
 | ||
|   if (aFlexItem.IsStretched()) {
 | ||
|     childRIForMeasuringBSize.SetComputedISize(aFlexItem.GetCrossSize());
 | ||
|     childRIForMeasuringBSize.SetIResize(true);
 | ||
|   }
 | ||
| 
 | ||
|   if (aForceBResizeForMeasuringReflow) {
 | ||
|     childRIForMeasuringBSize.SetBResize(true);
 | ||
|   }
 | ||
| 
 | ||
|   const CachedMeasuringReflowResult& reflowResult =
 | ||
|     MeasureAscentAndBSizeForFlexItem(aFlexItem, aPresContext,
 | ||
|                                      childRIForMeasuringBSize);
 | ||
| 
 | ||
|   aFlexItem.SetAscent(reflowResult.Ascent());
 | ||
| 
 | ||
|   // Subtract border/padding in block axis, to get _just_
 | ||
|   // the effective computed value of the BSize property.
 | ||
|   nscoord childDesiredBSize = reflowResult.BSize() -
 | ||
|     childRIForMeasuringBSize.ComputedLogicalBorderPadding().BStartEnd(wm);
 | ||
| 
 | ||
|   return std::max(0, childDesiredBSize);
 | ||
| }
 | ||
| 
 | ||
| FlexItem::FlexItem(ReflowInput& aFlexItemReflowInput,
 | ||
|                    float aFlexGrow, float aFlexShrink, nscoord aFlexBaseSize,
 | ||
|                    nscoord aMainMinSize,  nscoord aMainMaxSize,
 | ||
|                    nscoord aTentativeCrossSize,
 | ||
|                    nscoord aCrossMinSize, nscoord aCrossMaxSize,
 | ||
|                    const FlexboxAxisTracker& aAxisTracker)
 | ||
|   : mFrame(aFlexItemReflowInput.mFrame),
 | ||
|     mFlexGrow(aFlexGrow),
 | ||
|     mFlexShrink(aFlexShrink),
 | ||
|     // We store the intrinsic ratio in the *flex container's* WM:
 | ||
|     mIntrinsicRatio(aAxisTracker.GetWritingMode(), mFrame->GetIntrinsicRatio()),
 | ||
|     mBorderPadding(aFlexItemReflowInput.ComputedPhysicalBorderPadding()),
 | ||
|     mMargin(aFlexItemReflowInput.ComputedPhysicalMargin()),
 | ||
|     mMainMinSize(aMainMinSize),
 | ||
|     mMainMaxSize(aMainMaxSize),
 | ||
|     mCrossMinSize(aCrossMinSize),
 | ||
|     mCrossMaxSize(aCrossMaxSize),
 | ||
|     mMainPosn(0),
 | ||
|     mCrossSize(aTentativeCrossSize),
 | ||
|     mCrossPosn(0),
 | ||
|     mAscent(0),
 | ||
|     mShareOfWeightSoFar(0.0f),
 | ||
|     mWM(aFlexItemReflowInput.GetWritingMode()),
 | ||
|     mIsFrozen(false),
 | ||
|     mHadMinViolation(false),
 | ||
|     mHadMaxViolation(false),
 | ||
|     mHadMeasuringReflow(false),
 | ||
|     mIsStretched(false),
 | ||
|     mIsStrut(false),
 | ||
|     mIsInlineAxisMainAxis(aAxisTracker.IsRowOriented() !=
 | ||
|                           aAxisTracker.GetWritingMode().IsOrthogonalTo(mWM))
 | ||
|     // mNeedsMinSizeAutoResolution is initialized in CheckForMinSizeAuto()
 | ||
|     // mAlignSelf, mHasAnyAutoMargin see below
 | ||
| {
 | ||
|   MOZ_ASSERT(mFrame, "expecting a non-null child frame");
 | ||
|   MOZ_ASSERT(!mFrame->IsPlaceholderFrame(),
 | ||
|              "placeholder frames should not be treated as flex items");
 | ||
|   MOZ_ASSERT(!(mFrame->GetStateBits() & NS_FRAME_OUT_OF_FLOW),
 | ||
|              "out-of-flow frames should not be treated as flex items");
 | ||
|   MOZ_ASSERT(mIsInlineAxisMainAxis ==
 | ||
|              nsFlexContainerFrame::IsItemInlineAxisMainAxis(mFrame),
 | ||
|              "public API should be consistent with internal state (about "
 | ||
|              "whether flex item's inline axis is flex container's main axis)");
 | ||
| 
 | ||
|   const ReflowInput* containerRS = aFlexItemReflowInput.mParentReflowInput;
 | ||
|   if (IsLegacyBox(containerRS->mFrame)) {
 | ||
|     // For -webkit-{inline-}box and -moz-{inline-}box, we need to:
 | ||
|     // (1) Use prefixed "box-align" instead of "align-items" to determine the
 | ||
|     //     container's cross-axis alignment behavior.
 | ||
|     // (2) Suppress the ability for flex items to override that with their own
 | ||
|     //     cross-axis alignment. (The legacy box model doesn't support this.)
 | ||
|     // So, each FlexItem simply copies the container's converted "align-items"
 | ||
|     // value and disregards their own "align-self" property.
 | ||
|     const nsStyleXUL* containerStyleXUL = containerRS->mFrame->StyleXUL();
 | ||
|     mAlignSelf = ConvertLegacyStyleToAlignItems(containerStyleXUL);
 | ||
|   } else {
 | ||
|     mAlignSelf = aFlexItemReflowInput.mStylePosition->UsedAlignSelf(
 | ||
|                    containerRS->mFrame->Style());
 | ||
|     if (MOZ_LIKELY(mAlignSelf == NS_STYLE_ALIGN_NORMAL)) {
 | ||
|       mAlignSelf = NS_STYLE_ALIGN_STRETCH;
 | ||
|     }
 | ||
| 
 | ||
|     // XXX strip off the <overflow-position> bit until we implement that
 | ||
|     mAlignSelf &= ~NS_STYLE_ALIGN_FLAG_BITS;
 | ||
|   }
 | ||
| 
 | ||
|   SetFlexBaseSizeAndMainSize(aFlexBaseSize);
 | ||
|   CheckForMinSizeAuto(aFlexItemReflowInput, aAxisTracker);
 | ||
| 
 | ||
| 
 | ||
|   const nsStyleSides& styleMargin =
 | ||
|     aFlexItemReflowInput.mStyleMargin->mMargin;
 | ||
|   mHasAnyAutoMargin = styleMargin.HasInlineAxisAuto(mWM) ||
 | ||
|                       styleMargin.HasBlockAxisAuto(mWM);
 | ||
| 
 | ||
|   // Assert that any "auto" margin components are set to 0.
 | ||
|   // (We'll resolve them later; until then, we want to treat them as 0-sized.)
 | ||
| #ifdef DEBUG
 | ||
|   {
 | ||
|     NS_FOR_CSS_SIDES(side) {
 | ||
|       if (styleMargin.GetUnit(side) == eStyleUnit_Auto) {
 | ||
|         MOZ_ASSERT(GetMarginComponentForSide(side) == 0,
 | ||
|                    "Someone else tried to resolve our auto margin");
 | ||
|       }
 | ||
|     }
 | ||
|   }
 | ||
| #endif // DEBUG
 | ||
| 
 | ||
|   // Map align-self 'baseline' value to 'start' when baseline alignment
 | ||
|   // is not possible because the FlexItem's block axis is orthogonal to
 | ||
|   // the cross axis of the container. If that's the case, we just directly
 | ||
|   // convert our align-self value here, so that we don't have to handle this
 | ||
|   // with special cases elsewhere.
 | ||
|   // We are treating this case as one where it is appropriate to use the
 | ||
|   // fallback values defined at https://www.w3.org/TR/css-align/#baseline-values
 | ||
|   if (!IsBlockAxisCrossAxis()) {
 | ||
|     if (mAlignSelf == NS_STYLE_ALIGN_BASELINE) {
 | ||
|       mAlignSelf = NS_STYLE_ALIGN_FLEX_START;
 | ||
|     } else if (mAlignSelf == NS_STYLE_ALIGN_LAST_BASELINE) {
 | ||
|       mAlignSelf = NS_STYLE_ALIGN_FLEX_END;
 | ||
|     }
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| // Simplified constructor for creating a special "strut" FlexItem, for a child
 | ||
| // with visibility:collapse. The strut has 0 main-size, and it only exists to
 | ||
| // impose a minimum cross size on whichever FlexLine it ends up in.
 | ||
| FlexItem::FlexItem(nsIFrame* aChildFrame, nscoord aCrossSize,
 | ||
|                    WritingMode aContainerWM)
 | ||
|   : mFrame(aChildFrame),
 | ||
|     mFlexGrow(0.0f),
 | ||
|     mFlexShrink(0.0f),
 | ||
|     mIntrinsicRatio(aContainerWM),
 | ||
|     // mBorderPadding uses default constructor,
 | ||
|     // mMargin uses default constructor,
 | ||
|     mFlexBaseSize(0),
 | ||
|     mMainMinSize(0),
 | ||
|     mMainMaxSize(0),
 | ||
|     mCrossMinSize(0),
 | ||
|     mCrossMaxSize(0),
 | ||
|     mMainSize(0),
 | ||
|     mMainPosn(0),
 | ||
|     mCrossSize(aCrossSize),
 | ||
|     mCrossPosn(0),
 | ||
|     mAscent(0),
 | ||
|     mShareOfWeightSoFar(0.0f),
 | ||
|     // Struts don't do layout, so its WM doesn't matter at this point. So, we
 | ||
|     // just share container's WM for simplicity:
 | ||
|     mWM(aContainerWM),
 | ||
|     mIsFrozen(true),
 | ||
|     mHadMinViolation(false),
 | ||
|     mHadMaxViolation(false),
 | ||
|     mHadMeasuringReflow(false),
 | ||
|     mIsStretched(false),
 | ||
|     mIsStrut(true), // (this is the constructor for making struts, after all)
 | ||
|     mIsInlineAxisMainAxis(true), // (doesn't matter b/c we're not doing layout)
 | ||
|     mNeedsMinSizeAutoResolution(false),
 | ||
|     mHasAnyAutoMargin(false),
 | ||
|     mAlignSelf(NS_STYLE_ALIGN_FLEX_START)
 | ||
| {
 | ||
|   MOZ_ASSERT(mFrame, "expecting a non-null child frame");
 | ||
|   MOZ_ASSERT(NS_STYLE_VISIBILITY_COLLAPSE ==
 | ||
|              mFrame->StyleVisibility()->mVisible,
 | ||
|              "Should only make struts for children with 'visibility:collapse'");
 | ||
|   MOZ_ASSERT(!mFrame->IsPlaceholderFrame(),
 | ||
|              "placeholder frames should not be treated as flex items");
 | ||
|   MOZ_ASSERT(!(mFrame->GetStateBits() & NS_FRAME_OUT_OF_FLOW),
 | ||
|              "out-of-flow frames should not be treated as flex items");
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| FlexItem::CheckForMinSizeAuto(const ReflowInput& aFlexItemReflowInput,
 | ||
|                               const FlexboxAxisTracker& aAxisTracker)
 | ||
| {
 | ||
|   const nsStylePosition* pos = aFlexItemReflowInput.mStylePosition;
 | ||
|   const nsStyleDisplay* disp = aFlexItemReflowInput.mStyleDisplay;
 | ||
| 
 | ||
|   // We'll need special behavior for "min-[width|height]:auto" (whichever is in
 | ||
|   // the flex container's main axis) iff:
 | ||
|   // (a) its computed value is "auto"
 | ||
|   // (b) the "overflow" sub-property in the same axis (the main axis) has a
 | ||
|   //     computed value of "visible"
 | ||
|   const nsStyleCoord& mainMinSize = aAxisTracker.IsRowOriented()
 | ||
|     ? pos->MinISize(aAxisTracker.GetWritingMode())
 | ||
|     : pos->MinBSize(aAxisTracker.GetWritingMode());
 | ||
| 
 | ||
|   // NOTE: Technically we should be checking the 'overflow' subproperty in the
 | ||
|   // main axis. But since we only care whether it's 'visible', we can check
 | ||
|   // either subproperty -- because they must be BOTH 'visible' or BOTH
 | ||
|   // non-'visible' due to the way the subproperties interact.
 | ||
|   mNeedsMinSizeAutoResolution = (mainMinSize.GetUnit() == eStyleUnit_Auto &&
 | ||
|                                  disp->mOverflowX == NS_STYLE_OVERFLOW_VISIBLE);
 | ||
| }
 | ||
| 
 | ||
| nscoord
 | ||
| FlexItem::GetBaselineOffsetFromOuterCrossEdge(
 | ||
|   AxisEdgeType aEdge,
 | ||
|   const FlexboxAxisTracker& aAxisTracker,
 | ||
|   bool aUseFirstLineBaseline) const
 | ||
| {
 | ||
|   // NOTE:
 | ||
|   //  * We only use baselines for aligning in the flex container's cross axis.
 | ||
|   //  * Baselines are a measurement in the item's block axis.
 | ||
|   // ...so we only expect to get here if the item's block axis is parallel (or
 | ||
|   // antiparallel) to the container's cross axis.  (Otherwise, the FlexItem
 | ||
|   // constructor should've resolved mAlignSelf with a fallback value, which
 | ||
|   // would prevent this function from being called.)
 | ||
|   MOZ_ASSERT(IsBlockAxisCrossAxis(),
 | ||
|              "Only expecting to be doing baseline computations when the "
 | ||
|              "cross axis is the block axis");
 | ||
| 
 | ||
|   AxisOrientationType crossAxis = aAxisTracker.GetCrossAxis();
 | ||
|   mozilla::Side sideToMeasureFrom = kAxisOrientationToSidesMap[crossAxis][aEdge];
 | ||
| 
 | ||
|   // XXXdholbert The "top"/"bottom" physical-axis dependencies below need to be
 | ||
|   // logicalized -- see bug 1384266.
 | ||
|   nscoord marginTopToBaseline = ResolvedAscent(aUseFirstLineBaseline) +
 | ||
|                                 mMargin.top;
 | ||
| 
 | ||
|   if (sideToMeasureFrom == eSideTop) {
 | ||
|     // Measuring from top (normal case): the distance from the margin-box top
 | ||
|     // edge to the baseline is just ascent + margin-top.
 | ||
|     return marginTopToBaseline;
 | ||
|   }
 | ||
| 
 | ||
|   MOZ_ASSERT(sideToMeasureFrom == eSideBottom,
 | ||
|              "We already checked that we're dealing with a vertical axis, and "
 | ||
|              "we're not using the top side, so that only leaves the bottom...");
 | ||
| 
 | ||
|   // Measuring from bottom: The distance from the margin-box bottom edge to the
 | ||
|   // baseline is just the margin-box cross size (i.e. outer cross size), minus
 | ||
|   // the already-computed distance from margin-top to baseline.
 | ||
|   return GetOuterCrossSize(crossAxis) - marginTopToBaseline;
 | ||
| }
 | ||
| 
 | ||
| bool
 | ||
| FlexItem::IsCrossSizeAuto() const
 | ||
| {
 | ||
|   const nsStylePosition* stylePos = mFrame->StylePosition();
 | ||
|   // Check whichever component is in the flex container's cross axis.
 | ||
|   // (IsInlineAxisCrossAxis() tells us whether that's our ISize or BSize, in
 | ||
|   // terms of our own WritingMode, mWM.)
 | ||
|   return eStyleUnit_Auto == (IsInlineAxisCrossAxis()
 | ||
|                              ? stylePos->ISize(mWM).GetUnit()
 | ||
|                              : stylePos->BSize(mWM).GetUnit());
 | ||
| }
 | ||
| 
 | ||
| uint32_t
 | ||
| FlexItem::GetNumAutoMarginsInAxis(AxisOrientationType aAxis) const
 | ||
| {
 | ||
|   uint32_t numAutoMargins = 0;
 | ||
|   const nsStyleSides& styleMargin = mFrame->StyleMargin()->mMargin;
 | ||
|   for (uint32_t i = 0; i < eNumAxisEdges; i++) {
 | ||
|     mozilla::Side side = kAxisOrientationToSidesMap[aAxis][i];
 | ||
|     if (styleMargin.GetUnit(side) == eStyleUnit_Auto) {
 | ||
|       numAutoMargins++;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Mostly for clarity:
 | ||
|   MOZ_ASSERT(numAutoMargins <= 2,
 | ||
|              "We're just looking at one item along one dimension, so we "
 | ||
|              "should only have examined 2 margins");
 | ||
| 
 | ||
|   return numAutoMargins;
 | ||
| }
 | ||
| 
 | ||
| bool
 | ||
| FlexItem::CanMainSizeInfluenceCrossSize(
 | ||
|   const FlexboxAxisTracker& aAxisTracker) const
 | ||
| {
 | ||
|   if (mIsStretched) {
 | ||
|     // We've already had our cross-size stretched for "align-self:stretch").
 | ||
|     // The container is imposing its cross size on us.
 | ||
|     return false;
 | ||
|   }
 | ||
| 
 | ||
|   if (mIsStrut) {
 | ||
|     // Struts (for visibility:collapse items) have a predetermined size;
 | ||
|     // no need to measure anything.
 | ||
|     return false;
 | ||
|   }
 | ||
| 
 | ||
|   if (HasIntrinsicRatio()) {
 | ||
|     // For flex items that have an intrinsic ratio (and maintain it, i.e. are
 | ||
|     // not stretched, which we already checked above): changes to main-size
 | ||
|     // *do* influence the cross size.
 | ||
|     return true;
 | ||
|   }
 | ||
| 
 | ||
|   if (IsInlineAxisCrossAxis()) {
 | ||
|     // If we get here, this function is really asking: "can changes to this
 | ||
|     // item's block size have an influence on its inline size"?  For blocks and
 | ||
|     // tables, the answer is "no".
 | ||
|     if (mFrame->IsBlockFrame() ||
 | ||
|         mFrame->IsTableWrapperFrame()) {
 | ||
|       // XXXdholbert (Maybe use an IsFrameOfType query or something more
 | ||
|       // general to test this across all frame types? For now, I'm just
 | ||
|       // optimizing for block and table, since those are common containers that
 | ||
|       // can contain arbitrarily-large subtrees (and that reliably have ISize
 | ||
|       // being unaffected by BSize, per CSS2).  So optimizing away needless
 | ||
|       // relayout is possible & especially valuable for these containers.)
 | ||
|       return false;
 | ||
|     }
 | ||
|     // Other opt-outs can go here, as they're identified as being useful
 | ||
|     // (particularly for containers where an extra reflow is expensive). But in
 | ||
|     // general, we have to assume that a flexed BSize *could* influence the
 | ||
|     // ISize. Some examples where this can definitely happen:
 | ||
|     // * Intrinsically-sized multicol with fixed-ISize columns, which adds
 | ||
|     // columns (i.e. grows in inline axis) depending on its block size.
 | ||
|     // * Intrinsically-sized multi-line column-oriented flex container, which
 | ||
|     // adds flex lines (i.e. grows in inline axis) depending on its block size.
 | ||
|   }
 | ||
| 
 | ||
|   // Default assumption, if we haven't proven otherwise: the resolved main size
 | ||
|   // *can* change the cross size.
 | ||
|   return true;
 | ||
| }
 | ||
| 
 | ||
| // Keeps track of our position along a particular axis (where a '0' position
 | ||
| // corresponds to the 'start' edge of that axis).
 | ||
| // This class shouldn't be instantiated directly -- rather, it should only be
 | ||
| // instantiated via its subclasses defined below.
 | ||
| class MOZ_STACK_CLASS PositionTracker {
 | ||
| public:
 | ||
|   // Accessor for the current value of the position that we're tracking.
 | ||
|   inline nscoord GetPosition() const { return mPosition; }
 | ||
|   inline AxisOrientationType GetAxis() const { return mAxis; }
 | ||
| 
 | ||
|   // Advances our position across the start edge of the given margin, in the
 | ||
|   // axis we're tracking.
 | ||
|   void EnterMargin(const nsMargin& aMargin)
 | ||
|   {
 | ||
|     mozilla::Side side = kAxisOrientationToSidesMap[mAxis][eAxisEdge_Start];
 | ||
|     mPosition += aMargin.Side(side);
 | ||
|   }
 | ||
| 
 | ||
|   // Advances our position across the end edge of the given margin, in the axis
 | ||
|   // we're tracking.
 | ||
|   void ExitMargin(const nsMargin& aMargin)
 | ||
|   {
 | ||
|     mozilla::Side side = kAxisOrientationToSidesMap[mAxis][eAxisEdge_End];
 | ||
|     mPosition += aMargin.Side(side);
 | ||
|   }
 | ||
| 
 | ||
|   // Advances our current position from the start side of a child frame's
 | ||
|   // border-box to the frame's upper or left edge (depending on our axis).
 | ||
|   // (Note that this is a no-op if our axis grows in the same direction as
 | ||
|   // the corresponding logical axis.)
 | ||
|   void EnterChildFrame(nscoord aChildFrameSize)
 | ||
|   {
 | ||
|     if (mIsAxisReversed) {
 | ||
|       mPosition += aChildFrameSize;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Advances our current position from a frame's upper or left border-box edge
 | ||
|   // (whichever is in the axis we're tracking) to the 'end' side of the frame
 | ||
|   // in the axis that we're tracking. (Note that this is a no-op if our axis
 | ||
|   // is reversed with respect to the corresponding logical axis.)
 | ||
|   void ExitChildFrame(nscoord aChildFrameSize)
 | ||
|   {
 | ||
|     if (!mIsAxisReversed) {
 | ||
|       mPosition += aChildFrameSize;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
| protected:
 | ||
|   // Protected constructor, to be sure we're only instantiated via a subclass.
 | ||
|   PositionTracker(AxisOrientationType aAxis, bool aIsAxisReversed)
 | ||
|     : mPosition(0),
 | ||
|       mAxis(aAxis),
 | ||
|       mIsAxisReversed(aIsAxisReversed)
 | ||
|   {}
 | ||
| 
 | ||
|   // Delete copy-constructor & reassignment operator, to prevent accidental
 | ||
|   // (unnecessary) copying.
 | ||
|   PositionTracker(const PositionTracker&) = delete;
 | ||
|   PositionTracker& operator=(const PositionTracker&) = delete;
 | ||
| 
 | ||
|   // Member data:
 | ||
|   nscoord mPosition;               // The position we're tracking
 | ||
|   // XXXdholbert [BEGIN DEPRECATED]
 | ||
|   const AxisOrientationType mAxis; // The axis along which we're moving.
 | ||
|   // XXXdholbert [END DEPRECATED]
 | ||
|   const bool mIsAxisReversed; // Is the axis along which we're moving reversed
 | ||
|                               // (e.g. LTR vs RTL) with respect to the
 | ||
|                               // corresponding axis on the flex container's WM?
 | ||
| };
 | ||
| 
 | ||
| // Tracks our position in the main axis, when we're laying out flex items.
 | ||
| // The "0" position represents the main-start edge of the flex container's
 | ||
| // content-box.
 | ||
| class MOZ_STACK_CLASS MainAxisPositionTracker : public PositionTracker {
 | ||
| public:
 | ||
|   MainAxisPositionTracker(const FlexboxAxisTracker& aAxisTracker,
 | ||
|                           const FlexLine* aLine,
 | ||
|                           uint8_t aJustifyContent,
 | ||
|                           nscoord aContentBoxMainSize);
 | ||
| 
 | ||
|   ~MainAxisPositionTracker() {
 | ||
|     MOZ_ASSERT(mNumPackingSpacesRemaining == 0,
 | ||
|                "miscounted the number of packing spaces");
 | ||
|     MOZ_ASSERT(mNumAutoMarginsInMainAxis == 0,
 | ||
|                "miscounted the number of auto margins");
 | ||
|   }
 | ||
| 
 | ||
|   // Advances past the gap space (if any) between two flex items
 | ||
|   void TraverseGap(nscoord aGapSize) { mPosition += aGapSize; }
 | ||
| 
 | ||
|   // Advances past the packing space (if any) between two flex items
 | ||
|   void TraversePackingSpace();
 | ||
| 
 | ||
|   // If aItem has any 'auto' margins in the main axis, this method updates the
 | ||
|   // corresponding values in its margin.
 | ||
|   void ResolveAutoMarginsInMainAxis(FlexItem& aItem);
 | ||
| 
 | ||
| private:
 | ||
|   nscoord  mPackingSpaceRemaining;
 | ||
|   uint32_t mNumAutoMarginsInMainAxis;
 | ||
|   uint32_t mNumPackingSpacesRemaining;
 | ||
|   // XXX this should be uint16_t when we add explicit fallback handling
 | ||
|   uint8_t  mJustifyContent;
 | ||
| };
 | ||
| 
 | ||
| // Utility class for managing our position along the cross axis along
 | ||
| // the whole flex container (at a higher level than a single line).
 | ||
| // The "0" position represents the cross-start edge of the flex container's
 | ||
| // content-box.
 | ||
| class MOZ_STACK_CLASS CrossAxisPositionTracker : public PositionTracker {
 | ||
| public:
 | ||
|   CrossAxisPositionTracker(FlexLine* aFirstLine,
 | ||
|                            const ReflowInput& aReflowInput,
 | ||
|                            nscoord aContentBoxCrossSize,
 | ||
|                            bool aIsCrossSizeDefinite,
 | ||
|                            const FlexboxAxisTracker& aAxisTracker,
 | ||
|                            const nscoord aCrossGapSize);
 | ||
| 
 | ||
|   // Advances past the gap (if any) between two flex lines
 | ||
|   void TraverseGap() { mPosition += mCrossGapSize; }
 | ||
| 
 | ||
|   // Advances past the packing space (if any) between two flex lines
 | ||
|   void TraversePackingSpace();
 | ||
| 
 | ||
|   // Advances past the given FlexLine
 | ||
|   void TraverseLine(FlexLine& aLine) { mPosition += aLine.GetLineCrossSize(); }
 | ||
| 
 | ||
| private:
 | ||
|   // Redeclare the frame-related methods from PositionTracker as private with
 | ||
|   // = delete, to be sure (at compile time) that no client code can invoke
 | ||
|   // them. (Unlike the other PositionTracker derived classes, this class here
 | ||
|   // deals with FlexLines, not with individual FlexItems or frames.)
 | ||
|   void EnterMargin(const nsMargin& aMargin) = delete;
 | ||
|   void ExitMargin(const nsMargin& aMargin) = delete;
 | ||
|   void EnterChildFrame(nscoord aChildFrameSize) = delete;
 | ||
|   void ExitChildFrame(nscoord aChildFrameSize) = delete;
 | ||
| 
 | ||
|   nscoord  mPackingSpaceRemaining;
 | ||
|   uint32_t mNumPackingSpacesRemaining;
 | ||
|   // XXX this should be uint16_t when we add explicit fallback handling
 | ||
|   uint8_t  mAlignContent;
 | ||
| 
 | ||
|   nscoord mCrossGapSize = 0;
 | ||
| };
 | ||
| 
 | ||
| // Utility class for managing our position along the cross axis, *within* a
 | ||
| // single flex line.
 | ||
| class MOZ_STACK_CLASS SingleLineCrossAxisPositionTracker : public PositionTracker {
 | ||
| public:
 | ||
|   explicit SingleLineCrossAxisPositionTracker(const FlexboxAxisTracker& aAxisTracker);
 | ||
| 
 | ||
|   void ResolveAutoMarginsInCrossAxis(const FlexLine& aLine,
 | ||
|                                      FlexItem& aItem);
 | ||
| 
 | ||
|   void EnterAlignPackingSpace(const FlexLine& aLine,
 | ||
|                               const FlexItem& aItem,
 | ||
|                               const FlexboxAxisTracker& aAxisTracker);
 | ||
| 
 | ||
|   // Resets our position to the cross-start edge of this line.
 | ||
|   inline void ResetPosition() { mPosition = 0; }
 | ||
| };
 | ||
| 
 | ||
| //----------------------------------------------------------------------
 | ||
| 
 | ||
| // Frame class boilerplate
 | ||
| // =======================
 | ||
| 
 | ||
| NS_QUERYFRAME_HEAD(nsFlexContainerFrame)
 | ||
|   NS_QUERYFRAME_ENTRY(nsFlexContainerFrame)
 | ||
| NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
 | ||
| 
 | ||
| NS_IMPL_FRAMEARENA_HELPERS(nsFlexContainerFrame)
 | ||
| 
 | ||
| nsContainerFrame*
 | ||
| NS_NewFlexContainerFrame(nsIPresShell* aPresShell,
 | ||
|                          ComputedStyle* aStyle)
 | ||
| {
 | ||
|   return new (aPresShell) nsFlexContainerFrame(aStyle);
 | ||
| }
 | ||
| 
 | ||
| //----------------------------------------------------------------------
 | ||
| 
 | ||
| // nsFlexContainerFrame Method Implementations
 | ||
| // ===========================================
 | ||
| 
 | ||
| /* virtual */
 | ||
| nsFlexContainerFrame::~nsFlexContainerFrame()
 | ||
| {
 | ||
| }
 | ||
| 
 | ||
| /* virtual */
 | ||
| void
 | ||
| nsFlexContainerFrame::Init(nsIContent*       aContent,
 | ||
|                            nsContainerFrame* aParent,
 | ||
|                            nsIFrame*         aPrevInFlow)
 | ||
| {
 | ||
|   nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
 | ||
| 
 | ||
|   const nsStyleDisplay* styleDisp = Style()->StyleDisplay();
 | ||
| 
 | ||
|   // Figure out if we should set a frame state bit to indicate that this frame
 | ||
|   // represents a legacy -webkit-{inline-}box or -moz-{inline-}box container.
 | ||
|   // First, the trivial case: just check "display" directly.
 | ||
|   bool isLegacyBox = IsDisplayValueLegacyBox(styleDisp);
 | ||
| 
 | ||
|   // If this frame is for a scrollable element, then it will actually have
 | ||
|   // "display:block", and its *parent frame* will have the real
 | ||
|   // flex-flavored display value. So in that case, check the parent frame to
 | ||
|   // find out if we're legacy.
 | ||
|   if (!isLegacyBox && styleDisp->mDisplay == mozilla::StyleDisplay::Block) {
 | ||
|     ComputedStyle* parentComputedStyle = GetParent()->Style();
 | ||
|     NS_ASSERTION(parentComputedStyle &&
 | ||
|                  (mComputedStyle->GetPseudo() == nsCSSAnonBoxes::buttonContent ||
 | ||
|                   mComputedStyle->GetPseudo() == nsCSSAnonBoxes::scrolledContent),
 | ||
|                  "The only way a nsFlexContainerFrame can have 'display:block' "
 | ||
|                  "should be if it's the inner part of a scrollable or button "
 | ||
|                  "element");
 | ||
|     isLegacyBox = IsDisplayValueLegacyBox(parentComputedStyle->StyleDisplay());
 | ||
|   }
 | ||
| 
 | ||
|   if (isLegacyBox) {
 | ||
|     AddStateBits(NS_STATE_FLEX_IS_EMULATING_LEGACY_BOX);
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| #ifdef DEBUG_FRAME_DUMP
 | ||
| nsresult
 | ||
| nsFlexContainerFrame::GetFrameName(nsAString& aResult) const
 | ||
| {
 | ||
|   return MakeFrameName(NS_LITERAL_STRING("FlexContainer"), aResult);
 | ||
| }
 | ||
| #endif
 | ||
| 
 | ||
| nscoord
 | ||
| nsFlexContainerFrame::GetLogicalBaseline(mozilla::WritingMode aWM) const
 | ||
| {
 | ||
|   NS_ASSERTION(mBaselineFromLastReflow != NS_INTRINSIC_WIDTH_UNKNOWN,
 | ||
|                "baseline has not been set");
 | ||
| 
 | ||
|   if (HasAnyStateBits(NS_STATE_FLEX_SYNTHESIZE_BASELINE)) {
 | ||
|     // Return a baseline synthesized from our margin-box.
 | ||
|     return nsContainerFrame::GetLogicalBaseline(aWM);
 | ||
|   }
 | ||
|   return mBaselineFromLastReflow;
 | ||
| }
 | ||
| 
 | ||
| // Helper for BuildDisplayList, to implement this special-case for flex items
 | ||
| // from the spec:
 | ||
| //    Flex items paint exactly the same as block-level elements in the
 | ||
| //    normal flow, except that 'z-index' values other than 'auto' create
 | ||
| //    a stacking context even if 'position' is 'static'.
 | ||
| // http://www.w3.org/TR/2012/CR-css3-flexbox-20120918/#painting
 | ||
| static uint32_t
 | ||
| GetDisplayFlagsForFlexItem(nsIFrame* aFrame)
 | ||
| {
 | ||
|   MOZ_ASSERT(aFrame->IsFlexItem(), "Should only be called on flex items");
 | ||
| 
 | ||
|   const nsStylePosition* pos = aFrame->StylePosition();
 | ||
|   if (pos->mZIndex.GetUnit() == eStyleUnit_Integer) {
 | ||
|     return nsIFrame::DISPLAY_CHILD_FORCE_STACKING_CONTEXT;
 | ||
|   }
 | ||
|   return nsIFrame::DISPLAY_CHILD_FORCE_PSEUDO_STACKING_CONTEXT;
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| nsFlexContainerFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
 | ||
|                                        const nsDisplayListSet& aLists)
 | ||
| {
 | ||
|   DisplayBorderBackgroundOutline(aBuilder, aLists);
 | ||
| 
 | ||
|   // Our children are all block-level, so their borders/backgrounds all go on
 | ||
|   // the BlockBorderBackgrounds list.
 | ||
|   nsDisplayListSet childLists(aLists, aLists.BlockBorderBackgrounds());
 | ||
| 
 | ||
|   typedef CSSOrderAwareFrameIterator::OrderState OrderState;
 | ||
|   OrderState orderState =
 | ||
|     HasAnyStateBits(NS_STATE_FLEX_NORMAL_FLOW_CHILDREN_IN_CSS_ORDER)
 | ||
|     ? OrderState::eKnownOrdered
 | ||
|     : OrderState::eKnownUnordered;
 | ||
| 
 | ||
|   CSSOrderAwareFrameIterator iter(this, kPrincipalList,
 | ||
|                                   CSSOrderAwareFrameIterator::eIncludeAll,
 | ||
|                                   orderState,
 | ||
|                                   OrderingPropertyForIter(this));
 | ||
|   for (; !iter.AtEnd(); iter.Next()) {
 | ||
|     nsIFrame* childFrame = *iter;
 | ||
|     BuildDisplayListForChild(aBuilder, childFrame, childLists,
 | ||
|                              GetDisplayFlagsForFlexItem(childFrame));
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| FlexLine::FreezeItemsEarly(bool aIsUsingFlexGrow)
 | ||
| {
 | ||
|   // After we've established the type of flexing we're doing (growing vs.
 | ||
|   // shrinking), and before we try to flex any items, we freeze items that
 | ||
|   // obviously *can't* flex.
 | ||
|   //
 | ||
|   // Quoting the spec:
 | ||
|   //  # Freeze, setting its target main size to its hypothetical main size...
 | ||
|   //  #  - any item that has a flex factor of zero
 | ||
|   //  #  - if using the flex grow factor: any item that has a flex base size
 | ||
|   //  #    greater than its hypothetical main size
 | ||
|   //  #  - if using the flex shrink factor: any item that has a flex base size
 | ||
|   //  #    smaller than its hypothetical main size
 | ||
|   //  http://dev.w3.org/csswg/css-flexbox/#resolve-flexible-lengths-flex-factors
 | ||
|   //
 | ||
|   // (NOTE: At this point, item->GetMainSize() *is* the item's hypothetical
 | ||
|   // main size, since SetFlexBaseSizeAndMainSize() sets it up that way, and the
 | ||
|   // item hasn't had a chance to flex away from that yet.)
 | ||
| 
 | ||
|   // Since this loop only operates on unfrozen flex items, we can break as
 | ||
|   // soon as we have seen all of them.
 | ||
|   uint32_t numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
 | ||
|   for (FlexItem* item = mItems.getFirst();
 | ||
|        numUnfrozenItemsToBeSeen > 0; item = item->getNext()) {
 | ||
|     MOZ_ASSERT(item, "numUnfrozenItemsToBeSeen says items remain to be seen");
 | ||
| 
 | ||
|     if (!item->IsFrozen()) {
 | ||
|       numUnfrozenItemsToBeSeen--;
 | ||
|       bool shouldFreeze = (0.0f == item->GetFlexFactor(aIsUsingFlexGrow));
 | ||
|       if (!shouldFreeze) {
 | ||
|         if (aIsUsingFlexGrow) {
 | ||
|           if (item->GetFlexBaseSize() > item->GetMainSize()) {
 | ||
|             shouldFreeze = true;
 | ||
|           }
 | ||
|         } else { // using flex-shrink
 | ||
|           if (item->GetFlexBaseSize() < item->GetMainSize()) {
 | ||
|             shouldFreeze = true;
 | ||
|           }
 | ||
|         }
 | ||
|       }
 | ||
|       if (shouldFreeze) {
 | ||
|         // Freeze item! (at its hypothetical main size)
 | ||
|         item->Freeze();
 | ||
|         mNumFrozenItems++;
 | ||
|       }
 | ||
|     }
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| // Based on the sign of aTotalViolation, this function freezes a subset of our
 | ||
| // flexible sizes, and restores the remaining ones to their initial pref sizes.
 | ||
| void
 | ||
| FlexLine::FreezeOrRestoreEachFlexibleSize(const nscoord aTotalViolation,
 | ||
|                                           bool aIsFinalIteration)
 | ||
| {
 | ||
|   enum FreezeType {
 | ||
|     eFreezeEverything,
 | ||
|     eFreezeMinViolations,
 | ||
|     eFreezeMaxViolations
 | ||
|   };
 | ||
| 
 | ||
|   FreezeType freezeType;
 | ||
|   if (aTotalViolation == 0) {
 | ||
|     freezeType = eFreezeEverything;
 | ||
|   } else if (aTotalViolation > 0) {
 | ||
|     freezeType = eFreezeMinViolations;
 | ||
|   } else { // aTotalViolation < 0
 | ||
|     freezeType = eFreezeMaxViolations;
 | ||
|   }
 | ||
| 
 | ||
|   // Since this loop only operates on unfrozen flex items, we can break as
 | ||
|   // soon as we have seen all of them.
 | ||
|   uint32_t numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
 | ||
|   for (FlexItem* item = mItems.getFirst();
 | ||
|        numUnfrozenItemsToBeSeen > 0; item = item->getNext()) {
 | ||
|     MOZ_ASSERT(item, "numUnfrozenItemsToBeSeen says items remain to be seen");
 | ||
|     if (!item->IsFrozen()) {
 | ||
|       numUnfrozenItemsToBeSeen--;
 | ||
| 
 | ||
|       MOZ_ASSERT(!item->HadMinViolation() || !item->HadMaxViolation(),
 | ||
|                  "Can have either min or max violation, but not both");
 | ||
| 
 | ||
|       if (eFreezeEverything == freezeType ||
 | ||
|           (eFreezeMinViolations == freezeType && item->HadMinViolation()) ||
 | ||
|           (eFreezeMaxViolations == freezeType && item->HadMaxViolation())) {
 | ||
| 
 | ||
|         MOZ_ASSERT(item->GetMainSize() >= item->GetMainMinSize(),
 | ||
|                    "Freezing item at a size below its minimum");
 | ||
|         MOZ_ASSERT(item->GetMainSize() <= item->GetMainMaxSize(),
 | ||
|                    "Freezing item at a size above its maximum");
 | ||
| 
 | ||
|         item->Freeze();
 | ||
|         mNumFrozenItems++;
 | ||
|       } else if (MOZ_UNLIKELY(aIsFinalIteration)) {
 | ||
|         // XXXdholbert If & when bug 765861 is fixed, we should upgrade this
 | ||
|         // assertion to be fatal except in documents with enormous lengths.
 | ||
|         NS_ERROR("Final iteration still has unfrozen items, this shouldn't"
 | ||
|                  " happen unless there was nscoord under/overflow.");
 | ||
|         item->Freeze();
 | ||
|         mNumFrozenItems++;
 | ||
|       } // else, we'll reset this item's main size to its flex base size on the
 | ||
|         // next iteration of this algorithm.
 | ||
| 
 | ||
|       // Clear this item's violation(s), now that we've dealt with them
 | ||
|       item->ClearViolationFlags();
 | ||
|     }
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| FlexLine::ResolveFlexibleLengths(nscoord aFlexContainerMainSize,
 | ||
|                                  ComputedFlexLineInfo* aLineInfo)
 | ||
| {
 | ||
|   MOZ_LOG(gFlexContainerLog, LogLevel::Debug, ("ResolveFlexibleLengths\n"));
 | ||
| 
 | ||
|   // Determine whether we're going to be growing or shrinking items.
 | ||
|   const bool isUsingFlexGrow =
 | ||
|     (mTotalOuterHypotheticalMainSize < aFlexContainerMainSize);
 | ||
| 
 | ||
|   // Do an "early freeze" for flex items that obviously can't flex in the
 | ||
|   // direction we've chosen:
 | ||
|   FreezeItemsEarly(isUsingFlexGrow);
 | ||
| 
 | ||
|   if ((mNumFrozenItems == mNumItems) && !aLineInfo) {
 | ||
|     // All our items are frozen, so we have no flexible lengths to resolve,
 | ||
|     // and we aren't being asked to generate computed line info.
 | ||
|     return;
 | ||
|   }
 | ||
|   MOZ_ASSERT(!IsEmpty() || aLineInfo,
 | ||
|              "empty lines should take the early-return above");
 | ||
| 
 | ||
|   // Subtract space occupied by our items' margins/borders/padding/gaps, so
 | ||
|   // we can just be dealing with the space available for our flex items' content
 | ||
|   // boxes.
 | ||
|   nscoord spaceAvailableForFlexItemsContentBoxes =
 | ||
|     aFlexContainerMainSize - (mTotalItemMBP + GetSumOfGaps());
 | ||
| 
 | ||
|   nscoord origAvailableFreeSpace;
 | ||
|   bool isOrigAvailFreeSpaceInitialized = false;
 | ||
| 
 | ||
|   // NOTE: I claim that this chunk of the algorithm (the looping part) needs to
 | ||
|   // run the loop at MOST mNumItems times.  This claim should hold up
 | ||
|   // because we'll freeze at least one item on each loop iteration, and once
 | ||
|   // we've run out of items to freeze, there's nothing left to do.  However,
 | ||
|   // in most cases, we'll break out of this loop long before we hit that many
 | ||
|   // iterations.
 | ||
|   for (uint32_t iterationCounter = 0;
 | ||
|        iterationCounter < mNumItems; iterationCounter++) {
 | ||
|     // Set every not-yet-frozen item's used main size to its
 | ||
|     // flex base size, and subtract all the used main sizes from our
 | ||
|     // total amount of space to determine the 'available free space'
 | ||
|     // (positive or negative) to be distributed among our flexible items.
 | ||
|     nscoord availableFreeSpace = spaceAvailableForFlexItemsContentBoxes;
 | ||
|     for (FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
 | ||
|       if (!item->IsFrozen()) {
 | ||
|         item->SetMainSize(item->GetFlexBaseSize());
 | ||
|       }
 | ||
|       availableFreeSpace -= item->GetMainSize();
 | ||
|     }
 | ||
| 
 | ||
|     // If we have an aLineInfo structure to fill out, and this is the
 | ||
|     // first time through the loop, capture these sizes as mainBaseSizes.
 | ||
|     // We only care about the first iteration, because additional
 | ||
|     // iterations will only reset item base sizes to these values.
 | ||
|     // We also set a 0 mainDeltaSize. This will be modified later if
 | ||
|     // the item is stretched or shrunk.
 | ||
|     if (aLineInfo && (iterationCounter == 0)) {
 | ||
|       uint32_t itemIndex = 0;
 | ||
|       for (FlexItem* item = mItems.getFirst(); item; item = item->getNext(),
 | ||
|                                                      ++itemIndex) {
 | ||
|         aLineInfo->mItems[itemIndex].mMainBaseSize = item->GetMainSize();
 | ||
|         aLineInfo->mItems[itemIndex].mMainDeltaSize = 0;
 | ||
|       }
 | ||
|     }
 | ||
| 
 | ||
|     MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
 | ||
|            (" available free space = %d\n", availableFreeSpace));
 | ||
| 
 | ||
| 
 | ||
|     // The sign of our free space should agree with the type of flexing
 | ||
|     // (grow/shrink) that we're doing (except if we've had integer overflow;
 | ||
|     // then, all bets are off). Any disagreement should've made us use the
 | ||
|     // other type of flexing, or should've been resolved in FreezeItemsEarly.
 | ||
|     // XXXdholbert If & when bug 765861 is fixed, we should upgrade this
 | ||
|     // assertion to be fatal except in documents with enormous lengths.
 | ||
|     NS_ASSERTION((isUsingFlexGrow && availableFreeSpace >= 0) ||
 | ||
|                  (!isUsingFlexGrow && availableFreeSpace <= 0),
 | ||
|                  "availableFreeSpace's sign should match isUsingFlexGrow");
 | ||
| 
 | ||
|     // If we have any free space available, give each flexible item a portion
 | ||
|     // of availableFreeSpace.
 | ||
|     if (availableFreeSpace != 0) {
 | ||
|       // The first time we do this, we initialize origAvailableFreeSpace.
 | ||
|       if (!isOrigAvailFreeSpaceInitialized) {
 | ||
|         origAvailableFreeSpace = availableFreeSpace;
 | ||
|         isOrigAvailFreeSpaceInitialized = true;
 | ||
|       }
 | ||
| 
 | ||
|       // STRATEGY: On each item, we compute & store its "share" of the total
 | ||
|       // weight that we've seen so far:
 | ||
|       //   curWeight / weightSum
 | ||
|       //
 | ||
|       // Then, when we go to actually distribute the space (in the next loop),
 | ||
|       // we can simply walk backwards through the elements and give each item
 | ||
|       // its "share" multiplied by the remaining available space.
 | ||
|       //
 | ||
|       // SPECIAL CASE: If the sum of the weights is larger than the
 | ||
|       // maximum representable float (overflowing to infinity), then we can't
 | ||
|       // sensibly divide out proportional shares anymore. In that case, we
 | ||
|       // simply treat the flex item(s) with the largest weights as if
 | ||
|       // their weights were infinite (dwarfing all the others), and we
 | ||
|       // distribute all of the available space among them.
 | ||
|       float weightSum = 0.0f;
 | ||
|       float flexFactorSum = 0.0f;
 | ||
|       float largestWeight = 0.0f;
 | ||
|       uint32_t numItemsWithLargestWeight = 0;
 | ||
| 
 | ||
|       // Since this loop only operates on unfrozen flex items, we can break as
 | ||
|       // soon as we have seen all of them.
 | ||
|       uint32_t numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
 | ||
|       for (FlexItem* item = mItems.getFirst();
 | ||
|            numUnfrozenItemsToBeSeen > 0; item = item->getNext()) {
 | ||
|         MOZ_ASSERT(item,
 | ||
|                    "numUnfrozenItemsToBeSeen says items remain to be seen");
 | ||
|         if (!item->IsFrozen()) {
 | ||
|           numUnfrozenItemsToBeSeen--;
 | ||
| 
 | ||
|           float curWeight = item->GetWeight(isUsingFlexGrow);
 | ||
|           float curFlexFactor = item->GetFlexFactor(isUsingFlexGrow);
 | ||
|           MOZ_ASSERT(curWeight >= 0.0f, "weights are non-negative");
 | ||
|           MOZ_ASSERT(curFlexFactor >= 0.0f, "flex factors are non-negative");
 | ||
| 
 | ||
|           weightSum += curWeight;
 | ||
|           flexFactorSum += curFlexFactor;
 | ||
| 
 | ||
|           if (IsFinite(weightSum)) {
 | ||
|             if (curWeight == 0.0f) {
 | ||
|               item->SetShareOfWeightSoFar(0.0f);
 | ||
|             } else {
 | ||
|               item->SetShareOfWeightSoFar(curWeight / weightSum);
 | ||
|             }
 | ||
|           } // else, the sum of weights overflows to infinity, in which
 | ||
|             // case we don't bother with "SetShareOfWeightSoFar" since
 | ||
|             // we know we won't use it. (instead, we'll just give every
 | ||
|             // item with the largest weight an equal share of space.)
 | ||
| 
 | ||
|           // Update our largest-weight tracking vars
 | ||
|           if (curWeight > largestWeight) {
 | ||
|             largestWeight = curWeight;
 | ||
|             numItemsWithLargestWeight = 1;
 | ||
|           } else if (curWeight == largestWeight) {
 | ||
|             numItemsWithLargestWeight++;
 | ||
|           }
 | ||
|         }
 | ||
|       }
 | ||
| 
 | ||
|       if (weightSum != 0.0f) {
 | ||
|         MOZ_ASSERT(flexFactorSum != 0.0f,
 | ||
|                    "flex factor sum can't be 0, if a weighted sum "
 | ||
|                    "of its components (weightSum) is nonzero");
 | ||
|         if (flexFactorSum < 1.0f) {
 | ||
|           // Our unfrozen flex items don't want all of the original free space!
 | ||
|           // (Their flex factors add up to something less than 1.)
 | ||
|           // Hence, make sure we don't distribute any more than the portion of
 | ||
|           // our original free space that these items actually want.
 | ||
|           nscoord totalDesiredPortionOfOrigFreeSpace =
 | ||
|             NSToCoordRound(origAvailableFreeSpace * flexFactorSum);
 | ||
| 
 | ||
|           // Clamp availableFreeSpace to be no larger than that ^^.
 | ||
|           // (using min or max, depending on sign).
 | ||
|           // This should not change the sign of availableFreeSpace (except
 | ||
|           // possibly by setting it to 0), as enforced by this assertion:
 | ||
|           MOZ_ASSERT(totalDesiredPortionOfOrigFreeSpace == 0 ||
 | ||
|                      ((totalDesiredPortionOfOrigFreeSpace > 0) ==
 | ||
|                       (availableFreeSpace > 0)),
 | ||
|                      "When we reduce available free space for flex factors < 1,"
 | ||
|                      "we shouldn't change the sign of the free space...");
 | ||
| 
 | ||
|           if (availableFreeSpace > 0) {
 | ||
|             availableFreeSpace = std::min(availableFreeSpace,
 | ||
|                                           totalDesiredPortionOfOrigFreeSpace);
 | ||
|           } else {
 | ||
|             availableFreeSpace = std::max(availableFreeSpace,
 | ||
|                                           totalDesiredPortionOfOrigFreeSpace);
 | ||
|           }
 | ||
|         }
 | ||
| 
 | ||
|         MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
 | ||
|                (" Distributing available space:"));
 | ||
|         // Since this loop only operates on unfrozen flex items, we can break as
 | ||
|         // soon as we have seen all of them.
 | ||
|         numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
 | ||
| 
 | ||
|         // NOTE: It's important that we traverse our items in *reverse* order
 | ||
|         // here, for correct width distribution according to the items'
 | ||
|         // "ShareOfWeightSoFar" progressively-calculated values.
 | ||
|         for (FlexItem* item = mItems.getLast();
 | ||
|              numUnfrozenItemsToBeSeen > 0; item = item->getPrevious()) {
 | ||
|           MOZ_ASSERT(item,
 | ||
|                      "numUnfrozenItemsToBeSeen says items remain to be seen");
 | ||
|           if (!item->IsFrozen()) {
 | ||
|             numUnfrozenItemsToBeSeen--;
 | ||
| 
 | ||
|             // To avoid rounding issues, we compute the change in size for this
 | ||
|             // item, and then subtract it from the remaining available space.
 | ||
|             nscoord sizeDelta = 0;
 | ||
|             if (IsFinite(weightSum)) {
 | ||
|               float myShareOfRemainingSpace =
 | ||
|                 item->GetShareOfWeightSoFar();
 | ||
| 
 | ||
|               MOZ_ASSERT(myShareOfRemainingSpace >= 0.0f &&
 | ||
|                          myShareOfRemainingSpace <= 1.0f,
 | ||
|                          "my share should be nonnegative fractional amount");
 | ||
| 
 | ||
|               if (myShareOfRemainingSpace == 1.0f) {
 | ||
|                 // (We special-case 1.0f to avoid float error from converting
 | ||
|                 // availableFreeSpace from integer*1.0f --> float --> integer)
 | ||
|                 sizeDelta = availableFreeSpace;
 | ||
|               } else if (myShareOfRemainingSpace > 0.0f) {
 | ||
|                 sizeDelta = NSToCoordRound(availableFreeSpace *
 | ||
|                                            myShareOfRemainingSpace);
 | ||
|               }
 | ||
|             } else if (item->GetWeight(isUsingFlexGrow) == largestWeight) {
 | ||
|               // Total flexibility is infinite, so we're just distributing
 | ||
|               // the available space equally among the items that are tied for
 | ||
|               // having the largest weight (and this is one of those items).
 | ||
|               sizeDelta =
 | ||
|                 NSToCoordRound(availableFreeSpace /
 | ||
|                                float(numItemsWithLargestWeight));
 | ||
|               numItemsWithLargestWeight--;
 | ||
|             }
 | ||
| 
 | ||
|             availableFreeSpace -= sizeDelta;
 | ||
| 
 | ||
|             item->SetMainSize(item->GetMainSize() + sizeDelta);
 | ||
|             MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
 | ||
|                    ("  child %p receives %d, for a total of %d\n",
 | ||
|                     item, sizeDelta, item->GetMainSize()));
 | ||
|           }
 | ||
|         }
 | ||
| 
 | ||
|         // If we have an aLineInfo structure to fill out, capture any
 | ||
|         // size changes that may have occurred in the previous loop.
 | ||
|         // We don't do this inside the previous loop, because we don't
 | ||
|         // want to burden layout when aLineInfo is null.
 | ||
|         if (aLineInfo) {
 | ||
|           uint32_t itemIndex = 0;
 | ||
|           for (FlexItem* item = mItems.getFirst(); item; item = item->getNext(),
 | ||
|                                                          ++itemIndex) {
 | ||
|             // Calculate a deltaSize that represents how much the
 | ||
|             // flex sizing algorithm "wants" to stretch or shrink this
 | ||
|             // item during this pass through the algorithm. Later
 | ||
|             // passes through the algorithm may overwrite this value.
 | ||
|             // Also, this value may not reflect how much the size of
 | ||
|             // the item is actually changed, since the size of the
 | ||
|             // item will be clamped to min and max values later in
 | ||
|             // this pass. That's intentional, since we want to report
 | ||
|             // the value that the sizing algorithm tried to stretch
 | ||
|             // or shrink the item.
 | ||
|             nscoord deltaSize = item->GetMainSize() -
 | ||
|               aLineInfo->mItems[itemIndex].mMainBaseSize;
 | ||
| 
 | ||
|             aLineInfo->mItems[itemIndex].mMainDeltaSize = deltaSize;
 | ||
|             // If any item on the line is growing, mark the aLineInfo
 | ||
|             // structure; likewise if any item is shrinking. Items in
 | ||
|             // a line can't be both growing and shrinking.
 | ||
|             if (deltaSize > 0) {
 | ||
|               MOZ_ASSERT(item->IsFrozen() || isUsingFlexGrow,
 | ||
|                 "Unfrozen items shouldn't grow without isUsingFlexGrow.");
 | ||
|               MOZ_ASSERT(aLineInfo->mGrowthState !=
 | ||
|                          ComputedFlexLineInfo::GrowthState::SHRINKING);
 | ||
|               aLineInfo->mGrowthState =
 | ||
|                 ComputedFlexLineInfo::GrowthState::GROWING;
 | ||
|             } else if (deltaSize < 0) {
 | ||
|               MOZ_ASSERT(item->IsFrozen() || !isUsingFlexGrow,
 | ||
|                "Unfrozen items shouldn't shrink with isUsingFlexGrow.");
 | ||
|               MOZ_ASSERT(aLineInfo->mGrowthState !=
 | ||
|                          ComputedFlexLineInfo::GrowthState::GROWING);
 | ||
|               aLineInfo->mGrowthState =
 | ||
|                 ComputedFlexLineInfo::GrowthState::SHRINKING;
 | ||
|             }
 | ||
|           }
 | ||
|         }
 | ||
|       }
 | ||
|     }
 | ||
| 
 | ||
|     // Fix min/max violations:
 | ||
|     nscoord totalViolation = 0; // keeps track of adjustments for min/max
 | ||
|     MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
 | ||
|            (" Checking for violations:"));
 | ||
| 
 | ||
|     // Since this loop only operates on unfrozen flex items, we can break as
 | ||
|     // soon as we have seen all of them.
 | ||
|     uint32_t numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
 | ||
|     for (FlexItem* item = mItems.getFirst();
 | ||
|          numUnfrozenItemsToBeSeen > 0; item = item->getNext()) {
 | ||
|       MOZ_ASSERT(item, "numUnfrozenItemsToBeSeen says items remain to be seen");
 | ||
|       if (!item->IsFrozen()) {
 | ||
|         numUnfrozenItemsToBeSeen--;
 | ||
| 
 | ||
|         if (item->GetMainSize() < item->GetMainMinSize()) {
 | ||
|           // min violation
 | ||
|           totalViolation += item->GetMainMinSize() - item->GetMainSize();
 | ||
|           item->SetMainSize(item->GetMainMinSize());
 | ||
|           item->SetHadMinViolation();
 | ||
|         } else if (item->GetMainSize() > item->GetMainMaxSize()) {
 | ||
|           // max violation
 | ||
|           totalViolation += item->GetMainMaxSize() - item->GetMainSize();
 | ||
|           item->SetMainSize(item->GetMainMaxSize());
 | ||
|           item->SetHadMaxViolation();
 | ||
|         }
 | ||
|       }
 | ||
|     }
 | ||
| 
 | ||
|     FreezeOrRestoreEachFlexibleSize(totalViolation,
 | ||
|                                     iterationCounter + 1 == mNumItems);
 | ||
| 
 | ||
|     MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
 | ||
|            (" Total violation: %d\n", totalViolation));
 | ||
| 
 | ||
|     if (mNumFrozenItems == mNumItems) {
 | ||
|       break;
 | ||
|     }
 | ||
| 
 | ||
|     MOZ_ASSERT(totalViolation != 0,
 | ||
|                "Zero violation should've made us freeze all items & break");
 | ||
|   }
 | ||
| 
 | ||
| #ifdef DEBUG
 | ||
|   // Post-condition: all items should've been frozen.
 | ||
|   // Make sure the counts match:
 | ||
|   MOZ_ASSERT(mNumFrozenItems == mNumItems, "All items should be frozen");
 | ||
| 
 | ||
|   // For good measure, check each item directly, in case our counts are busted:
 | ||
|   for (const FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
 | ||
|     MOZ_ASSERT(item->IsFrozen(), "All items should be frozen");
 | ||
|   }
 | ||
| #endif // DEBUG
 | ||
| }
 | ||
| 
 | ||
| MainAxisPositionTracker::
 | ||
|   MainAxisPositionTracker(const FlexboxAxisTracker& aAxisTracker,
 | ||
|                           const FlexLine* aLine,
 | ||
|                           uint8_t aJustifyContent,
 | ||
|                           nscoord aContentBoxMainSize)
 | ||
|   : PositionTracker(aAxisTracker.GetMainAxis(),
 | ||
|                     aAxisTracker.IsMainAxisReversed()),
 | ||
|     mPackingSpaceRemaining(aContentBoxMainSize), // we chip away at this below
 | ||
|     mNumAutoMarginsInMainAxis(0),
 | ||
|     mNumPackingSpacesRemaining(0),
 | ||
|     mJustifyContent(aJustifyContent)
 | ||
| {
 | ||
|   // 'normal' behaves as 'stretch', and 'stretch' behaves as 'flex-start',
 | ||
|   // in the main axis
 | ||
|   // https://drafts.csswg.org/css-align-3/#propdef-justify-content
 | ||
|   if (mJustifyContent == NS_STYLE_JUSTIFY_NORMAL ||
 | ||
|       mJustifyContent == NS_STYLE_JUSTIFY_STRETCH) {
 | ||
|     mJustifyContent = NS_STYLE_JUSTIFY_FLEX_START;
 | ||
|   }
 | ||
| 
 | ||
|   // XXX strip off the <overflow-position> bit until we implement that
 | ||
|   mJustifyContent &= ~NS_STYLE_JUSTIFY_FLAG_BITS;
 | ||
| 
 | ||
|   // mPackingSpaceRemaining is initialized to the container's main size.  Now
 | ||
|   // we'll subtract out the main sizes of our flex items, so that it ends up
 | ||
|   // with the *actual* amount of packing space.
 | ||
|   for (const FlexItem* item = aLine->GetFirstItem(); item;
 | ||
|        item = item->getNext()) {
 | ||
|     mPackingSpaceRemaining -= item->GetOuterMainSize(mAxis);
 | ||
|     mNumAutoMarginsInMainAxis += item->GetNumAutoMarginsInAxis(mAxis);
 | ||
|   }
 | ||
| 
 | ||
|   // Subtract space required for row/col gap from the remaining packing space
 | ||
|   mPackingSpaceRemaining -= aLine->GetSumOfGaps();
 | ||
| 
 | ||
|   if (mPackingSpaceRemaining <= 0) {
 | ||
|     // No available packing space to use for resolving auto margins.
 | ||
|     mNumAutoMarginsInMainAxis = 0;
 | ||
|   }
 | ||
| 
 | ||
|   // If packing space is negative or we only have one item, 'space-between'
 | ||
|   // falls back to 'flex-start', and 'space-around' & 'space-evenly' fall back
 | ||
|   // to 'center'. In those cases, it's simplest to just pretend we have a
 | ||
|   // different 'justify-content' value and share code.
 | ||
|   if (mPackingSpaceRemaining < 0 || aLine->NumItems() == 1) {
 | ||
|     if (mJustifyContent == NS_STYLE_JUSTIFY_SPACE_BETWEEN) {
 | ||
|       mJustifyContent = NS_STYLE_JUSTIFY_FLEX_START;
 | ||
|     } else if (mJustifyContent == NS_STYLE_JUSTIFY_SPACE_AROUND ||
 | ||
|                mJustifyContent == NS_STYLE_JUSTIFY_SPACE_EVENLY) {
 | ||
|       mJustifyContent = NS_STYLE_JUSTIFY_CENTER;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Map 'left'/'right' to 'start'/'end'
 | ||
|   if (mJustifyContent == NS_STYLE_JUSTIFY_LEFT ||
 | ||
|       mJustifyContent == NS_STYLE_JUSTIFY_RIGHT) {
 | ||
|     if (aAxisTracker.IsColumnOriented()) {
 | ||
|       // Container's alignment axis is not parallel to the inline axis,
 | ||
|       // so we map both 'left' and 'right' to 'start'.
 | ||
|       mJustifyContent = NS_STYLE_JUSTIFY_START;
 | ||
|     } else {
 | ||
|       // Row-oriented, so we map 'left' and 'right' to 'start' or 'end',
 | ||
|       // depending on left-to-right writing mode.
 | ||
|       const bool isLTR = aAxisTracker.GetWritingMode().IsBidiLTR();
 | ||
|       const bool isJustifyLeft = (mJustifyContent == NS_STYLE_JUSTIFY_LEFT);
 | ||
|       mJustifyContent = (isJustifyLeft == isLTR) ? NS_STYLE_JUSTIFY_START
 | ||
|                                                  : NS_STYLE_JUSTIFY_END;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Map 'start'/'end' to 'flex-start'/'flex-end'.
 | ||
|   if (mJustifyContent == NS_STYLE_JUSTIFY_START) {
 | ||
|     mJustifyContent = NS_STYLE_JUSTIFY_FLEX_START;
 | ||
|   } else if (mJustifyContent == NS_STYLE_JUSTIFY_END) {
 | ||
|     mJustifyContent = NS_STYLE_JUSTIFY_FLEX_END;
 | ||
|   }
 | ||
| 
 | ||
|   // If our main axis is (internally) reversed, swap the justify-content
 | ||
|   // "flex-start" and "flex-end" behaviors:
 | ||
|   if (aAxisTracker.AreAxesInternallyReversed()) {
 | ||
|     if (mJustifyContent == NS_STYLE_JUSTIFY_FLEX_START) {
 | ||
|       mJustifyContent = NS_STYLE_JUSTIFY_FLEX_END;
 | ||
|     } else if (mJustifyContent == NS_STYLE_JUSTIFY_FLEX_END) {
 | ||
|       mJustifyContent = NS_STYLE_JUSTIFY_FLEX_START;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Figure out how much space we'll set aside for auto margins or
 | ||
|   // packing spaces, and advance past any leading packing-space.
 | ||
|   if (mNumAutoMarginsInMainAxis == 0 &&
 | ||
|       mPackingSpaceRemaining != 0 &&
 | ||
|       !aLine->IsEmpty()) {
 | ||
|     switch (mJustifyContent) {
 | ||
|       case NS_STYLE_JUSTIFY_BASELINE:
 | ||
|       case NS_STYLE_JUSTIFY_LAST_BASELINE:
 | ||
|         NS_WARNING("NYI: justify-content:left/right/baseline/last baseline");
 | ||
|         MOZ_FALLTHROUGH;
 | ||
|       case NS_STYLE_JUSTIFY_FLEX_START:
 | ||
|         // All packing space should go at the end --> nothing to do here.
 | ||
|         break;
 | ||
|       case NS_STYLE_JUSTIFY_FLEX_END:
 | ||
|         // All packing space goes at the beginning
 | ||
|         mPosition += mPackingSpaceRemaining;
 | ||
|         break;
 | ||
|       case NS_STYLE_JUSTIFY_CENTER:
 | ||
|         // Half the packing space goes at the beginning
 | ||
|         mPosition += mPackingSpaceRemaining / 2;
 | ||
|         break;
 | ||
|       case NS_STYLE_JUSTIFY_SPACE_BETWEEN:
 | ||
|       case NS_STYLE_JUSTIFY_SPACE_AROUND:
 | ||
|       case NS_STYLE_JUSTIFY_SPACE_EVENLY:
 | ||
|         nsFlexContainerFrame::CalculatePackingSpace(aLine->NumItems(),
 | ||
|                                                     mJustifyContent,
 | ||
|                                                     &mPosition,
 | ||
|                                                     &mNumPackingSpacesRemaining,
 | ||
|                                                     &mPackingSpaceRemaining);
 | ||
|         break;
 | ||
|       default:
 | ||
|         MOZ_ASSERT_UNREACHABLE("Unexpected justify-content value");
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   MOZ_ASSERT(mNumPackingSpacesRemaining == 0 ||
 | ||
|              mNumAutoMarginsInMainAxis == 0,
 | ||
|              "extra space should either go to packing space or to "
 | ||
|              "auto margins, but not to both");
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| MainAxisPositionTracker::ResolveAutoMarginsInMainAxis(FlexItem& aItem)
 | ||
| {
 | ||
|   if (mNumAutoMarginsInMainAxis) {
 | ||
|     const nsStyleSides& styleMargin = aItem.Frame()->StyleMargin()->mMargin;
 | ||
|     for (uint32_t i = 0; i < eNumAxisEdges; i++) {
 | ||
|       mozilla::Side side = kAxisOrientationToSidesMap[mAxis][i];
 | ||
|       if (styleMargin.GetUnit(side) == eStyleUnit_Auto) {
 | ||
|         // NOTE: This integer math will skew the distribution of remainder
 | ||
|         // app-units towards the end, which is fine.
 | ||
|         nscoord curAutoMarginSize =
 | ||
|           mPackingSpaceRemaining / mNumAutoMarginsInMainAxis;
 | ||
| 
 | ||
|         MOZ_ASSERT(aItem.GetMarginComponentForSide(side) == 0,
 | ||
|                    "Expecting auto margins to have value '0' before we "
 | ||
|                    "resolve them");
 | ||
|         aItem.SetMarginComponentForSide(side, curAutoMarginSize);
 | ||
| 
 | ||
|         mNumAutoMarginsInMainAxis--;
 | ||
|         mPackingSpaceRemaining -= curAutoMarginSize;
 | ||
|       }
 | ||
|     }
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| MainAxisPositionTracker::TraversePackingSpace()
 | ||
| {
 | ||
|   if (mNumPackingSpacesRemaining) {
 | ||
|     MOZ_ASSERT(mJustifyContent == NS_STYLE_JUSTIFY_SPACE_BETWEEN ||
 | ||
|                mJustifyContent == NS_STYLE_JUSTIFY_SPACE_AROUND ||
 | ||
|                mJustifyContent == NS_STYLE_JUSTIFY_SPACE_EVENLY,
 | ||
|                "mNumPackingSpacesRemaining only applies for "
 | ||
|                "space-between/space-around/space-evenly");
 | ||
| 
 | ||
|     MOZ_ASSERT(mPackingSpaceRemaining >= 0,
 | ||
|                "ran out of packing space earlier than we expected");
 | ||
| 
 | ||
|     // NOTE: This integer math will skew the distribution of remainder
 | ||
|     // app-units towards the end, which is fine.
 | ||
|     nscoord curPackingSpace =
 | ||
|       mPackingSpaceRemaining / mNumPackingSpacesRemaining;
 | ||
| 
 | ||
|     mPosition += curPackingSpace;
 | ||
|     mNumPackingSpacesRemaining--;
 | ||
|     mPackingSpaceRemaining -= curPackingSpace;
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| CrossAxisPositionTracker::
 | ||
|   CrossAxisPositionTracker(FlexLine* aFirstLine,
 | ||
|                            const ReflowInput& aReflowInput,
 | ||
|                            nscoord aContentBoxCrossSize,
 | ||
|                            bool aIsCrossSizeDefinite,
 | ||
|                            const FlexboxAxisTracker& aAxisTracker,
 | ||
|                            const nscoord aCrossGapSize)
 | ||
|   : PositionTracker(aAxisTracker.GetCrossAxis(),
 | ||
|                     aAxisTracker.IsCrossAxisReversed()),
 | ||
|     mPackingSpaceRemaining(0),
 | ||
|     mNumPackingSpacesRemaining(0),
 | ||
|     mAlignContent(aReflowInput.mStylePosition->mAlignContent),
 | ||
|     mCrossGapSize(aCrossGapSize)
 | ||
| {
 | ||
|   MOZ_ASSERT(aFirstLine, "null first line pointer");
 | ||
| 
 | ||
|   // 'normal' behaves as 'stretch'
 | ||
|   if (mAlignContent == NS_STYLE_ALIGN_NORMAL) {
 | ||
|     mAlignContent = NS_STYLE_ALIGN_STRETCH;
 | ||
|   }
 | ||
| 
 | ||
|   // XXX strip of the <overflow-position> bit until we implement that
 | ||
|   mAlignContent &= ~NS_STYLE_ALIGN_FLAG_BITS;
 | ||
| 
 | ||
|   const bool isSingleLine =
 | ||
|     NS_STYLE_FLEX_WRAP_NOWRAP == aReflowInput.mStylePosition->mFlexWrap;
 | ||
|   if (isSingleLine) {
 | ||
|     MOZ_ASSERT(!aFirstLine->getNext(),
 | ||
|                "If we're styled as single-line, we should only have 1 line");
 | ||
|     // "If the flex container is single-line and has a definite cross size, the
 | ||
|     // cross size of the flex line is the flex container's inner cross size."
 | ||
|     //
 | ||
|     // SOURCE: https://drafts.csswg.org/css-flexbox/#algo-cross-line
 | ||
|     // NOTE: This means (by definition) that there's no packing space, which
 | ||
|     // means we don't need to be concerned with "align-conent" at all and we
 | ||
|     // can return early. This is handy, because this is the usual case (for
 | ||
|     // single-line flexbox).
 | ||
|     if (aIsCrossSizeDefinite) {
 | ||
|       aFirstLine->SetLineCrossSize(aContentBoxCrossSize);
 | ||
|       return;
 | ||
|     }
 | ||
| 
 | ||
|     // "If the flex container is single-line, then clamp the line's
 | ||
|     // cross-size to be within the container's computed min and max cross-size
 | ||
|     // properties."
 | ||
|     aFirstLine->SetLineCrossSize(NS_CSS_MINMAX(aFirstLine->GetLineCrossSize(),
 | ||
|                                                aReflowInput.ComputedMinBSize(),
 | ||
|                                                aReflowInput.ComputedMaxBSize()));
 | ||
|   }
 | ||
| 
 | ||
|   // NOTE: The rest of this function should essentially match
 | ||
|   // MainAxisPositionTracker's constructor, though with FlexLines instead of
 | ||
|   // FlexItems, and with the additional value "stretch" (and of course with
 | ||
|   // cross sizes instead of main sizes.)
 | ||
| 
 | ||
|   // Figure out how much packing space we have (container's cross size minus
 | ||
|   // all the lines' cross sizes).  Also, share this loop to count how many
 | ||
|   // lines we have. (We need that count in some cases below.)
 | ||
|   mPackingSpaceRemaining = aContentBoxCrossSize;
 | ||
|   uint32_t numLines = 0;
 | ||
|   for (FlexLine* line = aFirstLine; line; line = line->getNext()) {
 | ||
|     mPackingSpaceRemaining -= line->GetLineCrossSize();
 | ||
|     numLines++;
 | ||
|   }
 | ||
| 
 | ||
|   // Subtract space required for row/col gap from the remaining packing space
 | ||
|   MOZ_ASSERT(numLines >= 1,
 | ||
|              "GenerateFlexLines should've produced at least 1 line");
 | ||
|   mPackingSpaceRemaining -= aCrossGapSize * (numLines - 1);
 | ||
| 
 | ||
|   // If packing space is negative, 'space-between' and 'stretch' behave like
 | ||
|   // 'flex-start', and 'space-around' and 'space-evenly' behave like 'center'.
 | ||
|   // In those cases, it's simplest to just pretend we have a different
 | ||
|   // 'align-content' value and share code. (If we only have one line, all of
 | ||
|   // the 'space-*' keywords fall back as well, but 'stretch' doesn't because
 | ||
|   // even a single line can still stretch.)
 | ||
|   if (mPackingSpaceRemaining < 0 && mAlignContent == NS_STYLE_ALIGN_STRETCH) {
 | ||
|       mAlignContent = NS_STYLE_ALIGN_FLEX_START;
 | ||
|   } else if (mPackingSpaceRemaining < 0 || numLines == 1) {
 | ||
|     if (mAlignContent == NS_STYLE_ALIGN_SPACE_BETWEEN) {
 | ||
|       mAlignContent = NS_STYLE_ALIGN_FLEX_START;
 | ||
|     } else if (mAlignContent == NS_STYLE_ALIGN_SPACE_AROUND ||
 | ||
|                mAlignContent == NS_STYLE_ALIGN_SPACE_EVENLY) {
 | ||
|       mAlignContent = NS_STYLE_ALIGN_CENTER;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Map 'left'/'right' to 'start'/'end'
 | ||
|   if (mAlignContent == NS_STYLE_ALIGN_LEFT ||
 | ||
|       mAlignContent == NS_STYLE_ALIGN_RIGHT) {
 | ||
|     if (aAxisTracker.IsRowOriented()) {
 | ||
|       // Container's alignment axis is not parallel to the inline axis,
 | ||
|       // so we map both 'left' and 'right' to 'start'.
 | ||
|       mAlignContent = NS_STYLE_ALIGN_START;
 | ||
|     } else {
 | ||
|       // Column-oriented, so we map 'left' and 'right' to 'start' or 'end',
 | ||
|       // depending on left-to-right writing mode.
 | ||
|       const bool isLTR = aAxisTracker.GetWritingMode().IsBidiLTR();
 | ||
|       const bool isAlignLeft = (mAlignContent == NS_STYLE_ALIGN_LEFT);
 | ||
|       mAlignContent = (isAlignLeft == isLTR) ? NS_STYLE_ALIGN_START
 | ||
|                                              : NS_STYLE_ALIGN_END;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Map 'start'/'end' to 'flex-start'/'flex-end'.
 | ||
|   if (mAlignContent == NS_STYLE_ALIGN_START) {
 | ||
|     mAlignContent = NS_STYLE_ALIGN_FLEX_START;
 | ||
|   } else if (mAlignContent == NS_STYLE_ALIGN_END) {
 | ||
|     mAlignContent = NS_STYLE_ALIGN_FLEX_END;
 | ||
|   }
 | ||
| 
 | ||
|   // If our cross axis is (internally) reversed, swap the align-content
 | ||
|   // "flex-start" and "flex-end" behaviors:
 | ||
|   if (aAxisTracker.AreAxesInternallyReversed()) {
 | ||
|     if (mAlignContent == NS_STYLE_ALIGN_FLEX_START) {
 | ||
|       mAlignContent = NS_STYLE_ALIGN_FLEX_END;
 | ||
|     } else if (mAlignContent == NS_STYLE_ALIGN_FLEX_END) {
 | ||
|       mAlignContent = NS_STYLE_ALIGN_FLEX_START;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Figure out how much space we'll set aside for packing spaces, and advance
 | ||
|   // past any leading packing-space.
 | ||
|   if (mPackingSpaceRemaining != 0) {
 | ||
|     switch (mAlignContent) {
 | ||
|       case NS_STYLE_ALIGN_SELF_START:
 | ||
|       case NS_STYLE_ALIGN_SELF_END:
 | ||
|       case NS_STYLE_ALIGN_BASELINE:
 | ||
|       case NS_STYLE_ALIGN_LAST_BASELINE:
 | ||
|         NS_WARNING("NYI: align-items/align-self:left/right/self-start/self-end/baseline/last baseline");
 | ||
|         MOZ_FALLTHROUGH;
 | ||
|       case NS_STYLE_ALIGN_FLEX_START:
 | ||
|         // All packing space should go at the end --> nothing to do here.
 | ||
|         break;
 | ||
|       case NS_STYLE_ALIGN_FLEX_END:
 | ||
|         // All packing space goes at the beginning
 | ||
|         mPosition += mPackingSpaceRemaining;
 | ||
|         break;
 | ||
|       case NS_STYLE_ALIGN_CENTER:
 | ||
|         // Half the packing space goes at the beginning
 | ||
|         mPosition += mPackingSpaceRemaining / 2;
 | ||
|         break;
 | ||
|       case NS_STYLE_ALIGN_SPACE_BETWEEN:
 | ||
|       case NS_STYLE_ALIGN_SPACE_AROUND:
 | ||
|       case NS_STYLE_ALIGN_SPACE_EVENLY:
 | ||
|         nsFlexContainerFrame::CalculatePackingSpace(numLines,
 | ||
|                                                     mAlignContent,
 | ||
|                                                     &mPosition,
 | ||
|                                                     &mNumPackingSpacesRemaining,
 | ||
|                                                     &mPackingSpaceRemaining);
 | ||
|         break;
 | ||
|       case NS_STYLE_ALIGN_STRETCH: {
 | ||
|         // Split space equally between the lines:
 | ||
|         MOZ_ASSERT(mPackingSpaceRemaining > 0,
 | ||
|                    "negative packing space should make us use 'flex-start' "
 | ||
|                    "instead of 'stretch' (and we shouldn't bother with this "
 | ||
|                    "code if we have 0 packing space)");
 | ||
| 
 | ||
|         uint32_t numLinesLeft = numLines;
 | ||
|         for (FlexLine* line = aFirstLine; line; line = line->getNext()) {
 | ||
|           // Our share is the amount of space remaining, divided by the number
 | ||
|           // of lines remainig.
 | ||
|           MOZ_ASSERT(numLinesLeft > 0, "miscalculated num lines");
 | ||
|           nscoord shareOfExtraSpace = mPackingSpaceRemaining / numLinesLeft;
 | ||
|           nscoord newSize = line->GetLineCrossSize() + shareOfExtraSpace;
 | ||
|           line->SetLineCrossSize(newSize);
 | ||
| 
 | ||
|           mPackingSpaceRemaining -= shareOfExtraSpace;
 | ||
|           numLinesLeft--;
 | ||
|         }
 | ||
|         MOZ_ASSERT(numLinesLeft == 0, "miscalculated num lines");
 | ||
|         break;
 | ||
|       }
 | ||
|       default:
 | ||
|         MOZ_ASSERT_UNREACHABLE("Unexpected align-content value");
 | ||
|     }
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| CrossAxisPositionTracker::TraversePackingSpace()
 | ||
| {
 | ||
|   if (mNumPackingSpacesRemaining) {
 | ||
|     MOZ_ASSERT(mAlignContent == NS_STYLE_ALIGN_SPACE_BETWEEN ||
 | ||
|                mAlignContent == NS_STYLE_ALIGN_SPACE_AROUND ||
 | ||
|                mAlignContent == NS_STYLE_ALIGN_SPACE_EVENLY,
 | ||
|                "mNumPackingSpacesRemaining only applies for "
 | ||
|                "space-between/space-around/space-evenly");
 | ||
| 
 | ||
|     MOZ_ASSERT(mPackingSpaceRemaining >= 0,
 | ||
|                "ran out of packing space earlier than we expected");
 | ||
| 
 | ||
|     // NOTE: This integer math will skew the distribution of remainder
 | ||
|     // app-units towards the end, which is fine.
 | ||
|     nscoord curPackingSpace =
 | ||
|       mPackingSpaceRemaining / mNumPackingSpacesRemaining;
 | ||
| 
 | ||
|     mPosition += curPackingSpace;
 | ||
|     mNumPackingSpacesRemaining--;
 | ||
|     mPackingSpaceRemaining -= curPackingSpace;
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| SingleLineCrossAxisPositionTracker::
 | ||
|   SingleLineCrossAxisPositionTracker(const FlexboxAxisTracker& aAxisTracker)
 | ||
|   : PositionTracker(aAxisTracker.GetCrossAxis(),
 | ||
|                     aAxisTracker.IsCrossAxisReversed())
 | ||
| {
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| FlexLine::ComputeCrossSizeAndBaseline(const FlexboxAxisTracker& aAxisTracker)
 | ||
| {
 | ||
|   nscoord crossStartToFurthestFirstBaseline = nscoord_MIN;
 | ||
|   nscoord crossEndToFurthestFirstBaseline = nscoord_MIN;
 | ||
|   nscoord crossStartToFurthestLastBaseline = nscoord_MIN;
 | ||
|   nscoord crossEndToFurthestLastBaseline = nscoord_MIN;
 | ||
|   nscoord largestOuterCrossSize = 0;
 | ||
|   for (const FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
 | ||
|     nscoord curOuterCrossSize =
 | ||
|       item->GetOuterCrossSize(aAxisTracker.GetCrossAxis());
 | ||
| 
 | ||
|     if ((item->GetAlignSelf() == NS_STYLE_ALIGN_BASELINE ||
 | ||
|         item->GetAlignSelf() == NS_STYLE_ALIGN_LAST_BASELINE) &&
 | ||
|         item->GetNumAutoMarginsInAxis(aAxisTracker.GetCrossAxis()) == 0) {
 | ||
|       const bool useFirst = (item->GetAlignSelf() == NS_STYLE_ALIGN_BASELINE);
 | ||
|       // FIXME: Once we support "writing-mode", we'll have to do baseline
 | ||
|       // alignment in vertical flex containers here (w/ horizontal cross-axes).
 | ||
| 
 | ||
|       // Find distance from our item's cross-start and cross-end margin-box
 | ||
|       // edges to its baseline.
 | ||
|       //
 | ||
|       // Here's a diagram of a flex-item that we might be doing this on.
 | ||
|       // "mmm" is the margin-box, "bbb" is the border-box. The bottom of
 | ||
|       // the text "BASE" is the baseline.
 | ||
|       //
 | ||
|       // ---(cross-start)---
 | ||
|       //                ___              ___            ___
 | ||
|       //   mmmmmmmmmmmm  |                |margin-start  |
 | ||
|       //   m          m  |               _|_   ___       |
 | ||
|       //   m bbbbbbbb m  |curOuterCrossSize     |        |crossStartToBaseline
 | ||
|       //   m b      b m  |                      |ascent  |
 | ||
|       //   m b BASE b m  |                     _|_      _|_
 | ||
|       //   m b      b m  |                               |
 | ||
|       //   m bbbbbbbb m  |                               |crossEndToBaseline
 | ||
|       //   m          m  |                               |
 | ||
|       //   mmmmmmmmmmmm _|_                             _|_
 | ||
|       //
 | ||
|       // ---(cross-end)---
 | ||
|       //
 | ||
|       // We already have the curOuterCrossSize, margin-start, and the ascent.
 | ||
|       // * We can get crossStartToBaseline by adding margin-start + ascent.
 | ||
|       // * If we subtract that from the curOuterCrossSize, we get
 | ||
|       //   crossEndToBaseline.
 | ||
| 
 | ||
|       nscoord crossStartToBaseline =
 | ||
|         item->GetBaselineOffsetFromOuterCrossEdge(eAxisEdge_Start,
 | ||
|                                                   aAxisTracker,
 | ||
|                                                   useFirst);
 | ||
|       nscoord crossEndToBaseline = curOuterCrossSize - crossStartToBaseline;
 | ||
| 
 | ||
|       // Now, update our "largest" values for these (across all the flex items
 | ||
|       // in this flex line), so we can use them in computing the line's cross
 | ||
|       // size below:
 | ||
|       if (useFirst) {
 | ||
|         crossStartToFurthestFirstBaseline =
 | ||
|           std::max(crossStartToFurthestFirstBaseline, crossStartToBaseline);
 | ||
|         crossEndToFurthestFirstBaseline =
 | ||
|           std::max(crossEndToFurthestFirstBaseline, crossEndToBaseline);
 | ||
|       } else {
 | ||
|         crossStartToFurthestLastBaseline =
 | ||
|           std::max(crossStartToFurthestLastBaseline, crossStartToBaseline);
 | ||
|         crossEndToFurthestLastBaseline =
 | ||
|           std::max(crossEndToFurthestLastBaseline, crossEndToBaseline);
 | ||
|       }
 | ||
|     } else {
 | ||
|       largestOuterCrossSize = std::max(largestOuterCrossSize, curOuterCrossSize);
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // The line's baseline offset is the distance from the line's edge (start or
 | ||
|   // end, depending on whether we've flipped the axes) to the furthest
 | ||
|   // item-baseline. The item(s) with that baseline will be exactly aligned with
 | ||
|   // the line's edge.
 | ||
|   mFirstBaselineOffset = aAxisTracker.AreAxesInternallyReversed() ?
 | ||
|     crossEndToFurthestFirstBaseline : crossStartToFurthestFirstBaseline;
 | ||
| 
 | ||
|   mLastBaselineOffset = aAxisTracker.AreAxesInternallyReversed() ?
 | ||
|     crossStartToFurthestLastBaseline : crossEndToFurthestLastBaseline;
 | ||
| 
 | ||
|   // The line's cross-size is the larger of:
 | ||
|   //  (a) [largest cross-start-to-baseline + largest baseline-to-cross-end] of
 | ||
|   //      all baseline-aligned items with no cross-axis auto margins...
 | ||
|   // and
 | ||
|   //  (b) [largest cross-start-to-baseline + largest baseline-to-cross-end] of
 | ||
|   //      all last baseline-aligned items with no cross-axis auto margins...
 | ||
|   // and
 | ||
|   //  (c) largest cross-size of all other children.
 | ||
|   mLineCrossSize = std::max(
 | ||
|     std::max(crossStartToFurthestFirstBaseline + crossEndToFurthestFirstBaseline,
 | ||
|              crossStartToFurthestLastBaseline + crossEndToFurthestLastBaseline),
 | ||
|     largestOuterCrossSize);
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| FlexItem::ResolveStretchedCrossSize(nscoord aLineCrossSize,
 | ||
|                                     const FlexboxAxisTracker& aAxisTracker)
 | ||
| {
 | ||
|   AxisOrientationType crossAxis = aAxisTracker.GetCrossAxis();
 | ||
|   // We stretch IFF we are align-self:stretch, have no auto margins in
 | ||
|   // cross axis, and have cross-axis size property == "auto". If any of those
 | ||
|   // conditions don't hold up, we won't stretch.
 | ||
|   if (mAlignSelf != NS_STYLE_ALIGN_STRETCH ||
 | ||
|       GetNumAutoMarginsInAxis(crossAxis) != 0 ||
 | ||
|       !IsCrossSizeAuto()) {
 | ||
|     return;
 | ||
|   }
 | ||
| 
 | ||
|   // If we've already been stretched, we can bail out early, too.
 | ||
|   // No need to redo the calculation.
 | ||
|   if (mIsStretched) {
 | ||
|     return;
 | ||
|   }
 | ||
| 
 | ||
|   // Reserve space for margins & border & padding, and then use whatever
 | ||
|   // remains as our item's cross-size (clamped to its min/max range).
 | ||
|   nscoord stretchedSize = aLineCrossSize -
 | ||
|     GetMarginBorderPaddingSizeInAxis(crossAxis);
 | ||
| 
 | ||
|   stretchedSize = NS_CSS_MINMAX(stretchedSize, mCrossMinSize, mCrossMaxSize);
 | ||
| 
 | ||
|   // Update the cross-size & make a note that it's stretched, so we know to
 | ||
|   // override the reflow state's computed cross-size in our final reflow.
 | ||
|   SetCrossSize(stretchedSize);
 | ||
|   mIsStretched = true;
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| SingleLineCrossAxisPositionTracker::
 | ||
|   ResolveAutoMarginsInCrossAxis(const FlexLine& aLine,
 | ||
|                                 FlexItem& aItem)
 | ||
| {
 | ||
|   // Subtract the space that our item is already occupying, to see how much
 | ||
|   // space (if any) is available for its auto margins.
 | ||
|   nscoord spaceForAutoMargins = aLine.GetLineCrossSize() -
 | ||
|     aItem.GetOuterCrossSize(mAxis);
 | ||
| 
 | ||
|   if (spaceForAutoMargins <= 0) {
 | ||
|     return; // No available space  --> nothing to do
 | ||
|   }
 | ||
| 
 | ||
|   uint32_t numAutoMargins = aItem.GetNumAutoMarginsInAxis(mAxis);
 | ||
|   if (numAutoMargins == 0) {
 | ||
|     return; // No auto margins --> nothing to do.
 | ||
|   }
 | ||
| 
 | ||
|   // OK, we have at least one auto margin and we have some available space.
 | ||
|   // Give each auto margin a share of the space.
 | ||
|   const nsStyleSides& styleMargin = aItem.Frame()->StyleMargin()->mMargin;
 | ||
|   for (uint32_t i = 0; i < eNumAxisEdges; i++) {
 | ||
|     mozilla::Side side = kAxisOrientationToSidesMap[mAxis][i];
 | ||
|     if (styleMargin.GetUnit(side) == eStyleUnit_Auto) {
 | ||
|       MOZ_ASSERT(aItem.GetMarginComponentForSide(side) == 0,
 | ||
|                  "Expecting auto margins to have value '0' before we "
 | ||
|                  "update them");
 | ||
| 
 | ||
|       // NOTE: integer divison is fine here; numAutoMargins is either 1 or 2.
 | ||
|       // If it's 2 & spaceForAutoMargins is odd, 1st margin gets smaller half.
 | ||
|       nscoord curAutoMarginSize = spaceForAutoMargins / numAutoMargins;
 | ||
|       aItem.SetMarginComponentForSide(side, curAutoMarginSize);
 | ||
|       numAutoMargins--;
 | ||
|       spaceForAutoMargins -= curAutoMarginSize;
 | ||
|     }
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| SingleLineCrossAxisPositionTracker::
 | ||
|   EnterAlignPackingSpace(const FlexLine& aLine,
 | ||
|                          const FlexItem& aItem,
 | ||
|                          const FlexboxAxisTracker& aAxisTracker)
 | ||
| {
 | ||
|   // We don't do align-self alignment on items that have auto margins
 | ||
|   // in the cross axis.
 | ||
|   if (aItem.GetNumAutoMarginsInAxis(mAxis)) {
 | ||
|     return;
 | ||
|   }
 | ||
| 
 | ||
|   uint8_t alignSelf = aItem.GetAlignSelf();
 | ||
|   // NOTE: 'stretch' behaves like 'flex-start' once we've stretched any
 | ||
|   // auto-sized items (which we've already done).
 | ||
|   if (alignSelf == NS_STYLE_ALIGN_STRETCH) {
 | ||
|     alignSelf = NS_STYLE_ALIGN_FLEX_START;
 | ||
|   }
 | ||
| 
 | ||
|   // Map 'left'/'right' to 'start'/'end'
 | ||
|   if (alignSelf == NS_STYLE_ALIGN_LEFT || alignSelf == NS_STYLE_ALIGN_RIGHT) {
 | ||
|     if (aAxisTracker.IsRowOriented()) {
 | ||
|       // Container's alignment axis is not parallel to the inline axis,
 | ||
|       // so we map both 'left' and 'right' to 'start'.
 | ||
|       alignSelf = NS_STYLE_ALIGN_START;
 | ||
|     } else {
 | ||
|       // Column-oriented, so we map 'left' and 'right' to 'start' or 'end',
 | ||
|       // depending on left-to-right writing mode.
 | ||
|       const bool isLTR = aAxisTracker.GetWritingMode().IsBidiLTR();
 | ||
|       const bool isAlignLeft = (alignSelf == NS_STYLE_ALIGN_LEFT);
 | ||
|       alignSelf = (isAlignLeft == isLTR) ? NS_STYLE_ALIGN_START
 | ||
|                                          : NS_STYLE_ALIGN_END;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Map 'start'/'end' to 'flex-start'/'flex-end'.
 | ||
|   if (alignSelf == NS_STYLE_ALIGN_START) {
 | ||
|     alignSelf = NS_STYLE_ALIGN_FLEX_START;
 | ||
|   } else if (alignSelf == NS_STYLE_ALIGN_END) {
 | ||
|     alignSelf = NS_STYLE_ALIGN_FLEX_END;
 | ||
|   }
 | ||
| 
 | ||
|   // If our cross axis is (internally) reversed, swap the align-self
 | ||
|   // "flex-start" and "flex-end" behaviors:
 | ||
|   if (aAxisTracker.AreAxesInternallyReversed()) {
 | ||
|     if (alignSelf == NS_STYLE_ALIGN_FLEX_START) {
 | ||
|       alignSelf = NS_STYLE_ALIGN_FLEX_END;
 | ||
|     } else if (alignSelf == NS_STYLE_ALIGN_FLEX_END) {
 | ||
|       alignSelf = NS_STYLE_ALIGN_FLEX_START;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   switch (alignSelf) {
 | ||
|     case NS_STYLE_ALIGN_SELF_START:
 | ||
|     case NS_STYLE_ALIGN_SELF_END:
 | ||
|       NS_WARNING("NYI: align-items/align-self:left/right/self-start/self-end");
 | ||
|       MOZ_FALLTHROUGH;
 | ||
|     case NS_STYLE_ALIGN_FLEX_START:
 | ||
|       // No space to skip over -- we're done.
 | ||
|       break;
 | ||
|     case NS_STYLE_ALIGN_FLEX_END:
 | ||
|       mPosition += aLine.GetLineCrossSize() - aItem.GetOuterCrossSize(mAxis);
 | ||
|       break;
 | ||
|     case NS_STYLE_ALIGN_CENTER:
 | ||
|       // Note: If cross-size is odd, the "after" space will get the extra unit.
 | ||
|       mPosition +=
 | ||
|         (aLine.GetLineCrossSize() - aItem.GetOuterCrossSize(mAxis)) / 2;
 | ||
|       break;
 | ||
|     case NS_STYLE_ALIGN_BASELINE:
 | ||
|     case NS_STYLE_ALIGN_LAST_BASELINE: {
 | ||
|       const bool useFirst = (alignSelf == NS_STYLE_ALIGN_BASELINE);
 | ||
| 
 | ||
|       // Normally, baseline-aligned items are collectively aligned with the
 | ||
|       // line's cross-start edge; however, if our cross axis is (internally)
 | ||
|       // reversed, we instead align them with the cross-end edge.
 | ||
|       // A similar logic holds for last baseline-aligned items, but in reverse.
 | ||
|       AxisEdgeType baselineAlignEdge =
 | ||
|         aAxisTracker.AreAxesInternallyReversed() == useFirst ?
 | ||
|         eAxisEdge_End : eAxisEdge_Start;
 | ||
| 
 | ||
|       nscoord itemBaselineOffset =
 | ||
|         aItem.GetBaselineOffsetFromOuterCrossEdge(baselineAlignEdge,
 | ||
|                                                   aAxisTracker,
 | ||
|                                                   useFirst);
 | ||
| 
 | ||
|       nscoord lineBaselineOffset = useFirst ? aLine.GetFirstBaselineOffset()
 | ||
|                                             : aLine.GetLastBaselineOffset();
 | ||
| 
 | ||
|       NS_ASSERTION(lineBaselineOffset >= itemBaselineOffset,
 | ||
|                    "failed at finding largest baseline offset");
 | ||
| 
 | ||
|       // How much do we need to adjust our position (from the line edge),
 | ||
|       // to get the item's baseline to hit the line's baseline offset:
 | ||
|       nscoord baselineDiff = lineBaselineOffset - itemBaselineOffset;
 | ||
| 
 | ||
|       if (aAxisTracker.AreAxesInternallyReversed() == useFirst) {
 | ||
|         // Advance to align item w/ line's flex-end edge (as in FLEX_END case):
 | ||
|         mPosition += aLine.GetLineCrossSize() - aItem.GetOuterCrossSize(mAxis);
 | ||
|         // ...and step *back* by the baseline adjustment:
 | ||
|         mPosition -= baselineDiff;
 | ||
|       } else {
 | ||
|         // mPosition is already at line's flex-start edge.
 | ||
|         // From there, we step *forward* by the baseline adjustment:
 | ||
|         mPosition += baselineDiff;
 | ||
|       }
 | ||
|       break;
 | ||
|     }
 | ||
|     default:
 | ||
|       MOZ_ASSERT_UNREACHABLE("Unexpected align-self value");
 | ||
|       break;
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| // Utility function to convert an InlineDir to an AxisOrientationType
 | ||
| static inline AxisOrientationType
 | ||
| InlineDirToAxisOrientation(WritingMode::InlineDir aInlineDir)
 | ||
| {
 | ||
|   switch (aInlineDir) {
 | ||
|     case WritingMode::eInlineLTR:
 | ||
|       return eAxis_LR;
 | ||
|     case WritingMode::eInlineRTL:
 | ||
|       return eAxis_RL;
 | ||
|     case WritingMode::eInlineTTB:
 | ||
|       return eAxis_TB;
 | ||
|     case WritingMode::eInlineBTT:
 | ||
|       return eAxis_BT;
 | ||
|   }
 | ||
| 
 | ||
|   MOZ_ASSERT_UNREACHABLE("Unhandled InlineDir");
 | ||
|   return eAxis_LR; // in case of unforseen error, assume English LTR text flow.
 | ||
| }
 | ||
| 
 | ||
| // Utility function to convert a BlockDir to an AxisOrientationType
 | ||
| static inline AxisOrientationType
 | ||
| BlockDirToAxisOrientation(WritingMode::BlockDir aBlockDir)
 | ||
| {
 | ||
|   switch (aBlockDir) {
 | ||
|     case WritingMode::eBlockLR:
 | ||
|       return eAxis_LR;
 | ||
|     case WritingMode::eBlockRL:
 | ||
|       return eAxis_RL;
 | ||
|     case WritingMode::eBlockTB:
 | ||
|       return eAxis_TB;
 | ||
|     // NOTE: WritingMode::eBlockBT (bottom-to-top) does not exist.
 | ||
|   }
 | ||
| 
 | ||
|   MOZ_ASSERT_UNREACHABLE("Unhandled BlockDir");
 | ||
|   return eAxis_TB; // in case of unforseen error, assume English TTB block-flow
 | ||
| }
 | ||
| 
 | ||
| FlexboxAxisTracker::FlexboxAxisTracker(
 | ||
|   const nsFlexContainerFrame* aFlexContainer,
 | ||
|   const WritingMode& aWM,
 | ||
|   AxisTrackerFlags aFlags)
 | ||
|   : mMainAxis(eAxis_LR),
 | ||
|     mWM(aWM),
 | ||
|     mIsRowOriented(true),
 | ||
|     mIsMainAxisReversed(false),
 | ||
|     mAreAxesInternallyReversed(false)
 | ||
| {
 | ||
|   if (IsLegacyBox(aFlexContainer)) {
 | ||
|     InitAxesFromLegacyProps(aFlexContainer);
 | ||
|   } else {
 | ||
|     InitAxesFromModernProps(aFlexContainer);
 | ||
|   }
 | ||
| 
 | ||
|   // Master switch to enable/disable bug 983427's code for reversing our axes
 | ||
|   // and reversing some logic, to avoid reflowing children in bottom-to-top
 | ||
|   // order. (This switch can be removed eventually, but for now, it allows
 | ||
|   // this special-case code path to be compared against the normal code path.)
 | ||
|   static bool sPreventBottomToTopChildOrdering = true;
 | ||
| 
 | ||
|   // Note: if the eAllowBottomToTopChildOrdering flag is set, that overrides
 | ||
|   // the static boolean and makes us skip this special case.
 | ||
|   if (!(aFlags & AxisTrackerFlags::eAllowBottomToTopChildOrdering) &&
 | ||
|       sPreventBottomToTopChildOrdering) {
 | ||
|     // If either axis is bottom-to-top, we flip both axes (and set a flag
 | ||
|     // so that we can flip some logic to make the reversal transparent).
 | ||
|     if (eAxis_BT == mMainAxis || eAxis_BT == mCrossAxis) {
 | ||
|       mMainAxis = GetReverseAxis(mMainAxis);
 | ||
|       mCrossAxis = GetReverseAxis(mCrossAxis);
 | ||
|       mAreAxesInternallyReversed = true;
 | ||
|       mIsMainAxisReversed = !mIsMainAxisReversed;
 | ||
|       mIsCrossAxisReversed = !mIsCrossAxisReversed;
 | ||
|     }
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| FlexboxAxisTracker::InitAxesFromLegacyProps(
 | ||
|   const nsFlexContainerFrame* aFlexContainer)
 | ||
| {
 | ||
|   const nsStyleXUL* styleXUL = aFlexContainer->StyleXUL();
 | ||
| 
 | ||
|   const bool boxOrientIsVertical = (styleXUL->mBoxOrient ==
 | ||
|                                     StyleBoxOrient::Vertical);
 | ||
|   const bool wmIsVertical = mWM.IsVertical();
 | ||
| 
 | ||
|   // If box-orient agrees with our writing-mode, then we're "row-oriented"
 | ||
|   // (i.e. the flexbox main axis is the same as our writing mode's inline
 | ||
|   // direction).  Otherwise, we're column-oriented (i.e. the flexbox's main
 | ||
|   // axis is perpendicular to the writing-mode's inline direction).
 | ||
|   mIsRowOriented = (boxOrientIsVertical == wmIsVertical);
 | ||
| 
 | ||
|   // XXXdholbert BEGIN CODE TO SET DEPRECATED MEMBER-VARS
 | ||
|   if (boxOrientIsVertical) {
 | ||
|     mMainAxis = eAxis_TB;
 | ||
|     mCrossAxis = eAxis_LR;
 | ||
|   } else {
 | ||
|     mMainAxis = eAxis_LR;
 | ||
|     mCrossAxis = eAxis_TB;
 | ||
|   }
 | ||
|   // "direction: rtl" reverses the writing-mode's inline axis.
 | ||
|   // So, we need to reverse the corresponding flex axis to match.
 | ||
|   // (Note this we don't toggle "mIsMainAxisReversed" for this condition,
 | ||
|   // because the main axis will still match mWM's inline direction.)
 | ||
|   if (!mWM.IsBidiLTR()) {
 | ||
|     AxisOrientationType& axisToFlip = mIsRowOriented ? mMainAxis : mCrossAxis;
 | ||
|     axisToFlip = GetReverseAxis(axisToFlip);
 | ||
|   }
 | ||
|   // XXXdholbert END CODE TO SET DEPRECATED MEMBER-VARS
 | ||
| 
 | ||
|   // Legacy flexbox can use "-webkit-box-direction: reverse" to reverse the
 | ||
|   // main axis (so it runs in the reverse direction of the inline axis):
 | ||
|   if (styleXUL->mBoxDirection == StyleBoxDirection::Reverse) {
 | ||
|     mMainAxis = GetReverseAxis(mMainAxis);
 | ||
|     mIsMainAxisReversed = true;
 | ||
|   } else {
 | ||
|     mIsMainAxisReversed = false;
 | ||
|   }
 | ||
| 
 | ||
|   // Legacy flexbox does not support reversing the cross axis -- it has no
 | ||
|   // equivalent of modern flexbox's "flex-wrap: wrap-reverse".
 | ||
|   mIsCrossAxisReversed = false;
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| FlexboxAxisTracker::InitAxesFromModernProps(
 | ||
|   const nsFlexContainerFrame* aFlexContainer)
 | ||
| {
 | ||
|   const nsStylePosition* stylePos = aFlexContainer->StylePosition();
 | ||
|   uint32_t flexDirection = stylePos->mFlexDirection;
 | ||
| 
 | ||
|   // Inline dimension ("start-to-end"):
 | ||
|   // (NOTE: I'm intentionally not calling these "inlineAxis"/"blockAxis", since
 | ||
|   // those terms have explicit definition in the writing-modes spec, which are
 | ||
|   // the opposite of how I'd be using them here.)
 | ||
|   AxisOrientationType inlineDimension =
 | ||
|     InlineDirToAxisOrientation(mWM.GetInlineDir());
 | ||
|   AxisOrientationType blockDimension =
 | ||
|     BlockDirToAxisOrientation(mWM.GetBlockDir());
 | ||
| 
 | ||
|   // Determine main axis:
 | ||
|   switch (flexDirection) {
 | ||
|     case NS_STYLE_FLEX_DIRECTION_ROW:
 | ||
|       mMainAxis = inlineDimension;
 | ||
|       mIsRowOriented = true;
 | ||
|       mIsMainAxisReversed = false;
 | ||
|       break;
 | ||
|     case NS_STYLE_FLEX_DIRECTION_ROW_REVERSE:
 | ||
|       mMainAxis = GetReverseAxis(inlineDimension);
 | ||
|       mIsRowOriented = true;
 | ||
|       mIsMainAxisReversed = true;
 | ||
|       break;
 | ||
|     case NS_STYLE_FLEX_DIRECTION_COLUMN:
 | ||
|       mMainAxis = blockDimension;
 | ||
|       mIsRowOriented = false;
 | ||
|       mIsMainAxisReversed = false;
 | ||
|       break;
 | ||
|     case NS_STYLE_FLEX_DIRECTION_COLUMN_REVERSE:
 | ||
|       mMainAxis = GetReverseAxis(blockDimension);
 | ||
|       mIsRowOriented = false;
 | ||
|       mIsMainAxisReversed = true;
 | ||
|       break;
 | ||
|     default:
 | ||
|       MOZ_ASSERT_UNREACHABLE("Unexpected flex-direction value");
 | ||
|   }
 | ||
| 
 | ||
|   // Determine cross axis:
 | ||
|   // (This is set up so that a bogus |flexDirection| value will
 | ||
|   // give us blockDimension.
 | ||
|   if (flexDirection == NS_STYLE_FLEX_DIRECTION_COLUMN ||
 | ||
|       flexDirection == NS_STYLE_FLEX_DIRECTION_COLUMN_REVERSE) {
 | ||
|     mCrossAxis = inlineDimension;
 | ||
|   } else {
 | ||
|     mCrossAxis = blockDimension;
 | ||
|   }
 | ||
| 
 | ||
|   // "flex-wrap: wrap-reverse" reverses our cross axis.
 | ||
|   if (stylePos->mFlexWrap == NS_STYLE_FLEX_WRAP_WRAP_REVERSE) {
 | ||
|     mCrossAxis = GetReverseAxis(mCrossAxis);
 | ||
|     mIsCrossAxisReversed = true;
 | ||
|   } else {
 | ||
|     mIsCrossAxisReversed = false;
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| // Allocates a new FlexLine, adds it to the given LinkedList (at the front or
 | ||
| // back depending on aShouldInsertAtFront), and returns a pointer to it.
 | ||
| static FlexLine*
 | ||
| AddNewFlexLineToList(LinkedList<FlexLine>& aLines,
 | ||
|                      bool aShouldInsertAtFront,
 | ||
|                      nscoord aMainGapSize)
 | ||
| {
 | ||
|   FlexLine* newLine = new FlexLine(aMainGapSize);
 | ||
|   if (aShouldInsertAtFront) {
 | ||
|     aLines.insertFront(newLine);
 | ||
|   } else {
 | ||
|     aLines.insertBack(newLine);
 | ||
|   }
 | ||
|   return newLine;
 | ||
| }
 | ||
| 
 | ||
| bool
 | ||
| nsFlexContainerFrame::ShouldUseMozBoxCollapseBehavior(
 | ||
|   const nsStyleDisplay* aThisStyleDisp)
 | ||
| {
 | ||
|   MOZ_ASSERT(StyleDisplay() == aThisStyleDisp, "wrong StyleDisplay passed in");
 | ||
| 
 | ||
|   // Quick filter to screen out *actual* (not-coopted-for-emulation)
 | ||
|   // flex containers, using state bit:
 | ||
|   if (!IsLegacyBox(this)) {
 | ||
|     return false;
 | ||
|   }
 | ||
| 
 | ||
|   // Check our own display value:
 | ||
|   if (aThisStyleDisp->mDisplay == mozilla::StyleDisplay::MozBox ||
 | ||
|       aThisStyleDisp->mDisplay == mozilla::StyleDisplay::MozInlineBox) {
 | ||
|     return true;
 | ||
|   }
 | ||
| 
 | ||
|   // Check our parent's display value, if we're an anonymous box (with a
 | ||
|   // potentially-untrustworthy display value):
 | ||
|   auto pseudoType = Style()->GetPseudo();
 | ||
|   if (pseudoType == nsCSSAnonBoxes::scrolledContent ||
 | ||
|       pseudoType == nsCSSAnonBoxes::buttonContent) {
 | ||
|     const nsStyleDisplay* disp = GetParent()->StyleDisplay();
 | ||
|     if (disp->mDisplay == mozilla::StyleDisplay::MozBox ||
 | ||
|         disp->mDisplay == mozilla::StyleDisplay::MozInlineBox) {
 | ||
|       return true;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   return false;
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| nsFlexContainerFrame::GenerateFlexLines(
 | ||
|   nsPresContext* aPresContext,
 | ||
|   const ReflowInput& aReflowInput,
 | ||
|   nscoord aContentBoxMainSize,
 | ||
|   nscoord aAvailableBSizeForContent,
 | ||
|   const nsTArray<StrutInfo>& aStruts,
 | ||
|   const FlexboxAxisTracker& aAxisTracker,
 | ||
|   nscoord aMainGapSize,
 | ||
|   nsTArray<nsIFrame*>& aPlaceholders, /* out */
 | ||
|   LinkedList<FlexLine>& aLines /* out */)
 | ||
| {
 | ||
|   MOZ_ASSERT(aLines.isEmpty(), "Expecting outparam to start out empty");
 | ||
| 
 | ||
|   const bool isSingleLine =
 | ||
|     NS_STYLE_FLEX_WRAP_NOWRAP == aReflowInput.mStylePosition->mFlexWrap;
 | ||
| 
 | ||
|   // If we're transparently reversing axes, then we'll need to link up our
 | ||
|   // FlexItems and FlexLines in the reverse order, so that the rest of flex
 | ||
|   // layout (with flipped axes) will still produce the correct result.
 | ||
|   // Here, we declare a convenience bool that we'll pass when adding a new
 | ||
|   // FlexLine or FlexItem, to make us insert it at the beginning of its list
 | ||
|   // (so the list ends up reversed).
 | ||
|   const bool shouldInsertAtFront = aAxisTracker.AreAxesInternallyReversed();
 | ||
| 
 | ||
|   // We have at least one FlexLine. Even an empty flex container has a single
 | ||
|   // (empty) flex line.
 | ||
|   FlexLine* curLine = AddNewFlexLineToList(aLines, shouldInsertAtFront,
 | ||
|                                            aMainGapSize);
 | ||
| 
 | ||
|   nscoord wrapThreshold;
 | ||
|   if (isSingleLine) {
 | ||
|     // Not wrapping. Set threshold to sentinel value that tells us not to wrap.
 | ||
|     wrapThreshold = NS_UNCONSTRAINEDSIZE;
 | ||
|   } else {
 | ||
|     // Wrapping! Set wrap threshold to flex container's content-box main-size.
 | ||
|     wrapThreshold = aContentBoxMainSize;
 | ||
| 
 | ||
|     // If the flex container doesn't have a definite content-box main-size
 | ||
|     // (e.g. if main axis is vertical & 'height' is 'auto'), make sure we at
 | ||
|     // least wrap when we hit its max main-size.
 | ||
|     if (wrapThreshold == NS_UNCONSTRAINEDSIZE) {
 | ||
|       const nscoord flexContainerMaxMainSize =
 | ||
|         GET_MAIN_COMPONENT_LOGICAL(aAxisTracker, aAxisTracker.GetWritingMode(),
 | ||
|                                    aReflowInput.ComputedMaxISize(),
 | ||
|                                    aReflowInput.ComputedMaxBSize());
 | ||
| 
 | ||
|       wrapThreshold = flexContainerMaxMainSize;
 | ||
|     }
 | ||
| 
 | ||
|     // Also: if we're column-oriented and paginating in the block dimension,
 | ||
|     // we may need to wrap to a new flex line sooner (before we grow past the
 | ||
|     // available BSize, potentially running off the end of the page).
 | ||
|     if (aAxisTracker.IsColumnOriented() &&
 | ||
|         aAvailableBSizeForContent != NS_UNCONSTRAINEDSIZE) {
 | ||
|       wrapThreshold = std::min(wrapThreshold, aAvailableBSizeForContent);
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Tracks the index of the next strut, in aStruts (and when this hits
 | ||
|   // aStruts.Length(), that means there are no more struts):
 | ||
|   uint32_t nextStrutIdx = 0;
 | ||
| 
 | ||
|   // Overall index of the current flex item in the flex container. (This gets
 | ||
|   // checked against entries in aStruts.)
 | ||
|   uint32_t itemIdxInContainer = 0;
 | ||
| 
 | ||
|   CSSOrderAwareFrameIterator iter(this, kPrincipalList,
 | ||
|                                   CSSOrderAwareFrameIterator::eIncludeAll,
 | ||
|                                   CSSOrderAwareFrameIterator::eUnknownOrder,
 | ||
|                                   OrderingPropertyForIter(this));
 | ||
| 
 | ||
|   if (iter.ItemsAreAlreadyInOrder()) {
 | ||
|     AddStateBits(NS_STATE_FLEX_NORMAL_FLOW_CHILDREN_IN_CSS_ORDER);
 | ||
|   } else {
 | ||
|     RemoveStateBits(NS_STATE_FLEX_NORMAL_FLOW_CHILDREN_IN_CSS_ORDER);
 | ||
|   }
 | ||
| 
 | ||
|   const bool useMozBoxCollapseBehavior =
 | ||
|     ShouldUseMozBoxCollapseBehavior(aReflowInput.mStyleDisplay);
 | ||
| 
 | ||
|   for (; !iter.AtEnd(); iter.Next()) {
 | ||
|     nsIFrame* childFrame = *iter;
 | ||
|     // Don't create flex items / lines for placeholder frames:
 | ||
|     if (childFrame->IsPlaceholderFrame()) {
 | ||
|       aPlaceholders.AppendElement(childFrame);
 | ||
|       continue;
 | ||
|     }
 | ||
| 
 | ||
|     // Honor "page-break-before", if we're multi-line and this line isn't empty:
 | ||
|     if (!isSingleLine && !curLine->IsEmpty() &&
 | ||
|         childFrame->StyleDisplay()->mBreakBefore) {
 | ||
|       curLine = AddNewFlexLineToList(aLines, shouldInsertAtFront, aMainGapSize);
 | ||
|     }
 | ||
| 
 | ||
|     UniquePtr<FlexItem> item;
 | ||
|     if (useMozBoxCollapseBehavior &&
 | ||
|         (NS_STYLE_VISIBILITY_COLLAPSE ==
 | ||
|          childFrame->StyleVisibility()->mVisible)) {
 | ||
|       // Legacy visibility:collapse behavior: make a 0-sized strut. (No need to
 | ||
|       // bother with aStruts and remembering cross size.)
 | ||
|       item = MakeUnique<FlexItem>(childFrame, 0, aReflowInput.GetWritingMode());
 | ||
|     } else if (nextStrutIdx < aStruts.Length() &&
 | ||
|                aStruts[nextStrutIdx].mItemIdx == itemIdxInContainer) {
 | ||
|       // Use the simplified "strut" FlexItem constructor:
 | ||
|       item = MakeUnique<FlexItem>(childFrame, aStruts[nextStrutIdx].mStrutCrossSize,
 | ||
|                                   aReflowInput.GetWritingMode());
 | ||
|       nextStrutIdx++;
 | ||
|     } else {
 | ||
|       item = GenerateFlexItemForChild(aPresContext, childFrame,
 | ||
|                                       aReflowInput, aAxisTracker);
 | ||
|     }
 | ||
| 
 | ||
|     nscoord itemInnerHypotheticalMainSize = item->GetMainSize();
 | ||
|     nscoord itemOuterHypotheticalMainSize =
 | ||
|       item->GetOuterMainSize(aAxisTracker.GetMainAxis());
 | ||
| 
 | ||
|     // Check if we need to wrap |item| to a new line
 | ||
|     // (i.e. check if its outer hypothetical main size pushes our line over
 | ||
|     // the threshold)
 | ||
|     if (wrapThreshold != NS_UNCONSTRAINEDSIZE && // Don't wrap if unconstrained.
 | ||
|         !curLine->IsEmpty()) { // Don't wrap if this will be line's first item.
 | ||
|       // If the line will be longer than wrapThreshold after adding this item,
 | ||
|       // then wrap to a new line before inserting this item.
 | ||
|       // NOTE: We have to account for the fact that
 | ||
|       // itemOuterHypotheticalMainSize might be huge, if our item is (or
 | ||
|       // contains) a table with "table-layout:fixed". So we use AddChecked()
 | ||
|       // rather than (possibly-overflowing) normal addition, to be sure we don't
 | ||
|       // make the wrong judgement about whether the item fits on this line.
 | ||
|       nscoord newOuterSize =
 | ||
|         AddChecked(curLine->GetTotalOuterHypotheticalMainSize(),
 | ||
|                    itemOuterHypotheticalMainSize);
 | ||
|       // Account for gap between this line's previous item and this item
 | ||
|       newOuterSize = AddChecked(newOuterSize, aMainGapSize);
 | ||
|       if (newOuterSize == nscoord_MAX || newOuterSize > wrapThreshold) {
 | ||
|         curLine = AddNewFlexLineToList(aLines, shouldInsertAtFront,
 | ||
|                                        aMainGapSize);
 | ||
|       }
 | ||
|     }
 | ||
| 
 | ||
|     // Add item to current flex line (and update the line's bookkeeping about
 | ||
|     // how large its items collectively are).
 | ||
|     curLine->AddItem(item.release(),
 | ||
|                      shouldInsertAtFront,
 | ||
|                      itemInnerHypotheticalMainSize,
 | ||
|                      itemOuterHypotheticalMainSize);
 | ||
| 
 | ||
|     // Honor "page-break-after", if we're multi-line and have more children:
 | ||
|     if (!isSingleLine && childFrame->GetNextSibling() &&
 | ||
|         childFrame->StyleDisplay()->mBreakAfter) {
 | ||
|       curLine = AddNewFlexLineToList(aLines, shouldInsertAtFront, aMainGapSize);
 | ||
|     }
 | ||
|     itemIdxInContainer++;
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| // Retrieves the content-box main-size of our flex container from the
 | ||
| // reflow state (specifically, the main-size of *this continuation* of the
 | ||
| // flex container).
 | ||
| nscoord
 | ||
| nsFlexContainerFrame::GetMainSizeFromReflowInput(
 | ||
|   const ReflowInput& aReflowInput,
 | ||
|   const FlexboxAxisTracker& aAxisTracker)
 | ||
| {
 | ||
|   if (aAxisTracker.IsRowOriented()) {
 | ||
|     // Row-oriented --> our main axis is the inline axis, so our main size
 | ||
|     // is our inline size (which should already be resolved).
 | ||
|     NS_WARNING_ASSERTION(
 | ||
|       aReflowInput.ComputedISize() != NS_UNCONSTRAINEDSIZE,
 | ||
|       "Unconstrained inline size; this should only result from huge sizes "
 | ||
|       "(not intrinsic sizing w/ orthogonal flows)");
 | ||
|     return aReflowInput.ComputedISize();
 | ||
|   }
 | ||
| 
 | ||
|   // Note: This may be unconstrained, if our block size is "auto":
 | ||
|   return GetEffectiveComputedBSize(aReflowInput);
 | ||
| }
 | ||
| 
 | ||
| // Returns the largest outer hypothetical main-size of any line in |aLines|.
 | ||
| // (i.e. the hypothetical main-size of the largest line)
 | ||
| static nscoord
 | ||
| GetLargestLineMainSize(const FlexLine* aFirstLine)
 | ||
| {
 | ||
|   nscoord largestLineOuterSize = 0;
 | ||
|   for (const FlexLine* line = aFirstLine; line; line = line->getNext()) {
 | ||
|     largestLineOuterSize = std::max(largestLineOuterSize,
 | ||
|                                     line->GetTotalOuterHypotheticalMainSize());
 | ||
|   }
 | ||
|   return largestLineOuterSize;
 | ||
| }
 | ||
| 
 | ||
| /* Resolves the content-box main-size of a flex container frame,
 | ||
|  * primarily based on:
 | ||
|  * - the "tentative" main size, taken from the reflow state ("tentative"
 | ||
|  *    because it may be unconstrained or may run off the page).
 | ||
|  * - the available BSize (needed if the main axis is the block axis).
 | ||
|  * - the sizes of our lines of flex items.
 | ||
|  *
 | ||
|  * Guaranteed to return a definite length, i.e. not NS_UNCONSTRAINEDSIZE,
 | ||
|  * aside from cases with huge lengths which happen to compute to that value.
 | ||
|  *
 | ||
|  * (Note: This function should be structurally similar to 'ComputeCrossSize()',
 | ||
|  * except that here, the caller has already grabbed the tentative size from the
 | ||
|  * reflow state.)
 | ||
|  */
 | ||
| static nscoord
 | ||
| ResolveFlexContainerMainSize(const ReflowInput& aReflowInput,
 | ||
|                              const FlexboxAxisTracker& aAxisTracker,
 | ||
|                              nscoord aTentativeMainSize,
 | ||
|                              nscoord aAvailableBSizeForContent,
 | ||
|                              const FlexLine* aFirstLine,
 | ||
|                              nsReflowStatus& aStatus)
 | ||
| {
 | ||
|   MOZ_ASSERT(aFirstLine, "null first line pointer");
 | ||
| 
 | ||
|   if (aAxisTracker.IsRowOriented()) {
 | ||
|     // Row-oriented --> our main axis is the inline axis, so our main size
 | ||
|     // is our inline size (which should already be resolved).
 | ||
|     return aTentativeMainSize;
 | ||
|   }
 | ||
| 
 | ||
|   if (aTentativeMainSize != NS_INTRINSICSIZE) {
 | ||
|     // Column-oriented case, with fixed BSize:
 | ||
|     if (aAvailableBSizeForContent == NS_UNCONSTRAINEDSIZE ||
 | ||
|         aTentativeMainSize < aAvailableBSizeForContent) {
 | ||
|       // Not in a fragmenting context, OR no need to fragment because we have
 | ||
|       // more available BSize than we need. Either way, we don't need to clamp.
 | ||
|       // (Note that the reflow state has already done the appropriate
 | ||
|       // min/max-BSize clamping.)
 | ||
|       return aTentativeMainSize;
 | ||
|     }
 | ||
| 
 | ||
|     // Fragmenting *and* our fixed BSize is larger than available BSize:
 | ||
|     // Mark incomplete so we get a next-in-flow, and take up all of the
 | ||
|     // available BSize (or the amount of BSize required by our children, if
 | ||
|     // that's larger; but of course not more than our own computed BSize).
 | ||
|     // XXXdholbert For now, we don't support pushing children to our next
 | ||
|     // continuation or splitting children, so "amount of BSize required by
 | ||
|     // our children" is just the main-size (BSize) of our longest flex line.
 | ||
|     aStatus.SetIncomplete();
 | ||
|     nscoord largestLineOuterSize = GetLargestLineMainSize(aFirstLine);
 | ||
| 
 | ||
|     if (largestLineOuterSize <= aAvailableBSizeForContent) {
 | ||
|       return aAvailableBSizeForContent;
 | ||
|     }
 | ||
|     return std::min(aTentativeMainSize, largestLineOuterSize);
 | ||
|   }
 | ||
| 
 | ||
|   // Column-oriented case, with size-containment:
 | ||
|   // Behave as if we had no content and just use our MinBSize.
 | ||
|   if (aReflowInput.mStyleDisplay->IsContainSize()) {
 | ||
|     return aReflowInput.ComputedMinBSize();
 | ||
|   }
 | ||
| 
 | ||
|   // Column-oriented case, with auto BSize:
 | ||
|   // Resolve auto BSize to the largest FlexLine length, clamped to our
 | ||
|   // computed min/max main-size properties.
 | ||
|   // XXXdholbert Handle constrained-aAvailableBSizeForContent case here.
 | ||
|   nscoord largestLineOuterSize = GetLargestLineMainSize(aFirstLine);
 | ||
|   return NS_CSS_MINMAX(largestLineOuterSize,
 | ||
|                        aReflowInput.ComputedMinBSize(),
 | ||
|                        aReflowInput.ComputedMaxBSize());
 | ||
| }
 | ||
| 
 | ||
| nscoord
 | ||
| nsFlexContainerFrame::ComputeCrossSize(const ReflowInput& aReflowInput,
 | ||
|                                        const FlexboxAxisTracker& aAxisTracker,
 | ||
|                                        nscoord aSumLineCrossSizes,
 | ||
|                                        nscoord aAvailableBSizeForContent,
 | ||
|                                        bool* aIsDefinite,
 | ||
|                                        nsReflowStatus& aStatus)
 | ||
| {
 | ||
|   MOZ_ASSERT(aIsDefinite, "outparam pointer must be non-null");
 | ||
| 
 | ||
|   if (aAxisTracker.IsColumnOriented()) {
 | ||
|     // Column-oriented --> our cross axis is the inline axis, so our cross size
 | ||
|     // is our inline size (which should already be resolved).
 | ||
|     NS_WARNING_ASSERTION(
 | ||
|       aReflowInput.ComputedISize() != NS_UNCONSTRAINEDSIZE,
 | ||
|       "Unconstrained inline size; this should only result from huge sizes "
 | ||
|       "(not intrinsic sizing w/ orthogonal flows)");
 | ||
|     *aIsDefinite = true;
 | ||
|     return aReflowInput.ComputedISize();
 | ||
|   }
 | ||
| 
 | ||
|   nscoord effectiveComputedBSize = GetEffectiveComputedBSize(aReflowInput);
 | ||
|   if (effectiveComputedBSize != NS_INTRINSICSIZE) {
 | ||
|     // Row-oriented case (cross axis is block-axis), with fixed BSize:
 | ||
|     *aIsDefinite = true;
 | ||
|     if (aAvailableBSizeForContent == NS_UNCONSTRAINEDSIZE ||
 | ||
|         effectiveComputedBSize < aAvailableBSizeForContent) {
 | ||
|       // Not in a fragmenting context, OR no need to fragment because we have
 | ||
|       // more available BSize than we need. Either way, just use our fixed
 | ||
|       // BSize.  (Note that the reflow state has already done the appropriate
 | ||
|       // min/max-BSize clamping.)
 | ||
|       return effectiveComputedBSize;
 | ||
|     }
 | ||
| 
 | ||
|     // Fragmenting *and* our fixed BSize is too tall for available BSize:
 | ||
|     // Mark incomplete so we get a next-in-flow, and take up all of the
 | ||
|     // available BSize (or the amount of BSize required by our children, if
 | ||
|     // that's larger; but of course not more than our own computed BSize).
 | ||
|     // XXXdholbert For now, we don't support pushing children to our next
 | ||
|     // continuation or splitting children, so "amount of BSize required by
 | ||
|     // our children" is just the sum of our FlexLines' BSizes (cross sizes).
 | ||
|     aStatus.SetIncomplete();
 | ||
|     if (aSumLineCrossSizes <= aAvailableBSizeForContent) {
 | ||
|       return aAvailableBSizeForContent;
 | ||
|     }
 | ||
|     return std::min(effectiveComputedBSize, aSumLineCrossSizes);
 | ||
|   }
 | ||
| 
 | ||
|   // Row-oriented case, with size-containment:
 | ||
|   // Behave as if we had no content and just use our MinBSize.
 | ||
|   if (aReflowInput.mStyleDisplay->IsContainSize()) {
 | ||
|     return aReflowInput.ComputedMinBSize();
 | ||
|   }
 | ||
| 
 | ||
|   // Row-oriented case (cross axis is block axis), with auto BSize:
 | ||
|   // Shrink-wrap our line(s), subject to our min-size / max-size
 | ||
|   // constraints in that (block) axis.
 | ||
|   // XXXdholbert Handle constrained-aAvailableBSizeForContent case here.
 | ||
|   *aIsDefinite = false;
 | ||
|   return NS_CSS_MINMAX(aSumLineCrossSizes,
 | ||
|                        aReflowInput.ComputedMinBSize(),
 | ||
|                        aReflowInput.ComputedMaxBSize());
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| FlexLine::PositionItemsInMainAxis(uint8_t aJustifyContent,
 | ||
|                                   nscoord aContentBoxMainSize,
 | ||
|                                   const FlexboxAxisTracker& aAxisTracker)
 | ||
| {
 | ||
|   MainAxisPositionTracker mainAxisPosnTracker(aAxisTracker, this,
 | ||
|                                               aJustifyContent,
 | ||
|                                               aContentBoxMainSize);
 | ||
|   for (FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
 | ||
|     nscoord itemMainBorderBoxSize =
 | ||
|       item->GetMainSize() +
 | ||
|       item->GetBorderPaddingSizeInAxis(mainAxisPosnTracker.GetAxis());
 | ||
| 
 | ||
|     // Resolve any main-axis 'auto' margins on aChild to an actual value.
 | ||
|     mainAxisPosnTracker.ResolveAutoMarginsInMainAxis(*item);
 | ||
| 
 | ||
|     // Advance our position tracker to child's upper-left content-box corner,
 | ||
|     // and use that as its position in the main axis.
 | ||
|     mainAxisPosnTracker.EnterMargin(item->GetMargin());
 | ||
|     mainAxisPosnTracker.EnterChildFrame(itemMainBorderBoxSize);
 | ||
| 
 | ||
|     item->SetMainPosition(mainAxisPosnTracker.GetPosition());
 | ||
| 
 | ||
|     mainAxisPosnTracker.ExitChildFrame(itemMainBorderBoxSize);
 | ||
|     mainAxisPosnTracker.ExitMargin(item->GetMargin());
 | ||
|     mainAxisPosnTracker.TraversePackingSpace();
 | ||
|     if (item->getNext()) {
 | ||
|       mainAxisPosnTracker.TraverseGap(mMainGapSize);
 | ||
|     }
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| /**
 | ||
|  * Given the flex container's "flex-relative ascent" (i.e. distance from the
 | ||
|  * flex container's content-box cross-start edge to its baseline), returns
 | ||
|  * its actual physical ascent value (the distance from the *border-box* top
 | ||
|  * edge to its baseline).
 | ||
|  */
 | ||
| static nscoord
 | ||
| ComputePhysicalAscentFromFlexRelativeAscent(
 | ||
|   nscoord aFlexRelativeAscent,
 | ||
|   nscoord aContentBoxCrossSize,
 | ||
|   const ReflowInput& aReflowInput,
 | ||
|   const FlexboxAxisTracker& aAxisTracker)
 | ||
| {
 | ||
|   return aReflowInput.ComputedPhysicalBorderPadding().top +
 | ||
|     PhysicalCoordFromFlexRelativeCoord(aFlexRelativeAscent,
 | ||
|                                        aContentBoxCrossSize,
 | ||
|                                        aAxisTracker.GetCrossAxis());
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| nsFlexContainerFrame::SizeItemInCrossAxis(
 | ||
|   nsPresContext* aPresContext,
 | ||
|   const FlexboxAxisTracker& aAxisTracker,
 | ||
|   ReflowInput& aChildReflowInput,
 | ||
|   FlexItem& aItem)
 | ||
| {
 | ||
|   // If cross axis is the item's inline axis, just use ISize from reflow state,
 | ||
|   // and don't bother with a full reflow.
 | ||
|   if (aItem.IsInlineAxisCrossAxis()) {
 | ||
|     aItem.SetCrossSize(aChildReflowInput.ComputedISize());
 | ||
|     return;
 | ||
|   }
 | ||
| 
 | ||
|   MOZ_ASSERT(!aItem.HadMeasuringReflow(),
 | ||
|              "We shouldn't need more than one measuring reflow");
 | ||
| 
 | ||
|   if (aItem.GetAlignSelf() == NS_STYLE_ALIGN_STRETCH) {
 | ||
|     // This item's got "align-self: stretch", so we probably imposed a
 | ||
|     // stretched computed cross-size on it during its previous
 | ||
|     // reflow. We're not imposing that BSize for *this* "measuring" reflow, so
 | ||
|     // we need to tell it to treat this reflow as a resize in its block axis
 | ||
|     // (regardless of whether any of its ancestors are actually being resized).
 | ||
|     // (Note: we know that the cross axis is the item's *block* axis -- if it
 | ||
|     // weren't, then we would've taken the early-return above.)
 | ||
|     aChildReflowInput.SetBResize(true);
 | ||
|   }
 | ||
| 
 | ||
|   // Potentially reflow the item, and get the sizing info.
 | ||
|   const CachedMeasuringReflowResult& reflowResult =
 | ||
|     MeasureAscentAndBSizeForFlexItem(aItem, aPresContext, aChildReflowInput);
 | ||
| 
 | ||
|   // Save the sizing info that we learned from this reflow
 | ||
|   // -----------------------------------------------------
 | ||
| 
 | ||
|   // Tentatively store the child's desired content-box cross-size.
 | ||
|   // Note that childDesiredSize is the border-box size, so we have to
 | ||
|   // subtract border & padding to get the content-box size.
 | ||
|   // (Note that at this point in the code, we know our cross axis is vertical,
 | ||
|   // so we don't bother with making aAxisTracker pick the cross-axis component
 | ||
|   // for us.)
 | ||
|   nscoord crossAxisBorderPadding = aItem.GetBorderPadding().TopBottom();
 | ||
|   if (reflowResult.BSize() < crossAxisBorderPadding) {
 | ||
|     // Child's requested size isn't large enough for its border/padding!
 | ||
|     // This is OK for the trivial nsFrame::Reflow() impl, but other frame
 | ||
|     // classes should know better. So, if we get here, the child had better be
 | ||
|     // an instance of nsFrame (i.e. it should return null from GetType()).
 | ||
|     // XXXdholbert Once we've fixed bug 765861, we should upgrade this to an
 | ||
|     // assertion that trivially passes if bug 765861's flag has been flipped.
 | ||
|     NS_WARNING_ASSERTION(
 | ||
|       aItem.Frame()->Type() == LayoutFrameType::None,
 | ||
|       "Child should at least request space for border/padding");
 | ||
|     aItem.SetCrossSize(0);
 | ||
|   } else {
 | ||
|     // (normal case)
 | ||
|     aItem.SetCrossSize(reflowResult.BSize() - crossAxisBorderPadding);
 | ||
|   }
 | ||
| 
 | ||
|   aItem.SetAscent(reflowResult.Ascent());
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| FlexLine::PositionItemsInCrossAxis(nscoord aLineStartPosition,
 | ||
|                                    const FlexboxAxisTracker& aAxisTracker)
 | ||
| {
 | ||
|   SingleLineCrossAxisPositionTracker lineCrossAxisPosnTracker(aAxisTracker);
 | ||
| 
 | ||
|   for (FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
 | ||
|     // First, stretch the item's cross size (if appropriate), and resolve any
 | ||
|     // auto margins in this axis.
 | ||
|     item->ResolveStretchedCrossSize(mLineCrossSize, aAxisTracker);
 | ||
|     lineCrossAxisPosnTracker.ResolveAutoMarginsInCrossAxis(*this, *item);
 | ||
| 
 | ||
|     // Compute the cross-axis position of this item
 | ||
|     nscoord itemCrossBorderBoxSize =
 | ||
|       item->GetCrossSize() +
 | ||
|       item->GetBorderPaddingSizeInAxis(aAxisTracker.GetCrossAxis());
 | ||
|     lineCrossAxisPosnTracker.EnterAlignPackingSpace(*this, *item, aAxisTracker);
 | ||
|     lineCrossAxisPosnTracker.EnterMargin(item->GetMargin());
 | ||
|     lineCrossAxisPosnTracker.EnterChildFrame(itemCrossBorderBoxSize);
 | ||
| 
 | ||
|     item->SetCrossPosition(aLineStartPosition +
 | ||
|                            lineCrossAxisPosnTracker.GetPosition());
 | ||
| 
 | ||
|     // Back out to cross-axis edge of the line.
 | ||
|     lineCrossAxisPosnTracker.ResetPosition();
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| nsFlexContainerFrame::Reflow(nsPresContext* aPresContext,
 | ||
|                              ReflowOutput& aDesiredSize,
 | ||
|                              const ReflowInput& aReflowInput,
 | ||
|                              nsReflowStatus& aStatus)
 | ||
| {
 | ||
|   MarkInReflow();
 | ||
|   DO_GLOBAL_REFLOW_COUNT("nsFlexContainerFrame");
 | ||
|   DISPLAY_REFLOW(aPresContext, this, aReflowInput, aDesiredSize, aStatus);
 | ||
|   MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");
 | ||
|   MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
 | ||
|          ("Reflow() for nsFlexContainerFrame %p\n", this));
 | ||
| 
 | ||
|   if (IsFrameTreeTooDeep(aReflowInput, aDesiredSize, aStatus)) {
 | ||
|     return;
 | ||
|   }
 | ||
| 
 | ||
|   // We (and our children) can only depend on our ancestor's bsize if we have
 | ||
|   // a percent-bsize, or if we're positioned and we have "block-start" and "block-end"
 | ||
|   // set and have block-size:auto.  (There are actually other cases, too -- e.g. if
 | ||
|   // our parent is itself a block-dir flex container and we're flexible -- but
 | ||
|   // we'll let our ancestors handle those sorts of cases.)
 | ||
|   WritingMode wm = aReflowInput.GetWritingMode();
 | ||
|   const nsStylePosition* stylePos = StylePosition();
 | ||
|   const nsStyleCoord& bsize = stylePos->BSize(wm);
 | ||
|   if (bsize.HasPercent() ||
 | ||
|       (StyleDisplay()->IsAbsolutelyPositionedStyle() &&
 | ||
|        eStyleUnit_Auto == bsize.GetUnit() &&
 | ||
|        eStyleUnit_Auto != stylePos->mOffset.GetBStartUnit(wm) &&
 | ||
|        eStyleUnit_Auto != stylePos->mOffset.GetBEndUnit(wm))) {
 | ||
|     AddStateBits(NS_FRAME_CONTAINS_RELATIVE_BSIZE);
 | ||
|   }
 | ||
| 
 | ||
|   RenumberList();
 | ||
| 
 | ||
|   const FlexboxAxisTracker axisTracker(this, aReflowInput.GetWritingMode());
 | ||
| 
 | ||
|   // Check to see if we need to create a computed info structure, to
 | ||
|   // be filled out for use by devtools.
 | ||
|   if (HasAnyStateBits(NS_STATE_FLEX_GENERATE_COMPUTED_VALUES)) {
 | ||
|     // This state bit will never be cleared. That's acceptable because
 | ||
|     // it's only set in a Chrome API invoked by devtools, and won't
 | ||
|     // impact normal browsing.
 | ||
| 
 | ||
|     // Re-use the ComputedFlexContainerInfo, if it exists.
 | ||
|     ComputedFlexContainerInfo* info = GetProperty(FlexContainerInfo());
 | ||
|     if (info) {
 | ||
|       // We can reuse, as long as we clear out old data.
 | ||
|       info->mLines.Clear();
 | ||
|     } else {
 | ||
|       info = new ComputedFlexContainerInfo();
 | ||
|       SetProperty(FlexContainerInfo(), info);
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // If we're being fragmented into a constrained BSize, then subtract off
 | ||
|   // borderpadding BStart from that constrained BSize, to get the available
 | ||
|   // BSize for our content box. (No need to subtract the borderpadding BStart
 | ||
|   // if we're already skipping it via GetLogicalSkipSides, though.)
 | ||
|   nscoord availableBSizeForContent = aReflowInput.AvailableBSize();
 | ||
|   if (availableBSizeForContent != NS_UNCONSTRAINEDSIZE &&
 | ||
|       !(GetLogicalSkipSides(&aReflowInput).BStart())) {
 | ||
|     availableBSizeForContent -=
 | ||
|       aReflowInput.ComputedLogicalBorderPadding().BStart(wm);
 | ||
|     // (Don't let that push availableBSizeForContent below zero, though):
 | ||
|     availableBSizeForContent = std::max(availableBSizeForContent, 0);
 | ||
|   }
 | ||
| 
 | ||
|   nscoord contentBoxMainSize = GetMainSizeFromReflowInput(aReflowInput,
 | ||
|                                                           axisTracker);
 | ||
|   // Calculate gap size for main and cross axis
 | ||
|   nscoord mainGapSize;
 | ||
|   nscoord crossGapSize;
 | ||
|   if (axisTracker.IsRowOriented()) {
 | ||
|     mainGapSize = nsLayoutUtils::ResolveGapToLength(stylePos->mColumnGap,
 | ||
|                                                     contentBoxMainSize);
 | ||
|     crossGapSize =
 | ||
|       nsLayoutUtils::ResolveGapToLength(stylePos->mRowGap,
 | ||
|                                         GetEffectiveComputedBSize(aReflowInput));
 | ||
|   } else {
 | ||
|     mainGapSize = nsLayoutUtils::ResolveGapToLength(stylePos->mRowGap,
 | ||
|                                                     contentBoxMainSize);
 | ||
|     NS_WARNING_ASSERTION(aReflowInput.ComputedISize() != NS_UNCONSTRAINEDSIZE,
 | ||
|                          "Unconstrained inline size; this should only result "
 | ||
|                          "from huge sizes (not intrinsic sizing w/ orthogonal "
 | ||
|                          "flows)");
 | ||
|     crossGapSize =
 | ||
|       nsLayoutUtils::ResolveGapToLength(stylePos->mColumnGap,
 | ||
|                                         aReflowInput.ComputedISize());
 | ||
|   }
 | ||
| 
 | ||
|   AutoTArray<StrutInfo, 1> struts;
 | ||
|   DoFlexLayout(aPresContext, aDesiredSize, aReflowInput, aStatus,
 | ||
|                contentBoxMainSize, availableBSizeForContent,
 | ||
|                struts, axisTracker, mainGapSize, crossGapSize);
 | ||
| 
 | ||
|   if (!struts.IsEmpty()) {
 | ||
|     // We're restarting flex layout, with new knowledge of collapsed items.
 | ||
|     aStatus.Reset();
 | ||
|     DoFlexLayout(aPresContext, aDesiredSize, aReflowInput, aStatus,
 | ||
|                  contentBoxMainSize, availableBSizeForContent,
 | ||
|                  struts, axisTracker, mainGapSize, crossGapSize);
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| // RAII class to clean up a list of FlexLines.
 | ||
| // Specifically, this removes each line from the list, deletes all the
 | ||
| // FlexItems in its list, and deletes the FlexLine.
 | ||
| class MOZ_RAII AutoFlexLineListClearer
 | ||
| {
 | ||
| public:
 | ||
|   explicit AutoFlexLineListClearer(LinkedList<FlexLine>& aLines
 | ||
|                                    MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
 | ||
|   : mLines(aLines)
 | ||
|   {
 | ||
|     MOZ_GUARD_OBJECT_NOTIFIER_INIT;
 | ||
|   }
 | ||
| 
 | ||
|   ~AutoFlexLineListClearer()
 | ||
|   {
 | ||
|     while (FlexLine* line = mLines.popFirst()) {
 | ||
|       while (FlexItem* item = line->mItems.popFirst()) {
 | ||
|         delete item;
 | ||
|       }
 | ||
|       delete line;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
| private:
 | ||
|   LinkedList<FlexLine>& mLines;
 | ||
|   MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
 | ||
| };
 | ||
| 
 | ||
| // Class to let us temporarily provide an override value for the the main-size
 | ||
| // CSS property ('width' or 'height') on a flex item, for use in
 | ||
| // nsFrame::ComputeSizeWithIntrinsicDimensions.
 | ||
| // (We could use this overridden size more broadly, too, but it's probably
 | ||
| // better to avoid property-table accesses.  So, where possible, we communicate
 | ||
| // the resolved main-size to the child via modifying its reflow state directly,
 | ||
| // instead of using this class.)
 | ||
| class MOZ_RAII AutoFlexItemMainSizeOverride final
 | ||
| {
 | ||
| public:
 | ||
|   explicit AutoFlexItemMainSizeOverride(FlexItem& aItem
 | ||
|                                         MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
 | ||
|     : mItemFrame(aItem.Frame())
 | ||
|   {
 | ||
|     MOZ_GUARD_OBJECT_NOTIFIER_INIT;
 | ||
| 
 | ||
|     MOZ_ASSERT(!mItemFrame->HasProperty(nsIFrame::FlexItemMainSizeOverride()),
 | ||
|                "FlexItemMainSizeOverride prop shouldn't be set already; "
 | ||
|                "it should only be set temporarily (& not recursively)");
 | ||
|     NS_ASSERTION(aItem.HasIntrinsicRatio(),
 | ||
|                  "This should only be needed for items with an aspect ratio");
 | ||
| 
 | ||
|     mItemFrame->SetProperty(nsIFrame::FlexItemMainSizeOverride(),
 | ||
|                             aItem.GetMainSize());
 | ||
|   }
 | ||
| 
 | ||
|   ~AutoFlexItemMainSizeOverride() {
 | ||
|     mItemFrame->RemoveProperty(nsIFrame::FlexItemMainSizeOverride());
 | ||
|   }
 | ||
| 
 | ||
| private:
 | ||
|   nsIFrame* mItemFrame;
 | ||
|   MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
 | ||
| };
 | ||
| 
 | ||
| void
 | ||
| nsFlexContainerFrame::CalculatePackingSpace(uint32_t aNumThingsToPack,
 | ||
|                                             uint8_t aAlignVal,
 | ||
|                                             nscoord* aFirstSubjectOffset,
 | ||
|                                             uint32_t* aNumPackingSpacesRemaining,
 | ||
|                                             nscoord* aPackingSpaceRemaining)
 | ||
| {
 | ||
|   MOZ_ASSERT(NS_STYLE_ALIGN_SPACE_BETWEEN == NS_STYLE_JUSTIFY_SPACE_BETWEEN &&
 | ||
|              NS_STYLE_ALIGN_SPACE_AROUND == NS_STYLE_JUSTIFY_SPACE_AROUND &&
 | ||
|              NS_STYLE_ALIGN_SPACE_EVENLY == NS_STYLE_JUSTIFY_SPACE_EVENLY,
 | ||
|              "CalculatePackingSpace assumes that NS_STYLE_ALIGN_SPACE and "
 | ||
|              "NS_STYLE_JUSTIFY_SPACE constants are interchangeable");
 | ||
| 
 | ||
|   MOZ_ASSERT(aAlignVal == NS_STYLE_ALIGN_SPACE_BETWEEN ||
 | ||
|              aAlignVal == NS_STYLE_ALIGN_SPACE_AROUND ||
 | ||
|              aAlignVal == NS_STYLE_ALIGN_SPACE_EVENLY,
 | ||
|              "Unexpected alignment value");
 | ||
| 
 | ||
|   MOZ_ASSERT(*aPackingSpaceRemaining >= 0,
 | ||
|              "Should not be called with negative packing space");
 | ||
| 
 | ||
|   // Note: In the aNumThingsToPack==1 case, the fallback behavior for
 | ||
|   // 'space-between' depends on precise information about the axes that we
 | ||
|   // don't have here. So, for that case, we just depend on the caller to
 | ||
|   // explicitly convert 'space-{between,around,evenly}' keywords to the
 | ||
|   // appropriate fallback alignment and skip this function.
 | ||
|   MOZ_ASSERT(aNumThingsToPack > 1,
 | ||
|              "Should not be called unless there's more than 1 thing to pack");
 | ||
| 
 | ||
|   // Packing spaces between items:
 | ||
|   *aNumPackingSpacesRemaining = aNumThingsToPack - 1;
 | ||
| 
 | ||
|   if (aAlignVal == NS_STYLE_ALIGN_SPACE_BETWEEN) {
 | ||
|     // No need to reserve space at beginning/end, so we're done.
 | ||
|     return;
 | ||
|   }
 | ||
| 
 | ||
|   // We need to add 1 or 2 packing spaces, split between beginning/end, for
 | ||
|   // space-around / space-evenly:
 | ||
|   size_t numPackingSpacesForEdges =
 | ||
|     aAlignVal == NS_STYLE_JUSTIFY_SPACE_AROUND ? 1 : 2;
 | ||
| 
 | ||
|   // How big will each "full" packing space be:
 | ||
|   nscoord packingSpaceSize = *aPackingSpaceRemaining /
 | ||
|     (*aNumPackingSpacesRemaining + numPackingSpacesForEdges);
 | ||
|   // How much packing-space are we allocating to the edges:
 | ||
|   nscoord totalEdgePackingSpace = numPackingSpacesForEdges * packingSpaceSize;
 | ||
| 
 | ||
|   // Use half of that edge packing space right now:
 | ||
|   *aFirstSubjectOffset += totalEdgePackingSpace / 2;
 | ||
|   // ...but we need to subtract all of it right away, so that we won't
 | ||
|   // hand out any of it to intermediate packing spaces.
 | ||
|   *aPackingSpaceRemaining -= totalEdgePackingSpace;
 | ||
| }
 | ||
| 
 | ||
| nsFlexContainerFrame*
 | ||
| nsFlexContainerFrame::GetFlexFrameWithComputedInfo(nsIFrame* aFrame)
 | ||
| {
 | ||
|   // Prepare a lambda function that we may need to call multiple times.
 | ||
|   auto GetFlexContainerFrame = [](nsIFrame *aFrame) {
 | ||
|     // Return the aFrame's content insertion frame, iff it is
 | ||
|     // a flex container frame.
 | ||
|     nsFlexContainerFrame* flexFrame = nullptr;
 | ||
| 
 | ||
|     if (aFrame) {
 | ||
|       nsIFrame* contentFrame = aFrame->GetContentInsertionFrame();
 | ||
|       if (contentFrame && (contentFrame->IsFlexContainerFrame())) {
 | ||
|         flexFrame = static_cast<nsFlexContainerFrame*>(contentFrame);
 | ||
|       }
 | ||
|     }
 | ||
|     return flexFrame;
 | ||
|   };
 | ||
| 
 | ||
|   nsFlexContainerFrame* flexFrame = GetFlexContainerFrame(aFrame);
 | ||
|   if (flexFrame) {
 | ||
|     // Generate the FlexContainerInfo data, if it's not already there.
 | ||
|     bool reflowNeeded = !flexFrame->HasProperty(FlexContainerInfo());
 | ||
| 
 | ||
|     if (reflowNeeded) {
 | ||
|       // Trigger a reflow that generates additional flex property data.
 | ||
|       // Hold onto aFrame while we do this, in case reflow destroys it.
 | ||
|       AutoWeakFrame weakFrameRef(aFrame);
 | ||
| 
 | ||
|       nsIPresShell* shell = flexFrame->PresContext()->PresShell();
 | ||
|       flexFrame->AddStateBits(NS_STATE_FLEX_GENERATE_COMPUTED_VALUES);
 | ||
|       shell->FrameNeedsReflow(flexFrame,
 | ||
|                               nsIPresShell::eResize,
 | ||
|                               NS_FRAME_IS_DIRTY);
 | ||
|       shell->FlushPendingNotifications(FlushType::Layout);
 | ||
| 
 | ||
|       // Since the reflow may have side effects, get the flex frame
 | ||
|       // again. But if the weakFrameRef is no longer valid, then we
 | ||
|       // must bail out.
 | ||
|       if (!weakFrameRef.IsAlive()) {
 | ||
|         return nullptr;
 | ||
|       }
 | ||
| 
 | ||
|       flexFrame = GetFlexContainerFrame(weakFrameRef.GetFrame());
 | ||
| 
 | ||
|       MOZ_ASSERT(!flexFrame ||
 | ||
|                   flexFrame->HasProperty(FlexContainerInfo()),
 | ||
|                   "The state bit should've made our forced-reflow "
 | ||
|                   "generate a FlexContainerInfo object");
 | ||
|     }
 | ||
|   }
 | ||
|   return flexFrame;
 | ||
| }
 | ||
| 
 | ||
| /* static */
 | ||
| bool
 | ||
| nsFlexContainerFrame::IsItemInlineAxisMainAxis(nsIFrame* aFrame)
 | ||
| {
 | ||
|   MOZ_ASSERT(aFrame && aFrame->IsFlexItem(), "expecting arg to be a flex item");
 | ||
|   const WritingMode flexItemWM = aFrame->GetWritingMode();
 | ||
|   const nsIFrame* flexContainer = aFrame->GetParent();
 | ||
| 
 | ||
|   if (IsLegacyBox(flexContainer)) {
 | ||
|     // For legacy boxes, the main axis is determined by "box-orient", and we can
 | ||
|     // just directly check if that's vertical, and compare that to whether the
 | ||
|     // item's WM is also vertical:
 | ||
|     bool boxOrientIsVertical =
 | ||
|       (flexContainer->StyleXUL()->mBoxOrient == StyleBoxOrient::Vertical);
 | ||
|     return flexItemWM.IsVertical() == boxOrientIsVertical;
 | ||
|   }
 | ||
| 
 | ||
|   // For modern CSS flexbox, we get our return value by asking two questions
 | ||
|   // and comparing their answers.
 | ||
|   // Question 1: does aFrame have the same inline axis as its flex container?
 | ||
|   bool itemInlineAxisIsParallelToParent =
 | ||
|     !flexItemWM.IsOrthogonalTo(flexContainer->GetWritingMode());
 | ||
| 
 | ||
|   // Question 2: is aFrame's flex container row-oriented? (This tells us
 | ||
|   // whether the flex container's main axis is its inline axis.)
 | ||
|   auto flexDirection = flexContainer->StylePosition()->mFlexDirection;
 | ||
|   bool flexContainerIsRowOriented =
 | ||
|     flexDirection == NS_STYLE_FLEX_DIRECTION_ROW ||
 | ||
|     flexDirection == NS_STYLE_FLEX_DIRECTION_ROW_REVERSE;
 | ||
| 
 | ||
|   // aFrame's inline axis is its flex container's main axis IFF the above
 | ||
|   // questions have the same answer.
 | ||
|   return flexContainerIsRowOriented == itemInlineAxisIsParallelToParent;
 | ||
| }
 | ||
| 
 | ||
| /* static */
 | ||
| bool
 | ||
| nsFlexContainerFrame::IsUsedFlexBasisContent(const nsStyleCoord* aFlexBasis,
 | ||
|                                              const nsStyleCoord* aMainSize)
 | ||
| {
 | ||
|   // We have a used flex-basis of 'content' if flex-basis explicitly has that
 | ||
|   // value, OR if flex-basis is 'auto' (deferring to the main-size property)
 | ||
|   // and the main-size property is also 'auto'.
 | ||
|   // See https://drafts.csswg.org/css-flexbox-1/#valdef-flex-basis-auto
 | ||
|   return
 | ||
|     (aFlexBasis->GetUnit() == eStyleUnit_Enumerated &&
 | ||
|      aFlexBasis->GetIntValue() == NS_STYLE_FLEX_BASIS_CONTENT) ||
 | ||
|     (aFlexBasis->GetUnit() == eStyleUnit_Auto &&
 | ||
|      aMainSize->GetUnit() == eStyleUnit_Auto);
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| nsFlexContainerFrame::DoFlexLayout(nsPresContext*           aPresContext,
 | ||
|                                    ReflowOutput&     aDesiredSize,
 | ||
|                                    const ReflowInput& aReflowInput,
 | ||
|                                    nsReflowStatus&          aStatus,
 | ||
|                                    nscoord aContentBoxMainSize,
 | ||
|                                    nscoord aAvailableBSizeForContent,
 | ||
|                                    nsTArray<StrutInfo>& aStruts,
 | ||
|                                    const FlexboxAxisTracker& aAxisTracker,
 | ||
|                                    nscoord aMainGapSize,
 | ||
|                                    nscoord aCrossGapSize)
 | ||
| {
 | ||
|   MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");
 | ||
| 
 | ||
|   LinkedList<FlexLine> lines;
 | ||
|   nsTArray<nsIFrame*> placeholderKids;
 | ||
|   AutoFlexLineListClearer cleanupLines(lines);
 | ||
| 
 | ||
|   GenerateFlexLines(aPresContext, aReflowInput,
 | ||
|                     aContentBoxMainSize,
 | ||
|                     aAvailableBSizeForContent,
 | ||
|                     aStruts, aAxisTracker,
 | ||
|                     aMainGapSize,
 | ||
|                     placeholderKids, lines);
 | ||
| 
 | ||
|   if ((lines.getFirst()->IsEmpty() && !lines.getFirst()->getNext()) ||
 | ||
|       aReflowInput.mStyleDisplay->IsContainSize()) {
 | ||
|     // If have no flex items, or if we  are size contained and
 | ||
|     // want to behave as if we have none, our parent
 | ||
|     // should synthesize a baseline if needed.
 | ||
|     AddStateBits(NS_STATE_FLEX_SYNTHESIZE_BASELINE);
 | ||
|   } else {
 | ||
|     RemoveStateBits(NS_STATE_FLEX_SYNTHESIZE_BASELINE);
 | ||
|   }
 | ||
| 
 | ||
|   // Construct our computed info if we've been asked to do so. This is
 | ||
|   // necessary to do now so we can capture some computed values for
 | ||
|   // FlexItems during layout that would not otherwise be saved (like
 | ||
|   // size adjustments). We'll later fix up the line properties,
 | ||
|   // because the correct values aren't available yet.
 | ||
|   ComputedFlexContainerInfo* containerInfo = nullptr;
 | ||
|   if (HasAnyStateBits(NS_STATE_FLEX_GENERATE_COMPUTED_VALUES)) {
 | ||
|     containerInfo = GetProperty(FlexContainerInfo());
 | ||
|     MOZ_ASSERT(containerInfo,
 | ||
|                "::Reflow() should have created container info.");
 | ||
| 
 | ||
|     if (!aStruts.IsEmpty()) {
 | ||
|       // We restarted DoFlexLayout, and may have stale mLines to clear:
 | ||
|       containerInfo->mLines.Clear();
 | ||
|     } else {
 | ||
|       MOZ_ASSERT(containerInfo->mLines.IsEmpty(),
 | ||
|                  "Shouldn't have lines yet.");
 | ||
|     }
 | ||
| 
 | ||
|     for (const FlexLine* line = lines.getFirst(); line;
 | ||
|          line = line->getNext()) {
 | ||
|       ComputedFlexLineInfo* lineInfo =
 | ||
|         containerInfo->mLines.AppendElement();
 | ||
|       // Most lineInfo properties will be set later, but we set
 | ||
|       // mGrowthState to UNCHANGED here because it may be later
 | ||
|       // modified by ResolveFlexibleLengths().
 | ||
|       lineInfo->mGrowthState =
 | ||
|         ComputedFlexLineInfo::GrowthState::UNCHANGED;
 | ||
| 
 | ||
|       // The remaining lineInfo properties will be filled out at the
 | ||
|       // end of this function, when we have real values. But we still
 | ||
|       // add all the items here, so we can capture computed data for
 | ||
|       // each item.
 | ||
|       for (const FlexItem* item = line->GetFirstItem(); item;
 | ||
|            item = item->getNext()) {
 | ||
|         nsIFrame* frame = item->Frame();
 | ||
| 
 | ||
|         // The frame may be for an element, or it may be for an
 | ||
|         // anonymous flex item, e.g. wrapping one or more text nodes.
 | ||
|         // DevTools wants the content node for the actual child in
 | ||
|         // the DOM tree, so we descend through anonymous boxes.
 | ||
|         nsIFrame* targetFrame = GetFirstNonAnonBoxDescendant(frame);
 | ||
|         nsIContent* content = targetFrame->GetContent();
 | ||
| 
 | ||
|         // Skip over content that is only whitespace, which might
 | ||
|         // have been broken off from a text node which is our real
 | ||
|         // target.
 | ||
|         while (content && content->TextIsOnlyWhitespace()) {
 | ||
|           // If content is only whitespace, try the frame sibling.
 | ||
|           targetFrame = targetFrame->GetNextSibling();
 | ||
|           if (targetFrame) {
 | ||
|             content = targetFrame->GetContent();
 | ||
|           } else {
 | ||
|             content = nullptr;
 | ||
|           }
 | ||
|         }
 | ||
| 
 | ||
|         ComputedFlexItemInfo* itemInfo =
 | ||
|           lineInfo->mItems.AppendElement();
 | ||
| 
 | ||
|         itemInfo->mNode = content;
 | ||
| 
 | ||
|         // mMainBaseSize and itemInfo->mMainDeltaSize will
 | ||
|         // be filled out in ResolveFlexibleLengths().
 | ||
| 
 | ||
|         // Other FlexItem properties can be captured now.
 | ||
|         itemInfo->mMainMinSize = item->GetMainMinSize();
 | ||
|         itemInfo->mMainMaxSize = item->GetMainMaxSize();
 | ||
|         itemInfo->mCrossMinSize = item->GetCrossMinSize();
 | ||
|         itemInfo->mCrossMaxSize = item->GetCrossMaxSize();
 | ||
|       }
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   aContentBoxMainSize =
 | ||
|     ResolveFlexContainerMainSize(aReflowInput, aAxisTracker,
 | ||
|                                  aContentBoxMainSize, aAvailableBSizeForContent,
 | ||
|                                  lines.getFirst(), aStatus);
 | ||
| 
 | ||
|   uint32_t lineIndex = 0;
 | ||
|   for (FlexLine* line = lines.getFirst(); line; line = line->getNext(),
 | ||
|                                                 ++lineIndex) {
 | ||
|     ComputedFlexLineInfo* lineInfo = containerInfo ?
 | ||
|                                      &containerInfo->mLines[lineIndex] :
 | ||
|                                      nullptr;
 | ||
|     line->ResolveFlexibleLengths(aContentBoxMainSize, lineInfo);
 | ||
|   }
 | ||
| 
 | ||
|   // Cross Size Determination - Flexbox spec section 9.4
 | ||
|   // ===================================================
 | ||
|   // Calculate the hypothetical cross size of each item:
 | ||
|   nscoord sumLineCrossSizes = 0;
 | ||
|   for (FlexLine* line = lines.getFirst(); line; line = line->getNext()) {
 | ||
|     for (FlexItem* item = line->GetFirstItem(); item; item = item->getNext()) {
 | ||
|       // The item may already have the correct cross-size; only recalculate
 | ||
|       // if the item's main size resolution (flexing) could have influenced it:
 | ||
|       if (item->CanMainSizeInfluenceCrossSize(aAxisTracker)) {
 | ||
|         Maybe<AutoFlexItemMainSizeOverride> sizeOverride;
 | ||
|         if (item->HasIntrinsicRatio()) {
 | ||
|           // For flex items with an aspect ratio, we have to impose an override
 | ||
|           // for the main-size property *before* we even instantiate the reflow
 | ||
|           // state, in order for aspect ratio calculations to produce the right
 | ||
|           // cross size in the reflow state. (For other flex items, it's OK
 | ||
|           // (and cheaper) to impose our main size *after* the reflow state has
 | ||
|           // been constructed, since the main size shouldn't influence anything
 | ||
|           // about cross-size measurement until we actually reflow the child.)
 | ||
|           sizeOverride.emplace(*item);
 | ||
|         }
 | ||
| 
 | ||
|         WritingMode wm = item->Frame()->GetWritingMode();
 | ||
|         LogicalSize availSize = aReflowInput.ComputedSize(wm);
 | ||
|         availSize.BSize(wm) = NS_UNCONSTRAINEDSIZE;
 | ||
|         ReflowInput childReflowInput(aPresContext, aReflowInput,
 | ||
|                                      item->Frame(), availSize);
 | ||
|         if (!sizeOverride) {
 | ||
|           // Directly override the computed main-size, by tweaking reflow state:
 | ||
|           if (item->IsInlineAxisMainAxis()) {
 | ||
|             childReflowInput.SetComputedISize(item->GetMainSize());
 | ||
|           } else {
 | ||
|             childReflowInput.SetComputedBSize(item->GetMainSize());
 | ||
|           }
 | ||
|         }
 | ||
| 
 | ||
|         SizeItemInCrossAxis(aPresContext, aAxisTracker,
 | ||
|                             childReflowInput, *item);
 | ||
|       }
 | ||
|     }
 | ||
|     // Now that we've finished with this line's items, size the line itself:
 | ||
|     line->ComputeCrossSizeAndBaseline(aAxisTracker);
 | ||
|     sumLineCrossSizes += line->GetLineCrossSize();
 | ||
|   }
 | ||
| 
 | ||
|   bool isCrossSizeDefinite;
 | ||
|   const nscoord contentBoxCrossSize =
 | ||
|     ComputeCrossSize(aReflowInput, aAxisTracker, sumLineCrossSizes,
 | ||
|                      aAvailableBSizeForContent, &isCrossSizeDefinite, aStatus);
 | ||
| 
 | ||
|   // Set up state for cross-axis alignment, at a high level (outside the
 | ||
|   // scope of a particular flex line)
 | ||
|   CrossAxisPositionTracker
 | ||
|     crossAxisPosnTracker(lines.getFirst(),
 | ||
|                          aReflowInput, contentBoxCrossSize,
 | ||
|                          isCrossSizeDefinite, aAxisTracker,
 | ||
|                          aCrossGapSize);
 | ||
| 
 | ||
|   // Now that we know the cross size of each line (including
 | ||
|   // "align-content:stretch" adjustments, from the CrossAxisPositionTracker
 | ||
|   // constructor), we can create struts for any flex items with
 | ||
|   // "visibility: collapse" (and restart flex layout).
 | ||
|   if (aStruts.IsEmpty() && // (Don't make struts if we already did)
 | ||
|       !ShouldUseMozBoxCollapseBehavior(aReflowInput.mStyleDisplay)) {
 | ||
|     BuildStrutInfoFromCollapsedItems(lines.getFirst(), aStruts);
 | ||
|     if (!aStruts.IsEmpty()) {
 | ||
|       // Restart flex layout, using our struts.
 | ||
|       return;
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // If the container should derive its baseline from the first FlexLine,
 | ||
|   // do that here (while crossAxisPosnTracker is conveniently pointing
 | ||
|   // at the cross-start edge of that line, which the line's baseline offset is
 | ||
|   // measured from):
 | ||
|   nscoord flexContainerAscent;
 | ||
|   if (!aAxisTracker.AreAxesInternallyReversed()) {
 | ||
|     nscoord firstLineBaselineOffset = lines.getFirst()->GetFirstBaselineOffset();
 | ||
|     if (firstLineBaselineOffset == nscoord_MIN) {
 | ||
|       // No baseline-aligned items in line. Use sentinel value to prompt us to
 | ||
|       // get baseline from the first FlexItem after we've reflowed it.
 | ||
|       flexContainerAscent = nscoord_MIN;
 | ||
|     } else  {
 | ||
|       flexContainerAscent =
 | ||
|         ComputePhysicalAscentFromFlexRelativeAscent(
 | ||
|           crossAxisPosnTracker.GetPosition() + firstLineBaselineOffset,
 | ||
|           contentBoxCrossSize, aReflowInput, aAxisTracker);
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   const auto justifyContent = IsLegacyBox(aReflowInput.mFrame) ?
 | ||
|     ConvertLegacyStyleToJustifyContent(StyleXUL()) :
 | ||
|     aReflowInput.mStylePosition->mJustifyContent;
 | ||
| 
 | ||
| 
 | ||
|   lineIndex = 0;
 | ||
|   for (FlexLine* line = lines.getFirst(); line; line = line->getNext(),
 | ||
|                                                 ++lineIndex) {
 | ||
|     // Main-Axis Alignment - Flexbox spec section 9.5
 | ||
|     // ==============================================
 | ||
|     line->PositionItemsInMainAxis(justifyContent,
 | ||
|                                   aContentBoxMainSize,
 | ||
|                                   aAxisTracker);
 | ||
| 
 | ||
|     // See if we need to extract some computed info for this line.
 | ||
|     if (MOZ_UNLIKELY(containerInfo)) {
 | ||
|       ComputedFlexLineInfo& lineInfo = containerInfo->mLines[lineIndex];
 | ||
|       lineInfo.mCrossStart = crossAxisPosnTracker.GetPosition();
 | ||
|     }
 | ||
| 
 | ||
|     // Cross-Axis Alignment - Flexbox spec section 9.6
 | ||
|     // ===============================================
 | ||
|     line->PositionItemsInCrossAxis(crossAxisPosnTracker.GetPosition(),
 | ||
|                                    aAxisTracker);
 | ||
|     crossAxisPosnTracker.TraverseLine(*line);
 | ||
|     crossAxisPosnTracker.TraversePackingSpace();
 | ||
| 
 | ||
|     if (line->getNext()) {
 | ||
|       crossAxisPosnTracker.TraverseGap();
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // If the container should derive its baseline from the last FlexLine,
 | ||
|   // do that here (while crossAxisPosnTracker is conveniently pointing
 | ||
|   // at the cross-end edge of that line, which the line's baseline offset is
 | ||
|   // measured from):
 | ||
|   if (aAxisTracker.AreAxesInternallyReversed()) {
 | ||
|     nscoord lastLineBaselineOffset = lines.getLast()->GetFirstBaselineOffset();
 | ||
|     if (lastLineBaselineOffset == nscoord_MIN) {
 | ||
|       // No baseline-aligned items in line. Use sentinel value to prompt us to
 | ||
|       // get baseline from the last FlexItem after we've reflowed it.
 | ||
|       flexContainerAscent = nscoord_MIN;
 | ||
|     } else {
 | ||
|       flexContainerAscent =
 | ||
|         ComputePhysicalAscentFromFlexRelativeAscent(
 | ||
|           crossAxisPosnTracker.GetPosition() - lastLineBaselineOffset,
 | ||
|           contentBoxCrossSize, aReflowInput, aAxisTracker);
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Before giving each child a final reflow, calculate the origin of the
 | ||
|   // flex container's content box (with respect to its border-box), so that
 | ||
|   // we can compute our flex item's final positions.
 | ||
|   WritingMode flexWM = aReflowInput.GetWritingMode();
 | ||
|   LogicalMargin containerBP = aReflowInput.ComputedLogicalBorderPadding();
 | ||
| 
 | ||
|   // Unconditionally skip block-end border & padding for now, regardless of
 | ||
|   // writing-mode/GetLogicalSkipSides.  We add it lower down, after we've
 | ||
|   // established baseline and decided whether bottom border-padding fits (if
 | ||
|   // we're fragmented).
 | ||
|   const nscoord blockEndContainerBP = containerBP.BEnd(flexWM);
 | ||
|   const LogicalSides skipSides =
 | ||
|     GetLogicalSkipSides(&aReflowInput) | LogicalSides(eLogicalSideBitsBEnd);
 | ||
|   containerBP.ApplySkipSides(skipSides);
 | ||
| 
 | ||
|   const LogicalPoint containerContentBoxOrigin(flexWM,
 | ||
|                                                containerBP.IStart(flexWM),
 | ||
|                                                containerBP.BStart(flexWM));
 | ||
| 
 | ||
|   // Determine flex container's border-box size (used in positioning children):
 | ||
|   LogicalSize logSize =
 | ||
|     aAxisTracker.LogicalSizeFromFlexRelativeSizes(aContentBoxMainSize,
 | ||
|                                                   contentBoxCrossSize);
 | ||
|   logSize += aReflowInput.ComputedLogicalBorderPadding().Size(flexWM);
 | ||
|   nsSize containerSize = logSize.GetPhysicalSize(flexWM);
 | ||
| 
 | ||
|   // If the flex container has no baseline-aligned items, it will use this item
 | ||
|   // (the first item, discounting any under-the-hood reversing that we've done)
 | ||
|   // to determine its baseline:
 | ||
|   const FlexItem* const firstItem =
 | ||
|     aAxisTracker.AreAxesInternallyReversed()
 | ||
|     ? lines.getLast()->GetLastItem()
 | ||
|     : lines.getFirst()->GetFirstItem();
 | ||
| 
 | ||
|   // FINAL REFLOW: Give each child frame another chance to reflow, now that
 | ||
|   // we know its final size and position.
 | ||
|   for (const FlexLine* line = lines.getFirst(); line; line = line->getNext()) {
 | ||
|     for (const FlexItem* item = line->GetFirstItem(); item;
 | ||
|          item = item->getNext()) {
 | ||
|       LogicalPoint framePos = aAxisTracker.LogicalPointFromFlexRelativePoint(
 | ||
|                                item->GetMainPosition(),
 | ||
|                                item->GetCrossPosition(),
 | ||
|                                aContentBoxMainSize,
 | ||
|                                contentBoxCrossSize);
 | ||
|       // Adjust framePos to be relative to the container's border-box
 | ||
|       // (i.e. its frame rect), instead of the container's content-box:
 | ||
|       framePos += containerContentBoxOrigin;
 | ||
| 
 | ||
|       // (Intentionally snapshotting this before ApplyRelativePositioning, to
 | ||
|       // maybe use for setting the flex container's baseline.)
 | ||
|       const nscoord itemNormalBPos = framePos.B(flexWM);
 | ||
| 
 | ||
|       // Check if we actually need to reflow the item -- if we already reflowed
 | ||
|       // it with the right size, we can just reposition it as-needed.
 | ||
|       bool itemNeedsReflow = true; // (Start out assuming the worst.)
 | ||
|       if (item->HadMeasuringReflow()) {
 | ||
|         LogicalSize finalFlexItemCBSize =
 | ||
|           aAxisTracker.LogicalSizeFromFlexRelativeSizes(item->GetMainSize(),
 | ||
|                                                         item->GetCrossSize());
 | ||
|         // We've already reflowed the child once. Was the size we gave it in
 | ||
|         // that reflow the same as its final (post-flexing/stretching) size?
 | ||
|         if (finalFlexItemCBSize ==
 | ||
|             LogicalSize(flexWM,
 | ||
|                         item->Frame()->GetContentRectRelativeToSelf().Size())) {
 | ||
|           // Even if our size hasn't changed, some of our descendants might
 | ||
|           // care that our bsize is now considered "definite" (whereas it
 | ||
|           // wasn't in our previous "measuring" reflow), if they have a
 | ||
|           // relative bsize.
 | ||
|           if (!(item->Frame()->GetStateBits() &
 | ||
|                 NS_FRAME_CONTAINS_RELATIVE_BSIZE)) {
 | ||
|             // Item has the correct size (and its children don't care that
 | ||
|             // it's now "definite"). Let's just make sure it's at the right
 | ||
|             // position.
 | ||
|             itemNeedsReflow = false;
 | ||
|             MoveFlexItemToFinalPosition(aReflowInput, *item, framePos,
 | ||
|                                         containerSize);
 | ||
|           }
 | ||
|         }
 | ||
|       }
 | ||
|       if (itemNeedsReflow) {
 | ||
|         ReflowFlexItem(aPresContext, aAxisTracker, aReflowInput,
 | ||
|                        *item, framePos, containerSize);
 | ||
|       }
 | ||
| 
 | ||
|       // If the item has auto margins, and we were tracking the UsedMargin
 | ||
|       // property, set the property to the computed margin values.
 | ||
|       if (item->HasAnyAutoMargin()) {
 | ||
|         nsMargin* propValue =
 | ||
|           item->Frame()->GetProperty(nsIFrame::UsedMarginProperty());
 | ||
|         if (propValue) {
 | ||
|           *propValue = item->GetMargin();
 | ||
|         }
 | ||
|       }
 | ||
| 
 | ||
|       // If this is our first item and we haven't established a baseline for
 | ||
|       // the container yet (i.e. if we don't have 'align-self: baseline' on any
 | ||
|       // children), then use this child's first baseline as the container's
 | ||
|       // baseline.
 | ||
|       if (item == firstItem &&
 | ||
|           flexContainerAscent == nscoord_MIN) {
 | ||
|         flexContainerAscent = itemNormalBPos + item->ResolvedAscent(true);
 | ||
|       }
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   if (!placeholderKids.IsEmpty()) {
 | ||
|     ReflowPlaceholders(aPresContext, aReflowInput,
 | ||
|                        placeholderKids, containerContentBoxOrigin,
 | ||
|                        containerSize);
 | ||
|   }
 | ||
| 
 | ||
|   // Compute flex container's desired size (in its own writing-mode),
 | ||
|   // starting w/ content-box size & growing from there:
 | ||
|   LogicalSize desiredSizeInFlexWM =
 | ||
|     aAxisTracker.LogicalSizeFromFlexRelativeSizes(aContentBoxMainSize,
 | ||
|                                                   contentBoxCrossSize);
 | ||
|   // Add border/padding (w/ skipSides already applied):
 | ||
|   desiredSizeInFlexWM.ISize(flexWM) += containerBP.IStartEnd(flexWM);
 | ||
|   desiredSizeInFlexWM.BSize(flexWM) += containerBP.BStartEnd(flexWM);
 | ||
| 
 | ||
|   if (flexContainerAscent == nscoord_MIN) {
 | ||
|     // Still don't have our baseline set -- this happens if we have no
 | ||
|     // children (or if our children are huge enough that they have nscoord_MIN
 | ||
|     // as their baseline... in which case, we'll use the wrong baseline, but no
 | ||
|     // big deal)
 | ||
|     NS_WARNING_ASSERTION(
 | ||
|       lines.getFirst()->IsEmpty(),
 | ||
|       "Have flex items but didn't get an ascent - that's odd (or there are "
 | ||
|       "just gigantic sizes involved)");
 | ||
|     // Per spec, synthesize baseline from the flex container's content box
 | ||
|     // (i.e. use block-end side of content-box)
 | ||
|     // XXXdholbert This only makes sense if parent's writing mode is
 | ||
|     // horizontal (& even then, really we should be using the BSize in terms
 | ||
|     // of the parent's writing mode, not ours). Clean up in bug 1155322.
 | ||
|     flexContainerAscent = desiredSizeInFlexWM.BSize(flexWM);
 | ||
|   }
 | ||
| 
 | ||
|   if (HasAnyStateBits(NS_STATE_FLEX_SYNTHESIZE_BASELINE)) {
 | ||
|     // This will force our parent to call GetLogicalBaseline, which will
 | ||
|     // synthesize a margin-box baseline.
 | ||
|     aDesiredSize.SetBlockStartAscent(ReflowOutput::ASK_FOR_BASELINE);
 | ||
|   } else {
 | ||
|     // XXXdholbert flexContainerAscent needs to be in terms of
 | ||
|     // our parent's writing-mode here. See bug 1155322.
 | ||
|     aDesiredSize.SetBlockStartAscent(flexContainerAscent);
 | ||
|   }
 | ||
| 
 | ||
|   // Now: If we're complete, add bottom border/padding to desired height (which
 | ||
|   // we skipped via skipSides) -- unless that pushes us over available height,
 | ||
|   // in which case we become incomplete (unless we already weren't asking for
 | ||
|   // any height, in which case we stay complete to avoid looping forever).
 | ||
|   // NOTE: If we're auto-height, we allow our bottom border/padding to push us
 | ||
|   // over the available height without requesting a continuation, for
 | ||
|   // consistency with the behavior of "display:block" elements.
 | ||
|   if (aStatus.IsComplete()) {
 | ||
|     nscoord desiredBSizeWithBEndBP =
 | ||
|       desiredSizeInFlexWM.BSize(flexWM) + blockEndContainerBP;
 | ||
| 
 | ||
|     if (aReflowInput.AvailableBSize() == NS_UNCONSTRAINEDSIZE ||
 | ||
|         desiredSizeInFlexWM.BSize(flexWM) == 0 ||
 | ||
|         desiredBSizeWithBEndBP <= aReflowInput.AvailableBSize() ||
 | ||
|         aReflowInput.ComputedBSize() == NS_INTRINSICSIZE) {
 | ||
|       // Update desired height to include block-end border/padding
 | ||
|       desiredSizeInFlexWM.BSize(flexWM) = desiredBSizeWithBEndBP;
 | ||
|     } else {
 | ||
|       // We couldn't fit bottom border/padding, so we'll need a continuation.
 | ||
|       aStatus.SetIncomplete();
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   // Calculate the container baselines so that our parent can baseline-align us.
 | ||
|   mBaselineFromLastReflow = flexContainerAscent;
 | ||
|   mLastBaselineFromLastReflow = lines.getLast()->GetLastBaselineOffset();
 | ||
|   if (mLastBaselineFromLastReflow == nscoord_MIN) {
 | ||
|     // XXX we fall back to a mirrored first baseline here for now, but this
 | ||
|     // should probably use the last baseline of the last item or something.
 | ||
|     mLastBaselineFromLastReflow =
 | ||
|       desiredSizeInFlexWM.BSize(flexWM) - flexContainerAscent;
 | ||
|   }
 | ||
| 
 | ||
|   // Convert flex container's final desired size to parent's WM, for outparam.
 | ||
|   aDesiredSize.SetSize(flexWM, desiredSizeInFlexWM);
 | ||
| 
 | ||
|   // Overflow area = union(my overflow area, kids' overflow areas)
 | ||
|   aDesiredSize.SetOverflowAreasToDesiredBounds();
 | ||
|   for (nsIFrame* childFrame : mFrames) {
 | ||
|     ConsiderChildOverflow(aDesiredSize.mOverflowAreas, childFrame);
 | ||
|   }
 | ||
| 
 | ||
|   FinishReflowWithAbsoluteFrames(aPresContext, aDesiredSize,
 | ||
|                                  aReflowInput, aStatus);
 | ||
| 
 | ||
|   NS_FRAME_SET_TRUNCATION(aStatus, aReflowInput, aDesiredSize)
 | ||
| 
 | ||
|   // Finally update our line sizing values in our containerInfo.
 | ||
|   if (MOZ_UNLIKELY(containerInfo)) {
 | ||
|     lineIndex = 0;
 | ||
|     for (const FlexLine* line = lines.getFirst(); line;
 | ||
|          line = line->getNext(), ++lineIndex) {
 | ||
|       ComputedFlexLineInfo& lineInfo = containerInfo->mLines[lineIndex];
 | ||
| 
 | ||
|       lineInfo.mCrossSize = line->GetLineCrossSize();
 | ||
|       lineInfo.mFirstBaselineOffset = line->GetFirstBaselineOffset();
 | ||
|       lineInfo.mLastBaselineOffset = line->GetLastBaselineOffset();
 | ||
|     }
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| nsFlexContainerFrame::MoveFlexItemToFinalPosition(
 | ||
|   const ReflowInput& aReflowInput,
 | ||
|   const FlexItem& aItem,
 | ||
|   LogicalPoint& aFramePos,
 | ||
|   const nsSize& aContainerSize)
 | ||
| {
 | ||
|   WritingMode outerWM = aReflowInput.GetWritingMode();
 | ||
| 
 | ||
|   // If item is relpos, look up its offsets (cached from prev reflow)
 | ||
|   LogicalMargin logicalOffsets(outerWM);
 | ||
|   if (NS_STYLE_POSITION_RELATIVE == aItem.Frame()->StyleDisplay()->mPosition) {
 | ||
|     nsMargin* cachedOffsets = aItem.Frame()->GetProperty(nsIFrame::ComputedOffsetProperty());
 | ||
|     MOZ_ASSERT(cachedOffsets,
 | ||
|                "relpos previously-reflowed frame should've cached its offsets");
 | ||
|     logicalOffsets = LogicalMargin(outerWM, *cachedOffsets);
 | ||
|   }
 | ||
|   ReflowInput::ApplyRelativePositioning(aItem.Frame(), outerWM,
 | ||
|                                               logicalOffsets, &aFramePos,
 | ||
|                                               aContainerSize);
 | ||
|   aItem.Frame()->SetPosition(outerWM, aFramePos, aContainerSize);
 | ||
|   PositionFrameView(aItem.Frame());
 | ||
|   PositionChildViews(aItem.Frame());
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| nsFlexContainerFrame::ReflowFlexItem(nsPresContext* aPresContext,
 | ||
|                                      const FlexboxAxisTracker& aAxisTracker,
 | ||
|                                      const ReflowInput& aReflowInput,
 | ||
|                                      const FlexItem& aItem,
 | ||
|                                      LogicalPoint& aFramePos,
 | ||
|                                      const nsSize& aContainerSize)
 | ||
| {
 | ||
|   WritingMode outerWM = aReflowInput.GetWritingMode();
 | ||
|   WritingMode wm = aItem.Frame()->GetWritingMode();
 | ||
|   LogicalSize availSize = aReflowInput.ComputedSize(wm);
 | ||
|   availSize.BSize(wm) = NS_UNCONSTRAINEDSIZE;
 | ||
|   ReflowInput childReflowInput(aPresContext, aReflowInput,
 | ||
|                                      aItem.Frame(), availSize);
 | ||
| 
 | ||
|   // Keep track of whether we've overriden the child's computed ISize
 | ||
|   // and/or BSize, so we can set its resize flags accordingly.
 | ||
|   bool didOverrideComputedISize = false;
 | ||
|   bool didOverrideComputedBSize = false;
 | ||
| 
 | ||
|   // Override computed main-size
 | ||
|   if (aItem.IsInlineAxisMainAxis()) {
 | ||
|     childReflowInput.SetComputedISize(aItem.GetMainSize());
 | ||
|     didOverrideComputedISize = true;
 | ||
|   } else {
 | ||
|     childReflowInput.SetComputedBSize(aItem.GetMainSize());
 | ||
|     didOverrideComputedBSize = true;
 | ||
|   }
 | ||
| 
 | ||
|   // Override reflow state's computed cross-size if either:
 | ||
|   // - the item was stretched (in which case we're imposing a cross size)
 | ||
|   // ...or...
 | ||
|   // - the item it has an aspect ratio (in which case the cross-size that's
 | ||
|   // currently in the reflow state is based on arithmetic involving a stale
 | ||
|   // main-size value that we just stomped on above). (Note that we could handle
 | ||
|   // this case using an AutoFlexItemMainSizeOverride, as we do elsewhere; but
 | ||
|   // given that we *already know* the correct cross size to use here, it's
 | ||
|   // cheaper to just directly set it instead of setting a frame property.)
 | ||
|   if (aItem.IsStretched() ||
 | ||
|       aItem.HasIntrinsicRatio()) {
 | ||
|     if (aItem.IsInlineAxisCrossAxis()) {
 | ||
|       childReflowInput.SetComputedISize(aItem.GetCrossSize());
 | ||
|       didOverrideComputedISize = true;
 | ||
|     } else {
 | ||
|       childReflowInput.SetComputedBSize(aItem.GetCrossSize());
 | ||
|       didOverrideComputedBSize = true;
 | ||
|     }
 | ||
|   }
 | ||
|   if (aItem.IsStretched() && aItem.IsBlockAxisCrossAxis()) {
 | ||
|     // This item is stretched (in the cross axis), and that axis is its block
 | ||
|     // axis.  That stretching effectively gives it a relative BSize.
 | ||
|     // XXXdholbert This flag only makes a difference if we use the flex items'
 | ||
|     // frame-state when deciding whether to reflow them -- and we don't, as of
 | ||
|     // the changes in bug 851607. So this has no effect right now, but it might
 | ||
|     // make a difference if we optimize to use dirty bits in the
 | ||
|     // future. (Reftests flexbox-resizeviewport-1.xhtml and -2.xhtml are
 | ||
|     // intended to catch any regressions here, if we end up relying on this bit
 | ||
|     // & neglecting to set it.)
 | ||
|     aItem.Frame()->AddStateBits(NS_FRAME_CONTAINS_RELATIVE_BSIZE);
 | ||
|   }
 | ||
| 
 | ||
|   // If we're overriding the computed width or height, *and* we had an
 | ||
|   // earlier "measuring" reflow, then this upcoming reflow needs to be
 | ||
|   // treated as a resize.
 | ||
|   if (aItem.HadMeasuringReflow()) {
 | ||
|     if (didOverrideComputedISize) {
 | ||
|       // (This is somewhat redundant, since ReflowInput::InitResizeFlags()
 | ||
|       // already calls SetIResize() whenever our computed ISize has changed
 | ||
|       // since the previous reflow. Still, it's nice for symmetry, and it might
 | ||
|       // be necessary for some edge cases.)
 | ||
|       childReflowInput.SetIResize(true);
 | ||
|     }
 | ||
|     if (didOverrideComputedBSize) {
 | ||
|       childReflowInput.SetBResize(true);
 | ||
|     }
 | ||
|   }
 | ||
|   // NOTE: Be very careful about doing anything else with childReflowInput
 | ||
|   // after this point, because some of its methods (e.g. SetComputedWidth)
 | ||
|   // internally call InitResizeFlags and stomp on mVResize & mHResize.
 | ||
| 
 | ||
|   ReflowOutput childDesiredSize(childReflowInput);
 | ||
|   nsReflowStatus childReflowStatus;
 | ||
|   ReflowChild(aItem.Frame(), aPresContext,
 | ||
|               childDesiredSize, childReflowInput,
 | ||
|               outerWM, aFramePos, aContainerSize,
 | ||
|               0, childReflowStatus);
 | ||
| 
 | ||
|   // XXXdholbert Once we do pagination / splitting, we'll need to actually
 | ||
|   // handle incomplete childReflowStatuses. But for now, we give our kids
 | ||
|   // unconstrained available height, which means they should always
 | ||
|   // complete.
 | ||
|   MOZ_ASSERT(childReflowStatus.IsComplete(),
 | ||
|              "We gave flex item unconstrained available height, so it "
 | ||
|              "should be complete");
 | ||
| 
 | ||
|   LogicalMargin offsets =
 | ||
|     childReflowInput.ComputedLogicalOffsets().ConvertTo(outerWM, wm);
 | ||
|   ReflowInput::ApplyRelativePositioning(aItem.Frame(), outerWM,
 | ||
|                                               offsets, &aFramePos,
 | ||
|                                               aContainerSize);
 | ||
| 
 | ||
|   FinishReflowChild(aItem.Frame(), aPresContext,
 | ||
|                     childDesiredSize, &childReflowInput,
 | ||
|                     outerWM, aFramePos, aContainerSize, 0);
 | ||
| 
 | ||
|   aItem.SetAscent(childDesiredSize.BlockStartAscent());
 | ||
| }
 | ||
| 
 | ||
| void
 | ||
| nsFlexContainerFrame::ReflowPlaceholders(nsPresContext* aPresContext,
 | ||
|                                          const ReflowInput& aReflowInput,
 | ||
|                                          nsTArray<nsIFrame*>& aPlaceholders,
 | ||
|                                          const LogicalPoint& aContentBoxOrigin,
 | ||
|                                          const nsSize& aContainerSize)
 | ||
| {
 | ||
|   WritingMode outerWM = aReflowInput.GetWritingMode();
 | ||
| 
 | ||
|   // As noted in this method's documentation, we'll reflow every entry in
 | ||
|   // |aPlaceholders| at the container's content-box origin.
 | ||
|   for (nsIFrame* placeholder : aPlaceholders) {
 | ||
|     MOZ_ASSERT(placeholder->IsPlaceholderFrame(),
 | ||
|                "placeholders array should only contain placeholder frames");
 | ||
|     WritingMode wm = placeholder->GetWritingMode();
 | ||
|     LogicalSize availSize = aReflowInput.ComputedSize(wm);
 | ||
|     ReflowInput childReflowInput(aPresContext, aReflowInput,
 | ||
|                                  placeholder, availSize);
 | ||
|     ReflowOutput childDesiredSize(childReflowInput);
 | ||
|     nsReflowStatus childReflowStatus;
 | ||
|     ReflowChild(placeholder, aPresContext,
 | ||
|                 childDesiredSize, childReflowInput,
 | ||
|                 outerWM, aContentBoxOrigin, aContainerSize, 0,
 | ||
|                 childReflowStatus);
 | ||
| 
 | ||
|     FinishReflowChild(placeholder, aPresContext,
 | ||
|                       childDesiredSize, &childReflowInput,
 | ||
|                       outerWM, aContentBoxOrigin, aContainerSize, 0);
 | ||
| 
 | ||
|     // Mark the placeholder frame to indicate that it's not actually at the
 | ||
|     // element's static position, because we need to apply CSS Alignment after
 | ||
|     // we determine the OOF's size:
 | ||
|     placeholder->AddStateBits(PLACEHOLDER_STATICPOS_NEEDS_CSSALIGN);
 | ||
|   }
 | ||
| }
 | ||
| 
 | ||
| nscoord
 | ||
| nsFlexContainerFrame::IntrinsicISize(gfxContext* aRenderingContext,
 | ||
|                                      IntrinsicISizeType aType)
 | ||
| {
 | ||
|   nscoord containerISize = 0;
 | ||
|   RenumberList();
 | ||
| 
 | ||
|   const nsStylePosition* stylePos = StylePosition();
 | ||
|   const FlexboxAxisTracker axisTracker(this, GetWritingMode());
 | ||
| 
 | ||
|   nscoord mainGapSize;
 | ||
|   if (axisTracker.IsRowOriented()) {
 | ||
|     mainGapSize = nsLayoutUtils::ResolveGapToLength(stylePos->mColumnGap,
 | ||
|                                                     NS_UNCONSTRAINEDSIZE);
 | ||
|   } else {
 | ||
|     mainGapSize = nsLayoutUtils::ResolveGapToLength(stylePos->mRowGap,
 | ||
|                                                     NS_UNCONSTRAINEDSIZE);
 | ||
|   }
 | ||
| 
 | ||
|   const bool useMozBoxCollapseBehavior =
 | ||
|     ShouldUseMozBoxCollapseBehavior(StyleDisplay());
 | ||
| 
 | ||
|   // The loop below sets aside space for a gap before each item besides the
 | ||
|   // first. This bool helps us handle that special-case.
 | ||
|   bool onFirstChild = true;
 | ||
| 
 | ||
|   for (nsIFrame* childFrame : mFrames) {
 | ||
|     // If we're using legacy "visibility:collapse" behavior, then we don't
 | ||
|     // care about the sizes of any collapsed children.
 | ||
|     if (!useMozBoxCollapseBehavior ||
 | ||
|         (NS_STYLE_VISIBILITY_COLLAPSE !=
 | ||
|          childFrame->StyleVisibility()->mVisible)) {
 | ||
|       nscoord childISize =
 | ||
|         nsLayoutUtils::IntrinsicForContainer(aRenderingContext, childFrame,
 | ||
|                                              aType);
 | ||
|       // * For a row-oriented single-line flex container, the intrinsic
 | ||
|       // {min/pref}-isize is the sum of its items' {min/pref}-isizes and
 | ||
|       // (n-1) column gaps.
 | ||
|       // * For a column-oriented flex container, the intrinsic min isize
 | ||
|       // is the max of its items' min isizes.
 | ||
|       // * For a row-oriented multi-line flex container, the intrinsic
 | ||
|       // pref isize is former (sum), and its min isize is the latter (max).
 | ||
|       bool isSingleLine = (NS_STYLE_FLEX_WRAP_NOWRAP == stylePos->mFlexWrap);
 | ||
|       if (axisTracker.IsRowOriented() &&
 | ||
|           (isSingleLine || aType == nsLayoutUtils::PREF_ISIZE)) {
 | ||
|         containerISize += childISize;
 | ||
|         if (!onFirstChild) {
 | ||
|           containerISize += mainGapSize;
 | ||
|         }
 | ||
|         onFirstChild = false;
 | ||
|       } else { // (col-oriented, or MIN_ISIZE for multi-line row flex container)
 | ||
|         containerISize = std::max(containerISize, childISize);
 | ||
|       }
 | ||
|     }
 | ||
|   }
 | ||
| 
 | ||
|   return containerISize;
 | ||
| }
 | ||
| 
 | ||
| /* virtual */ nscoord
 | ||
| nsFlexContainerFrame::GetMinISize(gfxContext* aRenderingContext)
 | ||
| {
 | ||
|   DISPLAY_MIN_WIDTH(this, mCachedMinISize);
 | ||
|   if (mCachedMinISize == NS_INTRINSIC_WIDTH_UNKNOWN) {
 | ||
|     mCachedMinISize = StyleDisplay()->IsContainSize()
 | ||
|       ? 0
 | ||
|       : IntrinsicISize(aRenderingContext, nsLayoutUtils::MIN_ISIZE);
 | ||
|   }
 | ||
| 
 | ||
|   return mCachedMinISize;
 | ||
| }
 | ||
| 
 | ||
| /* virtual */ nscoord
 | ||
| nsFlexContainerFrame::GetPrefISize(gfxContext* aRenderingContext)
 | ||
| {
 | ||
|   DISPLAY_PREF_WIDTH(this, mCachedPrefISize);
 | ||
|   if (mCachedPrefISize == NS_INTRINSIC_WIDTH_UNKNOWN) {
 | ||
|     mCachedPrefISize = StyleDisplay()->IsContainSize()
 | ||
|       ? 0
 | ||
|       : IntrinsicISize(aRenderingContext, nsLayoutUtils::PREF_ISIZE);
 | ||
|   }
 | ||
| 
 | ||
|   return mCachedPrefISize;
 | ||
| }
 | 
