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chromium / chromium / src / 333a7dd429e44a6562112fc29c667474fa2e92f9 / . / third_party / WebKit / Source / core / layout / LayoutBlockFlowLine.cpp
blob: bb2e639bcd3d00e0af940fb5b860ab0199f60259 [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 "core/dom/AXObjectCache.h"
#include "core/editing/EditingUtilities.h"
#include "core/layout/BidiRunForLine.h"
#include "core/layout/LayoutObject.h"
#include "core/layout/LayoutRubyRun.h"
#include "core/layout/LayoutView.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/text/BidiResolver.h"
#include "platform/text/Character.h"
#include "wtf/StdLibExtras.h"
#include "wtf/Vector.h"
#include "wtf/text/CharacterNames.h"
namespace blink {
using namespace WTF::Unicode;
class ExpansionOpportunities {
public:
ExpansionOpportunities()
: m_totalOpportunities(0)
{ }
void addRunWithExpansions(BidiRun& run, bool& isAfterExpansion, TextJustify textJustify)
{
LineLayoutText text = LineLayoutText(run.m_lineLayoutItem);
unsigned opportunitiesInRun;
if (text.is8Bit()) {
opportunitiesInRun = Character::expansionOpportunityCount(text.characters8() + run.m_start,
run.m_stop - run.m_start, run.m_box->direction(), isAfterExpansion, textJustify);
} else if (run.m_lineLayoutItem.isCombineText()) {
// Justfication applies to before and after the combined text as if
// it is an ideographic character, and is prohibited inside the
// combined text.
opportunitiesInRun = isAfterExpansion ? 1 : 2;
isAfterExpansion = true;
} else {
opportunitiesInRun = Character::expansionOpportunityCount(text.characters16() + run.m_start,
run.m_stop - run.m_start, run.m_box->direction(), isAfterExpansion, textJustify);
}
m_runsWithExpansions.append(opportunitiesInRun);
m_totalOpportunities += opportunitiesInRun;
}
void removeTrailingExpansion()
{
if (!m_totalOpportunities || !m_runsWithExpansions.last())
return;
m_runsWithExpansions.last()--;
m_totalOpportunities--;
}
unsigned count() { return m_totalOpportunities; }
unsigned opportunitiesInRun(size_t run) { return m_runsWithExpansions[run]; }
void computeExpansionsForJustifiedText(BidiRun* firstRun, BidiRun* trailingSpaceRun, LayoutUnit& totalLogicalWidth, LayoutUnit availableLogicalWidth)
{
if (!m_totalOpportunities || 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_lineLayoutItem.isText()) {
unsigned opportunitiesInRun = m_runsWithExpansions[i++];
RELEASE_ASSERT(opportunitiesInRun <= m_totalOpportunities);
// Don't justify for white-space: pre.
if (r->m_lineLayoutItem.style()->whiteSpace() != PRE) {
InlineTextBox* textBox = toInlineTextBox(r->m_box);
RELEASE_ASSERT(m_totalOpportunities);
int expansion = ((availableLogicalWidth - totalLogicalWidth) * opportunitiesInRun / m_totalOpportunities).toInt();
textBox->setExpansion(expansion);
totalLogicalWidth += expansion;
}
m_totalOpportunities -= opportunitiesInRun;
if (!m_totalOpportunities)
break;
}
}
}
private:
Vector<unsigned, 16> m_runsWithExpansions;
unsigned m_totalOpportunities;
};
static inline InlineBox* createInlineBoxForLayoutObject(LineLayoutItem lineLayoutItem, bool isRootLineBox, bool isOnlyRun = false)
{
// Callers should handle text themselves.
ASSERT(!lineLayoutItem.isText());
if (isRootLineBox)
return LineLayoutBlockFlow(lineLayoutItem).createAndAppendRootInlineBox();
if (lineLayoutItem.isBox())
return LineLayoutBox(lineLayoutItem).createInlineBox();
return LineLayoutInline(lineLayoutItem).createAndAppendInlineFlowBox();
}
static inline InlineTextBox* createInlineBoxForText(BidiRun& run, bool isOnlyRun)
{
ASSERT(run.m_lineLayoutItem.isText());
LineLayoutText text = LineLayoutText(run.m_lineLayoutItem);
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(LineLayoutItem lineLayoutItem, 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(lineLayoutItem.isLayoutInline() || lineLayoutItem.isEqual(this));
LineLayoutInline inlineFlow(!lineLayoutItem.isEqual(this) ? lineLayoutItem : nullptr);
// Get the last box we made for this layout object.
parentBox = inlineFlow ? inlineFlow.lastLineBox() : LineLayoutBlockFlow(lineLayoutItem).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(LineLayoutItem(lineLayoutItem), lineLayoutItem.isEqual(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 || lineLayoutItem.isEqual(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.
lineLayoutItem = (++lineDepth >= cMaxLineDepth) ? LineLayoutItem(this) : lineLayoutItem.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();
LineLayoutItem r = run->m_lineLayoutItem;
if (!r.isText() || r.isBR())
return false;
LineLayoutText layoutText(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_lineLayoutItem.isListMarker())
isOnlyRun = (!style()->isLeftToRightDirection() ? bidiRuns.lastRun() : bidiRuns.firstRun())->m_lineLayoutItem.isListMarker();
if (lineInfo.isEmpty())
continue;
InlineBox* box;
if (r->m_lineLayoutItem.isText())
box = createInlineBoxForText(*r, isOnlyRun);
else
box = createInlineBoxForLayoutObject(r->m_lineLayoutItem, false, isOnlyRun);
r->m_box = box;
ASSERT(box);
if (!box)
continue;
if (!rootHasSelectedChildren && box->getLineLayoutItem().getSelectionState() != 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->getLineLayoutItem() != r->m_lineLayoutItem.parent())) {
// Create new inline boxes all the way back to the appropriate insertion point.
parentBox = createLineBoxes(r->m_lineLayoutItem.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_lineLayoutItem);
}
}
// 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_lineLayoutItem && bidiRuns.logicallyLastRun()->m_lineLayoutItem.isText() ? !reachedEndOfTextRun(bidiRuns) : true;
lastLineBox()->determineSpacingForFlowBoxes(lineInfo.isLastLine(), isLogicallyLastRunWrapped, bidiRuns.logicallyLastRun()->m_lineLayoutItem);
// 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()->getTextAlignLast();
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(LayoutUnit());
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(LayoutUnit());
}
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_lineLayoutItem.isOutOfFlowPositioned() && !runWithNextObject->m_box->isLineBreak()) {
nextObject = runWithNextObject->m_lineLayoutItem.layoutObject();
break;
}
}
layoutRubyRun->getOverhang(lineInfo.isFirstLine(), layoutRubyRun->style()->isLeftToRightDirection() ? previousObject : nextObject, layoutRubyRun->style()->isLeftToRightDirection() ? nextObject : previousObject, startOverhang, endOverhang);
setMarginStartForChild(*layoutRubyRun, LayoutUnit(-startOverhang));
setMarginEndForChild(*layoutRubyRun, LayoutUnit(-endOverhang));
}
static inline size_t findWordMeasurement(LineLayoutText layoutText, int offset,
WordMeasurements& wordMeasurements, size_t lastIndex)
{
// In LTR, lastIndex should match since the order of BidiRun (visual) and
// WordMeasurement (logical) are the same.
size_t size = wordMeasurements.size();
if (lastIndex < size) {
const WordMeasurement& wordMeasurement = wordMeasurements[lastIndex];
if (wordMeasurement.layoutText == layoutText && wordMeasurement.startOffset == offset)
return lastIndex;
}
// In RTL, scan the whole array because they are not the same.
for (size_t i = 0; i < size; ++i) {
const WordMeasurement& wordMeasurement = wordMeasurements[i];
if (wordMeasurement.layoutText != layoutText)
continue;
if (wordMeasurement.startOffset == offset)
return i;
if (wordMeasurement.startOffset > offset)
break;
}
// In RTL with space collpasing or in LTR/RTL mixed lines, there can be no
// matches because spaces are handled differently in BidiRun and
// WordMeasurement. This can cause slight performance hit and slight
// differences in glyph positions since we re-measure the whole run.
return size;
}
static inline void setLogicalWidthForTextRun(RootInlineBox* lineBox, BidiRun* run, LineLayoutText layoutText, LayoutUnit xPos, const LineInfo& lineInfo,
GlyphOverflowAndFallbackFontsMap& textBoxDataMap, VerticalPositionCache& verticalPositionCache, WordMeasurements& wordMeasurements,
size_t& wordMeasurementsIndex)
{
HashSet<const SimpleFontData*> fallbackFonts;
GlyphOverflow glyphOverflow;
const Font& font = layoutText.style(lineInfo.isFirstLine())->font();
LayoutUnit hyphenWidth;
if (toInlineTextBox(run->m_box)->hasHyphen())
hyphenWidth = LayoutUnit(layoutText.hyphenWidth(font, run->direction()));
float measuredWidth = 0;
FloatRect glyphBounds;
bool kerningIsEnabled = font.getFontDescription().getTypesettingFeatures() & 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 canUseCachedWordMeasurements = font.canShapeWordByWord() && !font.getFontDescription().featureSettings();
#else
bool canUseCachedWordMeasurements = font.canShapeWordByWord();
#endif
if (canUseCachedWordMeasurements) {
int lastEndOffset = run->m_start;
size_t i = findWordMeasurement(layoutText, lastEndOffset, wordMeasurements, wordMeasurementsIndex);
for (size_t 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)
break;
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);
}
}
wordMeasurementsIndex = i;
if (lastEndOffset != run->m_stop) {
// If we don't have enough cached data, we'll measure the run again.
canUseCachedWordMeasurements = false;
fallbackFonts.clear();
}
}
// Don't put this into 'else' part of the above 'if' because canUseCachedWordMeasurements may be modified in the 'if' block.
if (!canUseCachedWordMeasurements)
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.getFontMetrics().floatAscent(), font.getFontMetrics().floatDescent(), measuredWidth);
run->m_box->setLogicalWidth(LayoutUnit(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.isApproximatelyZero()) {
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();
}
}
void LayoutBlockFlow::updateLogicalWidthForAlignment(const ETextAlign& textAlign, const RootInlineBox* rootInlineBox, BidiRun* trailingSpaceRun, LayoutUnit& logicalLeft, LayoutUnit& totalLogicalWidth, LayoutUnit& availableLogicalWidth, unsigned expansionOpportunityCount)
{
TextDirection direction;
if (rootInlineBox && rootInlineBox->getLineLayoutItem().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(LayoutUnit());
}
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 (shouldPlaceBlockDirectionScrollbarOnLogicalLeft())
logicalLeft += verticalScrollbarWidth();
}
static void updateLogicalInlinePositions(LayoutBlockFlow* block, LayoutUnit& lineLogicalLeft, LayoutUnit& lineLogicalRight, LayoutUnit& availableLogicalWidth, bool firstLine, IndentTextOrNot indentText, LayoutUnit boxLogicalHeight)
{
LayoutUnit lineLogicalHeight = block->minLineHeightForReplacedObject(firstLine, boxLogicalHeight);
lineLogicalLeft = block->logicalLeftOffsetForLine(block->logicalHeight(), indentText, lineLogicalHeight);
lineLogicalRight = block->logicalRightOffsetForLine(block->logicalHeight(), 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 indentText = requiresIndent(isFirstLine, isAfterHardLineBreak, styleRef());
LayoutUnit lineLogicalLeft;
LayoutUnit lineLogicalRight;
LayoutUnit availableLogicalWidth;
updateLogicalInlinePositions(this, lineLogicalLeft, lineLogicalRight, availableLogicalWidth, isFirstLine, indentText, LayoutUnit());
bool needsWordSpacing;
if (firstRun && firstRun->m_lineLayoutItem.isAtomicInlineLevel()) {
LineLayoutBox layoutBox(firstRun->m_lineLayoutItem);
updateLogicalInlinePositions(this, lineLogicalLeft, lineLogicalRight, availableLogicalWidth, isFirstLine, indentText, 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();
bool isAfterExpansion = true;
ExpansionOpportunities expansions;
LayoutObject* previousObject = nullptr;
TextJustify textJustify = style()->getTextJustify();
BidiRun* r = firstRun;
size_t wordMeasurementsIndex = 0;
for (; r; r = r->next()) {
if (!r->m_box || r->m_lineLayoutItem.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_lineLayoutItem.isText()) {
LineLayoutText rt(r->m_lineLayoutItem);
if (textAlign == JUSTIFY && r != trailingSpaceRun && textJustify != TextJustifyNone) {
if (!isAfterExpansion)
toInlineTextBox(r->m_box)->setCanHaveLeadingExpansion(true);
expansions.addRunWithExpansions(*r, isAfterExpansion, textJustify);
}
if (rt.textLength()) {
if (!r->m_start && needsWordSpacing && isSpaceOrNewline(rt.characterAt(r->m_start)))
totalLogicalWidth += rt.style(lineInfo.isFirstLine())->font().getFontDescription().wordSpacing();
needsWordSpacing = !isSpaceOrNewline(rt.characterAt(r->m_stop - 1));
}
setLogicalWidthForTextRun(lineBox, r, rt, totalLogicalWidth, lineInfo, textBoxDataMap, verticalPositionCache, wordMeasurements, wordMeasurementsIndex);
} else {
isAfterExpansion = false;
if (!r->m_lineLayoutItem.isLayoutInline()) {
LayoutBox* layoutBox = toLayoutBox(r->m_lineLayoutItem.layoutObject());
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_lineLayoutItem.layoutObject();
}
if (isAfterExpansion)
expansions.removeTrailingExpansion();
updateLogicalWidthForAlignment(textAlign, lineBox, trailingSpaceRun, logicalLeft, totalLogicalWidth, availableLogicalWidth, expansions.count());
expansions.computeExpansionsForJustifiedText(firstRun, trailingSpaceRun, 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_lineLayoutItem.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_lineLayoutItem.isText())
toLayoutText(r->m_lineLayoutItem.layoutObject())->positionLineBox(r->m_box);
else if (r->m_lineLayoutItem.isBox())
toLayoutBox(r->m_lineLayoutItem.layoutObject())->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.getLineLayoutItem());
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) {
// 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)
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.toInt());
setLogicalHeight(newLogicalHeight);
resolver.setPositionIgnoringNestedIsolates(oldEnd);
return oldEnd;
}
void LayoutBlockFlow::appendFloatsToLastLine(LineLayoutState& layoutState, const InlineIterator& cleanLineStart, const InlineBidiResolver& resolver, const BidiStatus& cleanLineBidiStatus)
{
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.
if (cleanLineStart.getLineLayoutItem().isEqual(floatingObject.layoutObject()) && layoutState.endLine()) {
layoutState.setEndLineMatched(layoutState.endLineMatched() || matchedEndLine(layoutState, resolver, cleanLineStart, cleanLineBidiStatus));
if (layoutState.endLineMatched()) {
layoutState.setLastFloat(&floatingObject);
return;
}
}
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()) {
// Delete all the remaining lines.
deleteLineRange(layoutState, layoutState.endLine());
layoutState.setEndLine(nullptr);
}
layoutState.setFloatIndex(layoutState.floatIndex() + 1);
}
layoutState.setLastFloat(!floatingObjectSet.isEmpty() ? floatingObjectSet.last().get() : 0);
}
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();
LayoutTextInfo layoutTextInfo;
VerticalPositionCache verticalPositionCache;
// Pagination may require us to delete and re-create a line due to floats. When this happens,
// we need to store the pagination strut in the meantime.
LayoutUnit paginationStrutFromDeletedLine;
LineBreaker lineBreaker(LineLayoutBlockFlow(this));
while (!endOfLine.atEnd()) {
// The runs from the previous line should have been cleaned up.
ASSERT(!resolver.runs().runCount());
// FIXME: Is this check necessary before the first iteration or can it be moved to the end?
if (layoutState.endLine()) {
layoutState.setEndLineMatched(layoutState.endLineMatched() || 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, 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());
RootInlineBox* lineBox = nullptr;
// This is a short-cut for empty lines.
if (layoutState.lineInfo().isEmpty()) {
ASSERT(!paginationStrutFromDeletedLine);
if (lastRootBox())
lastRootBox()->setLineBreakInfo(endOfLine.getLineLayoutItem(), endOfLine.offset(), resolver.status());
resolver.runs().deleteRuns();
} 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().getLineLayoutItem(), 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();
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 we decided to re-create the line due to pagination, we better have a new line now.
ASSERT(lineBox || !paginationStrutFromDeletedLine);
if (lineBox) {
lineBox->setLineBreakInfo(endOfLine.getLineLayoutItem(), endOfLine.offset(), resolver.status());
if (paginated) {
if (paginationStrutFromDeletedLine) {
// This is a line that got re-created because it got pushed to the next fragmentainer, and there
// were floats in the vicinity that affected the available width. Restore the pagination info
// for this line.
lineBox->setIsFirstAfterPageBreak(true);
lineBox->setPaginationStrut(paginationStrutFromDeletedLine);
paginationStrutFromDeletedLine = LayoutUnit();
} else {
LayoutUnit adjustment;
adjustLinePositionForPagination(*lineBox, adjustment);
if (adjustment) {
LayoutUnit oldLineWidth = availableLogicalWidthForLine(oldLogicalHeight, layoutState.lineInfo().isFirstLine() ? IndentText : DoNotIndentText);
lineBox->moveInBlockDirection(adjustment);
if (availableLogicalWidthForLine(oldLogicalHeight + adjustment, layoutState.lineInfo().isFirstLine() ? IndentText: DoNotIndentText) != oldLineWidth) {
// We have to delete this line, remove all floats that got added, and let line layout
// re-run. We had just calculated the pagination strut for this line, and we need to
// stow it away, so that we can re-apply it when the new line has been created.
paginationStrutFromDeletedLine = lineBox->paginationStrut();
ASSERT(paginationStrutFromDeletedLine);
// We're also going to assume that we're right after a page break when re-creating this
// line, so it better be so.
ASSERT(lineBox->isFirstAfterPageBreak());
lineBox->deleteLine();
endOfLine = restartLayoutRunsAndFloatsInRange(oldLogicalHeight, oldLogicalHeight + adjustment, lastFloatFromPreviousLine, resolver, previousEndofLine);
} else {
setLogicalHeight(lineBox->lineBottomWithLeading());
}
}
}
}
}
}
if (!paginationStrutFromDeletedLine) {
for (const auto& positionedObject : lineBreaker.positionedObjects()) {
if (positionedObject.style()->isOriginalDisplayInlineType()) {
// Auto-positioend "inline" out-of-flow objects have already been positioned,
// but if we're paginated, we need to update their position now, since the line
// they "belong" to may have been pushed by a pagination strut.
if (paginated && lineBox)
positionedObject.layer()->setStaticBlockPosition(lineBox->lineTopWithLeading());
continue;
}
setStaticPositions(LineLayoutBlockFlow(this), positionedObject, DoNotIndentText);
}
if (!layoutState.lineInfo().isEmpty())
layoutState.lineInfo().setFirstLine(false);
clearFloats(lineBreaker.clear());
if (m_floatingObjects && lastRootBox()) {
InlineBidiResolver endOfLineResolver;
endOfLineResolver.setPosition(endOfLine, numberOfIsolateAncestors(endOfLine));
endOfLineResolver.setStatus(resolver.status());
appendFloatsToLastLine(layoutState, cleanLineStart, endOfLineResolver, cleanLineBidiStatus);
}
}
lineMidpointState.reset();
resolver.setPosition(endOfLine, numberOfIsolateAncestors(endOfLine));
}
// The resolver runs should have been cleared, otherwise they're leaking.
ASSERT(!resolver.runs().runCount());
// 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()->widows() > 1 && !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()->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)
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());
}
}
// 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
if (positionNewFloats() && lastRootBox())
appendFloatsToLastLine(layoutState, InlineIterator(), InlineBidiResolver(), BidiStatus());
}
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->isAtomicInlineLevel() && !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->isAtomicInlineLevel() || 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());
float spaceWidth = font.width(run);
inlineMax -= LayoutUnit::fromFloatCeil(spaceWidth + font.getFontDescription().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.
DISABLE_CFI_PERF
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->isAtomicInlineLevel() ? 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).
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()) {
const ComputedStyle& childStyle = child->styleRef();
clearPreviousFloat = (prevFloat
&& ((prevFloat->styleRef().floating() == EFloat::LeftFloat && (childStyle.clear() & ClearLeft))
|| (prevFloat->styleRef().floating() == EFloat::RightFloat && (childStyle.clear() & ClearRight))));
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 laid 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();
}
static inline bool shouldTruncateOverflowingText(const LayoutBlockFlow* block)
{
const LayoutObject* objectToCheck = block;
if (block->isAnonymousBlock()) {
const LayoutObject* parent = block->parent();
if (!parent || !parent->behavesLikeBlockContainer())
return false;
objectToCheck = parent;
}
return objectToCheck->hasOverflowClip() && objectToCheck->style()->getTextOverflow();
}
DISABLE_CFI_PERF
void LayoutBlockFlow::layoutInlineChildren(bool relayoutChildren, LayoutUnit afterEdge)
{
// Figure out if we should clear out our line boxes.
// FIXME: Handle resize eventually!
bool isFullLayout = !firstLineBox() || selfNeedsLayout() || relayoutChildren;
LineLayoutState layoutState(isFullLayout);
if (isFullLayout) {
// Ensure the old line boxes will be erased.
if (firstLineBox())
setShouldDoFullPaintInvalidation();
lineBoxes()->deleteLineBoxes();
}
// Text truncation kicks in if overflow isn't visible and text-overflow isn't 'clip'. If this is
// an anonymous block, we have to examine the parent.
// 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 its parent is clipped.
bool hasTextOverflow = shouldTruncateOverflowingText(this);
// Walk all the lines and delete our ellipsis line boxes if they exist.
if (hasTextOverflow)
deleteEllipsisLineBoxes();
if (firstChild()) {
for (InlineWalker walker(LineLayoutBlockFlow(this)); !walker.atEnd(); walker.advance()) {
LayoutObject* o = walker.current().layoutObject();
if (!layoutState.hasInlineChild() && o->isInline())
layoutState.setHasInlineChild(true);
if (o->isAtomicInlineLevel() || o->isFloating() || o->isOutOfFlowPositioned()) {
LayoutBox* box = toLayoutBox(o);
box->setMayNeedPaintInvalidation();
updateBlockChildDirtyBitsBeforeLayout(relayoutChildren, *box);
if (o->isOutOfFlowPositioned()) {
o->containingBlock()->insertPositionedObject(box);
} else if (o->isFloating()) {
layoutState.floats().append(FloatWithRect(box));
if (box->needsLayout()) {
box->layout();
// Dirty any lineboxes potentially affected by the float, but don't search outside this
// object as we are only interested in dirtying lineboxes to which we may attach the float.
dirtyLinesFromChangedChild(box, MarkOnlyThis);
}
} else if (isFullLayout || o->needsLayout()) {
// Atomic inline.
box->dirtyLineBoxes(isFullLayout);
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);
}
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).toInt();
else
lastLineAnnotationsAdjustment = lastRootBox()->computeOverAnnotationAdjustment(lowestAllowedPosition).toInt();
}
// 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;
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;
}
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().layoutObject())->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(LineLayoutItem(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->getLineLayoutItem().isBR() && lastBox->getLineLayoutItem().style()->clear() != ClearNone;
}
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)
{
if (!m_floatingObjects || !layoutState.endLine())
return true;
LayoutUnit lineDelta = logicalHeight() - layoutState.endLineLogicalTop();
bool paginated = view()->layoutState() && view()->layoutState()->isPaginated();
if (paginated) {
// 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()) {
// 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)
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().getLineLayoutItem() && 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();
// FIXME: Need to find another way to do this, since scrollbars could show when we don't want them to.
if (hasOverflowClip() && !endPadding && node() && isRootEditableElement(*node()) && style()->isLeftToRightDirection())
endPadding = LayoutUnit(1);
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(LineLayoutBlockFlow(this)); !walker.atEnd(); walker.advance()) {
const LayoutObject& o = *walker.current().layoutObject();
if (!isInlineWithOutlineAndContinuation(o))
continue;
Vector<LayoutRect> outlineRects;
toLayoutInline(o).addOutlineRectsForContinuations(outlineRects, LayoutPoint(), o.outlineRectsShouldIncludeBlockVisualOverflow());
if (!outlineRects.isEmpty()) {
LayoutRect outlineBounds = unionRectEvenIfEmpty(outlineRects);
outlineBounds.inflate(LayoutUnit(o.styleRef().outlineOutsetExtent()));
outlineBoundsOfAllContinuations.unite(outlineBounds);
}
}
addContentsVisualOverflow(outlineBoundsOfAllContinuations);
}
void LayoutBlockFlow::deleteEllipsisLineBoxes()
{
ETextAlign textAlign = style()->textAlign();
IndentTextOrNot indentText = IndentText;
for (RootInlineBox* curr = firstRootBox(); curr; curr = curr->nextRootBox()) {
if (curr->hasEllipsisBox()) {
curr->clearTruncation();
// Shift the line back where it belongs if we cannot accommodate an ellipsis.
LayoutUnit logicalLeft = logicalLeftOffsetForLine(curr->lineTop(), indentText);
LayoutUnit availableLogicalWidth = logicalRightOffsetForLine(curr->lineTop(), DoNotIndentText) - logicalLeft;
LayoutUnit totalLogicalWidth = curr->logicalWidth();
updateLogicalWidthForAlignment(textAlign, curr, 0, logicalLeft, totalLogicalWidth, availableLogicalWidth, 0);
curr->moveInInlineDirection(logicalLeft - curr->logicalLeft());
}
indentText = DoNotIndentText;
}
}
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();
IndentTextOrNot indentText = IndentText;
for (RootInlineBox* curr = firstRootBox(); curr; curr = curr->nextRootBox()) {
LayoutUnit currLogicalLeft = curr->logicalLeft();
LayoutUnit blockRightEdge = logicalRightOffsetForLine(curr->lineTop(), indentText);
LayoutUnit blockLeftEdge = logicalLeftOffsetForLine(curr->lineTop(), indentText);
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(indentText == IndentText ? firstLineEllipsisWidth : ellipsisWidth);
LayoutUnit blockEdge = ltr ? blockRightEdge : blockLeftEdge;
if (curr->lineCanAccommodateEllipsis(ltr, blockEdge.toInt(), lineBoxEdge.toInt(), width.toInt())) {
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));
}
}
indentText = DoNotIndentText;
}
}
void LayoutBlockFlow::markLinesDirtyInBlockRange(LayoutUnit logicalTop, LayoutUnit logicalBottom, RootInlineBox* highest)
{
if (logicalTop >= logicalBottom)
return;
RootInlineBox* lowestDirtyLine = lastRootBox();
RootInlineBox* afterLowest = lowestDirtyLine;
while (lowestDirtyLine && lowestDirtyLine->lineBottomWithLeading() >= logicalBottom && logicalBottom < LayoutUnit::max()) {
afterLowest = lowestDirtyLine;
lowestDirtyLine = lowestDirtyLine->prevRootBox();
}
while (afterLowest && afterLowest != highest && (afterLowest->lineBottomWithLeading() >= logicalTop || afterLowest->lineBottomWithLeading() < LayoutUnit())) {
afterLowest->markDirty();
afterLowest = afterLowest->prevRootBox();
}
}
LayoutUnit LayoutBlockFlow::startAlignedOffsetForLine(LayoutUnit position, IndentTextOrNot indentText)
{
ETextAlign textAlign = style()->textAlign();
bool applyIndentText;
switch (textAlign) { // FIXME: Handle TAEND here
case LEFT:
case WEBKIT_LEFT:
applyIndentText = style()->isLeftToRightDirection();
break;
case RIGHT:
case WEBKIT_RIGHT:
applyIndentText = !style()->isLeftToRightDirection();
break;
case TASTART:
applyIndentText = true;
break;
default:
applyIndentText = false;
}
if (applyIndentText)
return startOffsetForLine(position, indentText);
// updateLogicalWidthForAlignment() handles the direction of the block so no need to consider it here
LayoutUnit totalLogicalWidth;
LayoutUnit logicalLeft = logicalLeftOffsetForLine(logicalHeight(), DoNotIndentText);
LayoutUnit availableLogicalWidth = logicalRightOffsetForLine(logicalHeight(), DoNotIndentText) - logicalLeft;
updateLogicalWidthForAlignment(textAlign, 0, 0, logicalLeft, totalLogicalWidth, availableLogicalWidth, 0);
if (!style()->isLeftToRightDirection())
return logicalWidth() - logicalLeft;
return logicalLeft;
}
void LayoutBlockFlow::setShouldDoFullPaintInvalidationForFirstLine()
{
ASSERT(childrenInline());
if (RootInlineBox* firstRootBox = this->firstRootBox())
firstRootBox->setShouldDoFullPaintInvalidationRecursively();
}
bool LayoutBlockFlow::paintedOutputOfObjectHasNoEffectRegardlessOfSize() const
{
// LayoutBlockFlow is in charge of paint invalidation of the first line.
if (firstLineBox())
return false;
return LayoutBlock::paintedOutputOfObjectHasNoEffectRegardlessOfSize();
}
} // namespace blink