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fune/layout/generic/BlockReflowInput.cpp
Ting-Yu Lin bb1491fb5a Bug 1291110 Part 1 - Fix log and comment related to float. r=dbaron 
MozReview-Commit-ID: ICUflMUOsD2

--HG--
extra : rebase_source : ccba872d056edcfb07095f3f2995492324394ab0
2016-08-22 19:41:53 +08:00

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
// vim:cindent:ts=2:et:sw=2:
/* 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 */
#include "BlockReflowInput.h"
#include "LayoutLogging.h"
#include "nsBlockFrame.h"
#include "nsLineLayout.h"
#include "nsPresContext.h"
#include "nsIFrameInlines.h"
#include "mozilla/AutoRestore.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/Preferences.h"
#include <algorithm>
#ifdef DEBUG
#include "nsBlockDebugFlags.h"
#endif
using namespace mozilla;
using namespace mozilla::layout;
static bool sFloatFragmentsInsideColumnEnabled;
static bool sFloatFragmentsInsideColumnPrefCached;
BlockReflowInput::BlockReflowInput(const ReflowInput& aReflowInput,
nsPresContext* aPresContext,
nsBlockFrame* aFrame,
bool aBStartMarginRoot,
bool aBEndMarginRoot,
bool aBlockNeedsFloatManager,
nscoord aConsumedBSize)
: mBlock(aFrame),
mPresContext(aPresContext),
mReflowInput(aReflowInput),
mContentArea(aReflowInput.GetWritingMode()),
mPushedFloats(nullptr),
mOverflowTracker(nullptr),
mBorderPadding(mReflowInput.ComputedLogicalBorderPadding()),
mPrevBEndMargin(),
mLineNumber(0),
mFloatBreakType(StyleClear::None),
mConsumedBSize(aConsumedBSize)
{
if (!sFloatFragmentsInsideColumnPrefCached) {
sFloatFragmentsInsideColumnPrefCached = true;
Preferences::AddBoolVarCache(&sFloatFragmentsInsideColumnEnabled,
"layout.float-fragments-inside-column.enabled");
}
mFlags.mFloatFragmentsInsideColumnEnabled = sFloatFragmentsInsideColumnEnabled;
WritingMode wm = aReflowInput.GetWritingMode();
mFlags.mIsFirstInflow = !aFrame->GetPrevInFlow();
mFlags.mIsOverflowContainer = IS_TRUE_OVERFLOW_CONTAINER(aFrame);
nsIFrame::LogicalSides logicalSkipSides =
aFrame->GetLogicalSkipSides(&aReflowInput);
mBorderPadding.ApplySkipSides(logicalSkipSides);
// Note that mContainerSize is the physical size, needed to
// convert logical block-coordinates in vertical-rl writing mode
// (measured from a RHS origin) to physical coordinates within the
// containing block.
// If aReflowInput doesn't have a constrained ComputedWidth(), we set
// mContainerSize.width to zero, which means lines will be positioned
// (physically) incorrectly; we will fix them up at the end of
// nsBlockFrame::Reflow, after we know the total block-size of the
// frame.
mContainerSize.width = aReflowInput.ComputedWidth();
if (mContainerSize.width == NS_UNCONSTRAINEDSIZE) {
mContainerSize.width = 0;
}
mContainerSize.width += mBorderPadding.LeftRight(wm);
// For now at least, we don't do that fix-up for mContainerHeight.
// It's only used in nsBidiUtils::ReorderFrames for vertical rtl
// writing modes, which aren't fully supported for the time being.
mContainerSize.height = aReflowInput.ComputedHeight() +
mBorderPadding.TopBottom(wm);
if ((aBStartMarginRoot && !logicalSkipSides.BStart()) ||
0 != mBorderPadding.BStart(wm)) {
mFlags.mIsBStartMarginRoot = true;
mFlags.mShouldApplyBStartMargin = true;
}
if ((aBEndMarginRoot && !logicalSkipSides.BEnd()) ||
0 != mBorderPadding.BEnd(wm)) {
mFlags.mIsBEndMarginRoot = true;
}
if (aBlockNeedsFloatManager) {
mFlags.mBlockNeedsFloatManager = true;
}
mFloatManager = aReflowInput.mFloatManager;
NS_ASSERTION(mFloatManager,
"FloatManager should be set in BlockReflowInput" );
if (mFloatManager) {
// Save the coordinate system origin for later.
mFloatManager->GetTranslation(mFloatManagerI, mFloatManagerB);
mFloatManager->PushState(&mFloatManagerStateBefore); // never popped
}
mReflowStatus = NS_FRAME_COMPLETE;
mNextInFlow = static_cast<nsBlockFrame*>(mBlock->GetNextInFlow());
LAYOUT_WARN_IF_FALSE(NS_UNCONSTRAINEDSIZE != aReflowInput.ComputedISize(),
"have unconstrained width; this should only result "
"from very large sizes, not attempts at intrinsic "
"width calculation");
mContentArea.ISize(wm) = aReflowInput.ComputedISize();
// Compute content area height. Unlike the width, if we have a
// specified style height we ignore it since extra content is
// managed by the "overflow" property. When we don't have a
// specified style height then we may end up limiting our height if
// the availableHeight is constrained (this situation occurs when we
// are paginated).
if (NS_UNCONSTRAINEDSIZE != aReflowInput.AvailableBSize()) {
// We are in a paginated situation. The bottom edge is just inside
// the bottom border and padding. The content area height doesn't
// include either border or padding edge.
mBEndEdge = aReflowInput.AvailableBSize() - mBorderPadding.BEnd(wm);
mContentArea.BSize(wm) = std::max(0, mBEndEdge - mBorderPadding.BStart(wm));
}
else {
// When we are not in a paginated situation then we always use
// a constrained height.
mFlags.mHasUnconstrainedBSize = true;
mContentArea.BSize(wm) = mBEndEdge = NS_UNCONSTRAINEDSIZE;
}
mContentArea.IStart(wm) = mBorderPadding.IStart(wm);
mBCoord = mContentArea.BStart(wm) = mBorderPadding.BStart(wm);
mPrevChild = nullptr;
mCurrentLine = aFrame->LinesEnd();
mMinLineHeight = aReflowInput.CalcLineHeight();
}
nscoord
BlockReflowInput::GetConsumedBSize()
{
if (mConsumedBSize == NS_INTRINSICSIZE) {
mConsumedBSize = mBlock->GetConsumedBSize();
}
return mConsumedBSize;
}
void
BlockReflowInput::ComputeReplacedBlockOffsetsForFloats(
nsIFrame* aFrame,
const LogicalRect& aFloatAvailableSpace,
nscoord& aIStartResult,
nscoord& aIEndResult) const
{
WritingMode wm = mReflowInput.GetWritingMode();
// The frame is clueless about the float manager and therefore we
// only give it free space. An example is a table frame - the
// tables do not flow around floats.
// However, we can let its margins intersect floats.
NS_ASSERTION(aFloatAvailableSpace.IStart(wm) >= mContentArea.IStart(wm),
"bad avail space rect inline-coord");
NS_ASSERTION(aFloatAvailableSpace.ISize(wm) == 0 ||
aFloatAvailableSpace.IEnd(wm) <= mContentArea.IEnd(wm),
"bad avail space rect inline-size");
nscoord iStartOffset, iEndOffset;
if (aFloatAvailableSpace.ISize(wm) == mContentArea.ISize(wm)) {
// We don't need to compute margins when there are no floats around.
iStartOffset = 0;
iEndOffset = 0;
} else {
LogicalMargin frameMargin(wm);
SizeComputationInput os(aFrame, mReflowInput.mRenderingContext,
wm, mContentArea.ISize(wm));
frameMargin =
os.ComputedLogicalMargin().ConvertTo(wm, aFrame->GetWritingMode());
nscoord iStartFloatIOffset =
aFloatAvailableSpace.IStart(wm) - mContentArea.IStart(wm);
iStartOffset = std::max(iStartFloatIOffset, frameMargin.IStart(wm)) -
frameMargin.IStart(wm);
iStartOffset = std::max(iStartOffset, 0); // in case of negative margin
nscoord iEndFloatIOffset =
mContentArea.IEnd(wm) - aFloatAvailableSpace.IEnd(wm);
iEndOffset = std::max(iEndFloatIOffset, frameMargin.IEnd(wm)) -
frameMargin.IEnd(wm);
iEndOffset = std::max(iEndOffset, 0); // in case of negative margin
}
aIStartResult = iStartOffset;
aIEndResult = iEndOffset;
}
static nscoord
GetBEndMarginClone(nsIFrame* aFrame,
nsRenderingContext* aRenderingContext,
const LogicalRect& aContentArea,
WritingMode aWritingMode)
{
if (aFrame->StyleBorder()->mBoxDecorationBreak ==
StyleBoxDecorationBreak::Clone) {
SizeComputationInput os(aFrame, aRenderingContext, aWritingMode,
aContentArea.ISize(aWritingMode));
return os.ComputedLogicalMargin().
ConvertTo(aWritingMode,
aFrame->GetWritingMode()).BEnd(aWritingMode);
}
return 0;
}
// Compute the amount of available space for reflowing a block frame
// at the current Y coordinate. This method assumes that
// GetAvailableSpace has already been called.
void
BlockReflowInput::ComputeBlockAvailSpace(nsIFrame* aFrame,
const nsFlowAreaRect& aFloatAvailableSpace,
bool aBlockAvoidsFloats,
LogicalRect& aResult)
{
#ifdef REALLY_NOISY_REFLOW
printf("CBAS frame=%p has floats %d\n",
aFrame, aFloatAvailableSpace.mHasFloats);
#endif
WritingMode wm = mReflowInput.GetWritingMode();
aResult.BStart(wm) = mBCoord;
aResult.BSize(wm) = mFlags.mHasUnconstrainedBSize
? NS_UNCONSTRAINEDSIZE
: mReflowInput.AvailableBSize() - mBCoord
- GetBEndMarginClone(aFrame, mReflowInput.mRenderingContext, mContentArea, wm);
// mBCoord might be greater than mBEndEdge if the block's top margin pushes
// it off the page/column. Negative available height can confuse other code
// and is nonsense in principle.
// XXX Do we really want this condition to be this restrictive (i.e.,
// more restrictive than it used to be)? The |else| here is allowed
// by the CSS spec, but only out of desperation given implementations,
// and the behavior it leads to is quite undesirable (it can cause
// things to become extremely narrow when they'd fit quite well a
// little bit lower). Should the else be a quirk or something that
// applies to a specific set of frame classes and no new ones?
// If we did that, then for those frames where the condition below is
// true but nsBlockFrame::BlockCanIntersectFloats is false,
// nsBlockFrame::ISizeToClearPastFloats would need to use the
// shrink-wrap formula, max(MIN_ISIZE, min(avail width, PREF_ISIZE))
// rather than just using MIN_ISIZE.
NS_ASSERTION(nsBlockFrame::BlockCanIntersectFloats(aFrame) ==
!aBlockAvoidsFloats,
"unexpected replaced width");
if (!aBlockAvoidsFloats) {
if (aFloatAvailableSpace.mHasFloats) {
// Use the float-edge property to determine how the child block
// will interact with the float.
const nsStyleBorder* borderStyle = aFrame->StyleBorder();
switch (borderStyle->mFloatEdge) {
default:
case StyleFloatEdge::ContentBox: // content and only content does runaround of floats
// The child block will flow around the float. Therefore
// give it all of the available space.
aResult.IStart(wm) = mContentArea.IStart(wm);
aResult.ISize(wm) = mContentArea.ISize(wm);
break;
case StyleFloatEdge::MarginBox:
{
// The child block's margins should be placed adjacent to,
// but not overlap the float.
aResult.IStart(wm) = aFloatAvailableSpace.mRect.IStart(wm);
aResult.ISize(wm) = aFloatAvailableSpace.mRect.ISize(wm);
}
break;
}
}
else {
// Since there are no floats present the float-edge property
// doesn't matter therefore give the block element all of the
// available space since it will flow around the float itself.
aResult.IStart(wm) = mContentArea.IStart(wm);
aResult.ISize(wm) = mContentArea.ISize(wm);
}
}
else {
nscoord iStartOffset, iEndOffset;
ComputeReplacedBlockOffsetsForFloats(aFrame, aFloatAvailableSpace.mRect,
iStartOffset, iEndOffset);
aResult.IStart(wm) = mContentArea.IStart(wm) + iStartOffset;
aResult.ISize(wm) = mContentArea.ISize(wm) - iStartOffset - iEndOffset;
}
#ifdef REALLY_NOISY_REFLOW
printf(" CBAS: result %d %d %d %d\n", aResult.IStart(wm), aResult.BStart(wm),
aResult.ISize(wm), aResult.BSize(wm));
#endif
}
bool
BlockReflowInput::ReplacedBlockFitsInAvailSpace(nsIFrame* aReplacedBlock,
const nsFlowAreaRect& aFloatAvailableSpace) const
{
if (!aFloatAvailableSpace.mHasFloats) {
// If there aren't any floats here, then we always fit.
// We check this before calling ISizeToClearPastFloats, which is
// somewhat expensive.
return true;
}
WritingMode wm = mReflowInput.GetWritingMode();
nsBlockFrame::ReplacedElementISizeToClear replacedISize =
nsBlockFrame::ISizeToClearPastFloats(*this, aFloatAvailableSpace.mRect,
aReplacedBlock);
// The inline-start side of the replaced element should be offset by
// the larger of the float intrusion or the replaced element's own
// start margin. The inline-end side is similar, except for Web
// compatibility we ignore the margin.
return std::max(aFloatAvailableSpace.mRect.IStart(wm) -
mContentArea.IStart(wm),
replacedISize.marginIStart) +
replacedISize.borderBoxISize +
(mContentArea.IEnd(wm) -
aFloatAvailableSpace.mRect.IEnd(wm)) <=
mContentArea.ISize(wm);
}
nsFlowAreaRect
BlockReflowInput::GetFloatAvailableSpaceWithState(
nscoord aBCoord,
nsFloatManager::SavedState *aState) const
{
WritingMode wm = mReflowInput.GetWritingMode();
#ifdef DEBUG
// Verify that the caller setup the coordinate system properly
nscoord wI, wB;
mFloatManager->GetTranslation(wI, wB);
NS_ASSERTION((wI == mFloatManagerI) && (wB == mFloatManagerB),
"bad coord system");
#endif
nscoord blockSize = (mContentArea.BSize(wm) == nscoord_MAX)
? nscoord_MAX : std::max(mContentArea.BEnd(wm) - aBCoord, 0);
nsFlowAreaRect result =
mFloatManager->GetFlowArea(wm, aBCoord, nsFloatManager::BAND_FROM_POINT,
blockSize, mContentArea, aState,
ContainerSize());
// Keep the inline size >= 0 for compatibility with nsSpaceManager.
if (result.mRect.ISize(wm) < 0) {
result.mRect.ISize(wm) = 0;
}
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow) {
nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
printf("%s: band=%d,%d,%d,%d hasfloats=%d\n", __func__,
result.mRect.IStart(wm), result.mRect.BStart(wm),
result.mRect.ISize(wm), result.mRect.BSize(wm), result.mHasFloats);
}
#endif
return result;
}
nsFlowAreaRect
BlockReflowInput::GetFloatAvailableSpaceForBSize(
nscoord aBCoord, nscoord aBSize,
nsFloatManager::SavedState *aState) const
{
WritingMode wm = mReflowInput.GetWritingMode();
#ifdef DEBUG
// Verify that the caller setup the coordinate system properly
nscoord wI, wB;
mFloatManager->GetTranslation(wI, wB);
NS_ASSERTION((wI == mFloatManagerI) && (wB == mFloatManagerB),
"bad coord system");
#endif
nsFlowAreaRect result =
mFloatManager->GetFlowArea(wm, aBCoord, nsFloatManager::WIDTH_WITHIN_HEIGHT,
aBSize, mContentArea, aState, ContainerSize());
// Keep the width >= 0 for compatibility with nsSpaceManager.
if (result.mRect.ISize(wm) < 0) {
result.mRect.ISize(wm) = 0;
}
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow) {
nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
printf("%s: space=%d,%d,%d,%d hasfloats=%d\n", __func__,
result.mRect.IStart(wm), result.mRect.BStart(wm),
result.mRect.ISize(wm), result.mRect.BSize(wm), result.mHasFloats);
}
#endif
return result;
}
/*
* Reconstruct the vertical margin before the line |aLine| in order to
* do an incremental reflow that begins with |aLine| without reflowing
* the line before it. |aLine| may point to the fencepost at the end of
* the line list, and it is used this way since we (for now, anyway)
* always need to recover margins at the end of a block.
*
* The reconstruction involves walking backward through the line list to
* find any collapsed margins preceding the line that would have been in
* the reflow state's |mPrevBEndMargin| when we reflowed that line in
* a full reflow (under the rule in CSS2 that all adjacent vertical
* margins of blocks collapse).
*/
void
BlockReflowInput::ReconstructMarginBefore(nsLineList::iterator aLine)
{
mPrevBEndMargin.Zero();
nsBlockFrame *block = mBlock;
nsLineList::iterator firstLine = block->LinesBegin();
for (;;) {
--aLine;
if (aLine->IsBlock()) {
mPrevBEndMargin = aLine->GetCarriedOutBEndMargin();
break;
}
if (!aLine->IsEmpty()) {
break;
}
if (aLine == firstLine) {
// If the top margin was carried out (and thus already applied),
// set it to zero. Either way, we're done.
if (!mFlags.mIsBStartMarginRoot) {
mPrevBEndMargin.Zero();
}
break;
}
}
}
void
BlockReflowInput::SetupPushedFloatList()
{
MOZ_ASSERT(!mFlags.mIsFloatListInBlockPropertyTable == !mPushedFloats,
"flag mismatch");
if (!mFlags.mIsFloatListInBlockPropertyTable) {
// If we're being re-Reflow'd without our next-in-flow having been
// reflowed, some pushed floats from our previous reflow might
// still be on our pushed floats list. However, that's
// actually fine, since they'll all end up being stolen and
// reordered into the correct order again.
// (nsBlockFrame::ReflowDirtyLines ensures that any lines with
// pushed floats are reflowed.)
mPushedFloats = mBlock->EnsurePushedFloats();
mFlags.mIsFloatListInBlockPropertyTable = true;
}
}
void
BlockReflowInput::AppendPushedFloatChain(nsIFrame* aFloatCont)
{
SetupPushedFloatList();
while (true) {
aFloatCont->AddStateBits(NS_FRAME_IS_PUSHED_FLOAT);
mPushedFloats->AppendFrame(mBlock, aFloatCont);
aFloatCont = aFloatCont->GetNextInFlow();
if (!aFloatCont || aFloatCont->GetParent() != mBlock) {
break;
}
DebugOnly<nsresult> rv = mBlock->StealFrame(aFloatCont);
NS_ASSERTION(NS_SUCCEEDED(rv), "StealFrame should succeed");
}
}
/**
* Restore information about floats into the float manager for an
* incremental reflow, and simultaneously push the floats by
* |aDeltaBCoord|, which is the amount |aLine| was pushed relative to its
* parent. The recovery of state is one of the things that makes
* incremental reflow O(N^2) and this state should really be kept
* around, attached to the frame tree.
*/
void
BlockReflowInput::RecoverFloats(nsLineList::iterator aLine,
nscoord aDeltaBCoord)
{
WritingMode wm = mReflowInput.GetWritingMode();
if (aLine->HasFloats()) {
// Place the floats into the space-manager again. Also slide
// them, just like the regular frames on the line.
nsFloatCache* fc = aLine->GetFirstFloat();
while (fc) {
nsIFrame* floatFrame = fc->mFloat;
if (aDeltaBCoord != 0) {
floatFrame->MovePositionBy(nsPoint(0, aDeltaBCoord));
nsContainerFrame::PositionFrameView(floatFrame);
nsContainerFrame::PositionChildViews(floatFrame);
}
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow || nsBlockFrame::gNoisyFloatManager) {
nscoord tI, tB;
mFloatManager->GetTranslation(tI, tB);
nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
printf("RecoverFloats: tIB=%d,%d (%d,%d) ",
tI, tB, mFloatManagerI, mFloatManagerB);
nsFrame::ListTag(stdout, floatFrame);
LogicalRect region = nsFloatManager::GetRegionFor(wm, floatFrame,
ContainerSize());
printf(" aDeltaBCoord=%d region={%d,%d,%d,%d}\n",
aDeltaBCoord, region.IStart(wm), region.BStart(wm),
region.ISize(wm), region.BSize(wm));
}
#endif
mFloatManager->AddFloat(floatFrame,
nsFloatManager::GetRegionFor(wm, floatFrame,
ContainerSize()),
wm, ContainerSize());
fc = fc->Next();
}
} else if (aLine->IsBlock()) {
nsBlockFrame::RecoverFloatsFor(aLine->mFirstChild, *mFloatManager, wm,
ContainerSize());
}
}
/**
* Everything done in this function is done O(N) times for each pass of
* reflow so it is O(N*M) where M is the number of incremental reflow
* passes. That's bad. Don't do stuff here.
*
* When this function is called, |aLine| has just been slid by |aDeltaBCoord|
* and the purpose of RecoverStateFrom is to ensure that the
* BlockReflowInput is in the same state that it would have been in
* had the line just been reflowed.
*
* Most of the state recovery that we have to do involves floats.
*/
void
BlockReflowInput::RecoverStateFrom(nsLineList::iterator aLine,
nscoord aDeltaBCoord)
{
// Make the line being recovered the current line
mCurrentLine = aLine;
// Place floats for this line into the float manager
if (aLine->HasFloats() || aLine->IsBlock()) {
RecoverFloats(aLine, aDeltaBCoord);
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow || nsBlockFrame::gNoisyFloatManager) {
mFloatManager->List(stdout);
}
#endif
}
}
// This is called by the line layout's AddFloat method when a
// place-holder frame is reflowed in a line. If the float is a
// left-most child (it's x coordinate is at the line's left margin)
// then the float is place immediately, otherwise the float
// placement is deferred until the line has been reflowed.
// XXXldb This behavior doesn't quite fit with CSS1 and CSS2 --
// technically we're supposed let the current line flow around the
// float as well unless it won't fit next to what we already have.
// But nobody else implements it that way...
bool
BlockReflowInput::AddFloat(nsLineLayout* aLineLayout,
nsIFrame* aFloat,
nscoord aAvailableISize)
{
NS_PRECONDITION(aLineLayout, "must have line layout");
NS_PRECONDITION(mBlock->LinesEnd() != mCurrentLine, "null ptr");
NS_PRECONDITION(aFloat->GetStateBits() & NS_FRAME_OUT_OF_FLOW,
"aFloat must be an out-of-flow frame");
MOZ_ASSERT(aFloat->GetParent(), "float must have parent");
MOZ_ASSERT(aFloat->GetParent()->IsFrameOfType(nsIFrame::eBlockFrame),
"float's parent must be block");
MOZ_ASSERT(aFloat->GetParent() == mBlock ||
(aFloat->GetStateBits() & NS_FRAME_IS_PUSHED_FLOAT),
"float should be in this block unless it was marked as "
"pushed float");
if (aFloat->GetStateBits() & NS_FRAME_IS_PUSHED_FLOAT) {
// If, in a previous reflow, the float was pushed entirely to
// another column/page, we need to steal it back. (We might just
// push it again, though.) Likewise, if that previous reflow
// reflowed this block but not its next continuation, we might need
// to steal it from our own float-continuations list.
//
// For more about pushed floats, see the comment above
// nsBlockFrame::DrainPushedFloats.
nsBlockFrame *floatParent =
static_cast<nsBlockFrame*>(aFloat->GetParent());
floatParent->StealFrame(aFloat);
aFloat->RemoveStateBits(NS_FRAME_IS_PUSHED_FLOAT);
// Appending is fine, since if a float was pushed to the next
// page/column, all later floats were also pushed.
mBlock->mFloats.AppendFrame(mBlock, aFloat);
}
// Because we are in the middle of reflowing a placeholder frame
// within a line (and possibly nested in an inline frame or two
// that's a child of our block) we need to restore the space
// manager's translation to the space that the block resides in
// before placing the float.
nscoord oI, oB;
mFloatManager->GetTranslation(oI, oB);
nscoord dI = oI - mFloatManagerI;
nscoord dB = oB - mFloatManagerB;
mFloatManager->Translate(-dI, -dB);
bool placed;
// Now place the float immediately if possible. Otherwise stash it
// away in mBelowCurrentLineFloats and place it later.
// If one or more floats has already been pushed to the next line,
// don't let this one go on the current line, since that would violate
// float ordering.
LogicalRect floatAvailableSpace = GetFloatAvailableSpace().mRect;
if (mBelowCurrentLineFloats.IsEmpty() &&
(aLineLayout->LineIsEmpty() ||
mBlock->ComputeFloatISize(*this, floatAvailableSpace, aFloat)
<= aAvailableISize)) {
// And then place it
placed = FlowAndPlaceFloat(aFloat);
if (placed) {
// Pass on updated available space to the current inline reflow engine
WritingMode wm = mReflowInput.GetWritingMode();
nsFlowAreaRect floatAvailSpace = GetFloatAvailableSpace(mBCoord);
LogicalRect availSpace(wm, floatAvailSpace.mRect.IStart(wm), mBCoord,
floatAvailSpace.mRect.ISize(wm),
floatAvailSpace.mRect.BSize(wm));
aLineLayout->UpdateBand(wm, availSpace, aFloat);
// Record this float in the current-line list
mCurrentLineFloats.Append(mFloatCacheFreeList.Alloc(aFloat));
} else {
(*aLineLayout->GetLine())->SetHadFloatPushed();
}
}
else {
// Always claim to be placed; we don't know whether we fit yet, so we
// deal with this in PlaceBelowCurrentLineFloats
placed = true;
// This float will be placed after the line is done (it is a
// below-current-line float).
mBelowCurrentLineFloats.Append(mFloatCacheFreeList.Alloc(aFloat));
}
// Restore coordinate system
mFloatManager->Translate(dI, dB);
return placed;
}
bool
BlockReflowInput::CanPlaceFloat(nscoord aFloatISize,
const nsFlowAreaRect& aFloatAvailableSpace)
{
// A float fits at a given block-dir position if there are no floats
// at its inline-dir position (no matter what its inline size) or if
// its inline size fits in the space remaining after prior floats have
// been placed.
// FIXME: We should allow overflow by up to half a pixel here (bug 21193).
return !aFloatAvailableSpace.mHasFloats ||
aFloatAvailableSpace.mRect.ISize(mReflowInput.GetWritingMode()) >=
aFloatISize;
}
// Return the inline-size that the float (including margins) will take up
// in the writing mode of the containing block. If this returns
// NS_UNCONSTRAINEDSIZE, we're dealing with an orthogonal block that
// has block-size:auto, and we'll need to actually reflow it to find out
// how much inline-size it will occupy in the containing block's mode.
static nscoord
FloatMarginISize(const ReflowInput& aCBReflowInput,
nscoord aFloatAvailableISize,
nsIFrame *aFloat,
const SizeComputationInput& aFloatOffsetState)
{
AutoMaybeDisableFontInflation an(aFloat);
WritingMode wm = aFloatOffsetState.GetWritingMode();
LogicalSize floatSize =
aFloat->ComputeSize(
aCBReflowInput.mRenderingContext,
wm,
aCBReflowInput.ComputedSize(wm),
aFloatAvailableISize,
aFloatOffsetState.ComputedLogicalMargin().Size(wm),
aFloatOffsetState.ComputedLogicalBorderPadding().Size(wm) -
aFloatOffsetState.ComputedLogicalPadding().Size(wm),
aFloatOffsetState.ComputedLogicalPadding().Size(wm),
nsIFrame::ComputeSizeFlags::eShrinkWrap);
WritingMode cbwm = aCBReflowInput.GetWritingMode();
nscoord floatISize = floatSize.ConvertTo(cbwm, wm).ISize(cbwm);
if (floatISize == NS_UNCONSTRAINEDSIZE) {
return NS_UNCONSTRAINEDSIZE; // reflow is needed to get the true size
}
return floatISize +
aFloatOffsetState.ComputedLogicalMargin().Size(wm).
ConvertTo(cbwm, wm).ISize(cbwm) +
aFloatOffsetState.ComputedLogicalBorderPadding().Size(wm).
ConvertTo(cbwm, wm).ISize(cbwm);
}
bool
BlockReflowInput::FlowAndPlaceFloat(nsIFrame* aFloat)
{
WritingMode wm = mReflowInput.GetWritingMode();
// Save away the Y coordinate before placing the float. We will
// restore mBCoord at the end after placing the float. This is
// necessary because any adjustments to mBCoord during the float
// placement are for the float only, not for any non-floating
// content.
AutoRestore<nscoord> restoreBCoord(mBCoord);
// Grab the float's display information
const nsStyleDisplay* floatDisplay = aFloat->StyleDisplay();
// The float's old region, so we can propagate damage.
LogicalRect oldRegion = nsFloatManager::GetRegionFor(wm, aFloat,
ContainerSize());
// Enforce CSS2 9.5.1 rule [2], i.e., make sure that a float isn't
// ``above'' another float that preceded it in the flow.
mBCoord = std::max(mFloatManager->GetLowestFloatTop(), mBCoord);
// See if the float should clear any preceding floats...
// XXX We need to mark this float somehow so that it gets reflowed
// when floats are inserted before it.
if (StyleClear::None != floatDisplay->mBreakType) {
// XXXldb Does this handle vertical margins correctly?
mBCoord = ClearFloats(mBCoord, floatDisplay->PhysicalBreakType(wm));
}
// Get the band of available space
nsFlowAreaRect floatAvailableSpace = GetFloatAvailableSpace(mBCoord);
LogicalRect adjustedAvailableSpace =
mBlock->AdjustFloatAvailableSpace(*this, floatAvailableSpace.mRect, aFloat);
NS_ASSERTION(aFloat->GetParent() == mBlock,
"Float frame has wrong parent");
SizeComputationInput offsets(aFloat, mReflowInput.mRenderingContext,
wm, mReflowInput.ComputedISize());
nscoord floatMarginISize = FloatMarginISize(mReflowInput,
adjustedAvailableSpace.ISize(wm),
aFloat, offsets);
LogicalMargin floatMargin(wm); // computed margin
LogicalMargin floatOffsets(wm);
nsReflowStatus reflowStatus;
// If it's a floating first-letter, we need to reflow it before we
// know how wide it is (since we don't compute which letters are part
// of the first letter until reflow!).
// We also need to do this early reflow if FloatMarginISize returned
// an unconstrained inline-size, which can occur if the float had an
// orthogonal writing mode and 'auto' block-size (in its mode).
bool earlyFloatReflow =
aFloat->GetType() == nsGkAtoms::letterFrame ||
floatMarginISize == NS_UNCONSTRAINEDSIZE;
if (earlyFloatReflow) {
mBlock->ReflowFloat(*this, adjustedAvailableSpace, aFloat, floatMargin,
floatOffsets, false, reflowStatus);
floatMarginISize = aFloat->ISize(wm) + floatMargin.IStartEnd(wm);
NS_ASSERTION(NS_FRAME_IS_COMPLETE(reflowStatus),
"letter frames and orthogonal floats with auto block-size "
"shouldn't break, and if they do now, then they're breaking "
"at the wrong point");
}
// Find a place to place the float. The CSS2 spec doesn't want
// floats overlapping each other or sticking out of the containing
// block if possible (CSS2 spec section 9.5.1, see the rule list).
StyleFloat floatStyle = floatDisplay->PhysicalFloats(wm);
MOZ_ASSERT(StyleFloat::Left == floatStyle || StyleFloat::Right == floatStyle,
"Invalid float type!");
// Can the float fit here?
bool keepFloatOnSameLine = false;
// Are we required to place at least part of the float because we're
// at the top of the page (to avoid an infinite loop of pushing and
// breaking).
bool mustPlaceFloat =
mReflowInput.mFlags.mIsTopOfPage && IsAdjacentWithTop();
for (;;) {
if (mReflowInput.AvailableHeight() != NS_UNCONSTRAINEDSIZE &&
floatAvailableSpace.mRect.BSize(wm) <= 0 &&
!mustPlaceFloat) {
// No space, nowhere to put anything.
PushFloatPastBreak(aFloat);
return false;
}
if (CanPlaceFloat(floatMarginISize, floatAvailableSpace)) {
// We found an appropriate place.
break;
}
// Nope. try to advance to the next band.
if (StyleDisplay::Table != floatDisplay->mDisplay ||
eCompatibility_NavQuirks != mPresContext->CompatibilityMode() ) {
mBCoord += floatAvailableSpace.mRect.BSize(wm);
if (adjustedAvailableSpace.BSize(wm) != NS_UNCONSTRAINEDSIZE) {
adjustedAvailableSpace.BSize(wm) -= floatAvailableSpace.mRect.BSize(wm);
}
floatAvailableSpace = GetFloatAvailableSpace(mBCoord);
} else {
// This quirk matches the one in nsBlockFrame::AdjustFloatAvailableSpace
// IE handles float tables in a very special way
// see if the previous float is also a table and has "align"
nsFloatCache* fc = mCurrentLineFloats.Head();
nsIFrame* prevFrame = nullptr;
while (fc) {
if (fc->mFloat == aFloat) {
break;
}
prevFrame = fc->mFloat;
fc = fc->Next();
}
if(prevFrame) {
//get the frame type
if (nsGkAtoms::tableWrapperFrame == prevFrame->GetType()) {
//see if it has "align="
// IE makes a difference between align and he float property
nsIContent* content = prevFrame->GetContent();
if (content) {
// we're interested only if previous frame is align=left
// IE messes things up when "right" (overlapping frames)
if (content->AttrValueIs(kNameSpaceID_None, nsGkAtoms::align,
NS_LITERAL_STRING("left"), eIgnoreCase)) {
keepFloatOnSameLine = true;
// don't advance to next line (IE quirkie behaviour)
// it breaks rule CSS2/9.5.1/1, but what the hell
// since we cannot evangelize the world
break;
}
}
}
}
// the table does not fit anymore in this line so advance to next band
mBCoord += floatAvailableSpace.mRect.BSize(wm);
// To match nsBlockFrame::AdjustFloatAvailableSpace, we have to
// get a new width for the new band.
floatAvailableSpace = GetFloatAvailableSpace(mBCoord);
adjustedAvailableSpace = mBlock->AdjustFloatAvailableSpace(*this,
floatAvailableSpace.mRect, aFloat);
floatMarginISize = FloatMarginISize(mReflowInput,
adjustedAvailableSpace.ISize(wm),
aFloat, offsets);
}
mustPlaceFloat = false;
}
// If the float is continued, it will get the same absolute x value as its prev-in-flow
// We don't worry about the geometry of the prev in flow, let the continuation
// place and size itself as required.
// Assign inline and block dir coordinates to the float. We don't use
// LineLeft() and LineRight() here, because we would only have to
// convert the result back into this block's writing mode.
LogicalPoint floatPos(wm);
bool leftFloat = floatStyle == StyleFloat::Left;
if (leftFloat == wm.IsBidiLTR()) {
floatPos.I(wm) = floatAvailableSpace.mRect.IStart(wm);
}
else {
if (!keepFloatOnSameLine) {
floatPos.I(wm) = floatAvailableSpace.mRect.IEnd(wm) - floatMarginISize;
}
else {
// this is the IE quirk (see few lines above)
// the table is kept in the same line: don't let it overlap the
// previous float
floatPos.I(wm) = floatAvailableSpace.mRect.IStart(wm);
}
}
// CSS2 spec, 9.5.1 rule [4]: "A floating box's outer top may not
// be higher than the top of its containing block." (Since the
// containing block is the content edge of the block box, this
// means the margin edge of the float can't be higher than the
// content edge of the block that contains it.)
floatPos.B(wm) = std::max(mBCoord, ContentBStart());
// Reflow the float after computing its vertical position so it knows
// where to break.
if (!earlyFloatReflow) {
bool pushedDown = mBCoord != restoreBCoord.SavedValue();
mBlock->ReflowFloat(*this, adjustedAvailableSpace, aFloat, floatMargin,
floatOffsets, pushedDown, reflowStatus);
}
if (aFloat->GetPrevInFlow())
floatMargin.BStart(wm) = 0;
if (NS_FRAME_IS_NOT_COMPLETE(reflowStatus))
floatMargin.BEnd(wm) = 0;
// In the case that we're in columns and not splitting floats, we need
// to check here that the float's height fit, and if it didn't, bail.
// (controlled by the pref "layout.float-fragments-inside-column.enabled")
//
// Likewise, if none of the float fit, and it needs to be pushed in
// its entirety to the next page (NS_FRAME_IS_TRUNCATED or
// NS_INLINE_IS_BREAK_BEFORE), we need to do the same.
if ((ContentBSize() != NS_UNCONSTRAINEDSIZE &&
!mFlags.mFloatFragmentsInsideColumnEnabled &&
adjustedAvailableSpace.BSize(wm) == NS_UNCONSTRAINEDSIZE &&
!mustPlaceFloat &&
aFloat->BSize(wm) + floatMargin.BStartEnd(wm) >
ContentBEnd() - floatPos.B(wm)) ||
NS_FRAME_IS_TRUNCATED(reflowStatus) ||
NS_INLINE_IS_BREAK_BEFORE(reflowStatus)) {
PushFloatPastBreak(aFloat);
return false;
}
// We can't use aFloat->ShouldAvoidBreakInside(mReflowInput) here since
// its mIsTopOfPage may be true even though the float isn't at the
// top when floatPos.B(wm) > 0.
if (ContentBSize() != NS_UNCONSTRAINEDSIZE &&
!mustPlaceFloat &&
(!mReflowInput.mFlags.mIsTopOfPage || floatPos.B(wm) > 0) &&
NS_STYLE_PAGE_BREAK_AVOID == aFloat->StyleDisplay()->mBreakInside &&
(!NS_FRAME_IS_FULLY_COMPLETE(reflowStatus) ||
aFloat->BSize(wm) + floatMargin.BStartEnd(wm) >
ContentBEnd() - floatPos.B(wm)) &&
!aFloat->GetPrevInFlow()) {
PushFloatPastBreak(aFloat);
return false;
}
// Calculate the actual origin of the float frame's border rect
// relative to the parent block; the margin must be added in
// to get the border rect
LogicalPoint origin(wm, floatMargin.IStart(wm) + floatPos.I(wm),
floatMargin.BStart(wm) + floatPos.B(wm));
// If float is relatively positioned, factor that in as well
ReflowInput::ApplyRelativePositioning(aFloat, wm, floatOffsets,
&origin, ContainerSize());
// Position the float and make sure and views are properly
// positioned. We need to explicitly position its child views as
// well, since we're moving the float after flowing it.
bool moved = aFloat->GetLogicalPosition(wm, ContainerSize()) != origin;
if (moved) {
aFloat->SetPosition(wm, origin, ContainerSize());
nsContainerFrame::PositionFrameView(aFloat);
nsContainerFrame::PositionChildViews(aFloat);
}
// Update the float combined area state
// XXX Floats should really just get invalidated here if necessary
mFloatOverflowAreas.UnionWith(aFloat->GetOverflowAreas() +
aFloat->GetPosition());
// Place the float in the float manager
// calculate region
LogicalRect region =
nsFloatManager::CalculateRegionFor(wm, aFloat, floatMargin,
ContainerSize());
// if the float split, then take up all of the vertical height
if (NS_FRAME_IS_NOT_COMPLETE(reflowStatus) &&
(NS_UNCONSTRAINEDSIZE != ContentBSize())) {
region.BSize(wm) = std::max(region.BSize(wm),
ContentBSize() - floatPos.B(wm));
}
DebugOnly<nsresult> rv = mFloatManager->AddFloat(aFloat, region, wm,
ContainerSize());
MOZ_ASSERT(NS_SUCCEEDED(rv), "bad float placement");
// store region
nsFloatManager::StoreRegionFor(wm, aFloat, region, ContainerSize());
// If the float's dimensions have changed, note the damage in the
// float manager.
if (!region.IsEqualEdges(oldRegion)) {
// XXXwaterson conservative: we could probably get away with noting
// less damage; e.g., if only height has changed, then only note the
// area into which the float has grown or from which the float has
// shrunk.
nscoord blockStart = std::min(region.BStart(wm), oldRegion.BStart(wm));
nscoord blockEnd = std::max(region.BEnd(wm), oldRegion.BEnd(wm));
mFloatManager->IncludeInDamage(blockStart, blockEnd);
}
if (!NS_FRAME_IS_FULLY_COMPLETE(reflowStatus)) {
mBlock->SplitFloat(*this, aFloat, reflowStatus);
} else {
MOZ_ASSERT(!aFloat->GetNextInFlow());
}
#ifdef DEBUG
if (nsBlockFrame::gNoisyFloatManager) {
nscoord tI, tB;
mFloatManager->GetTranslation(tI, tB);
nsIFrame::ListTag(stdout, mBlock);
printf(": FlowAndPlaceFloat: AddFloat: tIB=%d,%d (%d,%d) {%d,%d,%d,%d}\n",
tI, tB, mFloatManagerI, mFloatManagerB,
region.IStart(wm), region.BStart(wm),
region.ISize(wm), region.BSize(wm));
}
if (nsBlockFrame::gNoisyReflow) {
nsRect r = aFloat->GetRect();
nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
printf("placed float: ");
nsFrame::ListTag(stdout, aFloat);
printf(" %d,%d,%d,%d\n", r.x, r.y, r.width, r.height);
}
#endif
return true;
}
void
BlockReflowInput::PushFloatPastBreak(nsIFrame *aFloat)
{
// This ensures that we:
// * don't try to place later but smaller floats (which CSS says
// must have their tops below the top of this float)
// * don't waste much time trying to reflow this float again until
// after the break
StyleFloat floatStyle =
aFloat->StyleDisplay()->PhysicalFloats(mReflowInput.GetWritingMode());
if (floatStyle == StyleFloat::Left) {
mFloatManager->SetPushedLeftFloatPastBreak();
} else {
MOZ_ASSERT(floatStyle == StyleFloat::Right, "Unexpected float value!");
mFloatManager->SetPushedRightFloatPastBreak();
}
// Put the float on the pushed floats list, even though it
// isn't actually a continuation.
DebugOnly<nsresult> rv = mBlock->StealFrame(aFloat);
NS_ASSERTION(NS_SUCCEEDED(rv), "StealFrame should succeed");
AppendPushedFloatChain(aFloat);
NS_FRAME_SET_OVERFLOW_INCOMPLETE(mReflowStatus);
}
/**
* Place below-current-line floats.
*/
void
BlockReflowInput::PlaceBelowCurrentLineFloats(nsFloatCacheFreeList& aList,
nsLineBox* aLine)
{
nsFloatCache* fc = aList.Head();
while (fc) {
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow) {
nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
printf("placing bcl float: ");
nsFrame::ListTag(stdout, fc->mFloat);
printf("\n");
}
#endif
// Place the float
bool placed = FlowAndPlaceFloat(fc->mFloat);
nsFloatCache *next = fc->Next();
if (!placed) {
aList.Remove(fc);
delete fc;
aLine->SetHadFloatPushed();
}
fc = next;
}
}
nscoord
BlockReflowInput::ClearFloats(nscoord aBCoord, StyleClear aBreakType,
nsIFrame *aReplacedBlock,
uint32_t aFlags)
{
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow) {
nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
printf("clear floats: in: aBCoord=%d\n", aBCoord);
}
#endif
#ifdef NOISY_FLOAT_CLEARING
printf("BlockReflowInput::ClearFloats: aBCoord=%d breakType=%s\n",
aBCoord, nsLineBox::BreakTypeToString(aBreakType));
mFloatManager->List(stdout);
#endif
if (!mFloatManager->HasAnyFloats()) {
return aBCoord;
}
nscoord newBCoord = aBCoord;
if (aBreakType != StyleClear::None) {
newBCoord = mFloatManager->ClearFloats(newBCoord, aBreakType, aFlags);
}
if (aReplacedBlock) {
for (;;) {
nsFlowAreaRect floatAvailableSpace = GetFloatAvailableSpace(newBCoord);
if (ReplacedBlockFitsInAvailSpace(aReplacedBlock, floatAvailableSpace)) {
break;
}
// See the analogous code for inlines in nsBlockFrame::DoReflowInlineFrames
if (!AdvanceToNextBand(floatAvailableSpace.mRect, &newBCoord)) {
// Stop trying to clear here; we'll just get pushed to the
// next column or page and try again there.
break;
}
}
}
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow) {
nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
printf("clear floats: out: y=%d\n", newBCoord);
}
#endif
return newBCoord;
}
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