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chromium / playground / chromium / blink_format / 39cc81ded1ba679622d5c968f49a7087e17b8b9d / . / third_party / WebKit / Source / core / layout / LayoutBlockFlowLine.cpp
blob: fb3acb5ada2d5d3b86a5d34f280300b02b1d92a8 [file] [log] [blame]
/*
* Copyright (C) 2000 Lars Knoll (knoll@kde.org)
* Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All
* right reserved.
* Copyright (C) 2010 Google Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#include "config.h"
#include "core/dom/AXObjectCache.h"
#include "core/layout/BidiRunForLine.h"
#include "core/layout/LayoutCounter.h"
#include "core/layout/LayoutFlowThread.h"
#include "core/layout/LayoutListMarker.h"
#include "core/layout/LayoutObject.h"
#include "core/layout/LayoutRubyRun.h"
#include "core/layout/LayoutView.h"
#include "core/layout/TextRunConstructor.h"
#include "core/layout/VerticalPositionCache.h"
#include "core/layout/api/LineLayoutItem.h"
#include "core/layout/api/SelectionState.h"
#include "core/layout/line/BreakingContextInlineHeaders.h"
#include "core/layout/line/GlyphOverflow.h"
#include "core/layout/line/LayoutTextInfo.h"
#include "core/layout/line/LineLayoutState.h"
#include "core/layout/line/LineWidth.h"
#include "core/layout/line/WordMeasurement.h"
#include "core/layout/svg/line/SVGRootInlineBox.h"
#include "platform/fonts/Character.h"
#include "platform/text/BidiResolver.h"
#include "wtf/RefCountedLeakCounter.h"
#include "wtf/StdLibExtras.h"
#include "wtf/Vector.h"
#include "wtf/text/CharacterNames.h"
namespace blink {
using namespace WTF::Unicode;
static inline InlineBox* createInlineBoxForLayoutObject(
LayoutObject* obj,
bool isRootLineBox,
bool isOnlyRun = false) {
// Callers should handle text themselves.
ASSERT(!obj->isText());
if (isRootLineBox)
return toLayoutBlockFlow(obj)->createAndAppendRootInlineBox();
if (obj->isBox())
return toLayoutBox(obj)->createInlineBox();
return toLayoutInline(obj)->createAndAppendInlineFlowBox();
}
static inline InlineTextBox* createInlineBoxForText(BidiRun& run,
bool isOnlyRun) {
ASSERT(run.m_object->isText());
LayoutText* text = toLayoutText(run.m_object);
InlineTextBox* textBox =
text->createInlineTextBox(run.m_start, run.m_stop - run.m_start);
// We only treat a box as text for a <br> if we are on a line by ourself or in
// strict mode
// (Note the use of strict mode. In "almost strict" mode, we don't treat the
// box for <br> as text.)
if (text->isBR())
textBox->setIsText(isOnlyRun || text->document().inNoQuirksMode());
textBox->setDirOverride(
run.dirOverride(text->style()->rtlOrdering() == VisualOrder));
if (run.m_hasHyphen)
textBox->setHasHyphen(true);
return textBox;
}
static inline void dirtyLineBoxesForObject(LayoutObject* o, bool fullLayout) {
if (o->isText()) {
LayoutText* layoutText = toLayoutText(o);
layoutText->dirtyOrDeleteLineBoxesIfNeeded(fullLayout);
} else {
toLayoutInline(o)->dirtyLineBoxes(fullLayout);
}
}
static bool parentIsConstructedOrHaveNext(InlineFlowBox* parentBox) {
do {
if (parentBox->isConstructed() || parentBox->nextOnLine())
return true;
parentBox = parentBox->parent();
} while (parentBox);
return false;
}
InlineFlowBox* LayoutBlockFlow::createLineBoxes(LayoutObject* obj,
const LineInfo& lineInfo,
InlineBox* childBox) {
// See if we have an unconstructed line box for this object that is also
// the last item on the line.
unsigned lineDepth = 1;
InlineFlowBox* parentBox = nullptr;
InlineFlowBox* result = nullptr;
do {
ASSERT_WITH_SECURITY_IMPLICATION(obj->isLayoutInline() || obj == this);
LayoutInline* inlineFlow = (obj != this) ? toLayoutInline(obj) : 0;
// Get the last box we made for this layout object.
parentBox = inlineFlow ? inlineFlow->lastLineBox()
: toLayoutBlock(obj)->lastLineBox();
// If this box or its ancestor is constructed then it is from a previous
// line, and we need
// to make a new box for our line. If this box or its ancestor is
// unconstructed but it has
// something following it on the line, then we know we have to make a new
// box
// as well. In this situation our inline has actually been split in two on
// the same line (this can happen with very fancy language mixtures).
bool constructedNewBox = false;
bool allowedToConstructNewBox =
!inlineFlow || inlineFlow->alwaysCreateLineBoxes();
bool canUseExistingParentBox =
parentBox && !parentIsConstructedOrHaveNext(parentBox);
if (allowedToConstructNewBox && !canUseExistingParentBox) {
// We need to make a new box for this layout object. Once
// made, we need to place it at the end of the current line.
InlineBox* newBox = createInlineBoxForLayoutObject(obj, obj == this);
ASSERT_WITH_SECURITY_IMPLICATION(newBox->isInlineFlowBox());
parentBox = toInlineFlowBox(newBox);
parentBox->setFirstLineStyleBit(lineInfo.isFirstLine());
parentBox->setIsHorizontal(isHorizontalWritingMode());
constructedNewBox = true;
}
if (constructedNewBox || canUseExistingParentBox) {
if (!result)
result = parentBox;
// If we have hit the block itself, then |box| represents the root
// inline box for the line, and it doesn't have to be appended to any
// parent
// inline.
if (childBox)
parentBox->addToLine(childBox);
if (!constructedNewBox || obj == this)
break;
childBox = parentBox;
}
// If we've exceeded our line depth, then jump straight to the root and skip
// all the remaining
// intermediate inline flows.
obj = (++lineDepth >= cMaxLineDepth) ? this : obj->parent();
} while (true);
return result;
}
template <typename CharacterType>
static inline bool endsWithASCIISpaces(const CharacterType* characters,
unsigned pos,
unsigned end) {
while (isASCIISpace(characters[pos])) {
pos++;
if (pos >= end)
return true;
}
return false;
}
static bool reachedEndOfTextRun(const BidiRunList<BidiRun>& bidiRuns) {
BidiRun* run = bidiRuns.logicallyLastRun();
if (!run)
return true;
unsigned pos = run->stop();
LayoutObject* r = run->m_object;
if (!r->isText() || r->isBR())
return false;
LayoutText* layoutText = toLayoutText(r);
unsigned length = layoutText->textLength();
if (pos >= length)
return true;
if (layoutText->is8Bit())
return endsWithASCIISpaces(layoutText->characters8(), pos, length);
return endsWithASCIISpaces(layoutText->characters16(), pos, length);
}
RootInlineBox* LayoutBlockFlow::constructLine(BidiRunList<BidiRun>& bidiRuns,
const LineInfo& lineInfo) {
ASSERT(bidiRuns.firstRun());
bool rootHasSelectedChildren = false;
InlineFlowBox* parentBox = nullptr;
int runCount = bidiRuns.runCount() - lineInfo.runsFromLeadingWhitespace();
for (BidiRun* r = bidiRuns.firstRun(); r; r = r->next()) {
// Create a box for our object.
bool isOnlyRun = (runCount == 1);
if (runCount == 2 && !r->m_object->isListMarker())
isOnlyRun = (!style()->isLeftToRightDirection() ? bidiRuns.lastRun()
: bidiRuns.firstRun())
->m_object->isListMarker();
if (lineInfo.isEmpty())
continue;
InlineBox* box;
if (r->m_object->isText())
box = createInlineBoxForText(*r, isOnlyRun);
else
box = createInlineBoxForLayoutObject(r->m_object, false, isOnlyRun);
r->m_box = box;
ASSERT(box);
if (!box)
continue;
if (!rootHasSelectedChildren &&
box->layoutObject().selectionState() != SelectionNone)
rootHasSelectedChildren = true;
// If we have no parent box yet, or if the run is not simply a sibling,
// then we need to construct inline boxes as necessary to properly enclose
// the
// run's inline box. Segments can only be siblings at the root level, as
// they are positioned separately.
if (!parentBox || parentBox->layoutObject() != r->m_object->parent()) {
// Create new inline boxes all the way back to the appropriate insertion
// point.
parentBox = createLineBoxes(r->m_object->parent(), lineInfo, box);
} else {
// Append the inline box to this line.
parentBox->addToLine(box);
}
box->setBidiLevel(r->level());
if (box->isInlineTextBox()) {
if (AXObjectCache* cache = document().existingAXObjectCache())
cache->inlineTextBoxesUpdated(r->m_object);
}
}
// We should have a root inline box. It should be unconstructed and
// be the last continuation of our line list.
ASSERT(lastLineBox() && !lastLineBox()->isConstructed());
// Set the m_selectedChildren flag on the root inline box if one of the leaf
// inline box
// from the bidi runs walk above has a selection state.
if (rootHasSelectedChildren)
lastLineBox()->root().setHasSelectedChildren(true);
// Set bits on our inline flow boxes that indicate which sides should
// paint borders/margins/padding. This knowledge will ultimately be used when
// we determine the horizontal positions and widths of all the inline boxes on
// the line.
bool isLogicallyLastRunWrapped =
bidiRuns.logicallyLastRun()->m_object &&
bidiRuns.logicallyLastRun()->m_object->isText()
? !reachedEndOfTextRun(bidiRuns)
: true;
lastLineBox()->determineSpacingForFlowBoxes(
lineInfo.isLastLine(), isLogicallyLastRunWrapped,
bidiRuns.logicallyLastRun()->m_object);
// Now mark the line boxes as being constructed.
lastLineBox()->setConstructed();
// Return the last line.
return lastRootBox();
}
ETextAlign LayoutBlockFlow::textAlignmentForLine(bool endsWithSoftBreak) const {
ETextAlign alignment = style()->textAlign();
if (endsWithSoftBreak)
return alignment;
TextAlignLast alignmentLast = style()->textAlignLast();
switch (alignmentLast) {
case TextAlignLastStart:
return TASTART;
case TextAlignLastEnd:
return TAEND;
case TextAlignLastLeft:
return LEFT;
case TextAlignLastRight:
return RIGHT;
case TextAlignLastCenter:
return CENTER;
case TextAlignLastJustify:
return JUSTIFY;
case TextAlignLastAuto:
if (alignment == JUSTIFY)
return TASTART;
return alignment;
}
return alignment;
}
static void updateLogicalWidthForLeftAlignedBlock(
bool isLeftToRightDirection,
BidiRun* trailingSpaceRun,
LayoutUnit& logicalLeft,
LayoutUnit totalLogicalWidth,
LayoutUnit availableLogicalWidth) {
// The direction of the block should determine what happens with wide lines.
// In particular with RTL blocks, wide lines should still spill out to the
// left.
if (isLeftToRightDirection) {
if (totalLogicalWidth > availableLogicalWidth && trailingSpaceRun)
trailingSpaceRun->m_box->setLogicalWidth(std::max(
LayoutUnit(), trailingSpaceRun->m_box->logicalWidth() -
totalLogicalWidth + availableLogicalWidth));
return;
}
if (trailingSpaceRun)
trailingSpaceRun->m_box->setLogicalWidth(0);
else if (totalLogicalWidth > availableLogicalWidth)
logicalLeft -= (totalLogicalWidth - availableLogicalWidth);
}
static void updateLogicalWidthForRightAlignedBlock(
bool isLeftToRightDirection,
BidiRun* trailingSpaceRun,
LayoutUnit& logicalLeft,
LayoutUnit& totalLogicalWidth,
LayoutUnit availableLogicalWidth) {
// Wide lines spill out of the block based off direction.
// So even if text-align is right, if direction is LTR, wide lines should
// overflow out of the right
// side of the block.
if (isLeftToRightDirection) {
if (trailingSpaceRun) {
totalLogicalWidth -= trailingSpaceRun->m_box->logicalWidth();
trailingSpaceRun->m_box->setLogicalWidth(0);
}
if (totalLogicalWidth < availableLogicalWidth)
logicalLeft += availableLogicalWidth - totalLogicalWidth;
return;
}
if (totalLogicalWidth > availableLogicalWidth && trailingSpaceRun) {
trailingSpaceRun->m_box->setLogicalWidth(
std::max(LayoutUnit(), trailingSpaceRun->m_box->logicalWidth() -
totalLogicalWidth + availableLogicalWidth));
totalLogicalWidth -= trailingSpaceRun->m_box->logicalWidth();
} else {
logicalLeft += availableLogicalWidth - totalLogicalWidth;
}
}
static void updateLogicalWidthForCenterAlignedBlock(
bool isLeftToRightDirection,
BidiRun* trailingSpaceRun,
LayoutUnit& logicalLeft,
LayoutUnit& totalLogicalWidth,
LayoutUnit availableLogicalWidth) {
LayoutUnit trailingSpaceWidth;
if (trailingSpaceRun) {
totalLogicalWidth -= trailingSpaceRun->m_box->logicalWidth();
trailingSpaceWidth =
std::min(trailingSpaceRun->m_box->logicalWidth(),
(availableLogicalWidth - totalLogicalWidth + 1) / 2);
trailingSpaceRun->m_box->setLogicalWidth(
std::max(LayoutUnit(), trailingSpaceWidth));
}
if (isLeftToRightDirection)
logicalLeft +=
std::max((availableLogicalWidth - totalLogicalWidth) / 2, LayoutUnit());
else
logicalLeft += totalLogicalWidth > availableLogicalWidth
? (availableLogicalWidth - totalLogicalWidth)
: (availableLogicalWidth - totalLogicalWidth) / 2 -
trailingSpaceWidth;
}
void LayoutBlockFlow::setMarginsForRubyRun(BidiRun* run,
LayoutRubyRun* layoutRubyRun,
LayoutObject* previousObject,
const LineInfo& lineInfo) {
int startOverhang;
int endOverhang;
LayoutObject* nextObject = nullptr;
for (BidiRun* runWithNextObject = run->next(); runWithNextObject;
runWithNextObject = runWithNextObject->next()) {
if (!runWithNextObject->m_object->isOutOfFlowPositioned() &&
!runWithNextObject->m_box->isLineBreak()) {
nextObject = runWithNextObject->m_object;
break;
}
}
layoutRubyRun->getOverhang(
lineInfo.isFirstLine(),
layoutRubyRun->style()->isLeftToRightDirection() ? previousObject
: nextObject,
layoutRubyRun->style()->isLeftToRightDirection() ? nextObject
: previousObject,
startOverhang, endOverhang);
setMarginStartForChild(*layoutRubyRun, -startOverhang);
setMarginEndForChild(*layoutRubyRun, -endOverhang);
}
static inline void setLogicalWidthForTextRun(
RootInlineBox* lineBox,
BidiRun* run,
LayoutText* layoutText,
LayoutUnit xPos,
const LineInfo& lineInfo,
GlyphOverflowAndFallbackFontsMap& textBoxDataMap,
VerticalPositionCache& verticalPositionCache,
WordMeasurements& wordMeasurements) {
HashSet<const SimpleFontData*> fallbackFonts;
GlyphOverflow glyphOverflow;
const Font& font = layoutText->style(lineInfo.isFirstLine())->font();
LayoutUnit hyphenWidth = 0;
if (toInlineTextBox(run->m_box)->hasHyphen())
hyphenWidth = layoutText->hyphenWidth(font, run->direction());
float measuredWidth = 0;
FloatRect glyphBounds;
bool kerningIsEnabled =
font.fontDescription().typesettingFeatures() & Kerning;
#if OS(MACOSX)
// FIXME: Having any font feature settings enabled can lead to selection gaps
// on
// Chromium-mac. https://bugs.webkit.org/show_bug.cgi?id=113418
bool canUseSimpleFontCodePath = layoutText->canUseSimpleFontCodePath() &&
!font.fontDescription().featureSettings();
#else
bool canUseSimpleFontCodePath = layoutText->canUseSimpleFontCodePath();
#endif
if (canUseSimpleFontCodePath) {
int lastEndOffset = run->m_start;
for (size_t i = 0, size = wordMeasurements.size();
i < size && lastEndOffset < run->m_stop; ++i) {
const WordMeasurement& wordMeasurement = wordMeasurements[i];
if (wordMeasurement.startOffset == wordMeasurement.endOffset)
continue;
if (wordMeasurement.layoutText != layoutText ||
wordMeasurement.startOffset != lastEndOffset ||
wordMeasurement.endOffset > run->m_stop)
continue;
lastEndOffset = wordMeasurement.endOffset;
if (kerningIsEnabled && lastEndOffset == run->m_stop) {
int wordLength = lastEndOffset - wordMeasurement.startOffset;
measuredWidth +=
layoutText->width(wordMeasurement.startOffset, wordLength, xPos,
run->direction(), lineInfo.isFirstLine());
if (i > 0 && wordLength == 1 &&
layoutText->characterAt(wordMeasurement.startOffset) == ' ')
measuredWidth += layoutText->style()->wordSpacing();
} else {
FloatRect wordGlyphBounds = wordMeasurement.glyphBounds;
wordGlyphBounds.move(measuredWidth, 0);
glyphBounds.unite(wordGlyphBounds);
measuredWidth += wordMeasurement.width;
}
if (!wordMeasurement.fallbackFonts.isEmpty()) {
HashSet<const SimpleFontData*>::const_iterator end =
wordMeasurement.fallbackFonts.end();
for (HashSet<const SimpleFontData*>::const_iterator it =
wordMeasurement.fallbackFonts.begin();
it != end; ++it)
fallbackFonts.add(*it);
}
}
if (lastEndOffset != run->m_stop) {
// If we don't have enough cached data, we'll measure the run again.
canUseSimpleFontCodePath = false;
fallbackFonts.clear();
}
}
// Don't put this into 'else' part of the above 'if' because
// canUseSimpleFontCodePath may be modified in the 'if' block.
if (!canUseSimpleFontCodePath)
measuredWidth = layoutText->width(
run->m_start, run->m_stop - run->m_start, xPos, run->direction(),
lineInfo.isFirstLine(), &fallbackFonts, &glyphBounds);
// Negative word-spacing and/or letter-spacing may cause some glyphs to
// overflow the left boundary and result
// negative measured width. Reset measured width to 0 and adjust glyph bounds
// accordingly to cover the overflow.
if (measuredWidth < 0) {
if (measuredWidth < glyphBounds.x()) {
glyphBounds.expand(glyphBounds.x() - measuredWidth, 0);
glyphBounds.setX(measuredWidth);
}
measuredWidth = 0;
}
glyphOverflow.setFromBounds(glyphBounds, font.fontMetrics().floatAscent(),
font.fontMetrics().floatDescent(), measuredWidth);
run->m_box->setLogicalWidth(measuredWidth + hyphenWidth);
if (!fallbackFonts.isEmpty()) {
ASSERT(run->m_box->isText());
GlyphOverflowAndFallbackFontsMap::ValueType* it =
textBoxDataMap
.add(toInlineTextBox(run->m_box),
std::make_pair(Vector<const SimpleFontData*>(),
GlyphOverflow()))
.storedValue;
ASSERT(it->value.first.isEmpty());
copyToVector(fallbackFonts, it->value.first);
run->m_box->parent()->clearDescendantsHaveSameLineHeightAndBaseline();
}
if (!glyphOverflow.isZero()) {
ASSERT(run->m_box->isText());
GlyphOverflowAndFallbackFontsMap::ValueType* it =
textBoxDataMap
.add(toInlineTextBox(run->m_box),
std::make_pair(Vector<const SimpleFontData*>(),
GlyphOverflow()))
.storedValue;
it->value.second = glyphOverflow;
run->m_box->clearKnownToHaveNoOverflow();
}
}
static inline void computeExpansionForJustifiedText(
BidiRun* firstRun,
BidiRun* trailingSpaceRun,
Vector<unsigned, 16>& expansionOpportunities,
unsigned expansionOpportunityCount,
LayoutUnit& totalLogicalWidth,
LayoutUnit availableLogicalWidth) {
if (!expansionOpportunityCount || availableLogicalWidth <= totalLogicalWidth)
return;
size_t i = 0;
for (BidiRun* r = firstRun; r; r = r->next()) {
if (!r->m_box || r == trailingSpaceRun)
continue;
if (r->m_object->isText()) {
unsigned opportunitiesInRun = expansionOpportunities[i++];
ASSERT(opportunitiesInRun <= expansionOpportunityCount);
// Don't justify for white-space: pre.
if (r->m_object->style()->whiteSpace() != PRE) {
InlineTextBox* textBox = toInlineTextBox(r->m_box);
RELEASE_ASSERT(expansionOpportunityCount);
int expansion = (availableLogicalWidth - totalLogicalWidth) *
opportunitiesInRun / expansionOpportunityCount;
textBox->setExpansion(expansion);
totalLogicalWidth += expansion;
}
expansionOpportunityCount -= opportunitiesInRun;
if (!expansionOpportunityCount)
break;
}
}
}
void LayoutBlockFlow::updateLogicalWidthForAlignment(
const ETextAlign& textAlign,
const RootInlineBox* rootInlineBox,
BidiRun* trailingSpaceRun,
LayoutUnit& logicalLeft,
LayoutUnit& totalLogicalWidth,
LayoutUnit& availableLogicalWidth,
unsigned expansionOpportunityCount) {
TextDirection direction;
if (rootInlineBox &&
rootInlineBox->layoutObject().style()->unicodeBidi() == Plaintext)
direction = rootInlineBox->direction();
else
direction = style()->direction();
// Armed with the total width of the line (without justification),
// we now examine our text-align property in order to determine where to
// position the
// objects horizontally. The total width of the line can be increased if we
// end up
// justifying text.
switch (textAlign) {
case LEFT:
case WEBKIT_LEFT:
updateLogicalWidthForLeftAlignedBlock(
style()->isLeftToRightDirection(), trailingSpaceRun, logicalLeft,
totalLogicalWidth, availableLogicalWidth);
break;
case RIGHT:
case WEBKIT_RIGHT:
updateLogicalWidthForRightAlignedBlock(
style()->isLeftToRightDirection(), trailingSpaceRun, logicalLeft,
totalLogicalWidth, availableLogicalWidth);
break;
case CENTER:
case WEBKIT_CENTER:
updateLogicalWidthForCenterAlignedBlock(
style()->isLeftToRightDirection(), trailingSpaceRun, logicalLeft,
totalLogicalWidth, availableLogicalWidth);
break;
case JUSTIFY:
adjustInlineDirectionLineBounds(expansionOpportunityCount, logicalLeft,
availableLogicalWidth);
if (expansionOpportunityCount) {
if (trailingSpaceRun) {
totalLogicalWidth -= trailingSpaceRun->m_box->logicalWidth();
trailingSpaceRun->m_box->setLogicalWidth(0);
}
break;
}
// Fall through
case TASTART:
if (direction == LTR)
updateLogicalWidthForLeftAlignedBlock(
style()->isLeftToRightDirection(), trailingSpaceRun, logicalLeft,
totalLogicalWidth, availableLogicalWidth);
else
updateLogicalWidthForRightAlignedBlock(
style()->isLeftToRightDirection(), trailingSpaceRun, logicalLeft,
totalLogicalWidth, availableLogicalWidth);
break;
case TAEND:
if (direction == LTR)
updateLogicalWidthForRightAlignedBlock(
style()->isLeftToRightDirection(), trailingSpaceRun, logicalLeft,
totalLogicalWidth, availableLogicalWidth);
else
updateLogicalWidthForLeftAlignedBlock(
style()->isLeftToRightDirection(), trailingSpaceRun, logicalLeft,
totalLogicalWidth, availableLogicalWidth);
break;
}
if (style()->shouldPlaceBlockDirectionScrollbarOnLogicalLeft())
logicalLeft += verticalScrollbarWidth();
}
static void updateLogicalInlinePositions(LayoutBlockFlow* block,
LayoutUnit& lineLogicalLeft,
LayoutUnit& lineLogicalRight,
LayoutUnit& availableLogicalWidth,
bool firstLine,
IndentTextOrNot shouldIndentText,
LayoutUnit boxLogicalHeight) {
LayoutUnit lineLogicalHeight =
block->minLineHeightForReplacedObject(firstLine, boxLogicalHeight);
lineLogicalLeft = block->logicalLeftOffsetForLine(
block->logicalHeight(), shouldIndentText == IndentText,
lineLogicalHeight);
lineLogicalRight = block->logicalRightOffsetForLine(
block->logicalHeight(), shouldIndentText == IndentText,
lineLogicalHeight);
availableLogicalWidth = lineLogicalRight - lineLogicalLeft;
}
void LayoutBlockFlow::computeInlineDirectionPositionsForLine(
RootInlineBox* lineBox,
const LineInfo& lineInfo,
BidiRun* firstRun,
BidiRun* trailingSpaceRun,
bool reachedEnd,
GlyphOverflowAndFallbackFontsMap& textBoxDataMap,
VerticalPositionCache& verticalPositionCache,
WordMeasurements& wordMeasurements) {
ETextAlign textAlign =
textAlignmentForLine(!reachedEnd && !lineBox->endsWithBreak());
// CSS 2.1: "'Text-indent' only affects a line if it is the first formatted
// line of an element. For example, the first line of an anonymous block
// box is only affected if it is the first child of its parent element."
// CSS3 "text-indent", "each-line" affects the first line of the block
// container as well as each line after a forced line break,
// but does not affect lines after a soft wrap break.
bool isFirstLine =
lineInfo.isFirstLine() &&
!(isAnonymousBlock() && parent()->slowFirstChild() != this);
bool isAfterHardLineBreak =
lineBox->prevRootBox() && lineBox->prevRootBox()->endsWithBreak();
IndentTextOrNot shouldIndentText =
requiresIndent(isFirstLine, isAfterHardLineBreak, styleRef());
LayoutUnit lineLogicalLeft;
LayoutUnit lineLogicalRight;
LayoutUnit availableLogicalWidth;
updateLogicalInlinePositions(this, lineLogicalLeft, lineLogicalRight,
availableLogicalWidth, isFirstLine,
shouldIndentText, 0);
bool needsWordSpacing;
if (firstRun && firstRun->m_object->isReplaced()) {
LayoutBox* layoutBox = toLayoutBox(firstRun->m_object);
updateLogicalInlinePositions(this, lineLogicalLeft, lineLogicalRight,
availableLogicalWidth, isFirstLine,
shouldIndentText, layoutBox->logicalHeight());
}
computeInlineDirectionPositionsForSegment(
lineBox, lineInfo, textAlign, lineLogicalLeft, availableLogicalWidth,
firstRun, trailingSpaceRun, textBoxDataMap, verticalPositionCache,
wordMeasurements);
// The widths of all runs are now known. We can now place every inline box
// (and
// compute accurate widths for the inline flow boxes).
needsWordSpacing = lineBox->isLeftToRightDirection() ? false : true;
lineBox->placeBoxesInInlineDirection(lineLogicalLeft, needsWordSpacing);
}
BidiRun* LayoutBlockFlow::computeInlineDirectionPositionsForSegment(
RootInlineBox* lineBox,
const LineInfo& lineInfo,
ETextAlign textAlign,
LayoutUnit& logicalLeft,
LayoutUnit& availableLogicalWidth,
BidiRun* firstRun,
BidiRun* trailingSpaceRun,
GlyphOverflowAndFallbackFontsMap& textBoxDataMap,
VerticalPositionCache& verticalPositionCache,
WordMeasurements& wordMeasurements) {
bool needsWordSpacing = true;
LayoutUnit totalLogicalWidth = lineBox->getFlowSpacingLogicalWidth();
unsigned expansionOpportunityCount = 0;
bool isAfterExpansion = true;
Vector<unsigned, 16> expansionOpportunities;
LayoutObject* previousObject = nullptr;
TextJustify textJustify = style()->textJustify();
BidiRun* r = firstRun;
for (; r; r = r->next()) {
if (!r->m_box || r->m_object->isOutOfFlowPositioned() ||
r->m_box->isLineBreak()) {
continue; // Positioned objects are only participating to figure out
// their
// correct static x position. They have no effect on the width.
// Similarly, line break boxes have no effect on the width.
}
if (r->m_object->isText()) {
LayoutText* rt = toLayoutText(r->m_object);
if (textAlign == JUSTIFY && r != trailingSpaceRun &&
textJustify != TextJustifyNone) {
if (!isAfterExpansion)
toInlineTextBox(r->m_box)->setCanHaveLeadingExpansion(true);
unsigned opportunitiesInRun;
if (rt->is8Bit())
opportunitiesInRun = Character::expansionOpportunityCount(
rt->characters8() + r->m_start, r->m_stop - r->m_start,
r->m_box->direction(), isAfterExpansion, textJustify);
else
opportunitiesInRun = Character::expansionOpportunityCount(
rt->characters16() + r->m_start, r->m_stop - r->m_start,
r->m_box->direction(), isAfterExpansion, textJustify);
expansionOpportunities.append(opportunitiesInRun);
expansionOpportunityCount += opportunitiesInRun;
}
if (rt->textLength()) {
if (!r->m_start && needsWordSpacing &&
isSpaceOrNewline(rt->characterAt(r->m_start)))
totalLogicalWidth += rt->style(lineInfo.isFirstLine())
->font()
.fontDescription()
.wordSpacing();
needsWordSpacing = !isSpaceOrNewline(rt->characterAt(r->m_stop - 1));
}
setLogicalWidthForTextRun(lineBox, r, rt, totalLogicalWidth, lineInfo,
textBoxDataMap, verticalPositionCache,
wordMeasurements);
} else {
isAfterExpansion = false;
if (!r->m_object->isLayoutInline()) {
LayoutBox* layoutBox = toLayoutBox(r->m_object);
if (layoutBox->isRubyRun())
setMarginsForRubyRun(r, toLayoutRubyRun(layoutBox), previousObject,
lineInfo);
r->m_box->setLogicalWidth(logicalWidthForChild(*layoutBox));
totalLogicalWidth +=
marginStartForChild(*layoutBox) + marginEndForChild(*layoutBox);
needsWordSpacing = true;
}
}
totalLogicalWidth += r->m_box->logicalWidth();
previousObject = r->m_object;
}
if (isAfterExpansion && !expansionOpportunities.isEmpty()) {
expansionOpportunities.last()--;
expansionOpportunityCount--;
}
updateLogicalWidthForAlignment(
textAlign, lineBox, trailingSpaceRun, logicalLeft, totalLogicalWidth,
availableLogicalWidth, expansionOpportunityCount);
computeExpansionForJustifiedText(
firstRun, trailingSpaceRun, expansionOpportunities,
expansionOpportunityCount, totalLogicalWidth, availableLogicalWidth);
return r;
}
void LayoutBlockFlow::computeBlockDirectionPositionsForLine(
RootInlineBox* lineBox,
BidiRun* firstRun,
GlyphOverflowAndFallbackFontsMap& textBoxDataMap,
VerticalPositionCache& verticalPositionCache) {
setLogicalHeight(lineBox->alignBoxesInBlockDirection(
logicalHeight(), textBoxDataMap, verticalPositionCache));
// Now make sure we place replaced layout objects correctly.
for (BidiRun* r = firstRun; r; r = r->next()) {
ASSERT(r->m_box);
if (!r->m_box)
continue; // Skip runs with no line boxes.
// Align positioned boxes with the top of the line box. This is
// a reasonable approximation of an appropriate y position.
if (r->m_object->isOutOfFlowPositioned())
r->m_box->setLogicalTop(logicalHeight());
// Position is used to properly position both replaced elements and
// to update the static normal flow x/y of positioned elements.
if (r->m_object->isText())
toLayoutText(r->m_object)->positionLineBox(r->m_box);
else if (r->m_object->isBox())
toLayoutBox(r->m_object)->positionLineBox(r->m_box);
}
}
void LayoutBlockFlow::appendFloatingObjectToLastLine(
FloatingObject& floatingObject) {
ASSERT(!floatingObject.originatingLine());
floatingObject.setOriginatingLine(lastRootBox());
lastRootBox()->appendFloat(floatingObject.layoutObject());
}
// This function constructs line boxes for all of the text runs in the resolver
// and computes their position.
RootInlineBox* LayoutBlockFlow::createLineBoxesFromBidiRuns(
unsigned bidiLevel,
BidiRunList<BidiRun>& bidiRuns,
const InlineIterator& end,
LineInfo& lineInfo,
VerticalPositionCache& verticalPositionCache,
BidiRun* trailingSpaceRun,
WordMeasurements& wordMeasurements) {
if (!bidiRuns.runCount())
return nullptr;
// FIXME: Why is this only done when we had runs?
lineInfo.setLastLine(!end.object());
RootInlineBox* lineBox = constructLine(bidiRuns, lineInfo);
if (!lineBox)
return nullptr;
lineBox->setBidiLevel(bidiLevel);
lineBox->setEndsWithBreak(lineInfo.previousLineBrokeCleanly());
bool isSVGRootInlineBox = lineBox->isSVGRootInlineBox();
GlyphOverflowAndFallbackFontsMap textBoxDataMap;
// Now we position all of our text runs horizontally.
if (!isSVGRootInlineBox)
computeInlineDirectionPositionsForLine(
lineBox, lineInfo, bidiRuns.firstRun(), trailingSpaceRun, end.atEnd(),
textBoxDataMap, verticalPositionCache, wordMeasurements);
// Now position our text runs vertically.
computeBlockDirectionPositionsForLine(lineBox, bidiRuns.firstRun(),
textBoxDataMap, verticalPositionCache);
// SVG text layout code computes vertical & horizontal positions on its own.
// Note that we still need to execute computeVerticalPositionsForLine() as
// it calls InlineTextBox::positionLineBox(), which tracks whether the box
// contains reversed text or not. If we wouldn't do that editing and thus
// text selection in RTL boxes would not work as expected.
if (isSVGRootInlineBox) {
ASSERT(isSVGText());
toSVGRootInlineBox(lineBox)->computePerCharacterLayoutInformation();
}
// Compute our overflow now.
lineBox->computeOverflow(lineBox->lineTop(), lineBox->lineBottom(),
textBoxDataMap);
return lineBox;
}
static void deleteLineRange(LineLayoutState& layoutState,
RootInlineBox* startLine,
RootInlineBox* stopLine = 0) {
RootInlineBox* boxToDelete = startLine;
while (boxToDelete && boxToDelete != stopLine) {
layoutState.updatePaintInvalidationRangeFromBox(boxToDelete);
// Note: deleteLineRange(firstRootBox()) is not identical to
// deleteLineBoxTree().
// deleteLineBoxTree uses nextLineBox() instead of nextRootBox() when
// traversing.
RootInlineBox* next = boxToDelete->nextRootBox();
boxToDelete->deleteLine();
boxToDelete = next;
}
}
void LayoutBlockFlow::layoutRunsAndFloats(LineLayoutState& layoutState) {
// We want to skip ahead to the first dirty line
InlineBidiResolver resolver;
RootInlineBox* startLine = determineStartPosition(layoutState, resolver);
if (containsFloats())
layoutState.setLastFloat(m_floatingObjects->set().last().get());
// We also find the first clean line and extract these lines. We will add
// them back
// if we determine that we're able to synchronize after handling all our dirty
// lines.
InlineIterator cleanLineStart;
BidiStatus cleanLineBidiStatus;
if (!layoutState.isFullLayout() && startLine)
determineEndPosition(layoutState, startLine, cleanLineStart,
cleanLineBidiStatus);
if (startLine) {
if (!layoutState.usesPaintInvalidationBounds())
layoutState.setPaintInvalidationRange(logicalHeight());
deleteLineRange(layoutState, startLine);
}
layoutRunsAndFloatsInRange(layoutState, resolver, cleanLineStart,
cleanLineBidiStatus);
linkToEndLineIfNeeded(layoutState);
markDirtyFloatsForPaintInvalidation(layoutState.floats());
}
// Before restarting the layout loop with a new logicalHeight, remove all floats
// that were added and reset the resolver.
inline const InlineIterator& LayoutBlockFlow::restartLayoutRunsAndFloatsInRange(
LayoutUnit oldLogicalHeight,
LayoutUnit newLogicalHeight,
FloatingObject* lastFloatFromPreviousLine,
InlineBidiResolver& resolver,
const InlineIterator& oldEnd) {
removeFloatingObjectsBelow(lastFloatFromPreviousLine, oldLogicalHeight);
setLogicalHeight(newLogicalHeight);
resolver.setPositionIgnoringNestedIsolates(oldEnd);
return oldEnd;
}
void LayoutBlockFlow::layoutRunsAndFloatsInRange(
LineLayoutState& layoutState,
InlineBidiResolver& resolver,
const InlineIterator& cleanLineStart,
const BidiStatus& cleanLineBidiStatus) {
const ComputedStyle& styleToUse = styleRef();
bool paginated =
view()->layoutState() && view()->layoutState()->isPaginated();
LineMidpointState& lineMidpointState = resolver.midpointState();
InlineIterator endOfLine = resolver.position();
bool checkForEndLineMatch = layoutState.endLine();
LayoutTextInfo layoutTextInfo;
VerticalPositionCache verticalPositionCache;
LineBreaker lineBreaker(LineLayoutBlockFlow(this));
while (!endOfLine.atEnd()) {
bool logicalWidthIsAvailable = false;
// FIXME: Is this check necessary before the first iteration or can it be
// moved to the end?
if (checkForEndLineMatch) {
layoutState.setEndLineMatched(matchedEndLine(
layoutState, resolver, cleanLineStart, cleanLineBidiStatus));
if (layoutState.endLineMatched()) {
resolver.setPosition(InlineIterator(resolver.position().root(), 0, 0),
0);
break;
}
}
lineMidpointState.reset();
layoutState.lineInfo().setEmpty(true);
layoutState.lineInfo().resetRunsFromLeadingWhitespace();
const InlineIterator previousEndofLine = endOfLine;
bool isNewUBAParagraph = layoutState.lineInfo().previousLineBrokeCleanly();
FloatingObject* lastFloatFromPreviousLine =
(containsFloats()) ? m_floatingObjects->set().last().get() : 0;
WordMeasurements wordMeasurements;
endOfLine = lineBreaker.nextLineBreak(
resolver, layoutState.lineInfo(), layoutTextInfo,
lastFloatFromPreviousLine, wordMeasurements);
layoutTextInfo.m_lineBreakIterator.resetPriorContext();
if (resolver.position().atEnd()) {
// FIXME: We shouldn't be creating any runs in nextLineBreak to begin
// with!
// Once BidiRunList is separated from BidiResolver this will not be
// needed.
resolver.runs().deleteRuns();
resolver.markCurrentRunEmpty(); // FIXME: This can probably be replaced
// by an ASSERT (or just removed).
resolver.setPosition(InlineIterator(resolver.position().root(), 0, 0), 0);
break;
}
ASSERT(endOfLine != resolver.position());
// This is a short-cut for empty lines.
if (layoutState.lineInfo().isEmpty()) {
if (lastRootBox())
lastRootBox()->setLineBreakInfo(endOfLine.object(), endOfLine.offset(),
resolver.status());
} else {
VisualDirectionOverride override =
(styleToUse.rtlOrdering() == VisualOrder
? (styleToUse.direction() == LTR ? VisualLeftToRightOverride
: VisualRightToLeftOverride)
: NoVisualOverride);
if (isNewUBAParagraph && styleToUse.unicodeBidi() == Plaintext &&
!resolver.context()->parent()) {
TextDirection direction = determinePlaintextDirectionality(
resolver.position().root(), resolver.position().object(),
resolver.position().offset());
resolver.setStatus(
BidiStatus(direction, isOverride(styleToUse.unicodeBidi())));
}
// FIXME: This ownership is reversed. We should own the BidiRunList and
// pass it to createBidiRunsForLine.
BidiRunList<BidiRun>& bidiRuns = resolver.runs();
constructBidiRunsForLine(
resolver, bidiRuns, endOfLine, override,
layoutState.lineInfo().previousLineBrokeCleanly(), isNewUBAParagraph);
ASSERT(resolver.position() == endOfLine);
BidiRun* trailingSpaceRun = resolver.trailingSpaceRun();
if (bidiRuns.runCount() && lineBreaker.lineWasHyphenated())
bidiRuns.logicallyLastRun()->m_hasHyphen = true;
// Now that the runs have been ordered, we create the line boxes.
// At the same time we figure out where border/padding/margin should be
// applied for
// inline flow boxes.
LayoutUnit oldLogicalHeight = logicalHeight();
RootInlineBox* lineBox = createLineBoxesFromBidiRuns(
resolver.status().context->level(), bidiRuns, endOfLine,
layoutState.lineInfo(), verticalPositionCache, trailingSpaceRun,
wordMeasurements);
bidiRuns.deleteRuns();
resolver.markCurrentRunEmpty(); // FIXME: This can probably be replaced
// by an ASSERT (or just removed).
if (lineBox) {
lineBox->setLineBreakInfo(endOfLine.object(), endOfLine.offset(),
resolver.status());
if (layoutState.usesPaintInvalidationBounds())
layoutState.updatePaintInvalidationRangeFromBox(lineBox);
if (paginated) {
LayoutUnit adjustment = 0;
adjustLinePositionForPagination(*lineBox, adjustment);
if (adjustment) {
LayoutUnit oldLineWidth = availableLogicalWidthForLine(
oldLogicalHeight, layoutState.lineInfo().isFirstLine());
lineBox->moveInBlockDirection(adjustment);
if (layoutState.usesPaintInvalidationBounds())
layoutState.updatePaintInvalidationRangeFromBox(lineBox);
if (availableLogicalWidthForLine(
oldLogicalHeight + adjustment,
layoutState.lineInfo().isFirstLine()) != oldLineWidth) {
// We have to delete this line, remove all floats that got added,
// and let line layout re-run.
lineBox->deleteLine();
endOfLine = restartLayoutRunsAndFloatsInRange(
oldLogicalHeight, oldLogicalHeight + adjustment,
lastFloatFromPreviousLine, resolver, previousEndofLine);
logicalWidthIsAvailable = true;
} else {
setLogicalHeight(lineBox->lineBottomWithLeading());
}
}
}
}
}
if (!logicalWidthIsAvailable) {
for (size_t i = 0; i < lineBreaker.positionedObjects().size(); ++i)
setStaticPositions(LineLayoutBlockFlow(this),
LineLayoutBox(lineBreaker.positionedObjects()[i]));
if (!layoutState.lineInfo().isEmpty())
layoutState.lineInfo().setFirstLine(false);
clearFloats(lineBreaker.clear());
if (m_floatingObjects && lastRootBox()) {
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
FloatingObjectSetIterator it = floatingObjectSet.begin();
FloatingObjectSetIterator end = floatingObjectSet.end();
if (layoutState.lastFloat()) {
FloatingObjectSetIterator lastFloatIterator =
floatingObjectSet.find(layoutState.lastFloat());
ASSERT(lastFloatIterator != end);
++lastFloatIterator;
it = lastFloatIterator;
}
for (; it != end; ++it) {
FloatingObject& floatingObject = *it->get();
// If we've reached the start of clean lines any remaining floating
// children belong to them.
// We don't care about the 'last float' mechanism once we're in clean
// lines so it's ok to let it get set below.
if (floatingObject.layoutObject() == cleanLineStart.object())
break;
appendFloatingObjectToLastLine(floatingObject);
ASSERT(floatingObject.layoutObject() ==
layoutState.floats()[layoutState.floatIndex()].object);
// If a float's geometry has changed, give up on syncing with clean
// lines.
if (layoutState.floats()[layoutState.floatIndex()].rect !=
floatingObject.frameRect())
checkForEndLineMatch = false;
layoutState.setFloatIndex(layoutState.floatIndex() + 1);
}
layoutState.setLastFloat(
!floatingObjectSet.isEmpty() ? floatingObjectSet.last().get() : 0);
}
}
lineMidpointState.reset();
resolver.setPosition(endOfLine, numberOfIsolateAncestors(endOfLine));
}
// In case we already adjusted the line positions during this layout to avoid
// widows
// then we need to ignore the possibility of having a new widows situation.
// Otherwise, we risk leaving empty containers which is against the block
// fragmentation principles.
if (paginated && !style()->hasAutoWidows() && !didBreakAtLineToAvoidWidow()) {
// Check the line boxes to make sure we didn't create unacceptable widows.
// However, we'll prioritize orphans - so nothing we do here should create
// a new orphan.
RootInlineBox* lineBox = lastRootBox();
// Count from the end of the block backwards, to see how many hanging
// lines we have.
RootInlineBox* firstLineInBlock = firstRootBox();
int numLinesHanging = 1;
while (lineBox && lineBox != firstLineInBlock &&
!lineBox->isFirstAfterPageBreak()) {
++numLinesHanging;
lineBox = lineBox->prevRootBox();
}
// If there were no breaks in the block, we didn't create any widows.
if (!lineBox || !lineBox->isFirstAfterPageBreak() ||
lineBox == firstLineInBlock)
return;
if (numLinesHanging < style()->widows()) {
// We have detected a widow. Now we need to work out how many
// lines there are on the previous page, and how many we need
// to steal.
int numLinesNeeded = style()->widows() - numLinesHanging;
RootInlineBox* currentFirstLineOfNewPage = lineBox;
// Count the number of lines in the previous page.
lineBox = lineBox->prevRootBox();
int numLinesInPreviousPage = 1;
while (lineBox && lineBox != firstLineInBlock &&
!lineBox->isFirstAfterPageBreak()) {
++numLinesInPreviousPage;
lineBox = lineBox->prevRootBox();
}
// If there was an explicit value for orphans, respect that. If not, we
// still
// shouldn't create a situation where we make an orphan bigger than the
// initial value.
// This means that setting widows implies we also care about orphans, but
// given
// the specification says the initial orphan value is non-zero, this is
// ok. The
// author is always free to set orphans explicitly as well.
int orphans = style()->hasAutoOrphans() ? style()->initialOrphans()
: style()->orphans();
int numLinesAvailable = numLinesInPreviousPage - orphans;
if (numLinesAvailable <= 0)
return;
int numLinesToTake = std::min(numLinesAvailable, numLinesNeeded);
// Wind back from our first widowed line.
lineBox = currentFirstLineOfNewPage;
for (int i = 0; i < numLinesToTake; ++i)
lineBox = lineBox->prevRootBox();
// We now want to break at this line. Remember for next layout and trigger
// relayout.
setBreakAtLineToAvoidWidow(lineCount(lineBox));
markLinesDirtyInBlockRange(lastRootBox()->lineBottomWithLeading(),
lineBox->lineBottomWithLeading(), lineBox);
}
}
clearDidBreakAtLineToAvoidWidow();
}
void LayoutBlockFlow::linkToEndLineIfNeeded(LineLayoutState& layoutState) {
if (layoutState.endLine()) {
if (layoutState.endLineMatched()) {
bool paginated =
view()->layoutState() && view()->layoutState()->isPaginated();
// Attach all the remaining lines, and then adjust their y-positions as
// needed.
LayoutUnit delta = logicalHeight() - layoutState.endLineLogicalTop();
for (RootInlineBox* line = layoutState.endLine(); line;
line = line->nextRootBox()) {
line->attachLine();
if (paginated) {
delta -= line->paginationStrut();
adjustLinePositionForPagination(*line, delta);
}
if (delta) {
layoutState.updatePaintInvalidationRangeFromBox(line, delta);
line->moveInBlockDirection(delta);
}
if (Vector<LayoutBox*>* cleanLineFloats = line->floatsPtr()) {
for (auto* box : *cleanLineFloats) {
FloatingObject* floatingObject = insertFloatingObject(*box);
ASSERT(!floatingObject->originatingLine());
floatingObject->setOriginatingLine(line);
setLogicalHeight(logicalTopForChild(*box) -
marginBeforeForChild(*box) + delta);
positionNewFloats();
}
}
}
setLogicalHeight(lastRootBox()->lineBottomWithLeading());
} else {
// Delete all the remaining lines.
deleteLineRange(layoutState, layoutState.endLine());
}
}
if (positionNewFloats() && lastRootBox()) {
// In case we have a float on the last line, it might not be positioned up
// to now.
// This has to be done before adding in the bottom border/padding, or the
// float will
// include the padding incorrectly. -dwh
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
FloatingObjectSetIterator it = floatingObjectSet.begin();
FloatingObjectSetIterator end = floatingObjectSet.end();
if (layoutState.lastFloat()) {
FloatingObjectSetIterator lastFloatIterator =
floatingObjectSet.find(layoutState.lastFloat());
ASSERT(lastFloatIterator != end);
++lastFloatIterator;
it = lastFloatIterator;
}
layoutState.setLastFloat(
!floatingObjectSet.isEmpty() ? floatingObjectSet.last().get() : 0);
if (it == end)
return;
for (; it != end; ++it)
appendFloatingObjectToLastLine(*it->get());
}
}
void LayoutBlockFlow::markDirtyFloatsForPaintInvalidation(
Vector<FloatWithRect>& floats) {
size_t floatCount = floats.size();
// Floats that did not have layout did not paint invalidations when we laid
// them out. They would have
// painted by now if they had moved, but if they stayed at (0, 0), they still
// need to be
// painted.
for (size_t i = 0; i < floatCount; ++i) {
LayoutBox* f = floats[i].object;
if (!floats[i].everHadLayout) {
if (!f->location().x() && !f->location().y())
f->setShouldDoFullPaintInvalidation();
}
insertFloatingObject(*f);
}
positionNewFloats();
}
struct InlineMinMaxIterator {
/* InlineMinMaxIterator is a class that will iterate over all layout objects
that contribute to
inline min/max width calculations. Note the following about the way it
walks:
(1) Positioned content is skipped (since it does not contribute to min/max
width of a block)
(2) We do not drill into the children of floats or replaced elements, since
you can't break
in the middle of such an element.
(3) Inline flows (e.g., <a>, <span>, <i>) are walked twice, since each side
can have
distinct borders/margin/padding that contribute to the min/max width.
*/
LayoutObject* parent;
LayoutObject* current;
bool endOfInline;
InlineMinMaxIterator(LayoutObject* p, bool end = false)
: parent(p), current(p), endOfInline(end) {}
LayoutObject* next();
};
LayoutObject* InlineMinMaxIterator::next() {
LayoutObject* result = nullptr;
bool oldEndOfInline = endOfInline;
endOfInline = false;
while (current || current == parent) {
if (!oldEndOfInline && (current == parent ||
(!current->isFloating() && !current->isReplaced() &&
!current->isOutOfFlowPositioned())))
result = current->slowFirstChild();
if (!result) {
// We hit the end of our inline. (It was empty, e.g., <span></span>.)
if (!oldEndOfInline && current->isLayoutInline()) {
result = current;
endOfInline = true;
break;
}
while (current && current != parent) {
result = current->nextSibling();
if (result)
break;
current = current->parent();
if (current && current != parent && current->isLayoutInline()) {
result = current;
endOfInline = true;
break;
}
}
}
if (!result)
break;
if (!result->isOutOfFlowPositioned() &&
(result->isText() || result->isFloating() || result->isReplaced() ||
result->isLayoutInline()))
break;
current = result;
result = nullptr;
}
// Update our position.
current = result;
return current;
}
static LayoutUnit getBPMWidth(LayoutUnit childValue, Length cssUnit) {
if (cssUnit.type() != Auto)
return (cssUnit.isFixed() ? static_cast<LayoutUnit>(cssUnit.value())
: childValue);
return LayoutUnit();
}
static LayoutUnit getBorderPaddingMargin(const LayoutBoxModelObject& child,
bool endOfInline) {
const ComputedStyle& childStyle = child.styleRef();
if (endOfInline) {
return getBPMWidth(child.marginEnd(), childStyle.marginEnd()) +
getBPMWidth(child.paddingEnd(), childStyle.paddingEnd()) +
child.borderEnd();
}
return getBPMWidth(child.marginStart(), childStyle.marginStart()) +
getBPMWidth(child.paddingStart(), childStyle.paddingStart()) +
child.borderStart();
}
static inline void stripTrailingSpace(LayoutUnit& inlineMax,
LayoutUnit& inlineMin,
LayoutObject* trailingSpaceChild) {
if (trailingSpaceChild && trailingSpaceChild->isText()) {
// Collapse away the trailing space at the end of a block by finding
// the first white-space character and subtracting its width. Subsequent
// white-space characters have been collapsed into the first one (which
// can be either a space or a tab character).
LayoutText* text = toLayoutText(trailingSpaceChild);
UChar trailingWhitespaceChar = ' ';
for (unsigned i = text->textLength(); i > 0; i--) {
UChar c = text->characterAt(i - 1);
if (!Character::treatAsSpace(c))
break;
trailingWhitespaceChar = c;
}
// FIXME: This ignores first-line.
const Font& font = text->style()->font();
TextRun run =
constructTextRun(font, &trailingWhitespaceChar, 1, text->styleRef(),
text->style()->direction());
run.setCodePath(text->canUseSimpleFontCodePath() ? TextRun::ForceSimple
: TextRun::ForceComplex);
float spaceWidth = font.width(run);
inlineMax -= LayoutUnit::fromFloatCeil(
spaceWidth + font.fontDescription().wordSpacing());
if (inlineMin > inlineMax)
inlineMin = inlineMax;
}
}
// When converting between floating point and LayoutUnits we risk losing
// precision
// with each conversion. When this occurs while accumulating our preferred
// widths,
// we can wind up with a line width that's larger than our maxPreferredWidth due
// to
// pure float accumulation.
static inline LayoutUnit adjustFloatForSubPixelLayout(float value) {
return LayoutUnit::fromFloatCeil(value);
}
static inline void adjustMinMaxForInlineFlow(LayoutObject* child,
bool endOfInline,
LayoutUnit& childMin,
LayoutUnit& childMax) {
// Add in padding/border/margin from the appropriate side of
// the element.
LayoutUnit bpm = getBorderPaddingMargin(toLayoutInline(*child), endOfInline);
childMin += bpm;
childMax += bpm;
}
static inline void adjustMarginForInlineReplaced(LayoutObject* child,
LayoutUnit& childMin,
LayoutUnit& childMax) {
// Inline replaced elts add in their margins to their min/max values.
const ComputedStyle& childStyle = child->styleRef();
Length startMargin = childStyle.marginStart();
Length endMargin = childStyle.marginEnd();
LayoutUnit margins;
if (startMargin.isFixed())
margins += adjustFloatForSubPixelLayout(startMargin.value());
if (endMargin.isFixed())
margins += adjustFloatForSubPixelLayout(endMargin.value());
childMin += margins;
childMax += margins;
}
// FIXME: This function should be broken into something less monolithic.
// FIXME: The main loop here is very similar to LineBreaker::nextSegmentBreak.
// They can probably reuse code.
void LayoutBlockFlow::computeInlinePreferredLogicalWidths(
LayoutUnit& minLogicalWidth,
LayoutUnit& maxLogicalWidth) {
LayoutUnit inlineMax;
LayoutUnit inlineMin;
const ComputedStyle& styleToUse = styleRef();
LayoutBlock* containingBlock = this->containingBlock();
LayoutUnit cw =
containingBlock ? containingBlock->contentLogicalWidth() : LayoutUnit();
// If we are at the start of a line, we want to ignore all white-space.
// Also strip spaces if we previously had text that ended in a trailing space.
bool stripFrontSpaces = true;
LayoutObject* trailingSpaceChild = nullptr;
// Firefox and Opera will allow a table cell to grow to fit an image inside it
// under
// very specific cirucumstances (in order to match common WinIE layouts).
// Not supporting the quirk has caused us to mis-layout some real sites. (See
// Bugzilla 10517.)
bool allowImagesToBreak = !document().inQuirksMode() || !isTableCell() ||
!styleToUse.logicalWidth().isIntrinsicOrAuto();
bool autoWrap, oldAutoWrap;
autoWrap = oldAutoWrap = styleToUse.autoWrap();
InlineMinMaxIterator childIterator(this);
// Only gets added to the max preffered width once.
bool addedTextIndent = false;
// Signals the text indent was more negative than the min preferred width
bool hasRemainingNegativeTextIndent = false;
LayoutUnit textIndent = minimumValueForLength(styleToUse.textIndent(), cw);
LayoutObject* prevFloat = nullptr;
bool isPrevChildInlineFlow = false;
bool shouldBreakLineAfterText = false;
while (LayoutObject* child = childIterator.next()) {
autoWrap = child->isReplaced() ? child->parent()->style()->autoWrap()
: child->style()->autoWrap();
if (!child->isBR()) {
// Step One: determine whether or not we need to go ahead and
// terminate our current line. Each discrete chunk can become
// the new min-width, if it is the widest chunk seen so far, and
// it can also become the max-width.
// Children fall into three categories:
// (1) An inline flow object. These objects always have a min/max of 0,
// and are included in the iteration solely so that their margins can
// be added in.
//
// (2) An inline non-text non-flow object, e.g., an inline replaced
// element.
// These objects can always be on a line by themselves, so in this
// situation
// we need to go ahead and break the current line, and then add in our own
// margins and min/max width on its own line, and then terminate the line.
//
// (3) A text object. Text runs can have breakable characters at the
// start,
// the middle or the end. They may also lose whitespace off the front if
// we're already ignoring whitespace. In order to compute accurate
// min-width
// information, we need three pieces of information.
// (a) the min-width of the first non-breakable run. Should be 0 if the
// text string
// starts with whitespace.
// (b) the min-width of the last non-breakable run. Should be 0 if the
// text string
// ends with whitespace.
// (c) the min/max width of the string (trimmed for whitespace).
//
// If the text string starts with whitespace, then we need to go ahead and
// terminate our current line (unless we're already in a whitespace
// stripping
// mode.
//
// If the text string has a breakable character in the middle, but didn't
// start
// with whitespace, then we add the width of the first non-breakable run
// and
// then end the current line. We then need to use the intermediate min/max
// width
// values (if any of them are larger than our current min/max). We then
// look at
// the width of the last non-breakable run and use that to start a new
// line
// (unless we end in whitespace).
const ComputedStyle& childStyle = child->styleRef();
LayoutUnit childMin;
LayoutUnit childMax;
if (!child->isText()) {
// Case (1) and (2). Inline replaced and inline flow elements.
if (child->isLayoutInline()) {
adjustMinMaxForInlineFlow(child, childIterator.endOfInline, childMin,
childMax);
inlineMin += childMin;
inlineMax += childMax;
child->clearPreferredLogicalWidthsDirty();
} else {
adjustMarginForInlineReplaced(child, childMin, childMax);
}
}
if (!child->isLayoutInline() && !child->isText()) {
// Case (2). Inline replaced elements and floats.
// Go ahead and terminate the current line as far as
// minwidth is concerned.
LayoutUnit childMinPreferredLogicalWidth, childMaxPreferredLogicalWidth;
computeChildPreferredLogicalWidths(*child,
childMinPreferredLogicalWidth,
childMaxPreferredLogicalWidth);
childMin += childMinPreferredLogicalWidth;
childMax += childMaxPreferredLogicalWidth;
bool clearPreviousFloat;
if (child->isFloating()) {
clearPreviousFloat =
(prevFloat && ((prevFloat->styleRef().floating() == LeftFloat &&
(childStyle.clear() & CLEFT)) ||
(prevFloat->styleRef().floating() == RightFloat &&
(childStyle.clear() & CRIGHT))));
prevFloat = child;
} else {
clearPreviousFloat = false;
}
bool canBreakReplacedElement = !child->isImage() || allowImagesToBreak;
if ((canBreakReplacedElement && (autoWrap || oldAutoWrap) &&
(!isPrevChildInlineFlow || shouldBreakLineAfterText)) ||
clearPreviousFloat) {
minLogicalWidth = std::max(minLogicalWidth, inlineMin);
inlineMin = LayoutUnit();
}
// If we're supposed to clear the previous float, then terminate
// maxwidth as well.
if (clearPreviousFloat) {
maxLogicalWidth = std::max(maxLogicalWidth, inlineMax);
inlineMax = LayoutUnit();
}
// Add in text-indent. This is added in only once.
if (!addedTextIndent && !child->isFloating()) {
childMin += textIndent;
childMax += textIndent;
if (childMin < LayoutUnit())
textIndent = childMin;
else
addedTextIndent = true;
}
// Add our width to the max.
inlineMax += std::max(LayoutUnit(), childMax);
if (!autoWrap || !canBreakReplacedElement ||
(isPrevChildInlineFlow && !shouldBreakLineAfterText)) {
if (child->isFloating())
minLogicalWidth = std::max(minLogicalWidth, childMin);
else
inlineMin += childMin;
} else {
// Now check our line.
minLogicalWidth = std::max(minLogicalWidth, childMin);
// Now start a new line.
inlineMin = LayoutUnit();
}
if (autoWrap && canBreakReplacedElement && isPrevChildInlineFlow) {
minLogicalWidth = std::max(minLogicalWidth, inlineMin);
inlineMin = LayoutUnit();
}
// We are no longer stripping whitespace at the start of
// a line.
if (!child->isFloating()) {
stripFrontSpaces = false;
trailingSpaceChild = nullptr;
}
} else if (child->isText()) {
// Case (3). Text.
LayoutText* t = toLayoutText(child);
if (t->isWordBreak()) {
minLogicalWidth = std::max(minLogicalWidth, inlineMin);
inlineMin = LayoutUnit();
continue;
}
// Determine if we have a breakable character. Pass in
// whether or not we should ignore any spaces at the front
// of the string. If those are going to be stripped out,
// then they shouldn't be considered in the breakable char
// check.
bool hasBreakableChar, hasBreak;
LayoutUnit firstLineMinWidth, lastLineMinWidth;
bool hasBreakableStart, hasBreakableEnd;
LayoutUnit firstLineMaxWidth, lastLineMaxWidth;
t->trimmedPrefWidths(inlineMax, firstLineMinWidth, hasBreakableStart,
lastLineMinWidth, hasBreakableEnd,
hasBreakableChar, hasBreak, firstLineMaxWidth,
lastLineMaxWidth, childMin, childMax,
stripFrontSpaces, styleToUse.direction());
// This text object will not be layed out, but it may still provide a
// breaking opportunity.
if (!hasBreak && !childMax) {
if (autoWrap && (hasBreakableStart || hasBreakableEnd)) {
minLogicalWidth = std::max(minLogicalWidth, inlineMin);
inlineMin = LayoutUnit();
}
continue;
}
if (stripFrontSpaces)
trailingSpaceChild = child;
else
trailingSpaceChild = nullptr;
// Add in text-indent. This is added in only once.
LayoutUnit ti;
if (!addedTextIndent || hasRemainingNegativeTextIndent) {
ti = textIndent;
childMin += ti;
firstLineMinWidth += ti;
// It the text indent negative and larger than the child minimum, we
// re-use the remainder
// in future minimum calculations, but using the negative value again
// on the maximum
// will lead to under-counting the max pref width.
if (!addedTextIndent) {
childMax += ti;
firstLineMaxWidth += ti;
addedTextIndent = true;
}
if (childMin < LayoutUnit()) {
textIndent = childMin;
hasRemainingNegativeTextIndent = true;
}
}
// If we have no breakable characters at all,
// then this is the easy case. We add ourselves to the current
// min and max and continue.
if (!hasBreakableChar) {
inlineMin += childMin;
} else {
if (hasBreakableStart) {
minLogicalWidth = std::max(minLogicalWidth, inlineMin);
} else {
inlineMin += firstLineMinWidth;
minLogicalWidth = std::max(minLogicalWidth, inlineMin);
childMin -= ti;
}
inlineMin = childMin;
if (hasBreakableEnd) {
minLogicalWidth = std::max(minLogicalWidth, inlineMin);
inlineMin = LayoutUnit();
shouldBreakLineAfterText = false;
} else {
minLogicalWidth = std::max(minLogicalWidth, inlineMin);
inlineMin = lastLineMinWidth;
shouldBreakLineAfterText = true;
}
}
if (hasBreak) {
inlineMax += firstLineMaxWidth;
maxLogicalWidth = std::max(maxLogicalWidth, inlineMax);
maxLogicalWidth = std::max(maxLogicalWidth, childMax);
inlineMax = lastLineMaxWidth;
addedTextIndent = true;
} else {
inlineMax += std::max(LayoutUnit(), childMax);
}
}
// Ignore spaces after a list marker.
if (child->isListMarker())
stripFrontSpaces = true;
} else {
minLogicalWidth = std::max(minLogicalWidth, inlineMin);
maxLogicalWidth = std::max(maxLogicalWidth, inlineMax);
inlineMin = inlineMax = LayoutUnit();
stripFrontSpaces = true;
trailingSpaceChild = nullptr;
addedTextIndent = true;
}
if (!child->isText() && child->isLayoutInline())
isPrevChildInlineFlow = true;
else
isPrevChildInlineFlow = false;
oldAutoWrap = autoWrap;
}
if (styleToUse.collapseWhiteSpace())
stripTrailingSpace(inlineMax, inlineMin, trailingSpaceChild);
minLogicalWidth = std::max(minLogicalWidth, inlineMin);
maxLogicalWidth = std::max(maxLogicalWidth, inlineMax);
}
static bool isInlineWithOutlineAndContinuation(const LayoutObject& o) {
return o.isLayoutInline() && o.styleRef().hasOutline() &&
!o.isElementContinuation() && toLayoutInline(o).continuation();
}
void LayoutBlockFlow::layoutInlineChildren(
bool relayoutChildren,
LayoutUnit& paintInvalidationLogicalTop,
LayoutUnit& paintInvalidationLogicalBottom,
LayoutUnit afterEdge) {
LayoutFlowThread* flowThread = flowThreadContainingBlock();
bool clearLinesForPagination =
firstLineBox() && flowThread && !flowThread->hasColumnSets();
// Figure out if we should clear out our line boxes.
// FIXME: Handle resize eventually!
bool isFullLayout = !firstLineBox() || selfNeedsLayout() ||
relayoutChildren || clearLinesForPagination;
LineLayoutState layoutState(isFullLayout, paintInvalidationLogicalTop,
paintInvalidationLogicalBottom, flowThread);
if (isFullLayout) {
// Ensure the old line boxes will be erased.
if (firstLineBox())
setShouldDoFullPaintInvalidation();
lineBoxes()->deleteLineBoxes();
}
// Text truncation kicks in in two cases:
// 1) If your overflow isn't visible and your text-overflow-mode isn't
// clip.
// 2) If you're an anonymous block with a block parent that satisfies #1
// that was created
// to accomodate a block that has inline and block children. This
// excludes parents where
// canCollapseAnonymousBlockChild is false, notabley flex items and
// grid items.
// FIXME: CSS3 says that descendants that are clipped must also know how to
// truncate. This is insanely
// difficult to figure out in general (especially in the middle of doing
// layout), so we only handle the
// simple case of an anonymous block truncating when it's parent is clipped.
bool hasTextOverflow =
(style()->textOverflow() && hasOverflowClip()) ||
(isAnonymousBlock() && parent() && parent()->isLayoutBlock() &&
toLayoutBlock(parent())->canCollapseAnonymousBlockChild() &&
parent()->style()->textOverflow() && parent()->hasOverflowClip());
// Walk all the lines and delete our ellipsis line boxes if they exist.
if (hasTextOverflow)
deleteEllipsisLineBoxes();
if (firstChild()) {
// In full layout mode, clear the line boxes of children upfront. Otherwise,
// siblings can run into stale root lineboxes during layout. Then layout
// the replaced elements later. In partial layout mode, line boxes are not
// deleted and only dirtied. In that case, we can layout the replaced
// elements at the same time.
Vector<LayoutBox*> replacedChildren;
for (InlineWalker walker(this); !walker.atEnd(); walker.advance()) {
LayoutObject* o = walker.current();
if (!layoutState.hasInlineChild() && o->isInline())
layoutState.setHasInlineChild(true);
if (o->isReplaced() || o->isFloating() || o->isOutOfFlowPositioned()) {
LayoutBox* box = toLayoutBox(o);
updateBlockChildDirtyBitsBeforeLayout(relayoutChildren, *box);
if (o->isOutOfFlowPositioned()) {
o->containingBlock()->insertPositionedObject(box);
} else if (o->isFloating()) {
layoutState.floats().append(FloatWithRect(box));
if (box->needsLayout()) {
box->layout();
markLinesDirtyInBlockRange(toLayoutBox(o)->logicalTop(),
toLayoutBox(o)->logicalBottom());
}
} else if (isFullLayout || o->needsLayout()) {
// Replaced element.
box->dirtyLineBoxes(isFullLayout);
if (isFullLayout)
replacedChildren.append(box);
else
o->layoutIfNeeded();
}
} else if (o->isText() ||
(o->isLayoutInline() && !walker.atEndOfInline())) {
if (!o->isText())
toLayoutInline(o)->updateAlwaysCreateLineBoxes(
layoutState.isFullLayout());
if (layoutState.isFullLayout() || o->selfNeedsLayout())
dirtyLineBoxesForObject(o, layoutState.isFullLayout());
o->clearNeedsLayout();
}
if (isInlineWithOutlineAndContinuation(*o))
setContainsInlineWithOutlineAndContinuation(true);
}
for (size_t i = 0; i < replacedChildren.size(); i++)
replacedChildren[i]->layoutIfNeeded();
layoutRunsAndFloats(layoutState);
}
// Expand the last line to accommodate Ruby and emphasis marks.
int lastLineAnnotationsAdjustment = 0;
if (lastRootBox()) {
LayoutUnit lowestAllowedPosition =
std::max(lastRootBox()->lineBottom(), logicalHeight() + paddingAfter());
if (!style()->isFlippedLinesWritingMode())
lastLineAnnotationsAdjustment =
lastRootBox()->computeUnderAnnotationAdjustment(
lowestAllowedPosition);
else
lastLineAnnotationsAdjustment =
lastRootBox()->computeOverAnnotationAdjustment(lowestAllowedPosition);
}
// Now add in the bottom border/padding.
setLogicalHeight(logicalHeight() + lastLineAnnotationsAdjustment + afterEdge);
if (!firstLineBox() && hasLineIfEmpty())
setLogicalHeight(logicalHeight() +
lineHeight(true, isHorizontalWritingMode() ? HorizontalLine
: VerticalLine,
PositionOfInteriorLineBoxes));
// See if we have any lines that spill out of our block. If we do, then we
// will possibly need to
// truncate text.
if (hasTextOverflow)
checkLinesForTextOverflow();
// Ensure the new line boxes will be painted.
if (isFullLayout && firstLineBox())
setShouldDoFullPaintInvalidation();
}
RootInlineBox* LayoutBlockFlow::determineStartPosition(
LineLayoutState& layoutState,
InlineBidiResolver& resolver) {
RootInlineBox* curr = nullptr;
RootInlineBox* last = nullptr;
RootInlineBox* firstLineBoxWithBreakAndClearance = 0;
// FIXME: This entire float-checking block needs to be broken into a new
// function.
if (!layoutState.isFullLayout()) {
// Paginate all of the clean lines.
bool paginated =
view()->layoutState() && view()->layoutState()->isPaginated();
LayoutUnit paginationDelta = 0;
for (curr = firstRootBox(); curr && !curr->isDirty();
curr = curr->nextRootBox()) {
if (paginated) {
paginationDelta -= curr->paginationStrut();
adjustLinePositionForPagination(*curr, paginationDelta);
if (paginationDelta) {
if (containsFloats() || !layoutState.floats().isEmpty()) {
// FIXME: Do better eventually. For now if we ever shift because of
// pagination and floats are present just go to a full layout.
layoutState.markForFullLayout();
break;
}
layoutState.updatePaintInvalidationRangeFromBox(curr,
paginationDelta);
curr->moveInBlockDirection(paginationDelta);
}
}
// If the linebox breaks cleanly and with clearance then dirty from at
// least this point onwards so that we can clear the correct floats
// without difficulty.
if (!firstLineBoxWithBreakAndClearance && lineBoxHasBRWithClearance(curr))
firstLineBoxWithBreakAndClearance = curr;
if (layoutState.isFullLayout())
break;
}
}
if (layoutState.isFullLayout()) {
// If we encountered a new float and have inline children, mark ourself to
// force us to issue paint invalidations.
if (layoutState.hasInlineChild() && !selfNeedsLayout()) {
setNeedsLayoutAndFullPaintInvalidation(
LayoutInvalidationReason::FloatDescendantChanged, MarkOnlyThis);
setShouldDoFullPaintInvalidation();
}
deleteLineBoxTree();
curr = nullptr;
ASSERT(!firstLineBox() && !lastLineBox());
} else {
if (firstLineBoxWithBreakAndClearance)
curr = firstLineBoxWithBreakAndClearance;
if (curr) {
// We have a dirty line.
if (RootInlineBox* prevRootBox = curr->prevRootBox()) {
// We have a previous line.
if (!prevRootBox->endsWithBreak() || !prevRootBox->lineBreakObj() ||
(prevRootBox->lineBreakObj().isText() &&
prevRootBox->lineBreakPos() >=
toLayoutText(prevRootBox->lineBreakObj())->textLength())) {
// The previous line didn't break cleanly or broke at a newline
// that has been deleted, so treat it as dirty too.
curr = prevRootBox;
}
}
} else {
// No dirty lines were found.
// If the last line didn't break cleanly, treat it as dirty.
if (lastRootBox() && !lastRootBox()->endsWithBreak())
curr = lastRootBox();
}
// If we have no dirty lines, then last is just the last root box.
last = curr ? curr->prevRootBox() : lastRootBox();
}
unsigned numCleanFloats = 0;
if (!layoutState.floats().isEmpty()) {
LayoutUnit savedLogicalHeight = logicalHeight();
// Restore floats from clean lines.
RootInlineBox* line = firstRootBox();
while (line != curr) {
if (Vector<LayoutBox*>* cleanLineFloats = line->floatsPtr()) {
for (auto* box : *cleanLineFloats) {
FloatingObject* floatingObject = insertFloatingObject(*box);
ASSERT(!floatingObject->originatingLine());
floatingObject->setOriginatingLine(line);
setLogicalHeight(logicalTopForChild(*box) -
marginBeforeForChild(*box));
positionNewFloats();
ASSERT(layoutState.floats()[numCleanFloats].object == box);
numCleanFloats++;
}
}
line = line->nextRootBox();
}
setLogicalHeight(savedLogicalHeight);
}
layoutState.setFloatIndex(numCleanFloats);
layoutState.lineInfo().setFirstLine(!last);
layoutState.lineInfo().setPreviousLineBrokeCleanly(!last ||
last->endsWithBreak());
if (last) {
setLogicalHeight(last->lineBottomWithLeading());
InlineIterator iter = InlineIterator(LineLayoutBlockFlow(this),
LineLayoutItem(last->lineBreakObj()),
last->lineBreakPos());
resolver.setPosition(iter, numberOfIsolateAncestors(iter));
resolver.setStatus(last->lineBreakBidiStatus());
} else {
TextDirection direction = style()->direction();
if (style()->unicodeBidi() == Plaintext)
direction = determinePlaintextDirectionality(this);
resolver.setStatus(
BidiStatus(direction, isOverride(style()->unicodeBidi())));
InlineIterator iter = InlineIterator(
LineLayoutBlockFlow(this),
bidiFirstSkippingEmptyInlines(LineLayoutBlockFlow(this),
resolver.runs(), &resolver),
0);
resolver.setPosition(iter, numberOfIsolateAncestors(iter));
}
return curr;
}
bool LayoutBlockFlow::lineBoxHasBRWithClearance(RootInlineBox* curr) {
// If the linebox breaks cleanly and with clearance then dirty from at least
// this point onwards so that we can clear the correct floats without
// difficulty.
if (!curr->endsWithBreak())
return false;
InlineBox* lastBox = style()->isLeftToRightDirection()
? curr->lastLeafChild()
: curr->firstLeafChild();
return lastBox && lastBox->layoutObject().isBR() &&
lastBox->layoutObject().style()->clear() != CNONE;
}
void LayoutBlockFlow::determineEndPosition(LineLayoutState& layoutState,
RootInlineBox* startLine,
InlineIterator& cleanLineStart,
BidiStatus& cleanLineBidiStatus) {
ASSERT(!layoutState.endLine());
RootInlineBox* last = nullptr;
for (RootInlineBox* curr = startLine->nextRootBox(); curr;
curr = curr->nextRootBox()) {
if (!curr->isDirty() && lineBoxHasBRWithClearance(curr))
return;
if (curr->isDirty())
last = nullptr;
else if (!last)
last = curr;
}
if (!last)
return;
// At this point, |last| is the first line in a run of clean lines that ends
// with the last line
// in the block.
RootInlineBox* prev = last->prevRootBox();
cleanLineStart =
InlineIterator(LineLayoutItem(this), LineLayoutItem(prev->lineBreakObj()),
prev->lineBreakPos());
cleanLineBidiStatus = prev->lineBreakBidiStatus();
layoutState.setEndLineLogicalTop(prev->lineBottomWithLeading());
for (RootInlineBox* line = last; line; line = line->nextRootBox())
line->extractLine(); // Disconnect all line boxes from their layout objects
// while preserving
// their connections to one another.
layoutState.setEndLine(last);
}
bool LayoutBlockFlow::checkPaginationAndFloatsAtEndLine(
LineLayoutState& layoutState) {
LayoutUnit lineDelta = logicalHeight() - layoutState.endLineLogicalTop();
bool paginated =
view()->layoutState() && view()->layoutState()->isPaginated();
if (paginated && layoutState.flowThread()) {
// Check all lines from here to the end, and see if the hypothetical new
// position for the lines will result
// in a different available line width.
for (RootInlineBox* lineBox = layoutState.endLine(); lineBox;
lineBox = lineBox->nextRootBox()) {
if (paginated) {
// This isn't the real move we're going to do, so don't update the line
// box's pagination
// strut yet.
LayoutUnit oldPaginationStrut = lineBox->paginationStrut();
lineDelta -= oldPaginationStrut;
adjustLinePositionForPagination(*lineBox, lineDelta);
lineBox->setPaginationStrut(oldPaginationStrut);
}
}
}
if (!lineDelta || !m_floatingObjects)
return true;
// See if any floats end in the range along which we want to shift the lines
// vertically.
LayoutUnit logicalTop =
std::min(logicalHeight(), layoutState.endLineLogicalTop());
RootInlineBox* lastLine = layoutState.endLine();
while (RootInlineBox* nextLine = lastLine->nextRootBox())
lastLine = nextLine;
LayoutUnit logicalBottom =
lastLine->lineBottomWithLeading() + absoluteValue(lineDelta);
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
FloatingObjectSetIterator end = floatingObjectSet.end();
for (FloatingObjectSetIterator it = floatingObjectSet.begin(); it != end;
++it) {
const FloatingObject& floatingObject = *it->get();
if (logicalBottomForFloat(floatingObject) >= logicalTop &&
logicalBottomForFloat(floatingObject) < logicalBottom)
return false;
}
return true;
}
bool LayoutBlockFlow::matchedEndLine(LineLayoutState& layoutState,
const InlineBidiResolver& resolver,
const InlineIterator& endLineStart,
const BidiStatus& endLineStatus) {
if (resolver.position() == endLineStart) {
if (resolver.status() != endLineStatus)
return false;
return checkPaginationAndFloatsAtEndLine(layoutState);
}
// The first clean line doesn't match, but we can check a handful of following
// lines to try
// to match back up.
static int numLines = 8; // The # of lines we're willing to match against.
RootInlineBox* originalEndLine = layoutState.endLine();
RootInlineBox* line = originalEndLine;
for (int i = 0; i < numLines && line; i++, line = line->nextRootBox()) {
if (line->lineBreakObj() == resolver.position().object() &&
line->lineBreakPos() == resolver.position().offset()) {
// We have a match.
if (line->lineBreakBidiStatus() != resolver.status())
return false; // ...but the bidi state doesn't match.
bool matched = false;
RootInlineBox* result = line->nextRootBox();
layoutState.setEndLine(result);
if (result) {
layoutState.setEndLineLogicalTop(line->lineBottomWithLeading());
matched = checkPaginationAndFloatsAtEndLine(layoutState);
}
// Now delete the lines that we failed to sync.
deleteLineRange(layoutState, originalEndLine, result);
return matched;
}
}
return false;
}
bool LayoutBlockFlow::generatesLineBoxesForInlineChild(
LayoutObject* inlineObj) {
ASSERT(inlineObj->parent() == this);
InlineIterator it(LineLayoutBlockFlow(this), LineLayoutItem(inlineObj), 0);
// FIXME: We should pass correct value for WhitespacePosition.
while (!it.atEnd() && !requiresLineBox(it))
it.increment();
return !it.atEnd();
}
void LayoutBlockFlow::addOverflowFromInlineChildren() {
LayoutUnit endPadding = hasOverflowClip() ? paddingEnd() : LayoutUnit();
for (RootInlineBox* curr = firstRootBox(); curr; curr = curr->nextRootBox()) {
addLayoutOverflow(curr->paddedLayoutOverflowRect(endPadding));
LayoutRect visualOverflow =
curr->visualOverflowRect(curr->lineTop(), curr->lineBottom());
addContentsVisualOverflow(visualOverflow);
}
if (!containsInlineWithOutlineAndContinuation())
return;
// Add outline rects of continuations of descendant inlines into visual
// overflow of this block.
LayoutRect outlineBoundsOfAllContinuations;
for (InlineWalker walker(this); !walker.atEnd(); walker.advance()) {
const LayoutObject& o = *walker.current();
if (!isInlineWithOutlineAndContinuation(o))
continue;
Vector<LayoutRect> outlineRects;
toLayoutInline(o).addOutlineRectsForContinuations(
outlineRects, LayoutPoint(),
o.outlineRectsShouldIncludeBlockVisualOverflow());
if (!outlineRects.isEmpty()) {
LayoutRect outlineBounds = unionRectEvenIfEmpty(outlineRects);
outlineBounds.inflate(o.styleRef().outlineOutsetExtent());
outlineBoundsOfAllContinuations.unite(outlineBounds);
}
}
addContentsVisualOverflow(outlineBoundsOfAllContinuations);
}
void LayoutBlockFlow::deleteEllipsisLineBoxes() {
ETextAlign textAlign = style()->textAlign();
bool firstLine = true;
for (RootInlineBox* curr = firstRootBox(); curr; curr = curr->nextRootBox()) {
if (curr->hasEllipsisBox()) {
curr->clearTruncation();
// Shift the line back where it belongs if we cannot accomodate an
// ellipsis.
LayoutUnit logicalLeft =
logicalLeftOffsetForLine(curr->lineTop(), firstLine);
LayoutUnit availableLogicalWidth =
logicalRightOffsetForLine(curr->lineTop(), false) - logicalLeft;
LayoutUnit totalLogicalWidth = curr->logicalWidth();
updateLogicalWidthForAlignment(textAlign, curr, 0, logicalLeft,
totalLogicalWidth, availableLogicalWidth,
0);
curr->moveInInlineDirection(logicalLeft - curr->logicalLeft());
}
firstLine = false;
}
}
void LayoutBlockFlow::checkLinesForTextOverflow() {
// Determine the width of the ellipsis using the current font.
const Font& font = style()->font();
const size_t fullStopStringLength = 3;
const UChar fullStopString[] = {fullstopCharacter, fullstopCharacter,
fullstopCharacter};
DEFINE_STATIC_LOCAL(AtomicString, fullstopCharacterStr,
(fullStopString, fullStopStringLength));
DEFINE_STATIC_LOCAL(AtomicString, ellipsisStr,
(&horizontalEllipsisCharacter, 1));
AtomicString& selectedEllipsisStr = ellipsisStr;
const Font& firstLineFont = firstLineStyle()->font();
// FIXME: We should probably not hard-code the direction here.
// https://crbug.com/333004
TextDirection ellipsisDirection = LTR;
float firstLineEllipsisWidth = 0;
float ellipsisWidth = 0;
// As per CSS3 http://www.w3.org/TR/2003/CR-css3-text-20030514/ sequence of
// three
// Full Stops (002E) can be used.
ASSERT(firstLineFont.primaryFont());
if (firstLineFont.primaryFont()->glyphForCharacter(
horizontalEllipsisCharacter)) {
firstLineEllipsisWidth = firstLineFont.width(
constructTextRun(firstLineFont, &horizontalEllipsisCharacter, 1,
*firstLineStyle(), ellipsisDirection));
} else {
selectedEllipsisStr = fullstopCharacterStr;
firstLineEllipsisWidth = firstLineFont.width(
constructTextRun(firstLineFont, fullStopString, fullStopStringLength,
*firstLineStyle(), ellipsisDirection));
}
ellipsisWidth = (font == firstLineFont) ? firstLineEllipsisWidth : 0;
if (!ellipsisWidth) {
ASSERT(font.primaryFont());
if (font.primaryFont()->glyphForCharacter(horizontalEllipsisCharacter)) {
selectedEllipsisStr = ellipsisStr;
ellipsisWidth =
font.width(constructTextRun(font, &horizontalEllipsisCharacter, 1,
styleRef(), ellipsisDirection));
} else {
selectedEllipsisStr = fullstopCharacterStr;
ellipsisWidth = font.width(
constructTextRun(font, fullStopString, fullStopStringLength,
styleRef(), ellipsisDirection));
}
}
// For LTR text truncation, we want to get the right edge of our padding box,
// and then we want to see
// if the right edge of a line box exceeds that. For RTL, we use the left
// edge of the padding box and
// check the left edge of the line box to see if it is less
// Include the scrollbar for overflow blocks, which means we want to use
// "contentWidth()"
bool ltr = style()->isLeftToRightDirection();
ETextAlign textAlign = style()->textAlign();
bool firstLine = true;
for (RootInlineBox* curr = firstRootBox(); curr; curr = curr->nextRootBox()) {
LayoutUnit currLogicalLeft = curr->logicalLeft();
LayoutUnit blockRightEdge =
logicalRightOffsetForLine(curr->lineTop(), firstLine);
LayoutUnit blockLeftEdge =
logicalLeftOffsetForLine(curr->lineTop(), firstLine);
LayoutUnit lineBoxEdge =
ltr ? currLogicalLeft + curr->logicalWidth() : currLogicalLeft;
if ((ltr && lineBoxEdge > blockRightEdge) ||
(!ltr && lineBoxEdge < blockLeftEdge)) {
// This line spills out of our box in the appropriate direction. Now we
// need to see if the line
// can be truncated. In order for truncation to be possible, the line
// must have sufficient space to
// accommodate our truncation string, and no replaced elements (images,
// tables) can overlap the ellipsis
// space.
LayoutUnit width = firstLine ? firstLineEllipsisWidth : ellipsisWidth;
LayoutUnit blockEdge = ltr ? blockRightEdge : blockLeftEdge;
if (curr->lineCanAccommodateEllipsis(ltr, blockEdge, lineBoxEdge,
width)) {
LayoutUnit totalLogicalWidth = curr->placeEllipsis(
selectedEllipsisStr, ltr, blockLeftEdge, blockRightEdge, width);
LayoutUnit logicalLeft; // We are only interested in the delta from the
// base position.
LayoutUnit availableLogicalWidth = blockRightEdge - blockLeftEdge;
updateLogicalWidthForAlignment(textAlign, curr, 0, logicalLeft,
totalLogicalWidth, availableLogicalWidth,
0);
if (ltr)
curr->moveInInlineDirection(logicalLeft);
else
curr->moveInInlineDirection(
logicalLeft - (availableLogicalWidth - totalLogicalWidth));
}
}
firstLine = false;
}
}
bool LayoutBlockFlow::positionNewFloatOnLine(
FloatingObject& newFloat,
FloatingObject* lastFloatFromPreviousLine,
LineInfo& lineInfo,
LineWidth& width) {
if (!positionNewFloats(&width))
return false;
// We only connect floats to lines for pagination purposes if the floats occur
// at the start of
// the line and the previous line had a hard break (so this line is either the
// first in the block
// or follows a <br>).
if (!newFloat.paginationStrut() || !lineInfo.previousLineBrokeCleanly() ||
!lineInfo.isEmpty())
return true;
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
ASSERT(floatingObjectSet.last() == &newFloat);
LayoutUnit floatLogicalTop = logicalTopForFloat(newFloat);
int paginationStrut = newFloat.paginationStrut();
if (floatLogicalTop - paginationStrut !=
logicalHeight() + lineInfo.floatPaginationStrut())
return true;
FloatingObjectSetIterator it = floatingObjectSet.end();
--it; // Last float is newFloat, skip that one.
FloatingObjectSetIterator begin = floatingObjectSet.begin();
while (it != begin) {
--it;
FloatingObject& floatingObject = *it->get();
if (&floatingObject == lastFloatFromPreviousLine)
break;
if (logicalTopForFloat(floatingObject) ==
logicalHeight() + lineInfo.floatPaginationStrut()) {
floatingObject.setPaginationStrut(paginationStrut +
floatingObject.paginationStrut());
LayoutBox* floatBox = floatingObject.layoutObject();
setLogicalTopForChild(*floatBox, logicalTopForChild(*floatBox) +
marginBeforeForChild(*floatBox) +
paginationStrut);
if (floatBox->isLayoutBlock())
floatBox->forceChildLayout();
else
floatBox->layoutIfNeeded();
// Save the old logical top before calling removePlacedObject which will
// set
// isPlaced to false. Otherwise it will trigger an assert in
// logicalTopForFloat.
LayoutUnit oldLogicalTop = logicalTopForFloat(floatingObject);
m_floatingObjects->removePlacedObject(floatingObject);
setLogicalTopForFloat(floatingObject, oldLogicalTop + paginationStrut);
m_floatingObjects->addPlacedObject(floatingObject);
}
}
// Just update the line info's pagination strut without altering our logical
// height yet. If the line ends up containing
// no content, then we don't want to improperly grow the height of the block.
lineInfo.setFloatPaginationStrut(lineInfo.floatPaginationStrut() +
paginationStrut);
return true;
}
LayoutUnit LayoutBlockFlow::startAlignedOffsetForLine(LayoutUnit position,
bool firstLine) {
ETextAlign textAlign = style()->textAlign();
if (textAlign == TASTART) // FIXME: Handle TAEND here
return startOffsetForLine(position, firstLine);
// updateLogicalWidthForAlignment() handles the direction of the block so no
// need to consider it here
LayoutUnit totalLogicalWidth;
LayoutUnit logicalLeft = logicalLeftOffsetForLine(logicalHeight(), false);
LayoutUnit availableLogicalWidth =
logicalRightOffsetForLine(logicalHeight(), false) - logicalLeft;
updateLogicalWidthForAlignment(textAlign, 0, 0, logicalLeft,
totalLogicalWidth, availableLogicalWidth, 0);
if (!style()->isLeftToRightDirection())
return logicalWidth() - logicalLeft;
return logicalLeft;
}
}