forked from mirrors/gecko-dev
		
	
		
			
				
	
	
		
			413 lines
		
	
	
	
		
			16 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			413 lines
		
	
	
	
		
			16 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/. */
 | |
| 
 | |
| /* state used in reflow of block frames */
 | |
| 
 | |
| #ifndef BlockReflowInput_h
 | |
| #define BlockReflowInput_h
 | |
| 
 | |
| #include "nsFloatManager.h"
 | |
| #include "nsLineBox.h"
 | |
| #include "mozilla/ReflowInput.h"
 | |
| 
 | |
| class nsBlockFrame;
 | |
| class nsFrameList;
 | |
| class nsOverflowContinuationTracker;
 | |
| 
 | |
| namespace mozilla {
 | |
| 
 | |
| // BlockReflowInput contains additional reflow input information that the
 | |
| // block frame uses along with ReflowInput. Like ReflowInput, this
 | |
| // is read-only data that is passed down from a parent frame to its children.
 | |
| class BlockReflowInput {
 | |
|   using BandInfoType = nsFloatManager::BandInfoType;
 | |
|   using ShapeType = nsFloatManager::ShapeType;
 | |
| 
 | |
|   // Block reflow input flags.
 | |
|   struct Flags {
 | |
|     Flags()
 | |
|       : mHasUnconstrainedBSize(false)
 | |
|       , mIsBStartMarginRoot(false)
 | |
|       , mIsBEndMarginRoot(false)
 | |
|       , mShouldApplyBStartMargin(false)
 | |
|       , mIsFirstInflow(false)
 | |
|       , mHasLineAdjacentToTop(false)
 | |
|       , mBlockNeedsFloatManager(false)
 | |
|       , mIsLineLayoutEmpty(false)
 | |
|       , mIsOverflowContainer(false)
 | |
|       , mIsFloatListInBlockPropertyTable(false)
 | |
|       , mFloatFragmentsInsideColumnEnabled(false)
 | |
|       , mCanHaveTextOverflow(false)
 | |
|     {}
 | |
| 
 | |
|     // Set in the BlockReflowInput constructor when the frame being reflowed has
 | |
|     // been given NS_UNCONSTRAINEDSIZE as its available BSize in the
 | |
|     // ReflowInput. If set, NS_UNCONSTRAINEDSIZE is passed to nsLineLayout as
 | |
|     // the available BSize.
 | |
|     bool mHasUnconstrainedBSize : 1;
 | |
| 
 | |
|     // Set in the BlockReflowInput constructor when reflowing a "block margin
 | |
|     // root" frame (i.e. a frame with the NS_BLOCK_MARGIN_ROOT flag set, for
 | |
|     // which margins apply by default).
 | |
|     //
 | |
|     // The flag is also set when reflowing a frame whose computed BStart border
 | |
|     // padding is non-zero.
 | |
|     bool mIsBStartMarginRoot : 1;
 | |
| 
 | |
|     // Set in the BlockReflowInput constructor when reflowing a "block margin
 | |
|     // root" frame (i.e. a frame with the NS_BLOCK_MARGIN_ROOT flag set, for
 | |
|     // which margins apply by default).
 | |
|     //
 | |
|     // The flag is also set when reflowing a frame whose computed BEnd border
 | |
|     // padding is non-zero.
 | |
|     bool mIsBEndMarginRoot : 1;
 | |
| 
 | |
|     // Set if the BStart margin should be considered when placing a linebox that
 | |
|     // contains a block frame. It may be set as a side-effect of calling
 | |
|     // nsBlockFrame::ShouldApplyBStartMargin(); once set,
 | |
|     // ShouldApplyBStartMargin() uses it as a fast-path way to return whether
 | |
|     // the BStart margin should apply.
 | |
|     //
 | |
|     // If the flag hasn't been set in the block reflow input, then
 | |
|     // ShouldApplyBStartMargin() will crawl the line list to see if a block frame
 | |
|     // precedes the specified frame. If so, the BStart margin should be applied, and
 | |
|     // the flag is set to cache the result. (If not, the BStart margin will be
 | |
|     // applied as a result of the generational margin collapsing logic in
 | |
|     // nsBlockReflowContext::ComputeCollapsedBStartMargin(). In this case, the flag
 | |
|     // won't be set, so subsequent calls to ShouldApplyBStartMargin() will continue
 | |
|     // crawl the line list.)
 | |
|     //
 | |
|     // This flag is also set in the BlockReflowInput constructor if
 | |
|     // mIsBStartMarginRoot is set; that is, the frame being reflowed is a margin
 | |
|     // root by default.
 | |
|     bool mShouldApplyBStartMargin : 1;
 | |
| 
 | |
|     bool mIsFirstInflow : 1;
 | |
| 
 | |
|     // Set when mLineAdjacentToTop is valid.
 | |
|     bool mHasLineAdjacentToTop : 1;
 | |
| 
 | |
|     // Set when the block has the equivalent of NS_BLOCK_FLOAT_MGR.
 | |
|     bool mBlockNeedsFloatManager : 1;
 | |
| 
 | |
|     // Set when nsLineLayout::LineIsEmpty was true at the end of reflowing
 | |
|     // the current line.
 | |
|     bool mIsLineLayoutEmpty : 1;
 | |
| 
 | |
|     bool mIsOverflowContainer : 1;
 | |
| 
 | |
|     // Set when our mPushedFloats list is stored on the block's property table.
 | |
|     bool mIsFloatListInBlockPropertyTable : 1;
 | |
| 
 | |
|     // Set when the pref layout.float-fragments-inside-column.enabled is true.
 | |
|     bool mFloatFragmentsInsideColumnEnabled : 1;
 | |
| 
 | |
|     // Set when we need text-overflow processing.
 | |
|     bool mCanHaveTextOverflow : 1;
 | |
|   };
 | |
| 
 | |
| public:
 | |
|   BlockReflowInput(const ReflowInput& aReflowInput,
 | |
|                      nsPresContext* aPresContext,
 | |
|                      nsBlockFrame* aFrame,
 | |
|                      bool aBStartMarginRoot, bool aBEndMarginRoot,
 | |
|                      bool aBlockNeedsFloatManager,
 | |
|                      nscoord aConsumedBSize = NS_INTRINSICSIZE);
 | |
| 
 | |
|   /**
 | |
|    * Get the available reflow space (the area not occupied by floats)
 | |
|    * for the current y coordinate. The available space is relative to
 | |
|    * our coordinate system, which is the content box, with (0, 0) in the
 | |
|    * upper left.
 | |
|    *
 | |
|    * Returns whether there are floats present at the given block-direction
 | |
|    * coordinate and within the inline size of the content rect.
 | |
|    */
 | |
|   nsFlowAreaRect GetFloatAvailableSpace() const
 | |
|     { return GetFloatAvailableSpace(mBCoord); }
 | |
|   nsFlowAreaRect GetFloatAvailableSpaceForPlacingFloat(nscoord aBCoord) const
 | |
|     { return GetFloatAvailableSpaceWithState(
 | |
|         aBCoord, ShapeType::Margin, nullptr); }
 | |
|   nsFlowAreaRect GetFloatAvailableSpace(nscoord aBCoord) const
 | |
|     { return GetFloatAvailableSpaceWithState(
 | |
|         aBCoord, ShapeType::ShapeOutside, nullptr); }
 | |
|   nsFlowAreaRect
 | |
|     GetFloatAvailableSpaceWithState(nscoord aBCoord, ShapeType aShapeType,
 | |
|                                     nsFloatManager::SavedState *aState) const;
 | |
|   nsFlowAreaRect
 | |
|     GetFloatAvailableSpaceForBSize(nscoord aBCoord, nscoord aBSize,
 | |
|                                    nsFloatManager::SavedState *aState) const;
 | |
| 
 | |
|   /*
 | |
|    * The following functions all return true if they were able to
 | |
|    * place the float, false if the float did not fit in available
 | |
|    * space.
 | |
|    * aLineLayout is null when we are reflowing pushed floats (because
 | |
|    * they are not associated with a line box).
 | |
|    */
 | |
|   bool AddFloat(nsLineLayout*       aLineLayout,
 | |
|                 nsIFrame*           aFloat,
 | |
|                 nscoord             aAvailableISize);
 | |
| 
 | |
|   bool FlowAndPlaceFloat(nsIFrame* aFloat);
 | |
| 
 | |
|   void PlaceBelowCurrentLineFloats(nsFloatCacheFreeList& aFloats,
 | |
|                                    nsLineBox* aLine);
 | |
| 
 | |
|   // Returns the first coordinate >= aBCoord that clears the
 | |
|   // floats indicated by aBreakType and has enough inline size between floats
 | |
|   // (or no floats remaining) to accomodate aReplacedBlock.
 | |
|   nscoord ClearFloats(nscoord aBCoord, mozilla::StyleClear aBreakType,
 | |
|                       nsIFrame *aReplacedBlock = nullptr,
 | |
|                       uint32_t aFlags = 0);
 | |
| 
 | |
|   nsFloatManager* FloatManager() const {
 | |
|     MOZ_ASSERT(mReflowInput.mFloatManager,
 | |
|                "Float manager should be valid during the lifetime of "
 | |
|                "BlockReflowInput!");
 | |
|     return mReflowInput.mFloatManager;
 | |
|   }
 | |
| 
 | |
|   // Advances to the next band, i.e., the next horizontal stripe in
 | |
|   // which there is a different set of floats.
 | |
|   // Return false if it did not advance, which only happens for
 | |
|   // constrained heights (and means that we should get pushed to the
 | |
|   // next column/page).
 | |
|   bool AdvanceToNextBand(const mozilla::LogicalRect& aFloatAvailableSpace,
 | |
|                          nscoord *aBCoord) const {
 | |
|     mozilla::WritingMode wm = mReflowInput.GetWritingMode();
 | |
|     if (aFloatAvailableSpace.BSize(wm) > 0) {
 | |
|       // See if there's room in the next band.
 | |
|       *aBCoord += aFloatAvailableSpace.BSize(wm);
 | |
|     } else {
 | |
|       if (mReflowInput.AvailableHeight() != NS_UNCONSTRAINEDSIZE) {
 | |
|         // Stop trying to clear here; we'll just get pushed to the
 | |
|         // next column or page and try again there.
 | |
|         return false;
 | |
|       }
 | |
|       MOZ_ASSERT_UNREACHABLE("avail space rect with zero height!");
 | |
|       *aBCoord += 1;
 | |
|     }
 | |
|     return true;
 | |
|   }
 | |
| 
 | |
|   bool ReplacedBlockFitsInAvailSpace(nsIFrame* aReplacedBlock,
 | |
|                             const nsFlowAreaRect& aFloatAvailableSpace) const;
 | |
| 
 | |
|   bool IsAdjacentWithTop() const {
 | |
|     return mBCoord == mBorderPadding.BStart(mReflowInput.GetWritingMode());
 | |
|   }
 | |
| 
 | |
|   /**
 | |
|    * Return mBlock's computed physical border+padding with GetSkipSides applied.
 | |
|    */
 | |
|   const mozilla::LogicalMargin& BorderPadding() const {
 | |
|     return mBorderPadding;
 | |
|   }
 | |
| 
 | |
|   /**
 | |
|    * Retrieve the block-axis content size "consumed" by any prev-in-flows.
 | |
|    * @note the value is cached so subsequent calls will return the same value
 | |
|    */
 | |
|   nscoord ConsumedBSize();
 | |
| 
 | |
|   // Reconstruct the previous block-end margin that goes before |aLine|.
 | |
|   void ReconstructMarginBefore(nsLineList::iterator aLine);
 | |
| 
 | |
|   // Caller must have called GetAvailableSpace for the correct position
 | |
|   // (which need not be the current mBCoord).
 | |
|   void ComputeReplacedBlockOffsetsForFloats(nsIFrame* aFrame,
 | |
|                           const mozilla::LogicalRect& aFloatAvailableSpace,
 | |
|                                             nscoord&  aIStartResult,
 | |
|                                             nscoord&  aIEndResult) const;
 | |
| 
 | |
|   // Caller must have called GetAvailableSpace for the current mBCoord
 | |
|   void ComputeBlockAvailSpace(nsIFrame* aFrame,
 | |
|                               const nsFlowAreaRect& aFloatAvailableSpace,
 | |
|                               bool aBlockAvoidsFloats,
 | |
|                               mozilla::LogicalRect& aResult);
 | |
| 
 | |
|   void RecoverStateFrom(nsLineList::iterator aLine, nscoord aDeltaBCoord);
 | |
| 
 | |
|   void AdvanceToNextLine() {
 | |
|     if (mFlags.mIsLineLayoutEmpty) {
 | |
|       mFlags.mIsLineLayoutEmpty = false;
 | |
|     } else {
 | |
|       mLineNumber++;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   //----------------------------------------
 | |
| 
 | |
|   // This state is the "global" state computed once for the reflow of
 | |
|   // the block.
 | |
| 
 | |
|   // The block frame that is using this object
 | |
|   nsBlockFrame* mBlock;
 | |
| 
 | |
|   nsPresContext* mPresContext;
 | |
| 
 | |
|   const ReflowInput& mReflowInput;
 | |
| 
 | |
|   // The coordinates within the float manager where the block is being
 | |
|   // placed <b>after</b> taking into account the blocks border and
 | |
|   // padding. This, therefore, represents the inner "content area" (in
 | |
|   // float manager coordinates) where child frames will be placed,
 | |
|   // including child blocks and floats.
 | |
|   nscoord mFloatManagerI, mFloatManagerB;
 | |
| 
 | |
|   // XXX get rid of this
 | |
|   nsReflowStatus mReflowStatus;
 | |
| 
 | |
|   // The float manager state as it was before the contents of this
 | |
|   // block.  This is needed for positioning bullets, since we only want
 | |
|   // to move the bullet to flow around floats that were before this
 | |
|   // block, not floats inside of it.
 | |
|   nsFloatManager::SavedState mFloatManagerStateBefore;
 | |
| 
 | |
|   nscoord mBEndEdge;
 | |
| 
 | |
|   // The content area to reflow child frames within.  This is within
 | |
|   // this frame's coordinate system and writing mode, which means
 | |
|   // mContentArea.IStart == BorderPadding().IStart and
 | |
|   // mContentArea.BStart == BorderPadding().BStart.
 | |
|   // The block size may be NS_UNCONSTRAINEDSIZE, which indicates that there
 | |
|   // is no page/column boundary below (the common case).
 | |
|   // mContentArea.BEnd() should only be called after checking that
 | |
|   // mContentArea.BSize is not NS_UNCONSTRAINEDSIZE; otherwise
 | |
|   // coordinate overflow may occur.
 | |
|   mozilla::LogicalRect mContentArea;
 | |
|   nscoord ContentIStart() const {
 | |
|     return mContentArea.IStart(mReflowInput.GetWritingMode());
 | |
|   }
 | |
|   nscoord ContentISize() const {
 | |
|     return mContentArea.ISize(mReflowInput.GetWritingMode());
 | |
|   }
 | |
|   nscoord ContentIEnd() const {
 | |
|     return mContentArea.IEnd(mReflowInput.GetWritingMode());
 | |
|   }
 | |
|   nscoord ContentBStart() const {
 | |
|     return mContentArea.BStart(mReflowInput.GetWritingMode());
 | |
|   }
 | |
|   nscoord ContentBSize() const {
 | |
|     return mContentArea.BSize(mReflowInput.GetWritingMode());
 | |
|   }
 | |
|   nscoord ContentBEnd() const {
 | |
|     return mContentArea.BEnd(mReflowInput.GetWritingMode());
 | |
|   }
 | |
|   mozilla::LogicalSize ContentSize(mozilla::WritingMode aWM) const {
 | |
|     mozilla::WritingMode wm = mReflowInput.GetWritingMode();
 | |
|     return mContentArea.Size(wm).ConvertTo(aWM, wm);
 | |
|   }
 | |
| 
 | |
|   // Physical size. Use only for physical <-> logical coordinate conversion.
 | |
|   nsSize mContainerSize;
 | |
|   const nsSize& ContainerSize() const { return mContainerSize; }
 | |
| 
 | |
|   // Continuation out-of-flow float frames that need to move to our
 | |
|   // next in flow are placed here during reflow.  It's a pointer to
 | |
|   // a frame list stored in the block's property table.
 | |
|   nsFrameList *mPushedFloats;
 | |
|   // This method makes sure pushed floats are accessible to
 | |
|   // StealFrame. Call it before adding any frames to mPushedFloats.
 | |
|   void SetupPushedFloatList();
 | |
|   /**
 | |
|    * Append aFloatCont and its next-in-flows within the same block to
 | |
|    * mPushedFloats.  aFloatCont should not be on any child list when
 | |
|    * making this call.  Its next-in-flows will be removed from
 | |
|    * mBlock using StealFrame() before being added to mPushedFloats.
 | |
|    * All appended frames will be marked NS_FRAME_IS_PUSHED_FLOAT.
 | |
|    */
 | |
|   void AppendPushedFloatChain(nsIFrame* aFloatCont);
 | |
| 
 | |
|   // Track child overflow continuations.
 | |
|   nsOverflowContinuationTracker* mOverflowTracker;
 | |
| 
 | |
|   //----------------------------------------
 | |
| 
 | |
|   // This state is "running" state updated by the reflow of each line
 | |
|   // in the block. This same state is "recovered" when a line is not
 | |
|   // dirty and is passed over during incremental reflow.
 | |
| 
 | |
|   // The current line being reflowed
 | |
|   // If it is mBlock->end_lines(), then it is invalid.
 | |
|   nsLineList::iterator mCurrentLine;
 | |
| 
 | |
|   // When mHasLineAdjacentToTop is set, this refers to a line
 | |
|   // which we know is adjacent to the top of the block (in other words,
 | |
|   // all lines before it are empty and do not have clearance. This line is
 | |
|   // always before the current line.
 | |
|   nsLineList::iterator mLineAdjacentToTop;
 | |
| 
 | |
|   // The current block-direction coordinate in the block
 | |
|   nscoord mBCoord;
 | |
| 
 | |
|   // mBlock's computed physical border+padding with GetSkipSides applied.
 | |
|   mozilla::LogicalMargin mBorderPadding;
 | |
| 
 | |
|   // The overflow areas of all floats placed so far
 | |
|   nsOverflowAreas mFloatOverflowAreas;
 | |
| 
 | |
|   nsFloatCacheFreeList mFloatCacheFreeList;
 | |
| 
 | |
|   // Previous child. This is used when pulling up a frame to update
 | |
|   // the sibling list.
 | |
|   nsIFrame* mPrevChild;
 | |
| 
 | |
|   // The previous child frames collapsed bottom margin value.
 | |
|   nsCollapsingMargin mPrevBEndMargin;
 | |
| 
 | |
|   // The current next-in-flow for the block. When lines are pulled
 | |
|   // from a next-in-flow, this is used to know which next-in-flow to
 | |
|   // pull from. When a next-in-flow is emptied of lines, we advance
 | |
|   // this to the next next-in-flow.
 | |
|   nsBlockFrame* mNextInFlow;
 | |
| 
 | |
|   //----------------------------------------
 | |
| 
 | |
|   // Temporary line-reflow state. This state is used during the reflow
 | |
|   // of a given line, but doesn't have meaning before or after.
 | |
| 
 | |
|   // The list of floats that are "current-line" floats. These are
 | |
|   // added to the line after the line has been reflowed, to keep the
 | |
|   // list fiddling from being N^2.
 | |
|   nsFloatCacheFreeList mCurrentLineFloats;
 | |
| 
 | |
|   // The list of floats which are "below current-line"
 | |
|   // floats. These are reflowed/placed after the line is reflowed
 | |
|   // and placed. Again, this is done to keep the list fiddling from
 | |
|   // being N^2.
 | |
|   nsFloatCacheFreeList mBelowCurrentLineFloats;
 | |
| 
 | |
|   nscoord mMinLineHeight;
 | |
| 
 | |
|   int32_t mLineNumber;
 | |
| 
 | |
|   Flags mFlags;
 | |
| 
 | |
|   StyleClear mFloatBreakType;
 | |
| 
 | |
|   // The amount of computed block-direction size "consumed" by previous-in-flows.
 | |
|   nscoord mConsumedBSize;
 | |
| 
 | |
|   // Cache the current line's BSize if nsBlockFrame::PlaceLine() fails to
 | |
|   // place the line. When redoing the line, it will be used to query the
 | |
|   // accurate float available space in AddFloat() and
 | |
|   // nsBlockFrame::PlaceLine().
 | |
|   mozilla::Maybe<nscoord> mLineBSize;
 | |
| 
 | |
| private:
 | |
|   bool CanPlaceFloat(nscoord aFloatISize,
 | |
|                      const nsFlowAreaRect& aFloatAvailableSpace);
 | |
| 
 | |
|   void PushFloatPastBreak(nsIFrame* aFloat);
 | |
| 
 | |
|   void RecoverFloats(nsLineList::iterator aLine, nscoord aDeltaBCoord);
 | |
| };
 | |
| 
 | |
| }; // namespace mozilla
 | |
| 
 | |
| #endif // BlockReflowInput_h
 | 
