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webkit / WebKit / 40d9a847568ff9976450dcc37c680efd7351c7ed / . / Source / WebCore / rendering / RenderBlockFlow.cpp
blob: d973bee9b179fa72a4c580c0afe5bcc610709030 [file] [log] [blame]
/*
* Copyright (C) 1999 Lars Knoll (knoll@kde.org)
* (C) 1999 Antti Koivisto (koivisto@kde.org)
* (C) 2007 David Smith (catfish.man@gmail.com)
* Copyright (C) 2003-2015 Apple Inc. All rights reserved.
* Copyright (C) Research In Motion Limited 2010. 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 "RenderBlockFlow.h"
#include "ComplexLineLayout.h"
#include "Editor.h"
#include "FloatingObjects.h"
#include "Frame.h"
#include "FrameSelection.h"
#include "HTMLElement.h"
#include "HTMLInputElement.h"
#include "HTMLParserIdioms.h"
#include "HTMLTextAreaElement.h"
#include "HitTestLocation.h"
#include "InlineTextBox.h"
#include "LayoutIntegrationLineLayout.h"
#include "LayoutRepainter.h"
#include "Logging.h"
#include "RenderCombineText.h"
#include "RenderFlexibleBox.h"
#include "RenderInline.h"
#include "RenderIterator.h"
#include "RenderLayer.h"
#include "RenderLayoutState.h"
#include "RenderLineBreak.h"
#include "RenderListItem.h"
#include "RenderMarquee.h"
#include "RenderMultiColumnFlow.h"
#include "RenderMultiColumnSet.h"
#include "RenderTableCell.h"
#include "RenderText.h"
#include "RenderTreeBuilder.h"
#include "RenderView.h"
#include "Settings.h"
#include "SimpleLineLayoutFunctions.h"
#include "SimpleLineLayoutPagination.h"
#include "SimpleLineLayoutResolver.h"
#include "TextAutoSizing.h"
#include "VerticalPositionCache.h"
#include "VisiblePosition.h"
#include <wtf/IsoMallocInlines.h>
namespace WebCore {
WTF_MAKE_ISO_ALLOCATED_IMPL(RenderBlockFlow);
bool RenderBlock::s_canPropagateFloatIntoSibling = false;
struct SameSizeAsMarginInfo {
uint32_t bitfields : 16;
LayoutUnit margins[2];
};
COMPILE_ASSERT(sizeof(RenderBlockFlow::MarginValues) == sizeof(LayoutUnit[4]), MarginValues_should_stay_small);
COMPILE_ASSERT(sizeof(RenderBlockFlow::MarginInfo) == sizeof(SameSizeAsMarginInfo), MarginInfo_should_stay_small);
// Our MarginInfo state used when laying out block children.
RenderBlockFlow::MarginInfo::MarginInfo(const RenderBlockFlow& block, LayoutUnit beforeBorderPadding, LayoutUnit afterBorderPadding)
: m_atBeforeSideOfBlock(true)
, m_atAfterSideOfBlock(false)
, m_hasMarginBeforeQuirk(false)
, m_hasMarginAfterQuirk(false)
, m_determinedMarginBeforeQuirk(false)
, m_discardMargin(false)
{
const RenderStyle& blockStyle = block.style();
ASSERT(block.isRenderView() || block.parent());
m_canCollapseWithChildren = !block.createsNewFormattingContext() && !block.isRenderView();
m_canCollapseMarginBeforeWithChildren = m_canCollapseWithChildren && !beforeBorderPadding && blockStyle.marginBeforeCollapse() != MarginCollapse::Separate;
// If any height other than auto is specified in CSS, then we don't collapse our bottom
// margins with our children's margins. To do otherwise would be to risk odd visual
// effects when the children overflow out of the parent block and yet still collapse
// with it. We also don't collapse if we have any bottom border/padding.
m_canCollapseMarginAfterWithChildren = m_canCollapseWithChildren && !afterBorderPadding
&& (blockStyle.logicalHeight().isAuto() && !blockStyle.logicalHeight().value()) && blockStyle.marginAfterCollapse() != MarginCollapse::Separate;
m_quirkContainer = block.isTableCell() || block.isBody();
m_discardMargin = m_canCollapseMarginBeforeWithChildren && block.mustDiscardMarginBefore();
m_positiveMargin = (m_canCollapseMarginBeforeWithChildren && !block.mustDiscardMarginBefore()) ? block.maxPositiveMarginBefore() : 0_lu;
m_negativeMargin = (m_canCollapseMarginBeforeWithChildren && !block.mustDiscardMarginBefore()) ? block.maxNegativeMarginBefore() : 0_lu;
}
RenderBlockFlow::RenderBlockFlow(Element& element, RenderStyle&& style)
: RenderBlock(element, WTFMove(style), RenderBlockFlowFlag)
#if ENABLE(TEXT_AUTOSIZING)
, m_widthForTextAutosizing(-1)
, m_lineCountForTextAutosizing(NOT_SET)
#endif
{
setChildrenInline(true);
}
RenderBlockFlow::RenderBlockFlow(Document& document, RenderStyle&& style)
: RenderBlock(document, WTFMove(style), RenderBlockFlowFlag)
#if ENABLE(TEXT_AUTOSIZING)
, m_widthForTextAutosizing(-1)
, m_lineCountForTextAutosizing(NOT_SET)
#endif
{
setChildrenInline(true);
}
RenderBlockFlow::~RenderBlockFlow()
{
// Do not add any code here. Add it to willBeDestroyed() instead.
}
void RenderBlockFlow::willBeDestroyed()
{
if (!renderTreeBeingDestroyed()) {
if (firstRootBox()) {
// We can't wait for RenderBox::destroy to clear the selection,
// because by then we will have nuked the line boxes.
if (isSelectionBorder())
frame().selection().setNeedsSelectionUpdate();
// If we are an anonymous block, then our line boxes might have children
// that will outlast this block. In the non-anonymous block case those
// children will be destroyed by the time we return from this function.
if (isAnonymousBlock()) {
for (auto* box = firstRootBox(); box; box = box->nextRootBox()) {
while (auto childBox = box->firstChild())
childBox->removeFromParent();
}
}
} else if (parent())
parent()->dirtyLinesFromChangedChild(*this);
}
if (complexLineLayout())
complexLineLayout()->lineBoxes().deleteLineBoxes();
blockWillBeDestroyed();
// NOTE: This jumps down to RenderBox, bypassing RenderBlock since it would do duplicate work.
RenderBox::willBeDestroyed();
}
RenderMultiColumnFlow* RenderBlockFlow::multiColumnFlowSlowCase() const
{
return rareBlockFlowData()->m_multiColumnFlow.get();
}
RenderBlockFlow* RenderBlockFlow::previousSiblingWithOverhangingFloats(bool& parentHasFloats) const
{
// Attempt to locate a previous sibling with overhanging floats. We skip any elements that are
// out of flow (like floating/positioned elements), and we also skip over any objects that may have shifted
// to avoid floats.
parentHasFloats = false;
for (RenderObject* sibling = previousSibling(); sibling; sibling = sibling->previousSibling()) {
if (is<RenderBlockFlow>(*sibling)) {
auto& siblingBlock = downcast<RenderBlockFlow>(*sibling);
if (!siblingBlock.avoidsFloats())
return &siblingBlock;
}
if (sibling->isFloating())
parentHasFloats = true;
}
return nullptr;
}
void RenderBlockFlow::rebuildFloatingObjectSetFromIntrudingFloats()
{
if (m_floatingObjects)
m_floatingObjects->setHorizontalWritingMode(isHorizontalWritingMode());
HashSet<RenderBox*> oldIntrudingFloatSet;
if (!childrenInline() && m_floatingObjects) {
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
auto end = floatingObjectSet.end();
for (auto it = floatingObjectSet.begin(); it != end; ++it) {
FloatingObject* floatingObject = it->get();
if (!floatingObject->isDescendant())
oldIntrudingFloatSet.add(&floatingObject->renderer());
}
}
// Inline blocks are covered by the isReplaced() check in the avoidFloats method.
if (avoidsFloats() || isDocumentElementRenderer() || isRenderView() || isFloatingOrOutOfFlowPositioned() || isTableCell()) {
if (m_floatingObjects)
m_floatingObjects->clear();
if (!oldIntrudingFloatSet.isEmpty())
markAllDescendantsWithFloatsForLayout();
return;
}
RendererToFloatInfoMap floatMap;
if (m_floatingObjects) {
if (childrenInline())
m_floatingObjects->moveAllToFloatInfoMap(floatMap);
else
m_floatingObjects->clear();
}
// We should not process floats if the parent node is not a RenderBlock. Otherwise, we will add
// floats in an invalid context. This will cause a crash arising from a bad cast on the parent.
// See <rdar://problem/8049753>, where float property is applied on a text node in a SVG.
if (!is<RenderBlockFlow>(parent()))
return;
// First add in floats from the parent. Self-collapsing blocks let their parent track any floats that intrude into
// them (as opposed to floats they contain themselves) so check for those here too.
auto& parentBlock = downcast<RenderBlockFlow>(*parent());
bool parentHasFloats = false;
RenderBlockFlow* previousBlock = previousSiblingWithOverhangingFloats(parentHasFloats);
LayoutUnit logicalTopOffset = logicalTop();
if (parentHasFloats || (parentBlock.lowestFloatLogicalBottom() > logicalTopOffset && previousBlock && previousBlock->isSelfCollapsingBlock()))
addIntrudingFloats(&parentBlock, &parentBlock, parentBlock.logicalLeftOffsetForContent(), logicalTopOffset);
LayoutUnit logicalLeftOffset;
if (previousBlock)
logicalTopOffset -= previousBlock->logicalTop();
else {
previousBlock = &parentBlock;
logicalLeftOffset += parentBlock.logicalLeftOffsetForContent();
}
// Add overhanging floats from the previous RenderBlock, but only if it has a float that intrudes into our space.
if (previousBlock->m_floatingObjects && previousBlock->lowestFloatLogicalBottom() > logicalTopOffset)
addIntrudingFloats(previousBlock, &parentBlock, logicalLeftOffset, logicalTopOffset);
if (childrenInline()) {
LayoutUnit changeLogicalTop = LayoutUnit::max();
LayoutUnit changeLogicalBottom = LayoutUnit::min();
if (m_floatingObjects) {
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
auto end = floatingObjectSet.end();
for (auto it = floatingObjectSet.begin(); it != end; ++it) {
const auto& floatingObject = *it->get();
std::unique_ptr<FloatingObject> oldFloatingObject = floatMap.take(&floatingObject.renderer());
LayoutUnit logicalBottom = logicalBottomForFloat(floatingObject);
if (oldFloatingObject) {
LayoutUnit oldLogicalBottom = logicalBottomForFloat(*oldFloatingObject);
if (logicalWidthForFloat(floatingObject) != logicalWidthForFloat(*oldFloatingObject) || logicalLeftForFloat(floatingObject) != logicalLeftForFloat(*oldFloatingObject)) {
changeLogicalTop = 0;
changeLogicalBottom = std::max(changeLogicalBottom, std::max(logicalBottom, oldLogicalBottom));
} else {
if (logicalBottom != oldLogicalBottom) {
changeLogicalTop = std::min(changeLogicalTop, std::min(logicalBottom, oldLogicalBottom));
changeLogicalBottom = std::max(changeLogicalBottom, std::max(logicalBottom, oldLogicalBottom));
}
LayoutUnit logicalTop = logicalTopForFloat(floatingObject);
LayoutUnit oldLogicalTop = logicalTopForFloat(*oldFloatingObject);
if (logicalTop != oldLogicalTop) {
changeLogicalTop = std::min(changeLogicalTop, std::min(logicalTop, oldLogicalTop));
changeLogicalBottom = std::max(changeLogicalBottom, std::max(logicalTop, oldLogicalTop));
}
}
if (oldFloatingObject->originatingLine() && !selfNeedsLayout()) {
ASSERT(&oldFloatingObject->originatingLine()->renderer() == this);
oldFloatingObject->originatingLine()->markDirty();
}
} else {
changeLogicalTop = 0;
changeLogicalBottom = std::max(changeLogicalBottom, logicalBottom);
}
}
}
auto end = floatMap.end();
for (auto it = floatMap.begin(); it != end; ++it) {
const auto& floatingObject = *it->value.get();
if (!floatingObject.isDescendant()) {
changeLogicalTop = 0;
changeLogicalBottom = std::max(changeLogicalBottom, logicalBottomForFloat(floatingObject));
}
}
markLinesDirtyInBlockRange(changeLogicalTop, changeLogicalBottom);
} else if (!oldIntrudingFloatSet.isEmpty()) {
// If there are previously intruding floats that no longer intrude, then children with floats
// should also get layout because they might need their floating object lists cleared.
if (m_floatingObjects->set().size() < oldIntrudingFloatSet.size())
markAllDescendantsWithFloatsForLayout();
else {
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
auto end = floatingObjectSet.end();
for (auto it = floatingObjectSet.begin(); it != end && !oldIntrudingFloatSet.isEmpty(); ++it)
oldIntrudingFloatSet.remove(&(*it)->renderer());
if (!oldIntrudingFloatSet.isEmpty())
markAllDescendantsWithFloatsForLayout();
}
}
}
void RenderBlockFlow::adjustIntrinsicLogicalWidthsForColumns(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const
{
if (!style().hasAutoColumnCount() || !style().hasAutoColumnWidth()) {
// The min/max intrinsic widths calculated really tell how much space elements need when
// laid out inside the columns. In order to eventually end up with the desired column width,
// we need to convert them to values pertaining to the multicol container.
int columnCount = style().hasAutoColumnCount() ? 1 : style().columnCount();
LayoutUnit columnWidth;
LayoutUnit colGap = columnGap();
LayoutUnit gapExtra = (columnCount - 1) * colGap;
if (style().hasAutoColumnWidth())
minLogicalWidth = minLogicalWidth * columnCount + gapExtra;
else {
columnWidth = style().columnWidth();
minLogicalWidth = std::min(minLogicalWidth, columnWidth);
}
// FIXME: If column-count is auto here, we should resolve it to calculate the maximum
// intrinsic width, instead of pretending that it's 1. The only way to do that is by
// performing a layout pass, but this is not an appropriate time or place for layout. The
// good news is that if height is unconstrained and there are no explicit breaks, the
// resolved column-count really should be 1.
maxLogicalWidth = std::max(maxLogicalWidth, columnWidth) * columnCount + gapExtra;
}
}
void RenderBlockFlow::computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const
{
if (childrenInline())
computeInlinePreferredLogicalWidths(minLogicalWidth, maxLogicalWidth);
else
computeBlockPreferredLogicalWidths(minLogicalWidth, maxLogicalWidth);
maxLogicalWidth = std::max(minLogicalWidth, maxLogicalWidth);
adjustIntrinsicLogicalWidthsForColumns(minLogicalWidth, maxLogicalWidth);
if (!style().autoWrap() && childrenInline()) {
// A horizontal marquee with inline children has no minimum width.
if (layer() && layer()->marquee() && layer()->marquee()->isHorizontal())
minLogicalWidth = 0;
}
if (is<RenderTableCell>(*this)) {
Length tableCellWidth = downcast<RenderTableCell>(*this).styleOrColLogicalWidth();
if (tableCellWidth.isFixed() && tableCellWidth.value() > 0)
maxLogicalWidth = std::max(minLogicalWidth, adjustContentBoxLogicalWidthForBoxSizing(tableCellWidth.value()));
}
int scrollbarWidth = intrinsicScrollbarLogicalWidth();
maxLogicalWidth += scrollbarWidth;
minLogicalWidth += scrollbarWidth;
}
bool RenderBlockFlow::recomputeLogicalWidthAndColumnWidth()
{
bool changed = recomputeLogicalWidth();
LayoutUnit oldColumnWidth = computedColumnWidth();
computeColumnCountAndWidth();
return changed || oldColumnWidth != computedColumnWidth();
}
LayoutUnit RenderBlockFlow::columnGap() const
{
if (style().columnGap().isNormal())
return style().fontDescription().computedPixelSize(); // "1em" is recommended as the normal gap setting. Matches <p> margins.
return valueForLength(style().columnGap().length(), availableLogicalWidth());
}
void RenderBlockFlow::computeColumnCountAndWidth()
{
// Calculate our column width and column count.
// FIXME: Can overflow on fast/block/float/float-not-removed-from-next-sibling4.html, see https://bugs.webkit.org/show_bug.cgi?id=68744
unsigned desiredColumnCount = 1;
LayoutUnit desiredColumnWidth = contentLogicalWidth();
// For now, we don't support multi-column layouts when printing, since we have to do a lot of work for proper pagination.
if (document().paginated() || (style().hasAutoColumnCount() && style().hasAutoColumnWidth()) || !style().hasInlineColumnAxis()) {
setComputedColumnCountAndWidth(desiredColumnCount, desiredColumnWidth);
return;
}
LayoutUnit availWidth = desiredColumnWidth;
LayoutUnit colGap = columnGap();
LayoutUnit colWidth = std::max(1_lu, LayoutUnit(style().columnWidth()));
unsigned colCount = std::max<unsigned>(1, style().columnCount());
if (style().hasAutoColumnWidth() && !style().hasAutoColumnCount()) {
desiredColumnCount = colCount;
desiredColumnWidth = std::max<LayoutUnit>(0, (availWidth - ((desiredColumnCount - 1) * colGap)) / desiredColumnCount);
} else if (!style().hasAutoColumnWidth() && style().hasAutoColumnCount()) {
desiredColumnCount = std::max<unsigned>(1, ((availWidth + colGap) / (colWidth + colGap)).toUnsigned());
desiredColumnWidth = ((availWidth + colGap) / desiredColumnCount) - colGap;
} else {
desiredColumnCount = std::max<unsigned>(std::min(colCount, ((availWidth + colGap) / (colWidth + colGap)).toUnsigned()), 1);
desiredColumnWidth = ((availWidth + colGap) / desiredColumnCount) - colGap;
}
setComputedColumnCountAndWidth(desiredColumnCount, desiredColumnWidth);
}
bool RenderBlockFlow::willCreateColumns(Optional<unsigned> desiredColumnCount) const
{
// The following types are not supposed to create multicol context.
if (isFileUploadControl() || isTextControl() || isListBox())
return false;
if (isRenderSVGBlock() || isRubyRun())
return false;
#if ENABLE(MATHML)
if (isRenderMathMLBlock())
return false;
#endif // ENABLE(MATHML)
if (!firstChild())
return false;
if (style().styleType() != PseudoId::None)
return false;
// If overflow-y is set to paged-x or paged-y on the body or html element, we'll handle the paginating in the RenderView instead.
if ((style().overflowY() == Overflow::PagedX || style().overflowY() == Overflow::PagedY) && !(isDocumentElementRenderer() || isBody()))
return true;
if (!style().specifiesColumns())
return false;
// column-axis with opposite writing direction initiates MultiColumnFlow.
if (!style().hasInlineColumnAxis())
return true;
// Non-auto column-width always initiates MultiColumnFlow.
if (!style().hasAutoColumnWidth())
return true;
if (desiredColumnCount)
return desiredColumnCount.value() > 1;
// column-count > 1 always initiates MultiColumnFlow.
if (!style().hasAutoColumnCount())
return style().columnCount() > 1;
ASSERT_NOT_REACHED();
return false;
}
void RenderBlockFlow::layoutBlock(bool relayoutChildren, LayoutUnit pageLogicalHeight)
{
ASSERT(needsLayout());
if (!relayoutChildren && simplifiedLayout())
return;
LayoutRepainter repainter(*this, checkForRepaintDuringLayout());
if (recomputeLogicalWidthAndColumnWidth())
relayoutChildren = true;
rebuildFloatingObjectSetFromIntrudingFloats();
LayoutUnit previousHeight = logicalHeight();
// FIXME: should this start out as borderAndPaddingLogicalHeight() + scrollbarLogicalHeight(),
// for consistency with other render classes?
resetLogicalHeightBeforeLayoutIfNeeded();
bool pageLogicalHeightChanged = false;
checkForPaginationLogicalHeightChange(relayoutChildren, pageLogicalHeight, pageLogicalHeightChanged);
LayoutUnit repaintLogicalTop;
LayoutUnit repaintLogicalBottom;
LayoutUnit maxFloatLogicalBottom;
const RenderStyle& styleToUse = style();
{
LayoutStateMaintainer statePusher(*this, locationOffset(), hasTransform() || hasReflection() || styleToUse.isFlippedBlocksWritingMode(), pageLogicalHeight, pageLogicalHeightChanged);
preparePaginationBeforeBlockLayout(relayoutChildren);
// We use four values, maxTopPos, maxTopNeg, maxBottomPos, and maxBottomNeg, to track
// our current maximal positive and negative margins. These values are used when we
// are collapsed with adjacent blocks, so for example, if you have block A and B
// collapsing together, then you'd take the maximal positive margin from both A and B
// and subtract it from the maximal negative margin from both A and B to get the
// true collapsed margin. This algorithm is recursive, so when we finish layout()
// our block knows its current maximal positive/negative values.
//
// Start out by setting our margin values to our current margins. Table cells have
// no margins, so we don't fill in the values for table cells.
bool isCell = isTableCell();
if (!isCell) {
initMaxMarginValues();
setHasMarginBeforeQuirk(styleToUse.hasMarginBeforeQuirk());
setHasMarginAfterQuirk(styleToUse.hasMarginAfterQuirk());
setPaginationStrut(0);
}
if (!firstChild() && !isAnonymousBlock())
setChildrenInline(true);
if (childrenInline())
layoutInlineChildren(relayoutChildren, repaintLogicalTop, repaintLogicalBottom);
else
layoutBlockChildren(relayoutChildren, maxFloatLogicalBottom);
}
// Expand our intrinsic height to encompass floats.
LayoutUnit toAdd = borderAndPaddingAfter() + scrollbarLogicalHeight();
if (lowestFloatLogicalBottom() > (logicalHeight() - toAdd) && createsNewFormattingContext())
setLogicalHeight(lowestFloatLogicalBottom() + toAdd);
if (relayoutForPagination() || relayoutToAvoidWidows()) {
ASSERT(!shouldBreakAtLineToAvoidWidow());
return;
}
// Calculate our new height.
LayoutUnit oldHeight = logicalHeight();
LayoutUnit oldClientAfterEdge = clientLogicalBottom();
// Before updating the final size of the flow thread make sure a forced break is applied after the content.
// This ensures the size information is correctly computed for the last auto-height fragment receiving content.
if (is<RenderFragmentedFlow>(*this))
downcast<RenderFragmentedFlow>(*this).applyBreakAfterContent(oldClientAfterEdge);
updateLogicalHeight();
LayoutUnit newHeight = logicalHeight();
{
// FIXME: This could be removed once relayoutForPagination()/relayoutToAvoidWidows() either stop recursing or we manage to
// re-order them.
LayoutStateMaintainer statePusher(*this, locationOffset(), hasTransform() || hasReflection() || styleToUse.isFlippedBlocksWritingMode(), pageLogicalHeight, pageLogicalHeightChanged);
if (oldHeight != newHeight) {
if (oldHeight > newHeight && maxFloatLogicalBottom > newHeight && !childrenInline()) {
// One of our children's floats may have become an overhanging float for us. We need to look for it.
for (auto& blockFlow : childrenOfType<RenderBlockFlow>(*this)) {
if (blockFlow.isFloatingOrOutOfFlowPositioned())
continue;
if (blockFlow.lowestFloatLogicalBottom() + blockFlow.logicalTop() > newHeight)
addOverhangingFloats(blockFlow, false);
}
}
}
bool heightChanged = (previousHeight != newHeight);
if (heightChanged)
relayoutChildren = true;
layoutPositionedObjects(relayoutChildren || isDocumentElementRenderer());
}
// Add overflow from children (unless we're multi-column, since in that case all our child overflow is clipped anyway).
computeOverflow(oldClientAfterEdge);
fitBorderToLinesIfNeeded();
auto* state = view().frameView().layoutContext().layoutState();
if (state && state->pageLogicalHeight())
setPageLogicalOffset(state->pageLogicalOffset(this, logicalTop()));
updateLayerTransform();
// Update our scroll information if we're overflow:auto/scroll/hidden now that we know if
// we overflow or not.
updateScrollInfoAfterLayout();
// FIXME: This repaint logic should be moved into a separate helper function!
// Repaint with our new bounds if they are different from our old bounds.
bool didFullRepaint = repainter.repaintAfterLayout();
if (!didFullRepaint && repaintLogicalTop != repaintLogicalBottom && (styleToUse.visibility() == Visibility::Visible || enclosingLayer()->hasVisibleContent())) {
// FIXME: We could tighten up the left and right invalidation points if we let layoutInlineChildren fill them in based off the particular lines
// it had to lay out. We wouldn't need the hasOverflowClip() hack in that case either.
LayoutUnit repaintLogicalLeft = logicalLeftVisualOverflow();
LayoutUnit repaintLogicalRight = logicalRightVisualOverflow();
if (hasOverflowClip()) {
// If we have clipped overflow, we should use layout overflow as well, since visual overflow from lines didn't propagate to our block's overflow.
// Note the old code did this as well but even for overflow:visible. The addition of hasOverflowClip() at least tightens up the hack a bit.
// layoutInlineChildren should be patched to compute the entire repaint rect.
repaintLogicalLeft = std::min(repaintLogicalLeft, logicalLeftLayoutOverflow());
repaintLogicalRight = std::max(repaintLogicalRight, logicalRightLayoutOverflow());
}
LayoutRect repaintRect;
if (isHorizontalWritingMode())
repaintRect = LayoutRect(repaintLogicalLeft, repaintLogicalTop, repaintLogicalRight - repaintLogicalLeft, repaintLogicalBottom - repaintLogicalTop);
else
repaintRect = LayoutRect(repaintLogicalTop, repaintLogicalLeft, repaintLogicalBottom - repaintLogicalTop, repaintLogicalRight - repaintLogicalLeft);
if (hasOverflowClip()) {
// Adjust repaint rect for scroll offset
repaintRect.moveBy(-scrollPosition());
// Don't allow this rect to spill out of our overflow box.
repaintRect.intersect(LayoutRect(LayoutPoint(), size()));
}
// Make sure the rect is still non-empty after intersecting for overflow above
if (!repaintRect.isEmpty()) {
repaintRectangle(repaintRect); // We need to do a partial repaint of our content.
if (hasReflection())
repaintRectangle(reflectedRect(repaintRect));
}
}
clearNeedsLayout();
}
void RenderBlockFlow::layoutBlockChildren(bool relayoutChildren, LayoutUnit& maxFloatLogicalBottom)
{
dirtyForLayoutFromPercentageHeightDescendants();
LayoutUnit beforeEdge = borderAndPaddingBefore();
LayoutUnit afterEdge = borderAndPaddingAfter() + scrollbarLogicalHeight();
setLogicalHeight(beforeEdge);
// Lay out our hypothetical grid line as though it occurs at the top of the block.
if (view().frameView().layoutContext().layoutState()->lineGrid() == this)
layoutLineGridBox();
// The margin struct caches all our current margin collapsing state.
MarginInfo marginInfo(*this, beforeEdge, afterEdge);
// Fieldsets need to find their legend and position it inside the border of the object.
// The legend then gets skipped during normal layout. The same is true for ruby text.
// It doesn't get included in the normal layout process but is instead skipped.
layoutExcludedChildren(relayoutChildren);
LayoutUnit previousFloatLogicalBottom;
maxFloatLogicalBottom = 0;
RenderBox* next = firstChildBox();
while (next) {
RenderBox& child = *next;
next = child.nextSiblingBox();
if (child.isExcludedFromNormalLayout())
continue; // Skip this child, since it will be positioned by the specialized subclass (fieldsets and ruby runs).
updateBlockChildDirtyBitsBeforeLayout(relayoutChildren, child);
if (child.isOutOfFlowPositioned()) {
child.containingBlock()->insertPositionedObject(child);
adjustPositionedBlock(child, marginInfo);
continue;
}
if (child.isFloating()) {
insertFloatingObject(child);
adjustFloatingBlock(marginInfo);
continue;
}
// Lay out the child.
layoutBlockChild(child, marginInfo, previousFloatLogicalBottom, maxFloatLogicalBottom);
}
// Now do the handling of the bottom of the block, adding in our bottom border/padding and
// determining the correct collapsed bottom margin information.
handleAfterSideOfBlock(beforeEdge, afterEdge, marginInfo);
}
void RenderBlockFlow::layoutInlineChildren(bool relayoutChildren, LayoutUnit& repaintLogicalTop, LayoutUnit& repaintLogicalBottom)
{
auto computeLineLayoutPath = [&] {
#if ENABLE(LAYOUT_FORMATTING_CONTEXT)
if (LayoutIntegration::LineLayout::canUseFor(*this))
return LayoutFormattingContextPath;
#endif
if (SimpleLineLayout::canUseFor(*this))
return SimpleLinesPath;
return LineBoxesPath;
};
if (lineLayoutPath() == UndeterminedPath)
setLineLayoutPath(computeLineLayoutPath());
if (lineLayoutPath() == SimpleLinesPath) {
layoutSimpleLines(relayoutChildren, repaintLogicalTop, repaintLogicalBottom);
return;
}
#if ENABLE(LAYOUT_FORMATTING_CONTEXT)
if (lineLayoutPath() == LayoutFormattingContextPath) {
layoutLFCLines(relayoutChildren, repaintLogicalTop, repaintLogicalBottom);
return;
}
#endif
if (!complexLineLayout())
m_lineLayout = makeUnique<ComplexLineLayout>(*this);
complexLineLayout()->layoutLineBoxes(relayoutChildren, repaintLogicalTop, repaintLogicalBottom);
}
void RenderBlockFlow::layoutBlockChild(RenderBox& child, MarginInfo& marginInfo, LayoutUnit& previousFloatLogicalBottom, LayoutUnit& maxFloatLogicalBottom)
{
LayoutUnit oldPosMarginBefore = maxPositiveMarginBefore();
LayoutUnit oldNegMarginBefore = maxNegativeMarginBefore();
// The child is a normal flow object. Compute the margins we will use for collapsing now.
child.computeAndSetBlockDirectionMargins(*this);
// Try to guess our correct logical top position. In most cases this guess will
// be correct. Only if we're wrong (when we compute the real logical top position)
// will we have to potentially relayout.
LayoutUnit estimateWithoutPagination;
LayoutUnit logicalTopEstimate = estimateLogicalTopPosition(child, marginInfo, estimateWithoutPagination);
// Cache our old rect so that we can dirty the proper repaint rects if the child moves.
LayoutRect oldRect = child.frameRect();
LayoutUnit oldLogicalTop = logicalTopForChild(child);
#if !ASSERT_DISABLED
LayoutSize oldLayoutDelta = view().frameView().layoutContext().layoutDelta();
#endif
// Position the child as though it didn't collapse with the top.
setLogicalTopForChild(child, logicalTopEstimate, ApplyLayoutDelta);
estimateFragmentRangeForBoxChild(child);
RenderBlockFlow* childBlockFlow = is<RenderBlockFlow>(child) ? &downcast<RenderBlockFlow>(child) : nullptr;
bool markDescendantsWithFloats = false;
if (logicalTopEstimate != oldLogicalTop && !child.avoidsFloats() && childBlockFlow && childBlockFlow->containsFloats())
markDescendantsWithFloats = true;
else if (UNLIKELY(logicalTopEstimate.mightBeSaturated()))
// logicalTopEstimate, returned by estimateLogicalTopPosition, might be saturated for
// very large elements. If it does the comparison with oldLogicalTop might yield a
// false negative as adding and removing margins, borders etc from a saturated number
// might yield incorrect results. If this is the case always mark for layout.
markDescendantsWithFloats = true;
else if (!child.avoidsFloats() || child.shrinkToAvoidFloats()) {
// If an element might be affected by the presence of floats, then always mark it for
// layout.
LayoutUnit fb = std::max(previousFloatLogicalBottom, lowestFloatLogicalBottom());
if (fb > logicalTopEstimate)
markDescendantsWithFloats = true;
}
if (childBlockFlow) {
if (markDescendantsWithFloats)
childBlockFlow->markAllDescendantsWithFloatsForLayout();
if (!child.isWritingModeRoot())
previousFloatLogicalBottom = std::max(previousFloatLogicalBottom, oldLogicalTop + childBlockFlow->lowestFloatLogicalBottom());
}
child.markForPaginationRelayoutIfNeeded();
bool childHadLayout = child.everHadLayout();
bool childNeededLayout = child.needsLayout();
if (childNeededLayout)
child.layout();
// Cache if we are at the top of the block right now.
bool atBeforeSideOfBlock = marginInfo.atBeforeSideOfBlock();
// Now determine the correct ypos based off examination of collapsing margin
// values.
LayoutUnit logicalTopBeforeClear = collapseMargins(child, marginInfo);
// Now check for clear.
LayoutUnit logicalTopAfterClear = clearFloatsIfNeeded(child, marginInfo, oldPosMarginBefore, oldNegMarginBefore, logicalTopBeforeClear);
bool paginated = view().frameView().layoutContext().layoutState()->isPaginated();
if (paginated)
logicalTopAfterClear = adjustBlockChildForPagination(logicalTopAfterClear, estimateWithoutPagination, child, atBeforeSideOfBlock && logicalTopBeforeClear == logicalTopAfterClear);
setLogicalTopForChild(child, logicalTopAfterClear, ApplyLayoutDelta);
// Now we have a final top position. See if it really does end up being different from our estimate.
// clearFloatsIfNeeded can also mark the child as needing a layout even though we didn't move. This happens
// when collapseMargins dynamically adds overhanging floats because of a child with negative margins.
if (logicalTopAfterClear != logicalTopEstimate || child.needsLayout() || (paginated && childBlockFlow && childBlockFlow->shouldBreakAtLineToAvoidWidow())) {
if (child.shrinkToAvoidFloats()) {
// The child's width depends on the line width. When the child shifts to clear an item, its width can
// change (because it has more available line width). So mark the item as dirty.
child.setChildNeedsLayout(MarkOnlyThis);
}
if (childBlockFlow) {
if (!child.avoidsFloats() && childBlockFlow->containsFloats())
childBlockFlow->markAllDescendantsWithFloatsForLayout();
child.markForPaginationRelayoutIfNeeded();
}
}
if (updateFragmentRangeForBoxChild(child))
child.setNeedsLayout(MarkOnlyThis);
// In case our guess was wrong, relayout the child.
child.layoutIfNeeded();
// We are no longer at the top of the block if we encounter a non-empty child.
// This has to be done after checking for clear, so that margins can be reset if a clear occurred.
if (marginInfo.atBeforeSideOfBlock() && !child.isSelfCollapsingBlock())
marginInfo.setAtBeforeSideOfBlock(false);
// Now place the child in the correct left position
determineLogicalLeftPositionForChild(child, ApplyLayoutDelta);
// Update our height now that the child has been placed in the correct position.
setLogicalHeight(logicalHeight() + logicalHeightForChildForFragmentation(child));
if (mustSeparateMarginAfterForChild(child)) {
setLogicalHeight(logicalHeight() + marginAfterForChild(child));
marginInfo.clearMargin();
}
// If the child has overhanging floats that intrude into following siblings (or possibly out
// of this block), then the parent gets notified of the floats now.
if (childBlockFlow && childBlockFlow->containsFloats())
maxFloatLogicalBottom = std::max(maxFloatLogicalBottom, addOverhangingFloats(*childBlockFlow, !childNeededLayout));
LayoutSize childOffset = child.location() - oldRect.location();
if (childOffset.width() || childOffset.height()) {
view().frameView().layoutContext().addLayoutDelta(childOffset);
// If the child moved, we have to repaint it as well as any floating/positioned
// descendants. An exception is if we need a layout. In this case, we know we're going to
// repaint ourselves (and the child) anyway.
if (childHadLayout && !selfNeedsLayout() && child.checkForRepaintDuringLayout())
child.repaintDuringLayoutIfMoved(oldRect);
}
if (!childHadLayout && child.checkForRepaintDuringLayout()) {
child.repaint();
child.repaintOverhangingFloats(true);
}
if (paginated) {
if (RenderFragmentedFlow* fragmentedFlow = enclosingFragmentedFlow())
fragmentedFlow->fragmentedFlowDescendantBoxLaidOut(&child);
// Check for an after page/column break.
LayoutUnit newHeight = applyAfterBreak(child, logicalHeight(), marginInfo);
if (newHeight != height())
setLogicalHeight(newHeight);
}
ASSERT(view().frameView().layoutContext().layoutDeltaMatches(oldLayoutDelta));
}
void RenderBlockFlow::adjustPositionedBlock(RenderBox& child, const MarginInfo& marginInfo)
{
bool isHorizontal = isHorizontalWritingMode();
bool hasStaticBlockPosition = child.style().hasStaticBlockPosition(isHorizontal);
LayoutUnit logicalTop = logicalHeight();
updateStaticInlinePositionForChild(child, logicalTop, DoNotIndentText);
if (!marginInfo.canCollapseWithMarginBefore()) {
// Positioned blocks don't collapse margins, so add the margin provided by
// the container now. The child's own margin is added later when calculating its logical top.
LayoutUnit collapsedBeforePos = marginInfo.positiveMargin();
LayoutUnit collapsedBeforeNeg = marginInfo.negativeMargin();
logicalTop += collapsedBeforePos - collapsedBeforeNeg;
}
RenderLayer* childLayer = child.layer();
if (childLayer->staticBlockPosition() != logicalTop) {
childLayer->setStaticBlockPosition(logicalTop);
if (hasStaticBlockPosition)
child.setChildNeedsLayout(MarkOnlyThis);
}
}
LayoutUnit RenderBlockFlow::marginOffsetForSelfCollapsingBlock()
{
ASSERT(isSelfCollapsingBlock());
RenderBlockFlow* parentBlock = downcast<RenderBlockFlow>(parent());
if (parentBlock && style().clear() != Clear::None && parentBlock->getClearDelta(*this, logicalHeight()))
return marginValuesForChild(*this).positiveMarginBefore();
return 0_lu;
}
void RenderBlockFlow::determineLogicalLeftPositionForChild(RenderBox& child, ApplyLayoutDeltaMode applyDelta)
{
LayoutUnit startPosition = borderStart() + paddingStart();
if (shouldPlaceBlockDirectionScrollbarOnLeft())
startPosition += (style().isLeftToRightDirection() ? 1 : -1) * verticalScrollbarWidth();
LayoutUnit totalAvailableLogicalWidth = borderAndPaddingLogicalWidth() + availableLogicalWidth();
// Add in our start margin.
LayoutUnit childMarginStart = marginStartForChild(child);
LayoutUnit newPosition = startPosition + childMarginStart;
// Some objects (e.g., tables, horizontal rules, overflow:auto blocks) avoid floats. They need
// to shift over as necessary to dodge any floats that might get in the way.
if (child.avoidsFloats() && containsFloats())
newPosition += computeStartPositionDeltaForChildAvoidingFloats(child, marginStartForChild(child));
setLogicalLeftForChild(child, style().isLeftToRightDirection() ? newPosition : totalAvailableLogicalWidth - newPosition - logicalWidthForChild(child), applyDelta);
}
void RenderBlockFlow::adjustFloatingBlock(const MarginInfo& marginInfo)
{
// The float should be positioned taking into account the bottom margin
// of the previous flow. We add that margin into the height, get the
// float positioned properly, and then subtract the margin out of the
// height again. In the case of self-collapsing blocks, we always just
// use the top margins, since the self-collapsing block collapsed its
// own bottom margin into its top margin.
//
// Note also that the previous flow may collapse its margin into the top of
// our block. If this is the case, then we do not add the margin in to our
// height when computing the position of the float. This condition can be tested
// for by simply calling canCollapseWithMarginBefore. See
// http://www.hixie.ch/tests/adhoc/css/box/block/margin-collapse/046.html for
// an example of this scenario.
LayoutUnit marginOffset = marginInfo.canCollapseWithMarginBefore() ? 0_lu : marginInfo.margin();
setLogicalHeight(logicalHeight() + marginOffset);
positionNewFloats();
setLogicalHeight(logicalHeight() - marginOffset);
}
void RenderBlockFlow::updateStaticInlinePositionForChild(RenderBox& child, LayoutUnit logicalTop, IndentTextOrNot shouldIndentText)
{
if (child.style().isOriginalDisplayInlineType())
setStaticInlinePositionForChild(child, logicalTop, startAlignedOffsetForLine(logicalTop, shouldIndentText));
else
setStaticInlinePositionForChild(child, logicalTop, startOffsetForContent(logicalTop));
}
void RenderBlockFlow::setStaticInlinePositionForChild(RenderBox& child, LayoutUnit blockOffset, LayoutUnit inlinePosition)
{
if (enclosingFragmentedFlow()) {
// Shift the inline position to exclude the fragment offset.
inlinePosition += startOffsetForContent() - startOffsetForContent(blockOffset);
}
child.layer()->setStaticInlinePosition(inlinePosition);
}
LayoutUnit RenderBlockFlow::startAlignedOffsetForLine(LayoutUnit position, IndentTextOrNot shouldIndentText)
{
TextAlignMode textAlign = style().textAlign();
bool shouldApplyIndentText = false;
switch (textAlign) {
case TextAlignMode::Left:
case TextAlignMode::WebKitLeft:
shouldApplyIndentText = style().isLeftToRightDirection();
break;
case TextAlignMode::Right:
case TextAlignMode::WebKitRight:
shouldApplyIndentText = !style().isLeftToRightDirection();
break;
case TextAlignMode::Start:
shouldApplyIndentText = true;
break;
default:
shouldApplyIndentText = false;
}
// <rdar://problem/15427571>
// https://bugs.webkit.org/show_bug.cgi?id=124522
// This quirk is for legacy content that doesn't work properly with the center positioning scheme
// being honored (e.g., epubs).
if (shouldApplyIndentText || settings().useLegacyTextAlignPositionedElementBehavior()) // FIXME: Handle TextAlignMode::End here
return startOffsetForLine(position, shouldIndentText);
// updateLogicalWidthForAlignment() handles the direction of the block so no need to consider it here
float totalLogicalWidth = 0;
float logicalLeft = logicalLeftOffsetForLine(logicalHeight(), DoNotIndentText);
float availableLogicalWidth = logicalRightOffsetForLine(logicalHeight(), DoNotIndentText) - logicalLeft;
ComplexLineLayout::updateLogicalWidthForAlignment(*this, textAlign, nullptr, nullptr, logicalLeft, totalLogicalWidth, availableLogicalWidth, 0);
if (!style().isLeftToRightDirection())
return LayoutUnit(logicalWidth() - logicalLeft);
return LayoutUnit(logicalLeft);
}
RenderBlockFlow::MarginValues RenderBlockFlow::marginValuesForChild(RenderBox& child) const
{
LayoutUnit childBeforePositive;
LayoutUnit childBeforeNegative;
LayoutUnit childAfterPositive;
LayoutUnit childAfterNegative;
LayoutUnit beforeMargin;
LayoutUnit afterMargin;
RenderBlockFlow* childRenderBlock = is<RenderBlockFlow>(child) ? &downcast<RenderBlockFlow>(child) : nullptr;
// If the child has the same directionality as we do, then we can just return its
// margins in the same direction.
if (!child.isWritingModeRoot()) {
if (childRenderBlock) {
childBeforePositive = childRenderBlock->maxPositiveMarginBefore();
childBeforeNegative = childRenderBlock->maxNegativeMarginBefore();
childAfterPositive = childRenderBlock->maxPositiveMarginAfter();
childAfterNegative = childRenderBlock->maxNegativeMarginAfter();
} else {
beforeMargin = child.marginBefore();
afterMargin = child.marginAfter();
}
} else if (child.isHorizontalWritingMode() == isHorizontalWritingMode()) {
// The child has a different directionality. If the child is parallel, then it's just
// flipped relative to us. We can use the margins for the opposite edges.
if (childRenderBlock) {
childBeforePositive = childRenderBlock->maxPositiveMarginAfter();
childBeforeNegative = childRenderBlock->maxNegativeMarginAfter();
childAfterPositive = childRenderBlock->maxPositiveMarginBefore();
childAfterNegative = childRenderBlock->maxNegativeMarginBefore();
} else {
beforeMargin = child.marginAfter();
afterMargin = child.marginBefore();
}
} else {
// The child is perpendicular to us, which means its margins don't collapse but are on the
// "logical left/right" sides of the child box. We can just return the raw margin in this case.
beforeMargin = marginBeforeForChild(child);
afterMargin = marginAfterForChild(child);
}
// Resolve uncollapsing margins into their positive/negative buckets.
if (beforeMargin) {
if (beforeMargin > 0)
childBeforePositive = beforeMargin;
else
childBeforeNegative = -beforeMargin;
}
if (afterMargin) {
if (afterMargin > 0)
childAfterPositive = afterMargin;
else
childAfterNegative = -afterMargin;
}
return MarginValues(childBeforePositive, childBeforeNegative, childAfterPositive, childAfterNegative);
}
bool RenderBlockFlow::childrenPreventSelfCollapsing() const
{
if (!childrenInline())
return RenderBlock::childrenPreventSelfCollapsing();
return hasLines();
}
LayoutUnit RenderBlockFlow::collapseMargins(RenderBox& child, MarginInfo& marginInfo)
{
return collapseMarginsWithChildInfo(&child, child.previousSibling(), marginInfo);
}
LayoutUnit RenderBlockFlow::collapseMarginsWithChildInfo(RenderBox* child, RenderObject* prevSibling, MarginInfo& marginInfo)
{
bool childDiscardMarginBefore = child ? mustDiscardMarginBeforeForChild(*child) : false;
bool childDiscardMarginAfter = child ? mustDiscardMarginAfterForChild(*child) : false;
bool childIsSelfCollapsing = child ? child->isSelfCollapsingBlock() : false;
bool beforeQuirk = child ? hasMarginBeforeQuirk(*child) : false;
bool afterQuirk = child ? hasMarginAfterQuirk(*child) : false;
// The child discards the before margin when the after margin has discarded in the case of a self collapsing block.
childDiscardMarginBefore = childDiscardMarginBefore || (childDiscardMarginAfter && childIsSelfCollapsing);
// Get the four margin values for the child and cache them.
const MarginValues childMargins = child ? marginValuesForChild(*child) : MarginValues(0, 0, 0, 0);
// Get our max pos and neg top margins.
LayoutUnit posTop = childMargins.positiveMarginBefore();
LayoutUnit negTop = childMargins.negativeMarginBefore();
// For self-collapsing blocks, collapse our bottom margins into our
// top to get new posTop and negTop values.
if (childIsSelfCollapsing) {
posTop = std::max(posTop, childMargins.positiveMarginAfter());
negTop = std::max(negTop, childMargins.negativeMarginAfter());
}
if (marginInfo.canCollapseWithMarginBefore()) {
if (!childDiscardMarginBefore && !marginInfo.discardMargin()) {
// This child is collapsing with the top of the
// block. If it has larger margin values, then we need to update
// our own maximal values.
if (!document().inQuirksMode() || !marginInfo.quirkContainer() || !beforeQuirk)
setMaxMarginBeforeValues(std::max(posTop, maxPositiveMarginBefore()), std::max(negTop, maxNegativeMarginBefore()));
// The minute any of the margins involved isn't a quirk, don't
// collapse it away, even if the margin is smaller (www.webreference.com
// has an example of this, a <dt> with 0.8em author-specified inside
// a <dl> inside a <td>.
if (!marginInfo.determinedMarginBeforeQuirk() && !beforeQuirk && (posTop - negTop)) {
setHasMarginBeforeQuirk(false);
marginInfo.setDeterminedMarginBeforeQuirk(true);
}
if (!marginInfo.determinedMarginBeforeQuirk() && beforeQuirk && !marginBefore()) {
// We have no top margin and our top child has a quirky margin.
// We will pick up this quirky margin and pass it through.
// This deals with the <td><div><p> case.
// Don't do this for a block that split two inlines though. You do
// still apply margins in this case.
setHasMarginBeforeQuirk(true);
}
} else
// The before margin of the container will also discard all the margins it is collapsing with.
setMustDiscardMarginBefore();
}
// Once we find a child with discardMarginBefore all the margins collapsing with us must also discard.
if (childDiscardMarginBefore) {
marginInfo.setDiscardMargin(true);
marginInfo.clearMargin();
}
if (marginInfo.quirkContainer() && marginInfo.atBeforeSideOfBlock() && (posTop - negTop))
marginInfo.setHasMarginBeforeQuirk(beforeQuirk);
LayoutUnit beforeCollapseLogicalTop = logicalHeight();
LayoutUnit logicalTop = beforeCollapseLogicalTop;
LayoutUnit clearanceForSelfCollapsingBlock;
// If the child's previous sibling is a self-collapsing block that cleared a float then its top border edge has been set at the bottom border edge
// of the float. Since we want to collapse the child's top margin with the self-collapsing block's top and bottom margins we need to adjust our parent's height to match the
// margin top of the self-collapsing block. If the resulting collapsed margin leaves the child still intruding into the float then we will want to clear it.
if (!marginInfo.canCollapseWithMarginBefore() && is<RenderBlockFlow>(prevSibling) && downcast<RenderBlockFlow>(*prevSibling).isSelfCollapsingBlock()) {
clearanceForSelfCollapsingBlock = downcast<RenderBlockFlow>(*prevSibling).marginOffsetForSelfCollapsingBlock();
setLogicalHeight(logicalHeight() - clearanceForSelfCollapsingBlock);
}
if (childIsSelfCollapsing) {
// For a self collapsing block both the before and after margins get discarded. The block doesn't contribute anything to the height of the block.
// Also, the child's top position equals the logical height of the container.
if (!childDiscardMarginBefore && !marginInfo.discardMargin()) {
// This child has no height. We need to compute our
// position before we collapse the child's margins together,
// so that we can get an accurate position for the zero-height block.
LayoutUnit collapsedBeforePos = std::max(marginInfo.positiveMargin(), childMargins.positiveMarginBefore());
LayoutUnit collapsedBeforeNeg = std::max(marginInfo.negativeMargin(), childMargins.negativeMarginBefore());
marginInfo.setMargin(collapsedBeforePos, collapsedBeforeNeg);
// Now collapse the child's margins together, which means examining our
// bottom margin values as well.
marginInfo.setPositiveMarginIfLarger(childMargins.positiveMarginAfter());
marginInfo.setNegativeMarginIfLarger(childMargins.negativeMarginAfter());
if (!marginInfo.canCollapseWithMarginBefore())
// We need to make sure that the position of the self-collapsing block
// is correct, since it could have overflowing content
// that needs to be positioned correctly (e.g., a block that
// had a specified height of 0 but that actually had subcontent).
logicalTop = logicalHeight() + collapsedBeforePos - collapsedBeforeNeg;
}
} else {
if (child && mustSeparateMarginBeforeForChild(*child)) {
ASSERT(!marginInfo.discardMargin() || (marginInfo.discardMargin() && !marginInfo.margin()));
// If we are at the before side of the block and we collapse, ignore the computed margin
// and just add the child margin to the container height. This will correctly position
// the child inside the container.
LayoutUnit separateMargin = !marginInfo.canCollapseWithMarginBefore() ? marginInfo.margin() : 0_lu;
setLogicalHeight(logicalHeight() + separateMargin + marginBeforeForChild(*child));
logicalTop = logicalHeight();
} else if (!marginInfo.discardMargin() && (!marginInfo.atBeforeSideOfBlock()
|| (!marginInfo.canCollapseMarginBeforeWithChildren()
&& (!document().inQuirksMode() || !marginInfo.quirkContainer() || !marginInfo.hasMarginBeforeQuirk())))) {
// We're collapsing with a previous sibling's margins and not
// with the top of the block.
setLogicalHeight(logicalHeight() + std::max(marginInfo.positiveMargin(), posTop) - std::max(marginInfo.negativeMargin(), negTop));
logicalTop = logicalHeight();
}
marginInfo.setDiscardMargin(childDiscardMarginAfter);
if (!marginInfo.discardMargin()) {
marginInfo.setPositiveMargin(childMargins.positiveMarginAfter());
marginInfo.setNegativeMargin(childMargins.negativeMarginAfter());
} else
marginInfo.clearMargin();
if (marginInfo.margin())
marginInfo.setHasMarginAfterQuirk(afterQuirk);
}
// If margins would pull us past the top of the next page, then we need to pull back and pretend like the margins
// collapsed into the page edge.
auto* layoutState = view().frameView().layoutContext().layoutState();
if (layoutState->isPaginated() && layoutState->pageLogicalHeight() && logicalTop > beforeCollapseLogicalTop
&& hasNextPage(beforeCollapseLogicalTop)) {
LayoutUnit oldLogicalTop = logicalTop;
logicalTop = std::min(logicalTop, nextPageLogicalTop(beforeCollapseLogicalTop));
setLogicalHeight(logicalHeight() + (logicalTop - oldLogicalTop));
}
if (is<RenderBlockFlow>(prevSibling) && !prevSibling->isFloatingOrOutOfFlowPositioned()) {
// If |child| is a self-collapsing block it may have collapsed into a previous sibling and although it hasn't reduced the height of the parent yet
// any floats from the parent will now overhang.
RenderBlockFlow& block = downcast<RenderBlockFlow>(*prevSibling);
LayoutUnit oldLogicalHeight = logicalHeight();
setLogicalHeight(logicalTop);
if (block.containsFloats() && !block.avoidsFloats() && (block.logicalTop() + block.lowestFloatLogicalBottom()) > logicalTop)
addOverhangingFloats(block, false);
setLogicalHeight(oldLogicalHeight);
// If |child|'s previous sibling is a self-collapsing block that cleared a float and margin collapsing resulted in |child| moving up
// into the margin area of the self-collapsing block then the float it clears is now intruding into |child|. Layout again so that we can look for
// floats in the parent that overhang |child|'s new logical top.
bool logicalTopIntrudesIntoFloat = clearanceForSelfCollapsingBlock > 0 && logicalTop < beforeCollapseLogicalTop;
if (child && logicalTopIntrudesIntoFloat && containsFloats() && !child->avoidsFloats() && lowestFloatLogicalBottom() > logicalTop)
child->setNeedsLayout();
}
return logicalTop;
}
LayoutUnit RenderBlockFlow::clearFloatsIfNeeded(RenderBox& child, MarginInfo& marginInfo, LayoutUnit oldTopPosMargin, LayoutUnit oldTopNegMargin, LayoutUnit yPos)
{
LayoutUnit heightIncrease = getClearDelta(child, yPos);
if (!heightIncrease)
return yPos;
if (child.isSelfCollapsingBlock()) {
bool childDiscardMargin = mustDiscardMarginBeforeForChild(child) || mustDiscardMarginAfterForChild(child);
// For self-collapsing blocks that clear, they can still collapse their
// margins with following siblings. Reset the current margins to represent
// the self-collapsing block's margins only.
// If DISCARD is specified for -webkit-margin-collapse, reset the margin values.
MarginValues childMargins = marginValuesForChild(child);
if (!childDiscardMargin) {
marginInfo.setPositiveMargin(std::max(childMargins.positiveMarginBefore(), childMargins.positiveMarginAfter()));
marginInfo.setNegativeMargin(std::max(childMargins.negativeMarginBefore(), childMargins.negativeMarginAfter()));
} else
marginInfo.clearMargin();
marginInfo.setDiscardMargin(childDiscardMargin);
// CSS2.1 states:
// "If the top and bottom margins of an element with clearance are adjoining, its margins collapse with
// the adjoining margins of following siblings but that resulting margin does not collapse with the bottom margin of the parent block."
// So the parent's bottom margin cannot collapse through this block or any subsequent self-collapsing blocks. Check subsequent siblings
// for a block with height - if none is found then don't allow the margins to collapse with the parent.
bool wouldCollapseMarginsWithParent = marginInfo.canCollapseMarginAfterWithChildren();
for (RenderBox* curr = child.nextSiblingBox(); curr && wouldCollapseMarginsWithParent; curr = curr->nextSiblingBox()) {
if (!curr->isFloatingOrOutOfFlowPositioned() && !curr->isSelfCollapsingBlock())
wouldCollapseMarginsWithParent = false;
}
if (wouldCollapseMarginsWithParent)
marginInfo.setCanCollapseMarginAfterWithChildren(false);
// For now set the border-top of |child| flush with the bottom border-edge of the float so it can layout any floating or positioned children of
// its own at the correct vertical position. If subsequent siblings attempt to collapse with |child|'s margins in |collapseMargins| we will
// adjust the height of the parent to |child|'s margin top (which if it is positive sits up 'inside' the float it's clearing) so that all three
// margins can collapse at the correct vertical position.
// Per CSS2.1 we need to ensure that any negative margin-top clears |child| beyond the bottom border-edge of the float so that the top border edge of the child
// (i.e. its clearance) is at a position that satisfies the equation: "the amount of clearance is set so that clearance + margin-top = [height of float],
// i.e., clearance = [height of float] - margin-top".
setLogicalHeight(child.logicalTop() + childMargins.negativeMarginBefore());
} else
// Increase our height by the amount we had to clear.
setLogicalHeight(logicalHeight() + heightIncrease);
if (marginInfo.canCollapseWithMarginBefore()) {
// We can no longer collapse with the top of the block since a clear
// occurred. The empty blocks collapse into the cleared block.
// FIXME: This isn't quite correct. Need clarification for what to do
// if the height the cleared block is offset by is smaller than the
// margins involved.
setMaxMarginBeforeValues(oldTopPosMargin, oldTopNegMargin);
marginInfo.setAtBeforeSideOfBlock(false);
// In case the child discarded the before margin of the block we need to reset the mustDiscardMarginBefore flag to the initial value.
setMustDiscardMarginBefore(style().marginBeforeCollapse() == MarginCollapse::Discard);
}
return yPos + heightIncrease;
}
void RenderBlockFlow::marginBeforeEstimateForChild(RenderBox& child, LayoutUnit& positiveMarginBefore, LayoutUnit& negativeMarginBefore, bool& discardMarginBefore) const
{
// Give up if in quirks mode and we're a body/table cell and the top margin of the child box is quirky.
// Give up if the child specified -webkit-margin-collapse: separate that prevents collapsing.
// FIXME: Use writing mode independent accessor for marginBeforeCollapse.
if ((document().inQuirksMode() && hasMarginAfterQuirk(child) && (isTableCell() || isBody())) || child.style().marginBeforeCollapse() == MarginCollapse::Separate)
return;
// The margins are discarded by a child that specified -webkit-margin-collapse: discard.
// FIXME: Use writing mode independent accessor for marginBeforeCollapse.
if (child.style().marginBeforeCollapse() == MarginCollapse::Discard) {
positiveMarginBefore = 0;
negativeMarginBefore = 0;
discardMarginBefore = true;
return;
}
LayoutUnit beforeChildMargin = marginBeforeForChild(child);
positiveMarginBefore = std::max(positiveMarginBefore, beforeChildMargin);
negativeMarginBefore = std::max(negativeMarginBefore, -beforeChildMargin);
if (!is<RenderBlockFlow>(child))
return;
RenderBlockFlow& childBlock = downcast<RenderBlockFlow>(child);
if (childBlock.childrenInline() || childBlock.isWritingModeRoot())
return;
MarginInfo childMarginInfo(childBlock, childBlock.borderAndPaddingBefore(), childBlock.borderAndPaddingAfter());
if (!childMarginInfo.canCollapseMarginBeforeWithChildren())
return;
RenderBox* grandchildBox = childBlock.firstChildBox();
for (; grandchildBox; grandchildBox = grandchildBox->nextSiblingBox()) {
if (!grandchildBox->isFloatingOrOutOfFlowPositioned())
break;
}
// Give up if there is clearance on the box, since it probably won't collapse into us.
if (!grandchildBox || grandchildBox->style().clear() != Clear::None)
return;
// Make sure to update the block margins now for the grandchild box so that we're looking at current values.
if (grandchildBox->needsLayout()) {
grandchildBox->computeAndSetBlockDirectionMargins(*this);
if (is<RenderBlock>(*grandchildBox)) {
RenderBlock& grandchildBlock = downcast<RenderBlock>(*grandchildBox);
grandchildBlock.setHasMarginBeforeQuirk(grandchildBox->style().hasMarginBeforeQuirk());
grandchildBlock.setHasMarginAfterQuirk(grandchildBox->style().hasMarginAfterQuirk());
}
}
// Collapse the margin of the grandchild box with our own to produce an estimate.
childBlock.marginBeforeEstimateForChild(*grandchildBox, positiveMarginBefore, negativeMarginBefore, discardMarginBefore);
}
LayoutUnit RenderBlockFlow::estimateLogicalTopPosition(RenderBox& child, const MarginInfo& marginInfo, LayoutUnit& estimateWithoutPagination)
{
// FIXME: We need to eliminate the estimation of vertical position, because when it's wrong we sometimes trigger a pathological
// relayout if there are intruding floats.
LayoutUnit logicalTopEstimate = logicalHeight();
if (!marginInfo.canCollapseWithMarginBefore()) {
LayoutUnit positiveMarginBefore;
LayoutUnit negativeMarginBefore;
bool discardMarginBefore = false;
if (child.selfNeedsLayout()) {
// Try to do a basic estimation of how the collapse is going to go.
marginBeforeEstimateForChild(child, positiveMarginBefore, negativeMarginBefore, discardMarginBefore);
} else {
// Use the cached collapsed margin values from a previous layout. Most of the time they
// will be right.
MarginValues marginValues = marginValuesForChild(child);
positiveMarginBefore = std::max(positiveMarginBefore, marginValues.positiveMarginBefore());
negativeMarginBefore = std::max(negativeMarginBefore, marginValues.negativeMarginBefore());
discardMarginBefore = mustDiscardMarginBeforeForChild(child);
}
// Collapse the result with our current margins.
if (!discardMarginBefore)
logicalTopEstimate += std::max(marginInfo.positiveMargin(), positiveMarginBefore) - std::max(marginInfo.negativeMargin(), negativeMarginBefore);
}
// Adjust logicalTopEstimate down to the next page if the margins are so large that we don't fit on the current
// page.
auto* layoutState = view().frameView().layoutContext().layoutState();
if (layoutState->isPaginated() && layoutState->pageLogicalHeight() && logicalTopEstimate > logicalHeight()
&& hasNextPage(logicalHeight()))
logicalTopEstimate = std::min(logicalTopEstimate, nextPageLogicalTop(logicalHeight()));
logicalTopEstimate += getClearDelta(child, logicalTopEstimate);
estimateWithoutPagination = logicalTopEstimate;
if (layoutState->isPaginated()) {
// If the object has a page or column break value of "before", then we should shift to the top of the next page.
logicalTopEstimate = applyBeforeBreak(child, logicalTopEstimate);
// For replaced elements and scrolled elements, we want to shift them to the next page if they don't fit on the current one.
logicalTopEstimate = adjustForUnsplittableChild(child, logicalTopEstimate);
if (!child.selfNeedsLayout() && is<RenderBlock>(child))
logicalTopEstimate += downcast<RenderBlock>(child).paginationStrut();
}
return logicalTopEstimate;
}
void RenderBlockFlow::setCollapsedBottomMargin(const MarginInfo& marginInfo)
{
if (marginInfo.canCollapseWithMarginAfter() && !marginInfo.canCollapseWithMarginBefore()) {
// Update the after side margin of the container to discard if the after margin of the last child also discards and we collapse with it.
// Don't update the max margin values because we won't need them anyway.
if (marginInfo.discardMargin()) {
setMustDiscardMarginAfter();
return;
}
// Update our max pos/neg bottom margins, since we collapsed our bottom margins
// with our children.
setMaxMarginAfterValues(std::max(maxPositiveMarginAfter(), marginInfo.positiveMargin()), std::max(maxNegativeMarginAfter(), marginInfo.negativeMargin()));
if (!marginInfo.hasMarginAfterQuirk())
setHasMarginAfterQuirk(false);
if (marginInfo.hasMarginAfterQuirk() && !marginAfter())
// We have no bottom margin and our last child has a quirky margin.
// We will pick up this quirky margin and pass it through.
// This deals with the <td><div><p> case.
setHasMarginAfterQuirk(true);
}
}
void RenderBlockFlow::handleAfterSideOfBlock(LayoutUnit beforeSide, LayoutUnit afterSide, MarginInfo& marginInfo)
{
marginInfo.setAtAfterSideOfBlock(true);
// If our last child was a self-collapsing block with clearance then our logical height is flush with the
// bottom edge of the float that the child clears. The correct vertical position for the margin-collapsing we want
// to perform now is at the child's margin-top - so adjust our height to that position.
RenderObject* lastBlock = lastChild();
if (is<RenderBlockFlow>(lastBlock) && downcast<RenderBlockFlow>(*lastBlock).isSelfCollapsingBlock())
setLogicalHeight(logicalHeight() - downcast<RenderBlockFlow>(*lastBlock).marginOffsetForSelfCollapsingBlock());
// If we can't collapse with children then add in the bottom margin.
if (!marginInfo.discardMargin() && (!marginInfo.canCollapseWithMarginAfter() && !marginInfo.canCollapseWithMarginBefore()
&& (!document().inQuirksMode() || !marginInfo.quirkContainer() || !marginInfo.hasMarginAfterQuirk())))
setLogicalHeight(logicalHeight() + marginInfo.margin());
// Now add in our bottom border/padding.
setLogicalHeight(logicalHeight() + afterSide);
// Negative margins can cause our height to shrink below our minimal height (border/padding).
// If this happens, ensure that the computed height is increased to the minimal height.
setLogicalHeight(std::max(logicalHeight(), beforeSide + afterSide));
// Update our bottom collapsed margin info.
setCollapsedBottomMargin(marginInfo);
}
void RenderBlockFlow::setMaxMarginBeforeValues(LayoutUnit pos, LayoutUnit neg)
{
if (!hasRareBlockFlowData()) {
if (pos == RenderBlockFlowRareData::positiveMarginBeforeDefault(*this) && neg == RenderBlockFlowRareData::negativeMarginBeforeDefault(*this))
return;
materializeRareBlockFlowData();
}
rareBlockFlowData()->m_margins.setPositiveMarginBefore(pos);
rareBlockFlowData()->m_margins.setNegativeMarginBefore(neg);
}
void RenderBlockFlow::setMaxMarginAfterValues(LayoutUnit pos, LayoutUnit neg)
{
if (!hasRareBlockFlowData()) {
if (pos == RenderBlockFlowRareData::positiveMarginAfterDefault(*this) && neg == RenderBlockFlowRareData::negativeMarginAfterDefault(*this))
return;
materializeRareBlockFlowData();
}
rareBlockFlowData()->m_margins.setPositiveMarginAfter(pos);
rareBlockFlowData()->m_margins.setNegativeMarginAfter(neg);
}
void RenderBlockFlow::setMustDiscardMarginBefore(bool value)
{
if (style().marginBeforeCollapse() == MarginCollapse::Discard) {
ASSERT(value);
return;
}
if (!hasRareBlockFlowData()) {
if (!value)
return;
materializeRareBlockFlowData();
}
rareBlockFlowData()->m_discardMarginBefore = value;
}
void RenderBlockFlow::setMustDiscardMarginAfter(bool value)
{
if (style().marginAfterCollapse() == MarginCollapse::Discard) {
ASSERT(value);
return;
}
if (!hasRareBlockFlowData()) {
if (!value)
return;
materializeRareBlockFlowData();
}
rareBlockFlowData()->m_discardMarginAfter = value;
}
bool RenderBlockFlow::mustDiscardMarginBefore() const
{
return style().marginBeforeCollapse() == MarginCollapse::Discard || (hasRareBlockFlowData() && rareBlockFlowData()->m_discardMarginBefore);
}
bool RenderBlockFlow::mustDiscardMarginAfter() const
{
return style().marginAfterCollapse() == MarginCollapse::Discard || (hasRareBlockFlowData() && rareBlockFlowData()->m_discardMarginAfter);
}
bool RenderBlockFlow::mustDiscardMarginBeforeForChild(const RenderBox& child) const
{
ASSERT(!child.selfNeedsLayout());
if (!child.isWritingModeRoot())
return is<RenderBlockFlow>(child) ? downcast<RenderBlockFlow>(child).mustDiscardMarginBefore() : (child.style().marginBeforeCollapse() == MarginCollapse::Discard);
if (child.isHorizontalWritingMode() == isHorizontalWritingMode())
return is<RenderBlockFlow>(child) ? downcast<RenderBlockFlow>(child).mustDiscardMarginAfter() : (child.style().marginAfterCollapse() == MarginCollapse::Discard);
// FIXME: We return false here because the implementation is not geometrically complete. We have values only for before/after, not start/end.
// In case the boxes are perpendicular we assume the property is not specified.
return false;
}
bool RenderBlockFlow::mustDiscardMarginAfterForChild(const RenderBox& child) const
{
ASSERT(!child.selfNeedsLayout());
if (!child.isWritingModeRoot())
return is<RenderBlockFlow>(child) ? downcast<RenderBlockFlow>(child).mustDiscardMarginAfter() : (child.style().marginAfterCollapse() == MarginCollapse::Discard);
if (child.isHorizontalWritingMode() == isHorizontalWritingMode())
return is<RenderBlockFlow>(child) ? downcast<RenderBlockFlow>(child).mustDiscardMarginBefore() : (child.style().marginBeforeCollapse() == MarginCollapse::Discard);
// FIXME: See |mustDiscardMarginBeforeForChild| above.
return false;
}
bool RenderBlockFlow::mustSeparateMarginBeforeForChild(const RenderBox& child) const
{
ASSERT(!child.selfNeedsLayout());
const RenderStyle& childStyle = child.style();
if (!child.isWritingModeRoot())
return childStyle.marginBeforeCollapse() == MarginCollapse::Separate;
if (child.isHorizontalWritingMode() == isHorizontalWritingMode())
return childStyle.marginAfterCollapse() == MarginCollapse::Separate;
// FIXME: See |mustDiscardMarginBeforeForChild| above.
return false;
}
bool RenderBlockFlow::mustSeparateMarginAfterForChild(const RenderBox& child) const
{
ASSERT(!child.selfNeedsLayout());
const RenderStyle& childStyle = child.style();
if (!child.isWritingModeRoot())
return childStyle.marginAfterCollapse() == MarginCollapse::Separate;
if (child.isHorizontalWritingMode() == isHorizontalWritingMode())
return childStyle.marginBeforeCollapse() == MarginCollapse::Separate;
// FIXME: See |mustDiscardMarginBeforeForChild| above.
return false;
}
static bool inNormalFlow(RenderBox& child)
{
RenderBlock* curr = child.containingBlock();
while (curr && curr != &child.view()) {
if (curr->isRenderFragmentedFlow())
return true;
if (curr->isFloatingOrOutOfFlowPositioned())
return false;
curr = curr->containingBlock();
}
return true;
}
LayoutUnit RenderBlockFlow::applyBeforeBreak(RenderBox& child, LayoutUnit logicalOffset)
{
// FIXME: Add page break checking here when we support printing.
RenderFragmentedFlow* fragmentedFlow = enclosingFragmentedFlow();
bool isInsideMulticolFlow = fragmentedFlow;
bool checkColumnBreaks = fragmentedFlow && fragmentedFlow->shouldCheckColumnBreaks();
bool checkPageBreaks = !checkColumnBreaks && view().frameView().layoutContext().layoutState()->pageLogicalHeight(); // FIXME: Once columns can print we have to check this.
bool checkFragmentBreaks = false;
bool checkBeforeAlways = (checkColumnBreaks && child.style().breakBefore() == BreakBetween::Column)
|| (checkPageBreaks && alwaysPageBreak(child.style().breakBefore()));
if (checkBeforeAlways && inNormalFlow(child) && hasNextPage(logicalOffset, IncludePageBoundary)) {
if (checkColumnBreaks) {
if (isInsideMulticolFlow)
checkFragmentBreaks = true;
}
if (checkFragmentBreaks) {
LayoutUnit offsetBreakAdjustment;
if (fragmentedFlow->addForcedFragmentBreak(this, offsetFromLogicalTopOfFirstPage() + logicalOffset, &child, true, &offsetBreakAdjustment))
return logicalOffset + offsetBreakAdjustment;
}
return nextPageLogicalTop(logicalOffset, IncludePageBoundary);
}
return logicalOffset;
}
LayoutUnit RenderBlockFlow::applyAfterBreak(RenderBox& child, LayoutUnit logicalOffset, MarginInfo& marginInfo)
{
// FIXME: Add page break checking here when we support printing.
RenderFragmentedFlow* fragmentedFlow = enclosingFragmentedFlow();
bool isInsideMulticolFlow = fragmentedFlow;
bool checkColumnBreaks = fragmentedFlow && fragmentedFlow->shouldCheckColumnBreaks();
bool checkPageBreaks = !checkColumnBreaks && view().frameView().layoutContext().layoutState()->pageLogicalHeight(); // FIXME: Once columns can print we have to check this.
bool checkFragmentBreaks = false;
bool checkAfterAlways = (checkColumnBreaks && child.style().breakAfter() == BreakBetween::Column)
|| (checkPageBreaks && alwaysPageBreak(child.style().breakAfter()));
if (checkAfterAlways && inNormalFlow(child) && hasNextPage(logicalOffset, IncludePageBoundary)) {
LayoutUnit marginOffset = marginInfo.canCollapseWithMarginBefore() ? 0_lu : marginInfo.margin();
// So our margin doesn't participate in the next collapsing steps.
marginInfo.clearMargin();
if (checkColumnBreaks) {
if (isInsideMulticolFlow)
checkFragmentBreaks = true;
}
if (checkFragmentBreaks) {
LayoutUnit offsetBreakAdjustment;
if (fragmentedFlow->addForcedFragmentBreak(this, offsetFromLogicalTopOfFirstPage() + logicalOffset + marginOffset, &child, false, &offsetBreakAdjustment))
return logicalOffset + marginOffset + offsetBreakAdjustment;
}
return nextPageLogicalTop(logicalOffset, IncludePageBoundary);
}
return logicalOffset;
}
LayoutUnit RenderBlockFlow::adjustBlockChildForPagination(LayoutUnit logicalTopAfterClear, LayoutUnit estimateWithoutPagination, RenderBox& child, bool atBeforeSideOfBlock)
{
RenderBlock* childRenderBlock = is<RenderBlock>(child) ? &downcast<RenderBlock>(child) : nullptr;
if (estimateWithoutPagination != logicalTopAfterClear) {
// Our guess prior to pagination movement was wrong. Before we attempt to paginate, let's try again at the new
// position.
setLogicalHeight(logicalTopAfterClear);
setLogicalTopForChild(child, logicalTopAfterClear, ApplyLayoutDelta);
if (child.shrinkToAvoidFloats()) {
// The child's width depends on the line width. When the child shifts to clear an item, its width can
// change (because it has more available line width). So mark the item as dirty.
child.setChildNeedsLayout(MarkOnlyThis);
}
if (childRenderBlock) {
if (!child.avoidsFloats() && childRenderBlock->containsFloats())
downcast<RenderBlockFlow>(*childRenderBlock).markAllDescendantsWithFloatsForLayout();
child.markForPaginationRelayoutIfNeeded();
}
// Our guess was wrong. Make the child lay itself out again.
child.layoutIfNeeded();
}
LayoutUnit oldTop = logicalTopAfterClear;
// If the object has a page or column break value of "before", then we should shift to the top of the next page.
LayoutUnit result = applyBeforeBreak(child, logicalTopAfterClear);
if (pageLogicalHeightForOffset(result)) {
LayoutUnit remainingLogicalHeight = pageRemainingLogicalHeightForOffset(result, ExcludePageBoundary);
LayoutUnit spaceShortage = child.logicalHeight() - remainingLogicalHeight;
if (spaceShortage > 0) {
// If the child crosses a column boundary, report a break, in case nothing inside it has already
// done so. The column balancer needs to know how much it has to stretch the columns to make more
// content fit. If no breaks are reported (but do occur), the balancer will have no clue. FIXME:
// This should be improved, though, because here we just pretend that the child is
// unsplittable. A splittable child, on the other hand, has break opportunities at every position
// where there's no child content, border or padding. In other words, we risk stretching more
// than necessary.
setPageBreak(result, spaceShortage);
}
}
// For replaced elements and scrolled elements, we want to shift them to the next page if they don't fit on the current one.
LayoutUnit logicalTopBeforeUnsplittableAdjustment = result;
LayoutUnit logicalTopAfterUnsplittableAdjustment = adjustForUnsplittableChild(child, result);
LayoutUnit paginationStrut;
LayoutUnit unsplittableAdjustmentDelta = logicalTopAfterUnsplittableAdjustment - logicalTopBeforeUnsplittableAdjustment;
if (unsplittableAdjustmentDelta)
paginationStrut = unsplittableAdjustmentDelta;
else if (childRenderBlock && childRenderBlock->paginationStrut())
paginationStrut = childRenderBlock->paginationStrut();
if (paginationStrut) {
// We are willing to propagate out to our parent block as long as we were at the top of the block prior
// to collapsing our margins, and as long as we didn't clear or move as a result of other pagination.
if (atBeforeSideOfBlock && oldTop == result && !isOutOfFlowPositioned() && !isTableCell()) {
// FIXME: Should really check if we're exceeding the page height before propagating the strut, but we don't
// have all the information to do so (the strut only has the remaining amount to push). Gecko gets this wrong too
// and pushes to the next page anyway, so not too concerned about it.
setPaginationStrut(result + paginationStrut);
if (childRenderBlock)
childRenderBlock->setPaginationStrut(0);
} else
result += paginationStrut;
}
// Similar to how we apply clearance. Boost height() to be the place where we're going to position the child.
setLogicalHeight(logicalHeight() + (result - oldTop));
// Return the final adjusted logical top.
return result;
}
static inline LayoutUnit calculateMinimumPageHeight(const RenderStyle& renderStyle, RootInlineBox& lastLine, LayoutUnit lineTop, LayoutUnit lineBottom)
{
// We may require a certain minimum number of lines per page in order to satisfy
// orphans and widows, and that may affect the minimum page height.
unsigned lineCount = std::max<unsigned>(renderStyle.hasAutoOrphans() ? 1 : renderStyle.orphans(), renderStyle.hasAutoWidows() ? 1 : renderStyle.widows());
if (lineCount > 1) {
RootInlineBox* line = &lastLine;
for (unsigned i = 1; i < lineCount && line->prevRootBox(); i++)
line = line->prevRootBox();
// FIXME: Paginating using line overflow isn't all fine. See FIXME in
// adjustLinePositionForPagination() for more details.
LayoutRect overflow = line->logicalVisualOverflowRect(line->lineTop(), line->lineBottom());
lineTop = std::min(line->lineTopWithLeading(), overflow.y());
}
return lineBottom - lineTop;
}
static inline bool needsAppleMailPaginationQuirk(RootInlineBox& lineBox)
{
auto& renderer = lineBox.renderer();
if (!renderer.settings().appleMailPaginationQuirkEnabled())
return false;
if (renderer.element() && renderer.element()->idForStyleResolution() == "messageContentContainer")
return true;
return false;
}
static void clearShouldBreakAtLineToAvoidWidowIfNeeded(RenderBlockFlow& blockFlow)
{
if (!blockFlow.shouldBreakAtLineToAvoidWidow())
return;
blockFlow.clearShouldBreakAtLineToAvoidWidow();
blockFlow.setDidBreakAtLineToAvoidWidow();
}
void RenderBlockFlow::adjustLinePositionForPagination(RootInlineBox* lineBox, LayoutUnit& delta, bool& overflowsFragment, RenderFragmentedFlow* fragmentedFlow)
{
// FIXME: For now we paginate using line overflow. This ensures that lines don't overlap at all when we
// put a strut between them for pagination purposes. However, this really isn't the desired rendering, since
// the line on the top of the next page will appear too far down relative to the same kind of line at the top
// of the first column.
//
// The rendering we would like to see is one where the lineTopWithLeading is at the top of the column, and any line overflow
// simply spills out above the top of the column. This effect would match what happens at the top of the first column.
// We can't achieve this rendering, however, until we stop columns from clipping to the column bounds (thus allowing
// for overflow to occur), and then cache visible overflow for each column rect.
//
// Furthermore, the paint we have to do when a column has overflow has to be special. We need to exclude
// content that paints in a previous column (and content that paints in the following column).
//
// For now we'll at least honor the lineTopWithLeading when paginating if it is above the logical top overflow. This will
// at least make positive leading work in typical cases.
//
// FIXME: Another problem with simply moving lines is that the available line width may change (because of floats).
// Technically if the location we move the line to has a different line width than our old position, then we need to dirty the
// line and all following lines.
overflowsFragment = false;
LayoutRect logicalVisualOverflow = lineBox->logicalVisualOverflowRect(lineBox->lineTop(), lineBox->lineBottom());
LayoutUnit logicalOffset = std::min(lineBox->lineTopWithLeading(), logicalVisualOverflow.y());
LayoutUnit logicalBottom = std::max(lineBox->lineBottomWithLeading(), logicalVisualOverflow.maxY());
LayoutUnit lineHeight = logicalBottom - logicalOffset;
updateMinimumPageHeight(logicalOffset, calculateMinimumPageHeight(style(), *lineBox, logicalOffset, logicalBottom));
logicalOffset += delta;
lineBox->setPaginationStrut(0);
lineBox->setIsFirstAfterPageBreak(false);
LayoutUnit pageLogicalHeight = pageLogicalHeightForOffset(logicalOffset);
bool hasUniformPageLogicalHeight = !fragmentedFlow || fragmentedFlow->fragmentsHaveUniformLogicalHeight();
// If lineHeight is greater than pageLogicalHeight, but logicalVisualOverflow.height() still fits, we are
// still going to add a strut, so that the visible overflow fits on a single page.
if (!pageLogicalHeight || !hasNextPage(logicalOffset)) {
// FIXME: In case the line aligns with the top of the page (or it's slightly shifted downwards) it will not be marked as the first line in the page.
// From here, the fix is not straightforward because it's not easy to always determine when the current line is the first in the page.
return;
}
if (hasUniformPageLogicalHeight && logicalVisualOverflow.height() > pageLogicalHeight) {
// We are so tall that we are bigger than a page. Before we give up and just leave the line where it is, try drilling into the
// line and computing a new height that excludes anything we consider "blank space". We will discard margins, descent, and even overflow. If we are
// able to fit with the blank space and overflow excluded, we will give the line its own page with the highest non-blank element being aligned with the
// top of the page.
// FIXME: We are still honoring gigantic margins, which does leave open the possibility of blank pages caused by this heuristic. It remains to be seen whether or not
// this will be a real-world issue. For now we don't try to deal with this problem.
logicalOffset = intMaxForLayoutUnit;
logicalBottom = intMinForLayoutUnit;
lineBox->computeReplacedAndTextLineTopAndBottom(logicalOffset, logicalBottom);
lineHeight = logicalBottom - logicalOffset;
if (logicalOffset == intMaxForLayoutUnit || lineHeight > pageLogicalHeight) {
// Give up. We're genuinely too big even after excluding blank space and overflow.
clearShouldBreakAtLineToAvoidWidowIfNeeded(*this);
return;
}
pageLogicalHeight = pageLogicalHeightForOffset(logicalOffset);
}
LayoutUnit remainingLogicalHeight = pageRemainingLogicalHeightForOffset(logicalOffset, ExcludePageBoundary);
overflowsFragment = (lineHeight > remainingLogicalHeight);
int lineIndex = complexLineLayout()->lineCountUntil(lineBox);
if (remainingLogicalHeight < lineHeight || (shouldBreakAtLineToAvoidWidow() && lineBreakToAvoidWidow() == lineIndex)) {
if (lineBreakToAvoidWidow() == lineIndex)
clearShouldBreakAtLineToAvoidWidowIfNeeded(*this);
// If we have a non-uniform page height, then we have to shift further possibly.
if (!hasUniformPageLogicalHeight && !pushToNextPageWithMinimumLogicalHeight(remainingLogicalHeight, logicalOffset, lineHeight))
return;
if (lineHeight > pageLogicalHeight) {
// Split the top margin in order to avoid splitting the visible part of the line.
remainingLogicalHeight -= std::min(lineHeight - pageLogicalHeight, std::max<LayoutUnit>(0, logicalVisualOverflow.y() - lineBox->lineTopWithLeading()));
}
LayoutUnit remainingLogicalHeightAtNewOffset = pageRemainingLogicalHeightForOffset(logicalOffset + remainingLogicalHeight, ExcludePageBoundary);
overflowsFragment = (lineHeight > remainingLogicalHeightAtNewOffset);
LayoutUnit totalLogicalHeight = lineHeight + std::max<LayoutUnit>(0, logicalOffset);
LayoutUnit pageLogicalHeightAtNewOffset = hasUniformPageLogicalHeight ? pageLogicalHeight : pageLogicalHeightForOffset(logicalOffset + remainingLogicalHeight);
setPageBreak(logicalOffset, lineHeight - remainingLogicalHeight);
if (((lineBox == firstRootBox() && totalLogicalHeight < pageLogicalHeightAtNewOffset) || (!style().hasAutoOrphans() && style().orphans() >= lineIndex))
&& !isOutOfFlowPositioned() && !isTableCell()) {
auto firstRootBox = this->firstRootBox();
auto firstRootBoxOverflowRect = firstRootBox->logicalVisualOverflowRect(firstRootBox->lineTop(), firstRootBox->lineBottom());
auto firstLineUpperOverhang = std::max(-firstRootBoxOverflowRect.y(), 0_lu);
if (needsAppleMailPaginationQuirk(*lineBox))
return;
setPaginationStrut(remainingLogicalHeight + logicalOffset + firstLineUpperOverhang);
} else {
delta += remainingLogicalHeight;
lineBox->setPaginationStrut(remainingLogicalHeight);
lineBox->setIsFirstAfterPageBreak(true);
}
} else if (remainingLogicalHeight == pageLogicalHeight) {
// We're at the very top of a page or column.
if (lineBox != firstRootBox())
lineBox->setIsFirstAfterPageBreak(true);
if (lineBox != firstRootBox() || offsetFromLogicalTopOfFirstPage())
setPageBreak(logicalOffset, lineHeight);
}
}
void RenderBlockFlow::setBreakAtLineToAvoidWidow(int lineToBreak)
{
ASSERT(lineToBreak >= 0);
ASSERT(!ensureRareBlockFlowData().m_didBreakAtLineToAvoidWidow);
ensureRareBlockFlowData().m_lineBreakToAvoidWidow = lineToBreak;
}
void RenderBlockFlow::setDidBreakAtLineToAvoidWidow()
{
ASSERT(!shouldBreakAtLineToAvoidWidow());
if (!hasRareBlockFlowData())
return;
rareBlockFlowData()->m_didBreakAtLineToAvoidWidow = true;
}
void RenderBlockFlow::clearDidBreakAtLineToAvoidWidow()
{
if (!hasRareBlockFlowData())
return;
rareBlockFlowData()->m_didBreakAtLineToAvoidWidow = false;
}
void RenderBlockFlow::clearShouldBreakAtLineToAvoidWidow() const
{
ASSERT(shouldBreakAtLineToAvoidWidow());
if (!hasRareBlockFlowData())
return;
rareBlockFlowData()->m_lineBreakToAvoidWidow = -1;
}
bool RenderBlockFlow::relayoutToAvoidWidows()
{
if (!shouldBreakAtLineToAvoidWidow())
return false;
setEverHadLayout(true);
layoutBlock(false);
return true;
}
bool RenderBlockFlow::hasNextPage(LayoutUnit logicalOffset, PageBoundaryRule pageBoundaryRule) const
{
ASSERT(view().frameView().layoutContext().layoutState() && view().frameView().layoutContext().layoutState()->isPaginated());
RenderFragmentedFlow* fragmentedFlow = enclosingFragmentedFlow();
if (!fragmentedFlow)
return true; // Printing and multi-column both make new pages to accommodate content.
// See if we're in the last fragment.
LayoutUnit pageOffset = offsetFromLogicalTopOfFirstPage() + logicalOffset;
RenderFragmentContainer* fragment = fragmentedFlow->fragmentAtBlockOffset(this, pageOffset, true);
if (!fragment)
return false;
if (fragment->isLastFragment())
return fragment->isRenderFragmentContainerSet() || (pageBoundaryRule == IncludePageBoundary && pageOffset == fragment->logicalTopForFragmentedFlowContent());
RenderFragmentContainer* startFragment = nullptr;
RenderFragmentContainer* endFragment = nullptr;
fragmentedFlow->getFragmentRangeForBox(this, startFragment, endFragment);
return (endFragment && fragment != endFragment);
}
LayoutUnit RenderBlockFlow::adjustForUnsplittableChild(RenderBox& child, LayoutUnit logicalOffset, LayoutUnit childBeforeMargin, LayoutUnit childAfterMargin)
{
// When flexboxes are embedded inside a block flow, they don't perform any adjustments for unsplittable
// children. We'll treat flexboxes themselves as unsplittable just to get them to paginate properly inside
// a block flow.
bool isUnsplittable = childBoxIsUnsplittableForFragmentation(child);
if (!isUnsplittable && !(child.isFlexibleBox() && !downcast<RenderFlexibleBox>(child).isFlexibleBoxImpl()))
return logicalOffset;
RenderFragmentedFlow* fragmentedFlow = enclosingFragmentedFlow();
LayoutUnit childLogicalHeight = logicalHeightForChild(child) + childBeforeMargin + childAfterMargin;
LayoutUnit pageLogicalHeight = pageLogicalHeightForOffset(logicalOffset);
bool hasUniformPageLogicalHeight = !fragmentedFlow || fragmentedFlow->fragmentsHaveUniformLogicalHeight();
if (isUnsplittable)
updateMinimumPageHeight(logicalOffset, childLogicalHeight);
if (!pageLogicalHeight || (hasUniformPageLogicalHeight && childLogicalHeight > pageLogicalHeight)
|| !hasNextPage(logicalOffset))
return logicalOffset;
LayoutUnit remainingLogicalHeight = pageRemainingLogicalHeightForOffset(logicalOffset, ExcludePageBoundary);
if (remainingLogicalHeight < childLogicalHeight) {
if (!hasUniformPageLogicalHeight && !pushToNextPageWithMinimumLogicalHeight(remainingLogicalHeight, logicalOffset, childLogicalHeight))
return logicalOffset;
auto result = logicalOffset + remainingLogicalHeight;
bool isInitialLetter = child.isFloating() && child.style().styleType() == PseudoId::FirstLetter && child.style().initialLetterDrop() > 0;
if (isInitialLetter) {
// Increase our logical height to ensure that lines all get pushed along with the letter.
setLogicalHeight(logicalOffset + remainingLogicalHeight);
}
return result;
}
return logicalOffset;
}
bool RenderBlockFlow::pushToNextPageWithMinimumLogicalHeight(LayoutUnit& adjustment, LayoutUnit logicalOffset, LayoutUnit minimumLogicalHeight) const
{
bool checkFragment = false;
for (LayoutUnit pageLogicalHeight = pageLogicalHeightForOffset(logicalOffset + adjustment); pageLogicalHeight;
pageLogicalHeight = pageLogicalHeightForOffset(logicalOffset + adjustment)) {
if (minimumLogicalHeight <= pageLogicalHeight)
return true;
if (!hasNextPage(logicalOffset + adjustment))
return false;
adjustment += pageLogicalHeight;
checkFragment = true;
}
return !checkFragment;
}
void RenderBlockFlow::setPageBreak(LayoutUnit offset, LayoutUnit spaceShortage)
{
if (RenderFragmentedFlow* fragmentedFlow = enclosingFragmentedFlow())
fragmentedFlow->setPageBreak(this, offsetFromLogicalTopOfFirstPage() + offset, spaceShortage);
}
void RenderBlockFlow::updateMinimumPageHeight(LayoutUnit offset, LayoutUnit minHeight)
{
if (RenderFragmentedFlow* fragmentedFlow = enclosingFragmentedFlow())
fragmentedFlow->updateMinimumPageHeight(this, offsetFromLogicalTopOfFirstPage() + offset, minHeight);
}
LayoutUnit RenderBlockFlow::nextPageLogicalTop(LayoutUnit logicalOffset, PageBoundaryRule pageBoundaryRule) const
{
LayoutUnit pageLogicalHeight = pageLogicalHeightForOffset(logicalOffset);
if (!pageLogicalHeight)
return logicalOffset;
// The logicalOffset is in our coordinate space. We can add in our pushed offset.
LayoutUnit remainingLogicalHeight = pageRemainingLogicalHeightForOffset(logicalOffset);
if (pageBoundaryRule == ExcludePageBoundary)
return logicalOffset + (remainingLogicalHeight ? remainingLogicalHeight : pageLogicalHeight);
return logicalOffset + remainingLogicalHeight;
}
LayoutUnit RenderBlockFlow::pageLogicalTopForOffset(LayoutUnit offset) const
{
// Unsplittable objects clear out the pageLogicalHeight in the layout state as a way of signaling that no
// pagination should occur. Therefore we have to check this first and bail if the value has been set to 0.
auto* layoutState = view().frameView().layoutContext().layoutState();
LayoutUnit pageLogicalHeight = layoutState->pageLogicalHeight();
if (!pageLogicalHeight)
return 0;
LayoutUnit firstPageLogicalTop = isHorizontalWritingMode() ? layoutState->pageOffset().height() : layoutState->pageOffset().width();
LayoutUnit blockLogicalTop = isHorizontalWritingMode() ? layoutState->layoutOffset().height() : layoutState->layoutOffset().width();
LayoutUnit cumulativeOffset = offset + blockLogicalTop;
RenderFragmentedFlow* fragmentedFlow = enclosingFragmentedFlow();
if (!fragmentedFlow)
return cumulativeOffset - roundToInt(cumulativeOffset - firstPageLogicalTop) % roundToInt(pageLogicalHeight);
return firstPageLogicalTop + fragmentedFlow->pageLogicalTopForOffset(cumulativeOffset - firstPageLogicalTop);
}
LayoutUnit RenderBlockFlow::pageLogicalHeightForOffset(LayoutUnit offset) const
{
// Unsplittable objects clear out the pageLogicalHeight in the layout state as a way of signaling that no
// pagination should occur. Therefore we have to check this first and bail if the value has been set to 0.
LayoutUnit pageLogicalHeight = view().frameView().layoutContext().layoutState()->pageLogicalHeight();
if (!pageLogicalHeight)
return 0;
// Now check for a flow thread.
RenderFragmentedFlow* fragmentedFlow = enclosingFragmentedFlow();
if (!fragmentedFlow)
return pageLogicalHeight;
return fragmentedFlow->pageLogicalHeightForOffset(offset + offsetFromLogicalTopOfFirstPage());
}
LayoutUnit RenderBlockFlow::pageRemainingLogicalHeightForOffset(LayoutUnit offset, PageBoundaryRule pageBoundaryRule) const
{
offset += offsetFromLogicalTopOfFirstPage();
RenderFragmentedFlow* fragmentedFlow = enclosingFragmentedFlow();
if (!fragmentedFlow) {
LayoutUnit pageLogicalHeight = view().frameView().layoutContext().layoutState()->pageLogicalHeight();
LayoutUnit remainingHeight = pageLogicalHeight - intMod(offset, pageLogicalHeight);
if (pageBoundaryRule == IncludePageBoundary) {
// If includeBoundaryPoint is true the line exactly on the top edge of a
// column will act as being part of the previous column.
remainingHeight = intMod(remainingHeight, pageLogicalHeight);
}
return remainingHeight;
}
return fragmentedFlow->pageRemainingLogicalHeightForOffset(offset, pageBoundaryRule);
}
LayoutUnit RenderBlockFlow::logicalHeightForChildForFragmentation(const RenderBox& child) const
{
return logicalHeightForChild(child);
}
void RenderBlockFlow::layoutLineGridBox()
{
if (style().lineGrid() == RenderStyle::initialLineGrid()) {
setLineGridBox(0);
return;
}
setLineGridBox(0);
auto lineGridBox = makeUnique<RootInlineBox>(*this);
lineGridBox->setHasTextChildren(); // Needed to make the line ascent/descent actually be honored in quirks mode.
lineGridBox->setConstructed();
GlyphOverflowAndFallbackFontsMap textBoxDataMap;
VerticalPositionCache verticalPositionCache;
lineGridBox->alignBoxesInBlockDirection(logicalHeight(), textBoxDataMap, verticalPositionCache);
setLineGridBox(WTFMove(lineGridBox));
// FIXME: If any of the characteristics of the box change compared to the old one, then we need to do a deep dirtying
// (similar to what happens when the page height changes). Ideally, though, we only do this if someone is actually snapping
// to this grid.
}
bool RenderBlockFlow::containsFloat(RenderBox& renderer) const
{
return m_floatingObjects && m_floatingObjects->set().contains<FloatingObjectHashTranslator>(renderer);
}
void RenderBlockFlow::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
{
RenderBlock::styleDidChange(diff, oldStyle);
// After our style changed, if we lose our ability to propagate floats into next sibling
// blocks, then we need to find the top most parent containing that overhanging float and
// then mark its descendants with floats for layout and clear all floats from its next
// sibling blocks that exist in our floating objects list. See bug 56299 and 62875.
bool canPropagateFloatIntoSibling = !isFloatingOrOutOfFlowPositioned() && !avoidsFloats();
if (diff == StyleDifference::Layout && s_canPropagateFloatIntoSibling && !canPropagateFloatIntoSibling && hasOverhangingFloats()) {
RenderBlockFlow* parentBlock = this;
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
for (auto& ancestor : ancestorsOfType<RenderBlockFlow>(*this)) {
if (ancestor.isRenderView())
break;
if (ancestor.hasOverhangingFloats()) {
for (auto it = floatingObjectSet.begin(), end = floatingObjectSet.end(); it != end; ++it) {
RenderBox& renderer = (*it)->renderer();
if (ancestor.hasOverhangingFloat(renderer)) {
parentBlock = &ancestor;
break;
}
}
}
}
parentBlock->markAllDescendantsWithFloatsForLayout();
parentBlock->markSiblingsWithFloatsForLayout();
}
if (diff >= StyleDifference::Repaint) {
// FIXME: This could use a cheaper style-only test instead of SimpleLineLayout::canUseFor.
if (selfNeedsLayout() || !simpleLineLayout() || !SimpleLineLayout::canUseFor(*this))
invalidateLineLayoutPath();
}
if (multiColumnFlow())
updateStylesForColumnChildren();
}
void RenderBlockFlow::updateStylesForColumnChildren()
{
for (auto* child = firstChildBox(); child && (child->isInFlowRenderFragmentedFlow() || child->isRenderMultiColumnSet()); child = child->nextSiblingBox())
child->setStyle(RenderStyle::createAnonymousStyleWithDisplay(style(), DisplayType::Block));
}
void RenderBlockFlow::styleWillChange(StyleDifference diff, const RenderStyle& newStyle)
{
const RenderStyle* oldStyle = hasInitializedStyle() ? &style() : nullptr;
s_canPropagateFloatIntoSibling = oldStyle ? !isFloatingOrOutOfFlowPositioned() && !avoidsFloats() : false;
if (oldStyle) {
auto oldPosition = oldStyle->position();
auto newPosition = newStyle.position();
if (parent() && diff == StyleDifference::Layout && oldPosition != newPosition) {
if (containsFloats() && !isFloating() && !isOutOfFlowPositioned() && newStyle.hasOutOfFlowPosition())
markAllDescendantsWithFloatsForLayout();
}
}
RenderBlock::styleWillChange(diff, newStyle);
}
void RenderBlockFlow::deleteLines()
{
m_lineLayout = WTF::Monostate();
RenderBlock::deleteLines();
}
void RenderBlockFlow::addFloatsToNewParent(RenderBlockFlow& toBlockFlow) const
{
// When a portion of the render tree is being detached, anonymous blocks
// will be combined as their children are deleted. In this process, the
// anonymous block later in the tree is merged into the one preceeding it.
// It can happen that the later block (this) contains floats that the
// previous block (toBlockFlow) did not contain, and thus are not in the
// floating objects list for toBlockFlow. This can result in toBlockFlow
// containing floats that are not in it's floating objects list, but are in
// the floating objects lists of siblings and parents. This can cause
// problems when the float itself is deleted, since the deletion code
// assumes that if a float is not in it's containing block's floating
// objects list, it isn't in any floating objects list. In order to
// preserve this condition (removing it has serious performance
// implications), we need to copy the floating objects from the old block
// (this) to the new block (toBlockFlow). The float's metrics will likely
// all be wrong, but since toBlockFlow is already marked for layout, this
// will get fixed before anything gets displayed.
// See bug https://bugs.webkit.org/show_bug.cgi?id=115566
if (!m_floatingObjects)
return;
if (!toBlockFlow.m_floatingObjects)
toBlockFlow.createFloatingObjects();
for (auto& floatingObject : m_floatingObjects->set()) {
if (toBlockFlow.containsFloat(floatingObject->renderer()))
continue;
toBlockFlow.m_floatingObjects->add(floatingObject->cloneForNewParent());
}
}
void RenderBlockFlow::addOverflowFromFloats()
{
if (!m_floatingObjects)
return;
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
auto end = floatingObjectSet.end();
for (auto it = floatingObjectSet.begin(); it != end; ++it) {
const auto& floatingObject = *it->get();
if (floatingObject.isDescendant())
addOverflowFromChild(&floatingObject.renderer(), floatingObject.locationOffsetOfBorderBox());
}
}
void RenderBlockFlow::computeOverflow(LayoutUnit oldClientAfterEdge, bool recomputeFloats)
{
RenderBlock::computeOverflow(oldClientAfterEdge, recomputeFloats);
if (!multiColumnFlow() && (recomputeFloats || createsNewFormattingContext() || hasSelfPaintingLayer()))
addOverflowFromFloats();
}
void RenderBlockFlow::repaintOverhangingFloats(bool paintAllDescendants)
{
// Repaint any overhanging floats (if we know we're the one to paint them).
// Otherwise, bail out.
if (!hasOverhangingFloats())
return;
// FIXME: Avoid disabling LayoutState. At the very least, don't disable it for floats originating
// in this block. Better yet would be to push extra state for the containers of other floats.
LayoutStateDisabler layoutStateDisabler(view().frameView().layoutContext());
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
auto end = floatingObjectSet.end();
for (auto it = floatingObjectSet.begin(); it != end; ++it) {
const auto& floatingObject = *it->get();
// Only repaint the object if it is overhanging, is not in its own layer, and
// is our responsibility to paint (m_shouldPaint is set). When paintAllDescendants is true, the latter
// condition is replaced with being a descendant of us.
auto& renderer = floatingObject.renderer();
if (logicalBottomForFloat(floatingObject) > logicalHeight()
&& !renderer.hasSelfPaintingLayer()
&& (floatingObject.shouldPaint() || (paintAllDescendants && renderer.isDescendantOf(this)))) {
renderer.repaint();
renderer.repaintOverhangingFloats(false);
}
}
}
void RenderBlockFlow::paintColumnRules(PaintInfo& paintInfo, const LayoutPoint& point)
{
RenderBlock::paintColumnRules(paintInfo, point);
if (!multiColumnFlow() || paintInfo.context().paintingDisabled())
return;
// Iterate over our children and paint the column rules as needed.
for (auto& columnSet : childrenOfType<RenderMultiColumnSet>(*this)) {
LayoutPoint childPoint = columnSet.location() + flipForWritingModeForChild(&columnSet, point);
columnSet.paintColumnRules(paintInfo, childPoint);
}
}
void RenderBlockFlow::paintFloats(PaintInfo& paintInfo, const LayoutPoint& paintOffset, bool preservePhase)
{
if (!m_floatingObjects)
return;
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
auto end = floatingObjectSet.end();
for (auto it = floatingObjectSet.begin(); it != end; ++it) {
const auto& floatingObject = *it->get();
auto& renderer = floatingObject.renderer();
// Only paint the object if our m_shouldPaint flag is set.
if (floatingObject.shouldPaint() && !renderer.hasSelfPaintingLayer()) {
PaintInfo currentPaintInfo(paintInfo);
currentPaintInfo.phase = preservePhase ? paintInfo.phase : PaintPhase::BlockBackground;
LayoutPoint childPoint = flipFloatForWritingModeForChild(floatingObject, paintOffset + floatingObject.translationOffsetToAncestor());
renderer.paint(currentPaintInfo, childPoint);
if (!preservePhase) {
currentPaintInfo.phase = PaintPhase::ChildBlockBackgrounds;
renderer.paint(currentPaintInfo, childPoint);
currentPaintInfo.phase = PaintPhase::Float;
renderer.paint(currentPaintInfo, childPoint);
currentPaintInfo.phase = PaintPhase::Foreground;
renderer.paint(currentPaintInfo, childPoint);
currentPaintInfo.phase = PaintPhase::Outline;
renderer.paint(currentPaintInfo, childPoint);
}
}
}
}
void RenderBlockFlow::clipOutFloatingObjects(RenderBlock& rootBlock, const PaintInfo* paintInfo, const LayoutPoint& rootBlockPhysicalPosition, const LayoutSize& offsetFromRootBlock)
{
if (m_floatingObjects) {
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
auto end = floatingObjectSet.end();
for (auto it = floatingObjectSet.begin(); it != end; ++it) {
const auto& floatingObject = *it->get();
LayoutRect floatBox(offsetFromRootBlock.width(), offsetFromRootBlock.height(), floatingObject.renderer().width(), floatingObject.renderer().height());
floatBox.move(floatingObject.locationOffsetOfBorderBox());
rootBlock.flipForWritingMode(floatBox);
floatBox.move(rootBlockPhysicalPosition.x(), rootBlockPhysicalPosition.y());
paintInfo->context().clipOut(snappedIntRect(floatBox));
}
}
}
void RenderBlockFlow::createFloatingObjects()
{
m_floatingObjects = makeUnique<FloatingObjects>(*this);
}
void RenderBlockFlow::removeFloatingObjects()
{
if (!m_floatingObjects)
return;
markSiblingsWithFloatsForLayout();
m_floatingObjects->clear();
}
FloatingObject* RenderBlockFlow::insertFloatingObject(RenderBox& floatBox)
{
ASSERT(floatBox.isFloating());
// Create the list of special objects if we don't aleady have one
if (!m_floatingObjects)
createFloatingObjects();
else {
// Don't insert the floatingObject again if it's already in the list
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
auto it = floatingObjectSet.find<FloatingObjectHashTranslator>(floatBox);
if (it != floatingObjectSet.end())
return it->get();
}
// Create the special floatingObject entry & append it to the list
std::unique_ptr<FloatingObject> floatingObject = FloatingObject::create(floatBox);
// Our location is irrelevant if we're unsplittable or no pagination is in effect. Just lay out the float.
bool isChildRenderBlock = floatBox.isRenderBlock();
if (isChildRenderBlock && !floatBox.needsLayout() && view().frameView().layoutContext().layoutState()->pageLogicalHeightChanged())
floatBox.setChildNeedsLayout(MarkOnlyThis);
bool needsBlockDirectionLocationSetBeforeLayout = isChildRenderBlock && view().frameView().layoutContext().layoutState()->needsBlockDirectionLocationSetBeforeLayout();
if (!needsBlockDirectionLocationSetBeforeLayout || isWritingModeRoot()) {
// We are unsplittable if we're a block flow root.
floatBox.layoutIfNeeded();
floatingObject->setShouldPaint(!floatBox.hasSelfPaintingLayer());
}
else {
floatBox.updateLogicalWidth();
floatBox.computeAndSetBlockDirectionMargins(*this);
}
setLogicalWidthForFloat(*floatingObject, logicalWidthForChild(floatBox) + marginStartForChild(floatBox) + marginEndForChild(floatBox));
return m_floatingObjects->add(WTFMove(floatingObject));
}
void RenderBlockFlow::removeFloatingObject(RenderBox& floatBox)
{
if (m_floatingObjects) {
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
auto it = floatingObjectSet.find<FloatingObjectHashTranslator>(floatBox);
if (it != floatingObjectSet.end()) {
auto& floatingObject = *it->get();
if (childrenInline()) {
LayoutUnit logicalTop = logicalTopForFloat(floatingObject);
LayoutUnit logicalBottom = logicalBottomForFloat(floatingObject);
// Fix for https://bugs.webkit.org/show_bug.cgi?id=54995.
if (logicalBottom < 0 || logicalBottom < logicalTop || logicalTop == LayoutUnit::max())
logicalBottom = LayoutUnit::max();
else {
// Special-case zero- and less-than-zero-height floats: those don't touch
// the line that they're on, but it still needs to be dirtied. This is
// accomplished by pretending they have a height of 1.
logicalBottom = std::max(logicalBottom, logicalTop + 1);
}
if (floatingObject.originatingLine()) {
floatingObject.originatingLine()->removeFloat(floatBox);
if (!selfNeedsLayout()) {
ASSERT(&floatingObject.originatingLine()->renderer() == this);
floatingObject.originatingLine()->markDirty();
}
#if !ASSERT_DISABLED
floatingObject.clearOriginatingLine();
#endif
}
markLinesDirtyInBlockRange(0, logicalBottom);
}
m_floatingObjects->remove(&floatingObject);
}
}
}
void RenderBlockFlow::removeFloatingObjectsBelow(FloatingObject* lastFloat, int logicalOffset)
{
if (!containsFloats())
return;
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
FloatingObject* curr = floatingObjectSet.last().get();
while (curr != lastFloat && (!curr->isPlaced() || logicalTopForFloat(*curr) >= logicalOffset)) {
m_floatingObjects->remove(curr);
if (floatingObjectSet.isEmpty())
break;
curr = floatingObjectSet.last().get();
}
}
LayoutUnit RenderBlockFlow::logicalLeftOffsetForPositioningFloat(LayoutUnit logicalTop, LayoutUnit fixedOffset, bool applyTextIndent, LayoutUnit* heightRemaining) const
{
LayoutUnit offset = fixedOffset;
if (m_floatingObjects && m_floatingObjects->hasLeftObjects())
offset = m_floatingObjects->logicalLeftOffsetForPositioningFloat(fixedOffset, logicalTop, heightRemaining);
return adjustLogicalLeftOffsetForLine(offset, applyTextIndent);
}
LayoutUnit RenderBlockFlow::logicalRightOffsetForPositioningFloat(LayoutUnit logicalTop, LayoutUnit fixedOffset, bool applyTextIndent, LayoutUnit* heightRemaining) const
{
LayoutUnit offset = fixedOffset;
if (m_floatingObjects && m_floatingObjects->hasRightObjects())
offset = m_floatingObjects->logicalRightOffsetForPositioningFloat(fixedOffset, logicalTop, heightRemaining);
return adjustLogicalRightOffsetForLine(offset, applyTextIndent);
}
void RenderBlockFlow::computeLogicalLocationForFloat(FloatingObject& floatingObject, LayoutUnit& logicalTopOffset)
{
auto& childBox = floatingObject.renderer();
LayoutUnit logicalLeftOffset = logicalLeftOffsetForContent(logicalTopOffset); // Constant part of left offset.
LayoutUnit logicalRightOffset = logicalRightOffsetForContent(logicalTopOffset); // Constant part of right offset.
LayoutUnit floatLogicalWidth = std::min(logicalWidthForFloat(floatingObject), logicalRightOffset - logicalLeftOffset); // The width we look for.
LayoutUnit floatLogicalLeft;
bool insideFragmentedFlow = enclosingFragmentedFlow();
bool isInitialLetter = childBox.style().styleType() == PseudoId::FirstLetter && childBox.style().initialLetterDrop() > 0;
if (isInitialLetter) {
int letterClearance = lowestInitialLetterLogicalBottom() - logicalTopOffset;
if (letterClearance > 0) {
logicalTopOffset += letterClearance;
setLogicalHeight(logicalHeight() + letterClearance);
}
}
if (childBox.style().floating() == Float::Left) {
LayoutUnit heightRemainingLeft = 1_lu;
LayoutUnit heightRemainingRight = 1_lu;
floatLogicalLeft = logicalLeftOffsetForPositioningFloat(logicalTopOffset, logicalLeftOffset, false, &heightRemainingLeft);
while (logicalRightOffsetForPositioningFloat(logicalTopOffset, logicalRightOffset, false, &heightRemainingRight) - floatLogicalLeft < floatLogicalWidth) {
logicalTopOffset += std::min(heightRemainingLeft, heightRemainingRight);
floatLogicalLeft = logicalLeftOffsetForPositioningFloat(logicalTopOffset, logicalLeftOffset, false, &heightRemainingLeft);
if (insideFragmentedFlow) {
// Have to re-evaluate all of our offsets, since they may have changed.
logicalRightOffset = logicalRightOffsetForContent(logicalTopOffset); // Constant part of right offset.
logicalLeftOffset = logicalLeftOffsetForContent(logicalTopOffset); // Constant part of left offset.
floatLogicalWidth = std::min(logicalWidthForFloat(floatingObject), logicalRightOffset - logicalLeftOffset);
}
}
floatLogicalLeft = std::max(logicalLeftOffset - borderAndPaddingLogicalLeft(), floatLogicalLeft);
} else {
LayoutUnit heightRemainingLeft = 1_lu;
LayoutUnit heightRemainingRight = 1_lu;
floatLogicalLeft = logicalRightOffsetForPositioningFloat(logicalTopOffset, logicalRightOffset, false, &heightRemainingRight);
while (floatLogicalLeft - logicalLeftOffsetForPositioningFloat(logicalTopOffset, logicalLeftOffset, false, &heightRemainingLeft) < floatLogicalWidth) {
logicalTopOffset += std::min(heightRemainingLeft, heightRemainingRight);
floatLogicalLeft = logicalRightOffsetForPositioningFloat(logicalTopOffset, logicalRightOffset, false, &heightRemainingRight);
if (insideFragmentedFlow) {
// Have to re-evaluate all of our offsets, since they may have changed.
logicalRightOffset = logicalRightOffsetForContent(logicalTopOffset); // Constant part of right offset.
logicalLeftOffset = logicalLeftOffsetForContent(logicalTopOffset); // Constant part of left offset.
floatLogicalWidth = std::min(logicalWidthForFloat(floatingObject), logicalRightOffset - logicalLeftOffset);
}
}
// Use the original width of the float here, since the local variable
// |floatLogicalWidth| was capped to the available line width. See
// fast/block/float/clamped-right-float.html.
floatLogicalLeft -= logicalWidthForFloat(floatingObject);
}
LayoutUnit childLogicalLeftMargin = style().isLeftToRightDirection() ? marginStartForChild(childBox) : marginEndForChild(childBox);
LayoutUnit childBeforeMargin = marginBeforeForChild(childBox);
if (isInitialLetter)
adjustInitialLetterPosition(childBox, logicalTopOffset, childBeforeMargin);
setLogicalLeftForFloat(floatingObject, floatLogicalLeft);
setLogicalLeftForChild(childBox, floatLogicalLeft + childLogicalLeftMargin);
setLogicalTopForFloat(floatingObject, logicalTopOffset);
setLogicalTopForChild(childBox, logicalTopOffset + childBeforeMargin);
setLogicalMarginsForFloat(floatingObject, childLogicalLeftMargin, childBeforeMargin);
}
void RenderBlockFlow::adjustInitialLetterPosition(RenderBox& childBox, LayoutUnit& logicalTopOffset, LayoutUnit& marginBeforeOffset)
{
const RenderStyle& style = firstLineStyle();
const FontMetrics& fontMetrics = style.fontMetrics();
if (!fontMetrics.hasCapHeight())
return;
LayoutUnit heightOfLine = lineHeight(true, isHorizontalWritingMode() ? HorizontalLine : VerticalLine, PositionOfInteriorLineBoxes);
LayoutUnit beforeMarginBorderPadding = childBox.borderAndPaddingBefore() + childBox.marginBefore();
// Make an adjustment to align with the cap height of a theoretical block line.
LayoutUnit adjustment = fontMetrics.ascent() + (heightOfLine - fontMetrics.height()) / 2 - fontMetrics.capHeight() - beforeMarginBorderPadding;
logicalTopOffset += adjustment;
// For sunken and raised caps, we have to make some adjustments. Test if we're sunken or raised (dropHeightDelta will be
// positive for raised and negative for sunken).
int dropHeightDelta = childBox.style().initialLetterHeight() - childBox.style().initialLetterDrop();
// If we're sunken, the float needs to shift down but lines still need to avoid it. In order to do that we increase the float's margin.
if (dropHeightDelta < 0)
marginBeforeOffset += -dropHeightDelta * heightOfLine;
// If we're raised, then we actually have to grow the height of the block, since the lines have to be pushed down as though we're placing
// empty lines beside the first letter.
if (dropHeightDelta > 0)
setLogicalHeight(logicalHeight() + dropHeightDelta * heightOfLine);
}
bool RenderBlockFlow::positionNewFloats()
{
if (!m_floatingObjects)
return false;
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
if (floatingObjectSet.isEmpty())
return false;
// If all floats have already been positioned, then we have no work to do.
if (floatingObjectSet.last()->isPlaced())
return false;
// Move backwards through our floating object list until we find a float that has
// already been positioned. Then we'll be able to move forward, positioning all of
// the new floats that need it.
auto it = floatingObjectSet.end();
--it; // Go to last item.
auto begin = floatingObjectSet.begin();
FloatingObject* lastPlacedFloatingObject = 0;
while (it != begin) {
--it;
if ((*it)->isPlaced()) {
lastPlacedFloatingObject = it->get();
++it;
break;
}
}
LayoutUnit logicalTop = logicalHeight();
// The float cannot start above the top position of the last positioned float.
if (lastPlacedFloatingObject)
logicalTop = std::max(logicalTopForFloat(*lastPlacedFloatingObject), logicalTop);
auto end = floatingObjectSet.end();
// Now walk through the set of unpositioned floats and place them.
for (; it != end; ++it) {
auto& floatingObject = *it->get();
// The containing block is responsible for positioning floats, so if we have floats in our
// list that come from somewhere else, do not attempt to position them.
auto& childBox = floatingObject.renderer();
if (childBox.containingBlock() != this)
continue;
LayoutRect oldRect = childBox.frameRect();
if (childBox.style().clear() == Clear::Left || childBox.style().clear() == Clear::Both)
logicalTop = std::max(lowestFloatLogicalBottom(FloatingObject::FloatLeft), logicalTop);
if (childBox.style().clear() == Clear::Right || childBox.style().clear() == Clear::Both)
logicalTop = std::max(lowestFloatLogicalBottom(FloatingObject::FloatRight), logicalTop);
computeLogicalLocationForFloat(floatingObject, logicalTop);
LayoutUnit childLogicalTop = logicalTopForChild(childBox);
estimateFragmentRangeForBoxChild(childBox);
childBox.markForPaginationRelayoutIfNeeded();
childBox.layoutIfNeeded();
auto* layoutState = view().frameView().layoutContext().layoutState();
bool isPaginated = layoutState->isPaginated();
if (isPaginated) {
// If we are unsplittable and don't fit, then we need to move down.
// We include our margins as part of the unsplittable area.
LayoutUnit newLogicalTop = adjustForUnsplittableChild(childBox, logicalTop, childLogicalTop - logicalTop, marginAfterForChild(childBox));
// See if we have a pagination strut that is making us move down further.
// Note that an unsplittable child can't also have a pagination strut, so this
// is exclusive with the case above.
RenderBlock* childBlock = is<RenderBlock>(childBox) ? &downcast<RenderBlock>(childBox) : nullptr;
if (childBlock && childBlock->paginationStrut()) {
newLogicalTop += childBlock->paginationStrut();
childBlock->setPaginationStrut(0);
}
if (newLogicalTop != logicalTop) {
floatingObject.setPaginationStrut(newLogicalTop - logicalTop);
computeLogicalLocationForFloat(floatingObject, newLogicalTop);
if (childBlock)
childBlock->setChildNeedsLayout(MarkOnlyThis);
childBox.layoutIfNeeded();
logicalTop = newLogicalTop;
}
if (updateFragmentRangeForBoxChild(childBox)) {
childBox.setNeedsLayout(MarkOnlyThis);
childBox.layoutIfNeeded();
}
}
setLogicalHeightForFloat(floatingObject, logicalHeightForChildForFragmentation(childBox) + (logicalTopForChild(childBox) - logicalTop) + marginAfterForChild(childBox));
m_floatingObjects->addPlacedObject(&floatingObject);
if (ShapeOutsideInfo* shapeOutside = childBox.shapeOutsideInfo())
shapeOutside->setReferenceBoxLogicalSize(logicalSizeForChild(childBox));
// If the child moved, we have to repaint it.
if (childBox.checkForRepaintDuringLayout())
childBox.repaintDuringLayoutIfMoved(oldRect);
}
return true;
}
void RenderBlockFlow::clearFloats(Clear clear)
{
positionNewFloats();
// set y position
LayoutUnit newY;
switch (clear) {
case Clear::Left:
newY = lowestFloatLogicalBottom(FloatingObject::FloatLeft);
break;
case Clear::Right:
newY = lowestFloatLogicalBottom(FloatingObject::FloatRight);
break;
case Clear::Both:
newY = lowestFloatLogicalBottom();
break;
case Clear::None:
break;
}
if (height() < newY)
setLogicalHeight(newY);
}
LayoutUnit RenderBlockFlow::logicalLeftFloatOffsetForLine(LayoutUnit logicalTop, LayoutUnit fixedOffset, LayoutUnit logicalHeight) const
{
if (m_floatingObjects && m_floatingObjects->hasLeftObjects())
return m_floatingObjects->logicalLeftOffset(fixedOffset, logicalTop, logicalHeight);
return fixedOffset;
}
LayoutUnit RenderBlockFlow::logicalRightFloatOffsetForLine(LayoutUnit logicalTop, LayoutUnit fixedOffset, LayoutUnit logicalHeight) const
{
if (m_floatingObjects && m_floatingObjects->hasRightObjects())
return m_floatingObjects->logicalRightOffset(fixedOffset, logicalTop, logicalHeight);
return fixedOffset;
}
LayoutUnit RenderBlockFlow::nextFloatLogicalBottomBelow(LayoutUnit logicalHeight) const
{
if (!m_floatingObjects)
return logicalHeight;
return m_floatingObjects->findNextFloatLogicalBottomBelow(logicalHeight);
}
LayoutUnit RenderBlockFlow::nextFloatLogicalBottomBelowForBlock(LayoutUnit logicalHeight) const
{
if (!m_floatingObjects)
return logicalHeight;
return m_floatingObjects->findNextFloatLogicalBottomBelowForBlock(logicalHeight);
}
LayoutUnit RenderBlockFlow::lowestFloatLogicalBottom(FloatingObject::Type floatType) const
{
if (!m_floatingObjects)
return 0;
LayoutUnit lowestFloatBottom;
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
auto end = floatingObjectSet.end();
for (auto it = floatingObjectSet.begin(); it != end; ++it) {
const auto& floatingObject = *it->get();
if (floatingObject.isPlaced() && floatingObject.type() & floatType)
lowestFloatBottom = std::max(lowestFloatBottom, logicalBottomForFloat(floatingObject));
}
return lowestFloatBottom;
}
LayoutUnit RenderBlockFlow::lowestInitialLetterLogicalBottom() const
{
if (!m_floatingObjects)
return 0;
LayoutUnit lowestFloatBottom;
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
auto end = floatingObjectSet.end();
for (auto it = floatingObjectSet.begin(); it != end; ++it) {
const auto& floatingObject = *it->get();
if (floatingObject.isPlaced() && floatingObject.renderer().style().styleType() == PseudoId::FirstLetter && floatingObject.renderer().style().initialLetterDrop() > 0)
lowestFloatBottom = std::max(lowestFloatBottom, logicalBottomForFloat(floatingObject));
}
return lowestFloatBottom;
}
LayoutUnit RenderBlockFlow::addOverhangingFloats(RenderBlockFlow& child, bool makeChildPaintOtherFloats)
{
// Prevent floats from being added to the canvas by the root element, e.g., <html>.
if (!child.containsFloats() || child.createsNewFormattingContext())
return 0;
LayoutUnit childLogicalTop = child.logicalTop();
LayoutUnit childLogicalLeft = child.logicalLeft();
LayoutUnit lowestFloatLogicalBottom;
// Floats that will remain the child's responsibility to paint should factor into its
// overflow.
auto childEnd = child.m_floatingObjects->set().end();
for (auto childIt = child.m_floatingObjects->set().begin(); childIt != childEnd; ++childIt) {
auto& floatingObject = *childIt->get();
LayoutUnit floatLogicalBottom = std::min(logicalBottomForFloat(floatingObject), LayoutUnit::max() - childLogicalTop);
LayoutUnit logicalBottom = childLogicalTop + floatLogicalBottom;
lowestFloatLogicalBottom = std::max(lowestFloatLogicalBottom, logicalBottom);
if (logicalBottom > logicalHeight()) {
// If the object is not in the list, we add it now.
if (!containsFloat(floatingObject.renderer())) {
LayoutSize offset = isHorizontalWritingMode() ? LayoutSize(-childLogicalLeft, -childLogicalTop) : LayoutSize(-childLogicalTop, -childLogicalLeft);
bool shouldPaint = false;
// The nearest enclosing layer always paints the float (so that zindex and stacking
// behaves properly). We always want to propagate the desire to paint the float as
// far out as we can, to the outermost block that overlaps the float, stopping only
// if we hit a self-painting layer boundary.
if (floatingObject.renderer().enclosingFloatPaintingLayer() == enclosingFloatPaintingLayer()) {
floatingObject.setShouldPaint(false);
shouldPaint = true;
}
// We create the floating object list lazily.
if (!m_floatingObjects)
createFloatingObjects();
m_floatingObjects->add(floatingObject.copyToNewContainer(offset, shouldPaint, true));
}
} else {
const auto& renderer = floatingObject.renderer();
if (makeChildPaintOtherFloats && !floatingObject.shouldPaint() && !renderer.hasSelfPaintingLayer()
&& renderer.isDescendantOf(&child) && renderer.enclosingFloatPaintingLayer() == child.enclosingFloatPaintingLayer()) {
// The float is not overhanging from this block, so if it is a descendant of the child, the child should
// paint it (the other case is that it is intruding into the child), unless it has its own layer or enclosing
// layer.
// If makeChildPaintOtherFloats is false, it means that the child must already know about all the floats
// it should paint.
floatingObject.setShouldPaint(true);
}
// Since the float doesn't overhang, it didn't get put into our list. We need to add its overflow in to the child now.
if (floatingObject.isDescendant())
child.addOverflowFromChild(&renderer, floatingObject.locationOffsetOfBorderBox());
}
}
return lowestFloatLogicalBottom;
}
bool RenderBlockFlow::hasOverhangingFloat(RenderBox& renderer)
{
if (!m_floatingObjects || !parent())
return false;
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
const auto it = floatingObjectSet.find<FloatingObjectHashTranslator>(renderer);
if (it == floatingObjectSet.end())
return false;
return logicalBottomForFloat(*it->get()) > logicalHeight();
}
void RenderBlockFlow::addIntrudingFloats(RenderBlockFlow* prev, RenderBlockFlow* container, LayoutUnit logicalLeftOffset, LayoutUnit logicalTopOffset)
{
ASSERT(!avoidsFloats());
// If we create our own block formatting context then our contents don't interact with floats outside it, even those from our parent.
if (createsNewFormattingContext())
return;
// If the parent or previous sibling doesn't have any floats to add, don't bother.
if (!prev->m_floatingObjects)
return;
logicalLeftOffset += marginLogicalLeft();
const FloatingObjectSet& prevSet = prev->m_floatingObjects->set();
auto prevEnd = prevSet.end();
for (auto prevIt = prevSet.begin(); prevIt != prevEnd; ++prevIt) {
auto& floatingObject = *prevIt->get();
if (logicalBottomForFloat(floatingObject) > logicalTopOffset) {
if (!m_floatingObjects || !m_floatingObjects->set().contains(&floatingObject)) {
// We create the floating object list lazily.
if (!m_floatingObjects)
createFloatingObjects();
// Applying the child's margin makes no sense in the case where the child was passed in.
// since this margin was added already through the modification of the |logicalLeftOffset| variable
// above. |logicalLeftOffset| will equal the margin in this case, so it's already been taken
// into account. Only apply this code if prev is the parent, since otherwise the left margin
// will get applied twice.
LayoutSize offset = isHorizontalWritingMode()
? LayoutSize(logicalLeftOffset - (prev != container ? prev->marginLeft() : 0_lu), logicalTopOffset)
: LayoutSize(logicalTopOffset, logicalLeftOffset - (prev != container ? prev->marginTop() : 0_lu));
m_floatingObjects->add(floatingObject.copyToNewContainer(offset));
}
}
}
}
void RenderBlockFlow::markAllDescendantsWithFloatsForLayout(RenderBox* floatToRemove, bool inLayout)
{
if (!everHadLayout() && !containsFloats())
return;
MarkingBehavior markParents = inLayout ? MarkOnlyThis : MarkContainingBlockChain;
setChildNeedsLayout(markParents);
if (floatToRemove)
removeFloatingObject(*floatToRemove);
else if (childrenInline())
return;
// Iterate over our block children and mark them as needed.
for (auto& block : childrenOfType<RenderBlock>(*this)) {
if (!floatToRemove && block.isFloatingOrOutOfFlowPositioned())
continue;
if (!is<RenderBlockFlow>(block)) {
if (block.shrinkToAvoidFloats() && block.everHadLayout())
block.setChildNeedsLayout(markParents);
continue;
}
auto& blockFlow = downcast<RenderBlockFlow>(block);
if ((floatToRemove ? blockFlow.containsFloat(*floatToRemove) : blockFlow.containsFloats()) || blockFlow.shrinkToAvoidFloats())
blockFlow.markAllDescendantsWithFloatsForLayout(floatToRemove, inLayout);
}
}
void RenderBlockFlow::markSiblingsWithFloatsForLayout(RenderBox* floatToRemove)
{
if (!m_floatingObjects)
return;
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
auto end = floatingObjectSet.end();
for (RenderObject* next = nextSibling(); next; next = next->nextSibling()) {
if (!is<RenderBlockFlow>(*next) || next->isFloatingOrOutOfFlowPositioned())
continue;
RenderBlockFlow& nextBlock = downcast<RenderBlockFlow>(*next);
for (auto it = floatingObjectSet.begin(); it != end; ++it) {
RenderBox& floatingBox = (*it)->renderer();
if (floatToRemove && &floatingBox != floatToRemove)
continue;
if (nextBlock.containsFloat(floatingBox))
nextBlock.markAllDescendantsWithFloatsForLayout(&floatingBox);
}
}
}
LayoutPoint RenderBlockFlow::flipFloatForWritingModeForChild(const FloatingObject& child, const LayoutPoint& point) const
{
if (!style().isFlippedBlocksWritingMode())
return point;
// This is similar to RenderBox::flipForWritingModeForChild. We have to subtract out our left/top offsets twice, since
// it's going to get added back in. We hide this complication here so that the calling code looks normal for the unflipped
// case.
if (isHorizontalWritingMode())
return LayoutPoint(point.x(), point.y() + height() - child.renderer().height() - 2 * child.locationOffsetOfBorderBox().height());
return LayoutPoint(point.x() + width() - child.renderer().width() - 2 * child.locationOffsetOfBorderBox().width(), point.y());
}
LayoutUnit RenderBlockFlow::getClearDelta(RenderBox& child, LayoutUnit logicalTop)
{
// There is no need to compute clearance if we have no floats.
if (!containsFloats())
return 0;
// At least one float is present. We need to perform the clearance computation.
bool clearSet = child.style().clear() != Clear::None;
LayoutUnit logicalBottom;
switch (child.style().clear()) {
case Clear::None:
break;
case Clear::Left:
logicalBottom = lowestFloatLogicalBottom(FloatingObject::FloatLeft);
break;
case Clear::Right:
logicalBottom = lowestFloatLogicalBottom(FloatingObject::FloatRight);
break;
case Clear::Both:
logicalBottom = lowestFloatLogicalBottom();
break;
}
// We also clear floats if we are too big to sit on the same line as a float (and wish to avoid floats by default).
LayoutUnit result = clearSet ? std::max<LayoutUnit>(0, logicalBottom - logicalTop) : 0_lu;
if (!result && child.avoidsFloats()) {
LayoutUnit newLogicalTop = logicalTop;
while (true) {
LayoutUnit availableLogicalWidthAtNewLogicalTopOffset = availableLogicalWidthForLine(newLogicalTop, DoNotIndentText, logicalHeightForChild(child));
if (availableLogicalWidthAtNewLogicalTopOffset == availableLogicalWidthForContent(newLogicalTop))
return newLogicalTop - logicalTop;
RenderFragmentContainer* fragment = fragmentAtBlockOffset(logicalTopForChild(child));
LayoutRect borderBox = child.borderBoxRectInFragment(fragment, DoNotCacheRenderBoxFragmentInfo);
LayoutUnit childLogicalWidthAtOldLogicalTopOffset = isHorizontalWritingMode() ? borderBox.width() : borderBox.height();
// FIXME: None of this is right for perpendicular writing-mode children.
LayoutUnit childOldLogicalWidth = child.logicalWidth();
LayoutUnit childOldMarginLeft = child.marginLeft();
LayoutUnit childOldMarginRight = child.marginRight();
LayoutUnit childOldLogicalTop = child.logicalTop();
child.setLogicalTop(newLogicalTop);
child.updateLogicalWidth();
fragment = fragmentAtBlockOffset(logicalTopForChild(child));
borderBox = child.borderBoxRectInFragment(fragment, DoNotCacheRenderBoxFragmentInfo);
LayoutUnit childLogicalWidthAtNewLogicalTopOffset = isHorizontalWritingMode() ? borderBox.width() : borderBox.height();
child.setLogicalTop(childOldLogicalTop);
child.setLogicalWidth(childOldLogicalWidth);
child.setMarginLeft(childOldMarginLeft);
child.setMarginRight(childOldMarginRight);
if (childLogicalWidthAtNewLogicalTopOffset <= availableLogicalWidthAtNewLogicalTopOffset) {
// Even though we may not be moving, if the logical width did shrink because of the presence of new floats, then
// we need to force a relayout as though we shifted. This happens because of the dynamic addition of overhanging floats
// from previous siblings when negative margins exist on a child (see the addOverhangingFloats call at the end of collapseMargins).
if (childLogicalWidthAtOldLogicalTopOffset != childLogicalWidthAtNewLogicalTopOffset)
child.setChildNeedsLayout(MarkOnlyThis);
return newLogicalTop - logicalTop;
}
newLogicalTop = nextFloatLogicalBottomBelowForBlock(newLogicalTop);
ASSERT(newLogicalTop >= logicalTop);
if (newLogicalTop < logicalTop)
break;
}
ASSERT_NOT_REACHED();
}
return result;
}
bool RenderBlockFlow::hitTestFloats(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset)
{
if (!m_floatingObjects)
return false;
LayoutPoint adjustedLocation = accumulatedOffset;
if (is<RenderView>(*this))
adjustedLocation += toLayoutSize(downcast<RenderView>(*this).frameView().scrollPosition());
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
auto begin = floatingObjectSet.begin();
for (auto it = floatingObjectSet.end(); it != begin;) {
--it;
const auto& floatingObject = *it->get();
auto& renderer = floatingObject.renderer();
if (floatingObject.shouldPaint() && !renderer.hasSelfPaintingLayer()) {
LayoutPoint childPoint = flipFloatForWritingModeForChild(floatingObject, adjustedLocation + floatingObject.translationOffsetToAncestor());
if (renderer.hitTest(request, result, locationInContainer, childPoint)) {
updateHitTestResult(result, locationInContainer.point() - toLayoutSize(childPoint));
return true;
}
}
}
return false;
}
bool RenderBlockFlow::hitTestInlineChildren(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction hitTestAction)
{
ASSERT(childrenInline());
if (auto simpleLineLayout = this->simpleLineLayout())
return SimpleLineLayout::hitTestFlow(*this, *simpleLineLayout, request, result, locationInContainer, accumulatedOffset, hitTestAction);
return complexLineLayout() && complexLineLayout()->lineBoxes().hitTest(this, request, result, locationInContainer, accumulatedOffset, hitTestAction);
}
void RenderBlockFlow::addOverflowFromInlineChildren()
{
if (auto simpleLineLayout = this->simpleLineLayout()) {
ASSERT(!hasOverflowClip());
SimpleLineLayout::collectFlowOverflow(*this, *simpleLineLayout);
return;
}
if (complexLineLayout())
complexLineLayout()->addOverflowFromInlineChildren();
}
void RenderBlockFlow::adjustForBorderFit(LayoutUnit x, LayoutUnit& left, LayoutUnit& right) const
{
if (style().visibility() != Visibility::Visible)
return;
// We don't deal with relative positioning. Our assumption is that you shrink to fit the lines without accounting
// for either overflow or translations via relative positioning.
if (childrenInline()) {
const_cast<RenderBlockFlow&>(*this).ensureLineBoxes();
for (auto* box = firstRootBox(); box; box = box->nextRootBox()) {
if (box->firstChild())
left = std::min(left, x + LayoutUnit(box->firstChild()->x()));
if (box->lastChild())
right = std::max(right, x + LayoutUnit(ceilf(box->lastChild()->logicalRight())));
}
} else {
for (RenderBox* obj = firstChildBox(); obj; obj = obj->nextSiblingBox()) {
if (!obj->isFloatingOrOutOfFlowPositioned()) {
if (is<RenderBlockFlow>(*obj) && !obj->hasOverflowClip())
downcast<RenderBlockFlow>(*obj).adjustForBorderFit(x + obj->x(), left, right);
else if (obj->style().visibility() == Visibility::Visible) {
// We are a replaced element or some kind of non-block-flow object.
left = std::min(left, x + obj->x());
right = std::max(right, x + obj->x() + obj->width());
}
}
}
}
if (m_floatingObjects) {
const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set();
auto end = floatingObjectSet.end();
for (auto it = floatingObjectSet.begin(); it != end; ++it) {
const auto& floatingObject = *it->get();
// Only examine the object if our m_shouldPaint flag is set.
if (floatingObject.shouldPaint()) {
LayoutUnit floatLeft = floatingObject.translationOffsetToAncestor().width();
LayoutUnit floatRight = floatLeft + floatingObject.renderer().width();
left = std::min(left, floatLeft);
right = std::max(right, floatRight);
}
}
}
}
void RenderBlockFlow::fitBorderToLinesIfNeeded()
{
if (style().borderFit() == BorderFit::Border || hasOverrideContentLogicalWidth())
return;
// Walk any normal flow lines to snugly fit.
LayoutUnit left = LayoutUnit::max();
LayoutUnit right = LayoutUnit::min();
LayoutUnit oldWidth = contentWidth();
adjustForBorderFit(0, left, right);
// Clamp to our existing edges. We can never grow. We only shrink.
LayoutUnit leftEdge = borderLeft() + paddingLeft();
LayoutUnit rightEdge = leftEdge + oldWidth;
left = std::min(rightEdge, std::max(leftEdge, left));
right = std::max(leftEdge, std::min(rightEdge, right));
LayoutUnit newContentWidth = right - left;
if (newContentWidth == oldWidth)
return;
setOverrideContentLogicalWidth(newContentWidth);
layoutBlock(false);
clearOverrideContentLogicalWidth();
}
void RenderBlockFlow::markLinesDirtyInBlockRange(LayoutUnit logicalTop, LayoutUnit logicalBottom, RootInlineBox* highest)
{
if (logicalTop >= logicalBottom)
return;
// Floats currently affect the choice whether to use simple line layout path.
if (simpleLineLayout()) {
invalidateLineLayoutPath();
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() < 0)) {
afterLowest->markDirty();
afterLowest = afterLowest->prevRootBox();
}
}
Optional<int> RenderBlockFlow::firstLineBaseline() const
{
if (isWritingModeRoot() && !isRubyRun() && !isGridItem())
return WTF::nullopt;
if (!childrenInline())
return RenderBlock::firstLineBaseline();
if (!hasLines())
return WTF::nullopt;
if (auto simpleLineLayout = this->simpleLineLayout())
return Optional<int>(SimpleLineLayout::computeFlowFirstLineBaseline(*this, *simpleLineLayout));
ASSERT(firstRootBox());
if (style().isFlippedLinesWritingMode())
return firstRootBox()->logicalTop() + firstLineStyle().fontMetrics().descent(firstRootBox()->baselineType());
return firstRootBox()->logicalTop() + firstLineStyle().fontMetrics().ascent(firstRootBox()->baselineType());
}
Optional<int> RenderBlockFlow::inlineBlockBaseline(LineDirectionMode lineDirection) const
{
if (isWritingModeRoot() && !isRubyRun())
return WTF::nullopt;
// Note that here we only take the left and bottom into consideration. Our caller takes the right and top into consideration.
float boxHeight = lineDirection == HorizontalLine ? height() + m_marginBox.bottom() : width() + m_marginBox.left();
float lastBaseline;
if (!childrenInline()) {
Optional<int> inlineBlockBaseline = RenderBlock::inlineBlockBaseline(lineDirection);
if (!inlineBlockBaseline)
return inlineBlockBaseline;
lastBaseline = inlineBlockBaseline.value();
} else {
if (!hasLines()) {
if (!hasLineIfEmpty())
return WTF::nullopt;
const auto& fontMetrics = firstLineStyle().fontMetrics();
return Optional<int>(fontMetrics.ascent()
+ (lineHeight(true, lineDirection, PositionOfInteriorLineBoxes) - fontMetrics.height()) / 2
+ (lineDirection == HorizontalLine ? borderTop() + paddingTop() : borderRight() + paddingRight()));
}
if (auto simpleLineLayout = this->simpleLineLayout())
lastBaseline = SimpleLineLayout::computeFlowLastLineBaseline(*this, *simpleLineLayout);
else {
bool isFirstLine = lastRootBox() == firstRootBox();
const auto& style = isFirstLine ? firstLineStyle() : this->style();
// InlineFlowBox::placeBoxesInBlockDirection will flip lines in case of verticalLR mode, so we can assume verticalRL for now.
lastBaseline = style.fontMetrics().ascent(lastRootBox()->baselineType())
+ (style.isFlippedLinesWritingMode() ? logicalHeight() - lastRootBox()->logicalBottom() : lastRootBox()->logicalTop());
}
}
// According to the CSS spec http://www.w3.org/TR/CSS21/visudet.html, we shouldn't be performing this min, but should
// instead be returning boxHeight directly. However, we feel that a min here is better behavior (and is consistent
// enough with the spec to not cause tons of breakages).
return style().overflowY() == Overflow::Visible ? lastBaseline : std::min(boxHeight, lastBaseline);
}
void RenderBlockFlow::setSelectionState(SelectionState state)
{
if (state != SelectionNone)
ensureLineBoxes();
RenderBoxModelObject::setSelectionState(state);
}
GapRects RenderBlockFlow::inlineSelectionGaps(RenderBlock& rootBlock, const LayoutPoint& rootBlockPhysicalPosition, const LayoutSize& offsetFromRootBlock,
LayoutUnit& lastLogicalTop, LayoutUnit& lastLogicalLeft, LayoutUnit& lastLogicalRight, const LogicalSelectionOffsetCaches& cache, const PaintInfo* paintInfo)
{
ASSERT(!simpleLineLayout());
GapRects result;
bool containsStart = selectionState() == SelectionStart || selectionState() == SelectionBoth;
if (!hasLines()) {
if (containsStart) {
// Update our lastLogicalTop to be the bottom of the block. <hr>s or empty blocks with height can trip this case.
lastLogicalTop = blockDirectionOffset(rootBlock, offsetFromRootBlock) + logicalHeight();
lastLogicalLeft = logicalLeftSelectionOffset(rootBlock, logicalHeight(), cache);
lastLogicalRight = logicalRightSelectionOffset(rootBlock, logicalHeight(), cache);
}
return result;
}
RootInlineBox* lastSelectedLine = 0;
RootInlineBox* curr;
for (curr = firstRootBox(); curr && !curr->hasSelectedChildren(); curr = curr->nextRootBox()) { }
// Now paint the gaps for the lines.
for (; curr && curr->hasSelectedChildren(); curr = curr->nextRootBox()) {
LayoutUnit selTop = curr->selectionTopAdjustedForPrecedingBlock();
LayoutUnit selHeight = curr->selectionHeightAdjustedForPrecedingBlock();
if (!containsStart && !lastSelectedLine &&
selectionState() != SelectionStart && selectionState() != SelectionBoth && !isRubyBase())
result.uniteCenter(blockSelectionGap(rootBlock, rootBlockPhysicalPosition, offsetFromRootBlock, lastLogicalTop, lastLogicalLeft, lastLogicalRight, selTop, cache, paintInfo));
LayoutRect logicalRect { LayoutUnit(curr->logicalLeft()), selTop, LayoutUnit(curr->logicalWidth()), selTop + selHeight };
logicalRect.move(isHorizontalWritingMode() ? offsetFromRootBlock : offsetFromRootBlock.transposedSize());
LayoutRect physicalRect = rootBlock.logicalRectToPhysicalRect(rootBlockPhysicalPosition, logicalRect);
if (!paintInfo || (isHorizontalWritingMode() && physicalRect.y() < paintInfo->rect.maxY() && physicalRect.maxY() > paintInfo->rect.y())
|| (!isHorizontalWritingMode() && physicalRect.x() < paintInfo->rect.maxX() && physicalRect.maxX() > paintInfo->rect.x()))
result.unite(curr->lineSelectionGap(rootBlock, rootBlockPhysicalPosition, offsetFromRootBlock, selTop, selHeight, cache, paintInfo));
lastSelectedLine = curr;
}
if (containsStart && !lastSelectedLine)
// VisibleSelection must start just after our last line.
lastSelectedLine = lastRootBox();
if (lastSelectedLine && selectionState() != SelectionEnd && selectionState() != SelectionBoth) {
// Update our lastY to be the bottom of the last selected line.
lastLogicalTop = blockDirectionOffset(rootBlock, offsetFromRootBlock) + lastSelectedLine->selectionBottom();
lastLogicalLeft = logicalLeftSelectionOffset(rootBlock, lastSelectedLine->selectionBottom(), cache);
lastLogicalRight = logicalRightSelectionOffset(rootBlock, lastSelectedLine->selectionBottom(), cache);
}
return result;
}
bool RenderBlockFlow::needsLayoutAfterFragmentRangeChange() const
{
// A block without floats or that expands to enclose them won't need a relayout
// after a fragment range change. There is no overflow content needing relayout
// in the fragment chain because the fragment range can only shrink after the estimation.
if (!containsFloats() || createsNewFormattingContext())
return false;
return true;
}
void RenderBlockFlow::setMultiColumnFlow(RenderMultiColumnFlow& fragmentedFlow)
{
ASSERT(!hasRareBlockFlowData() || !rareBlockFlowData()->m_multiColumnFlow);
ensureRareBlockFlowData().m_multiColumnFlow = makeWeakPtr(fragmentedFlow);
}
void RenderBlockFlow::clearMultiColumnFlow()
{
ASSERT(hasRareBlockFlowData());
ASSERT(rareBlockFlowData()->m_multiColumnFlow);
rareBlockFlowData()->m_multiColumnFlow.clear();
}
static bool shouldCheckLines(const RenderBlockFlow& blockFlow)
{
return !blockFlow.isFloatingOrOutOfFlowPositioned() && blockFlow.style().height().isAuto();
}
RootInlineBox* RenderBlockFlow::lineAtIndex(int i) const
{
ASSERT(i >= 0);
if (style().visibility() != Visibility::Visible)
return nullptr;
if (childrenInline()) {
for (auto* box = firstRootBox(); box; box = box->nextRootBox()) {
if (!i--)
return box;
}
return nullptr;
}
for (auto& blockFlow : childrenOfType<RenderBlockFlow>(*this)) {
if (!shouldCheckLines(blockFlow))
continue;
if (RootInlineBox* box = blockFlow.lineAtIndex(i))
return box;
}
return nullptr;
}
int RenderBlockFlow::lineCount() const
{
// FIXME: This should be tested by clients.
if (style().visibility() != Visibility::Visible)
return 0;
if (childrenInline()) {
#if ENABLE(LAYOUT_FORMATTING_CONTEXT)
if (layoutFormattingContextLineLayout())
return layoutFormattingContextLineLayout()->lineCount();
#endif
if (simpleLineLayout())
return simpleLineLayout()->lineCount();
if (complexLineLayout())
return complexLineLayout()->lineCount();
return 0;
}
int count = 0;
for (auto& blockFlow : childrenOfType<RenderBlockFlow>(*this)) {
if (!shouldCheckLines(blockFlow))
continue;
count += blockFlow.lineCount();
}
return count;
}
static int getHeightForLineCount(const RenderBlockFlow& block, int lineCount, bool includeBottom, int& count)
{
if (block.style().visibility() != Visibility::Visible)
return -1;
if (block.childrenInline()) {
for (auto* box = block.firstRootBox(); box; box = box->nextRootBox()) {
if (++count == lineCount)
return box->lineBottom() + (includeBottom ? (block.borderBottom() + block.paddingBottom()) : 0_lu);
}
} else {
RenderBox* normalFlowChildWithoutLines = nullptr;
for (auto* obj = block.firstChildBox(); obj; obj = obj->nextSiblingBox()) {
if (is<RenderBlockFlow>(*obj) && shouldCheckLines(downcast<RenderBlockFlow>(*obj))) {
int result = getHeightForLineCount(downcast<RenderBlockFlow>(*obj), lineCount, false, count);
if (result != -1)
return result + obj->y() + (includeBottom ? (block.borderBottom() + block.paddingBottom()) : 0_lu);
} else if (!obj->isFloatingOrOutOfFlowPositioned())
normalFlowChildWithoutLines = obj;
}
if (normalFlowChildWithoutLines && !lineCount)
return normalFlowChildWithoutLines->y() + normalFlowChildWithoutLines->height();
}
return -1;
}
int RenderBlockFlow::heightForLineCount(int lineCount)
{
int count = 0;
return getHeightForLineCount(*this, lineCount, true, count);
}
void RenderBlockFlow::clearTruncation()
{
if (style().visibility() != Visibility::Visible)
return;
if (childrenInline() && hasMarkupTruncation()) {
ensureLineBoxes();
setHasMarkupTruncation(false);
for (auto* box = firstRootBox(); box; box = box->nextRootBox())
box->clearTruncation();
return;
}
for (auto& blockFlow : childrenOfType<RenderBlockFlow>(*this)) {
if (shouldCheckLines(blockFlow))
blockFlow.clearTruncation();
}
}
bool RenderBlockFlow::containsNonZeroBidiLevel() const
{
for (auto* root = firstRootBox(); root; root = root->nextRootBox()) {
for (auto* box = root->firstLeafDescendant(); box; box = box->nextLeafOnLine()) {
if (box->bidiLevel())
return true;
}
}
return false;
}
Position RenderBlockFlow::positionForBox(InlineBox *box, bool start) const
{
if (!box)
return Position();
if (!box->renderer().nonPseudoNode())
return createLegacyEditingPosition(nonPseudoElement(), start ? caretMinOffset() : caretMaxOffset());
if (!is<InlineTextBox>(*box))
return createLegacyEditingPosition(box->renderer().nonPseudoNode(), start ? box->renderer().caretMinOffset() : box->renderer().caretMaxOffset());
auto& textBox = downcast<InlineTextBox>(*box);
return createLegacyEditingPosition(textBox.renderer().nonPseudoNode(), start ? textBox.start() : textBox.start() + textBox.len());
}
RenderText* RenderBlockFlow::findClosestTextAtAbsolutePoint(const FloatPoint& point)
{
// A light, non-recursive version of RenderBlock::positionForCoordinates that looks at
// whether a point lies within the gaps between its root line boxes, to be called against
// a node returned from elementAtPoint. We make the assumption that either the node or one
// of its immediate children contains the root line boxes in question.
// See <rdar://problem/6824650> for context.
RenderBlock* block = this;
FloatPoint localPoint = block->absoluteToLocal(point);
if (!block->childrenInline()) {
// Look among our immediate children for an alternate box that contains the point.
for (RenderBox* child = block->firstChildBox(); child; child = child->nextSiblingBox()) {
if (!child->height() || child->style().visibility() != WebCore::Visibility::Visible || child->isFloatingOrOutOfFlowPositioned())
continue;
float top = child->y();
RenderBox* nextChild = child->nextSiblingBox();
while (nextChild && nextChild->isFloatingOrOutOfFlowPositioned())
nextChild = nextChild->nextSiblingBox();
if (!nextChild) {
if (localPoint.y() >= top) {
block = downcast<RenderBlock>(child);
break;
}
continue;
}
float bottom = nextChild->y();
if (localPoint.y() >= top && localPoint.y() < bottom && is<RenderBlock>(*child)) {
block = downcast<RenderBlock>(child);
break;
}
}
if (!block->childrenInline())
return nullptr;
localPoint = block->absoluteToLocal(point);
}
RenderBlockFlow& blockFlow = downcast<RenderBlockFlow>(*block);
// Only check the gaps between the root line boxes. We deliberately ignore overflow because
// experience has shown that hit tests on an exploded text node can fail when within the
// overflow fragment.
for (RootInlineBox* current = blockFlow.firstRootBox(); current && current != blockFlow.lastRootBox(); current = current->nextRootBox()) {
float currentBottom = current->y() + current->logicalHeight();
if (localPoint.y() < currentBottom)
return nullptr;
RootInlineBox* next = current->nextRootBox();
float nextTop = next->y();
if (localPoint.y() < nextTop) {
InlineBox* inlineBox = current->closestLeafChildForLogicalLeftPosition(localPoint.x());
if (inlineBox && inlineBox->behavesLikeText() && is<RenderText>(inlineBox->renderer()))
return &downcast<RenderText>(inlineBox->renderer());
}
}
return nullptr;
}
VisiblePosition RenderBlockFlow::positionForPointWithInlineChildren(const LayoutPoint& pointInLogicalContents, const RenderFragmentContainer* fragment)
{
ASSERT(childrenInline());
ensureLineBoxes();
if (!firstRootBox())
return createVisiblePosition(0, DOWNSTREAM);
bool linesAreFlipped = style().isFlippedLinesWritingMode();
bool blocksAreFlipped = style().isFlippedBlocksWritingMode();
// look for the closest line box in the root box which is at the passed-in y coordinate
InlineBox* closestBox = 0;
RootInlineBox* firstRootBoxWithChildren = 0;
RootInlineBox* lastRootBoxWithChildren = 0;
for (RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox()) {
if (fragment && root->containingFragment() != fragment)
continue;
if (!root->firstLeafDescendant())
continue;
if (!firstRootBoxWithChildren)
firstRootBoxWithChildren = root;
if (!linesAreFlipped && root->isFirstAfterPageBreak() && (pointInLogicalContents.y() < root->lineTopWithLeading()
|| (blocksAreFlipped && pointInLogicalContents.y() == root->lineTopWithLeading())))
break;
lastRootBoxWithChildren = root;
// check if this root line box is located at this y coordinate
if (pointInLogicalContents.y() < root->selectionBottom() || (blocksAreFlipped && pointInLogicalContents.y() == root->selectionBottom())) {
if (linesAreFlipped) {
RootInlineBox* nextRootBoxWithChildren = root->nextRootBox();
while (nextRootBoxWithChildren && !nextRootBoxWithChildren->firstLeafDescendant())
nextRootBoxWithChildren = nextRootBoxWithChildren->nextRootBox();
if (nextRootBoxWithChildren && nextRootBoxWithChildren->isFirstAfterPageBreak() && (pointInLogicalContents.y() > nextRootBoxWithChildren->lineTopWithLeading()
|| (!blocksAreFlipped && pointInLogicalContents.y() == nextRootBoxWithChildren->lineTopWithLeading())))
continue;
}
closestBox = root->closestLeafChildForLogicalLeftPosition(pointInLogicalContents.x());
if (closestBox)
break;
}
}
bool moveCaretToBoundary = frame().editor().behavior().shouldMoveCaretToHorizontalBoundaryWhenPastTopOrBottom();
if (!moveCaretToBoundary && !closestBox && lastRootBoxWithChildren) {
// y coordinate is below last root line box, pretend we hit it
closestBox = lastRootBoxWithChildren->closestLeafChildForLogicalLeftPosition(pointInLogicalContents.x());
}
if (closestBox) {
if (moveCaretToBoundary) {
LayoutUnit firstRootBoxWithChildrenTop = std::min(firstRootBoxWithChildren->selectionTop(), LayoutUnit(firstRootBoxWithChildren->logicalTop()));
if (pointInLogicalContents.y() < firstRootBoxWithChildrenTop
|| (blocksAreFlipped && pointInLogicalContents.y() == firstRootBoxWithChildrenTop)) {
InlineBox* box = firstRootBoxWithChildren->firstLeafDescendant();
if (box->isLineBreak()) {
if (InlineBox* newBox = box->nextLeafOnLineIgnoringLineBreak())
box = newBox;
}
// y coordinate is above first root line box, so return the start of the first
return VisiblePosition(positionForBox(box, true), DOWNSTREAM);
}
}
// pass the box a top position that is inside it
LayoutPoint point(pointInLogicalContents.x(), closestBox->root().blockDirectionPointInLine());
if (!isHorizontalWritingMode())
point = point.transposedPoint();
if (closestBox->renderer().isReplaced())
return positionForPointRespectingEditingBoundaries(*this, downcast<RenderBox>(closestBox->renderer()), point);
return closestBox->renderer().positionForPoint(point, nullptr);
}
if (lastRootBoxWithChildren) {
// We hit this case for Mac behavior when the Y coordinate is below the last box.
ASSERT(moveCaretToBoundary);
InlineBox* logicallyLastBox;
if (lastRootBoxWithChildren->getLogicalEndBoxWithNode(logicallyLastBox))
return VisiblePosition(positionForBox(logicallyLastBox, false), DOWNSTREAM);
}
// Can't reach this. We have a root line box, but it has no kids.
// FIXME: This should ASSERT_NOT_REACHED(), but clicking on placeholder text
// seems to hit this code path.
return createVisiblePosition(0, DOWNSTREAM);
}
Position RenderBlockFlow::positionForPoint(const LayoutPoint& point)
{
// FIXME: It supports single text child only (which is the majority of simple line layout supported content at this point).
if (!simpleLineLayout() || firstChild() != lastChild() || !is<RenderText>(firstChild()))
return positionForPoint(point, nullptr).deepEquivalent();
return downcast<RenderText>(*firstChild()).positionForPoint(point);
}
VisiblePosition RenderBlockFlow::positionForPoint(const LayoutPoint& point, const RenderFragmentContainer*)
{
return RenderBlock::positionForPoint(point, nullptr);
}
void RenderBlockFlow::addFocusRingRectsForInlineChildren(Vector<LayoutRect>& rects, const LayoutPoint& additionalOffset, const RenderLayerModelObject*)
{
ASSERT(childrenInline());
for (RootInlineBox* curr = firstRootBox(); curr; curr = curr->nextRootBox()) {
LayoutUnit top = std::max(curr->lineTop(), LayoutUnit(curr->top()));
LayoutUnit bottom = std::min(curr->lineBottom(), LayoutUnit(curr->top() + curr->height()));
LayoutRect rect { LayoutUnit(additionalOffset.x() + curr->x()), additionalOffset.y() + top, LayoutUnit(curr->width()), bottom - top };
if (!rect.isEmpty())
rects.append(rect);
}
}
void RenderBlockFlow::paintInlineChildren(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
ASSERT(childrenInline());
#if ENABLE(LAYOUT_FORMATTING_CONTEXT)
if (layoutFormattingContextLineLayout()) {
layoutFormattingContextLineLayout()->paint(paintInfo, paintOffset);
return;
}
#endif
if (auto simpleLineLayout = this->simpleLineLayout()) {
SimpleLineLayout::paintFlow(*this, *simpleLineLayout, paintInfo, paintOffset);
return;
}
if (complexLineLayout())
complexLineLayout()->lineBoxes().paint(this, paintInfo, paintOffset);
}
bool RenderBlockFlow::relayoutForPagination()
{
if (!multiColumnFlow() || !multiColumnFlow()->shouldRelayoutForPagination())
return false;
multiColumnFlow()->setNeedsHeightsRecalculation(false);
multiColumnFlow()->setInBalancingPass(true); // Prevent re-entering this method (and recursion into layout).
bool needsRelayout;
bool neededRelayout = false;
bool firstPass = true;
do {
// Column heights may change here because of balancing. We may have to do multiple layout
// passes, depending on how the contents is fitted to the changed column heights. In most
// cases, laying out again twice or even just once will suffice. Sometimes we need more
// passes than that, though, but the number of retries should not exceed the number of
// columns, unless we have a bug.
needsRelayout = false;
for (RenderMultiColumnSet* multicolSet = multiColumnFlow()->firstMultiColumnSet(); multicolSet; multicolSet = multicolSet->nextSiblingMultiColumnSet()) {
if (multicolSet->recalculateColumnHeight(firstPass))
needsRelayout = true;
if (needsRelayout) {
// Once a column set gets a new column height, that column set and all successive column
// sets need to be laid out over again, since their logical top will be affected by
// this, and therefore their column heights may change as well, at least if the multicol
// height is constrained.
multicolSet->setChildNeedsLayout(MarkOnlyThis);
}
}
if (needsRelayout) {
// Layout again. Column balancing resulted in a new height.
neededRelayout = true;
multiColumnFlow()->setChildNeedsLayout(MarkOnlyThis);
setChildNeedsLayout(MarkOnlyThis);
layoutBlock(false);
}
firstPass = false;
} while (needsRelayout);
multiColumnFlow()->setInBalancingPass(false);
return neededRelayout;
}
bool RenderBlockFlow::hasLines() const
{
if (!childrenInline())
return false;
#if ENABLE(LAYOUT_FORMATTING_CONTEXT)
if (layoutFormattingContextLineLayout())
return layoutFormattingContextLineLayout()->lineCount();
#endif
if (simpleLineLayout())
return simpleLineLayout()->lineCount();
return complexLineLayout() && complexLineLayout()->lineBoxes().firstLineBox();
}
void RenderBlockFlow::invalidateLineLayoutPath()
{
switch (lineLayoutPath()) {
case UndeterminedPath:
case ForceLineBoxesPath:
ASSERT(!simpleLineLayout());
return;
case LineBoxesPath:
ASSERT(!simpleLineLayout());
setLineLayoutPath(UndeterminedPath);
return;
case LayoutFormattingContextPath: // FIXME: Not all clients of invalidateLineLayoutPath() actually need to wipe the layout.
case SimpleLinesPath:
// The simple line layout may have become invalid.
m_lineLayout = WTF::Monostate();
setLineLayoutPath(UndeterminedPath);
if (needsLayout())
return;
// FIXME: We should just kick off a subtree layout here (if needed at all) see webkit.org/b/172947.
setNeedsLayout();
return;
}
ASSERT_NOT_REACHED();
}
void RenderBlockFlow::layoutSimpleLines(bool relayoutChildren, LayoutUnit& repaintLogicalTop, LayoutUnit& repaintLogicalBottom)
{
bool needsLayout = selfNeedsLayout() || relayoutChildren || !simpleLineLayout();
if (needsLayout)
m_lineLayout = SimpleLineLayout::create(*this);
auto& simpleLineLayout = *this->simpleLineLayout();
if (view().frameView().layoutContext().layoutState() && view().frameView().layoutContext().layoutState()->isPaginated()) {
simpleLineLayout.setIsPaginated();
SimpleLineLayout::adjustLinePositionsForPagination(simpleLineLayout, *this);
}
for (auto& renderer : childrenOfType<RenderObject>(*this))
renderer.clearNeedsLayout();
LayoutUnit lineLayoutHeight = SimpleLineLayout::computeFlowHeight(*this, simpleLineLayout);
LayoutUnit lineLayoutTop = borderAndPaddingBefore();
repaintLogicalTop = lineLayoutTop;
repaintLogicalBottom = needsLayout ? repaintLogicalTop + lineLayoutHeight + borderAndPaddingAfter() : repaintLogicalTop;
setLogicalHeight(lineLayoutTop + lineLayoutHeight + borderAndPaddingAfter());
}
#if ENABLE(LAYOUT_FORMATTING_CONTEXT)
void RenderBlockFlow::layoutLFCLines(bool, LayoutUnit& repaintLogicalTop, LayoutUnit& repaintLogicalBottom)
{
if (!layoutFormattingContextLineLayout())
m_lineLayout = makeUnique<LayoutIntegration::LineLayout>(*this);
auto& layoutFormattingContextLineLayout = *this->layoutFormattingContextLineLayout();
for (auto& renderer : childrenOfType<RenderObject>(*this))
renderer.clearNeedsLayout();
layoutFormattingContextLineLayout.layout();
auto contentHeight = layoutFormattingContextLineLayout.contentLogicalHeight();
auto contentTop = borderAndPaddingBefore();
auto contentBottom = contentTop + contentHeight;
auto totalHeight = contentBottom + borderAndPaddingAfter();
repaintLogicalTop = contentTop;
repaintLogicalBottom = contentBottom;
setLogicalHeight(totalHeight);
}
#endif
void RenderBlockFlow::ensureLineBoxes()
{
if (!childrenInline())
return;
setLineLayoutPath(ForceLineBoxesPath);
if (complexLineLayout() || !hasLineLayout())
return;
auto simpleLineLayout = makeRefPtr(this->simpleLineLayout());
m_lineLayout = makeUnique<ComplexLineLayout>(*this);
if (simpleLineLayout) {
if (SimpleLineLayout::canUseForLineBoxTree(*this, *simpleLineLayout)) {
SimpleLineLayout::generateLineBoxTree(*this, *simpleLineLayout);
return;
}
}
auto& complexLineLayout = *this->complexLineLayout();
#if !ASSERT_DISABLED
LayoutUnit oldHeight = logicalHeight();
#endif
bool didNeedLayout = needsLayout();
bool relayoutChildren = false;
LayoutUnit repaintLogicalTop;
LayoutUnit repaintLogicalBottom;
if (simpleLineLayout && simpleLineLayout->isPaginated()) {
PaginatedLayoutStateMaintainer state(*this);
complexLineLayout.layoutLineBoxes(relayoutChildren, repaintLogicalTop, repaintLogicalBottom);
// This matches relayoutToAvoidWidows.
if (shouldBreakAtLineToAvoidWidow())
complexLineLayout.layoutLineBoxes(relayoutChildren, repaintLogicalTop, repaintLogicalBottom);
// FIXME: This is needed as long as simple and normal line layout produce different line breakings.
repaint();
} else
complexLineLayout.layoutLineBoxes(relayoutChildren, repaintLogicalTop, repaintLogicalBottom);
updateLogicalHeight();
ASSERT(didNeedLayout || logicalHeight() == oldHeight);
if (!didNeedLayout)
clearNeedsLayout();
}
#if ENABLE(TREE_DEBUGGING)
void RenderBlockFlow::outputLineTreeAndMark(WTF::TextStream& stream, const InlineBox* markedBox, int depth) const
{
for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
root->outputLineTreeAndMark(stream, markedBox, depth);
if (auto simpleLineLayout = this->simpleLineLayout())
SimpleLineLayout::outputLineLayoutForFlow(stream, *this, *simpleLineLayout, depth);
}
#endif
RenderBlockFlow::RenderBlockFlowRareData& RenderBlockFlow::ensureRareBlockFlowData()
{
if (hasRareBlockFlowData())
return *m_rareBlockFlowData;
materializeRareBlockFlowData();
return *m_rareBlockFlowData;
}
void RenderBlockFlow::materializeRareBlockFlowData()
{
ASSERT(!hasRareBlockFlowData());
m_rareBlockFlowData = makeUnique<RenderBlockFlow::RenderBlockFlowRareData>(*this);
}
#if ENABLE(TEXT_AUTOSIZING)
static inline bool isVisibleRenderText(const RenderObject& renderer)
{
if (!is<RenderText>(renderer))
return false;
auto& renderText = downcast<RenderText>(renderer);
return !renderText.linesBoundingBox().isEmpty() && !renderText.text().isAllSpecialCharacters<isHTMLSpace>();
}
static inline bool resizeTextPermitted(const RenderObject& renderer)
{
// We disallow resizing for text input fields and textarea to address <rdar://problem/5792987> and <rdar://problem/8021123>
for (auto* ancestor = renderer.parent(); ancestor; ancestor = ancestor->parent()) {
// Get the first non-shadow HTMLElement and see if it's an input.
if (is<HTMLElement>(ancestor->element()) && !ancestor->element()->isInShadowTree()) {
auto& element = downcast<HTMLElement>(*ancestor->element());
return !is<HTMLInputElement>(element) && !is<HTMLTextAreaElement>(element);
}
}
return true;
}
int RenderBlockFlow::lineCountForTextAutosizing()
{
if (style().visibility() != Visibility::Visible)
return 0;
if (childrenInline())
return lineCount();
// Only descend into list items.
int count = 0;
for (auto& listItem : childrenOfType<RenderListItem>(*this))
count += listItem.lineCount();
return count;
}
static bool isNonBlocksOrNonFixedHeightListItems(const RenderObject& renderer)
{
if (!renderer.isRenderBlock())
return true;
if (renderer.isListItem())
return renderer.style().height().type() != Fixed;
return false;
}
// For now, we auto size single lines of text the same as multiple lines.
// We've been experimenting with low values for single lines of text.
static inline float oneLineTextMultiplier(RenderObject& renderer, float specifiedSize)
{
const float coefficient = renderer.settings().oneLineTextMultiplierCoefficient();
return std::max((1.0f / log10f(specifiedSize) * coefficient), 1.0f);
}
static inline float textMultiplier(RenderObject& renderer, float specifiedSize)
{
const float coefficient = renderer.settings().multiLineTextMultiplierCoefficient();
return std::max((1.0f / log10f(specifiedSize) * coefficient), 1.0f);
}
void RenderBlockFlow::adjustComputedFontSizes(float size, float visibleWidth)
{
LOG(TextAutosizing, "RenderBlockFlow %p adjustComputedFontSizes, size=%f visibleWidth=%f, width()=%f. Bailing: %d", this, size, visibleWidth, width().toFloat(), visibleWidth >= width());
// Don't do any work if the block is smaller than the visible area.
if (visibleWidth >= width())
return;
unsigned lineCount;
if (m_lineCountForTextAutosizing == NOT_SET) {
int count = lineCountForTextAutosizing();
if (!count)
lineCount = NO_LINE;
else if (count == 1)
lineCount = ONE_LINE;
else
lineCount = MULTI_LINE;
} else
lineCount = m_lineCountForTextAutosizing;
ASSERT(lineCount != NOT_SET);
if (lineCount == NO_LINE)
return;
float actualWidth = m_widthForTextAutosizing != -1 ? static_cast<float>(m_widthForTextAutosizing) : static_cast<float>(width());
float scale = visibleWidth / actualWidth;
float minFontSize = roundf(size / scale);
for (auto* descendant = RenderObjectTraversal::firstChild(*this); descendant; ) {
if (!isNonBlocksOrNonFixedHeightListItems(*descendant)) {
descendant = RenderObjectTraversal::nextSkippingChildren(*descendant, this);
continue;
}
if (!isVisibleRenderText(*descendant) || !resizeTextPermitted(*descendant)) {
descendant = RenderObjectTraversal::next(*descendant, this);
continue;
}
auto& text = downcast<RenderText>(*descendant);
auto& oldStyle = text.style();
auto& fontDescription = oldStyle.fontDescription();
float specifiedSize = fontDescription.specifiedSize();
float scaledSize = roundf(specifiedSize * scale);
if (scaledSize > 0 && scaledSize < minFontSize) {
// Record the width of the block and the line count the first time we resize text and use it from then on for text resizing.
// This makes text resizing consistent even if the block's width or line count changes (which can be caused by text resizing itself 5159915).
if (m_lineCountForTextAutosizing == NOT_SET)
m_lineCountForTextAutosizing = lineCount;
if (m_widthForTextAutosizing == -1)
m_widthForTextAutosizing = actualWidth;
float lineTextMultiplier = lineCount == ONE_LINE ? oneLineTextMultiplier(text, specifiedSize) : textMultiplier(text, specifiedSize);
float candidateNewSize = roundf(std::min(minFontSize, specifiedSize * lineTextMultiplier));
if (candidateNewSize > specifiedSize && candidateNewSize != fontDescription.computedSize() && text.textNode() && oldStyle.textSizeAdjust().isAuto())
document().textAutoSizing().addTextNode(*text.textNode(), candidateNewSize);
}
descendant = RenderObjectTraversal::nextSkippingChildren(text, this);
}
}
#endif // ENABLE(TEXT_AUTOSIZING)
void RenderBlockFlow::layoutExcludedChildren(bool relayoutChildren)
{
RenderBlock::layoutExcludedChildren(relayoutChildren);
auto* fragmentedFlow = multiColumnFlow();
if (!fragmentedFlow)
return;
fragmentedFlow->setIsExcludedFromNormalLayout(true);
setLogicalTopForChild(*fragmentedFlow, borderAndPaddingBefore());
if (relayoutChildren)
fragmentedFlow->setChildNeedsLayout(MarkOnlyThis);
if (fragmentedFlow->needsLayout()) {
for (RenderMultiColumnSet* columnSet = fragmentedFlow->firstMultiColumnSet(); columnSet; columnSet = columnSet->nextSiblingMultiColumnSet())
columnSet->prepareForLayout(!fragmentedFlow->inBalancingPass());
fragmentedFlow->invalidateFragments(MarkOnlyThis);
fragmentedFlow->setNeedsHeightsRecalculation(true);
fragmentedFlow->layout();
} else {
// At the end of multicol layout, relayoutForPagination() is called unconditionally, but if
// no children are to be laid out (e.g. fixed width with layout already being up-to-date),
// we want to prevent it from doing any work, so that the column balancing machinery doesn't
// kick in and trigger additional unnecessary layout passes. Actually, it's not just a good
// idea in general to not waste time on balancing content that hasn't been re-laid out; we
// are actually required to guarantee this. The calculation of implicit breaks needs to be
// preceded by a proper layout pass, since it's layout that sets up content runs, and the
// runs get deleted right after every pass.
fragmentedFlow->setNeedsHeightsRecalculation(false);
}
determineLogicalLeftPositionForChild(*fragmentedFlow);
}
void RenderBlockFlow::checkForPaginationLogicalHeightChange(bool& relayoutChildren, LayoutUnit& pageLogicalHeight, bool& pageLogicalHeightChanged)
{
// If we don't use columns or flow threads, then bail.
if (!isRenderFragmentedFlow() && !multiColumnFlow())
return;
// We don't actually update any of the variables. We just subclassed to adjust our column height.
if (RenderMultiColumnFlow* fragmentedFlow = multiColumnFlow()) {
LayoutUnit newColumnHeight;
if (hasDefiniteLogicalHeight() || view().frameView().pagination().mode != Pagination::Unpaginated) {
auto computedValues = computeLogicalHeight(0_lu, logicalTop());
newColumnHeight = std::max<LayoutUnit>(computedValues.m_extent - borderAndPaddingLogicalHeight() - scrollbarLogicalHeight(), 0);
if (fragmentedFlow->columnHeightAvailable() != newColumnHeight)
relayoutChildren = true;
}
fragmentedFlow->setColumnHeightAvailable(newColumnHeight);
} else if (is<RenderFragmentedFlow>(*this)) {
RenderFragmentedFlow& fragmentedFlow = downcast<RenderFragmentedFlow>(*this);
// FIXME: This is a hack to always make sure we have a page logical height, if said height
// is known. The page logical height thing in RenderLayoutState is meaningless for flow
// thread-based pagination (page height isn't necessarily uniform throughout the flow
// thread), but as long as it is used universally as a means to determine whether page
// height is known or not, we need this. Page height is unknown when column balancing is
// enabled and flow thread height is still unknown (i.e. during the first layout pass). When
// it's unknown, we need to prevent the pagination code from assuming page breaks everywhere
// and thereby eating every top margin. It should be trivial to clean up and get rid of this
// hack once the old multicol implementation is gone (see also RenderView::pushLayoutStateForPagination).
pageLogicalHeight = fragmentedFlow.isPageLogicalHeightKnown() ? 1_lu : 0_lu;
pageLogicalHeightChanged = fragmentedFlow.pageLogicalSizeChanged();
}
}
bool RenderBlockFlow::requiresColumns(int desiredColumnCount) const
{
return willCreateColumns(desiredColumnCount);
}
void RenderBlockFlow::setComputedColumnCountAndWidth(int count, LayoutUnit width)
{
ASSERT(!!multiColumnFlow() == requiresColumns(count));
if (!multiColumnFlow())
return;
multiColumnFlow()->setColumnCountAndWidth(count, width);
multiColumnFlow()->setProgressionIsInline(style().hasInlineColumnAxis());
multiColumnFlow()->setProgressionIsReversed(style().columnProgression() == ColumnProgression::Reverse);
}
void RenderBlockFlow::updateColumnProgressionFromStyle(RenderStyle& style)
{
if (!multiColumnFlow())
return;
bool needsLayout = false;
bool oldProgressionIsInline = multiColumnFlow()->progressionIsInline();
bool newProgressionIsInline = style.hasInlineColumnAxis();
if (oldProgressionIsInline != newProgressionIsInline) {
multiColumnFlow()->setProgressionIsInline(newProgressionIsInline);
needsLayout = true;
}
bool oldProgressionIsReversed = multiColumnFlow()->progressionIsReversed();
bool newProgressionIsReversed = style.columnProgression() == ColumnProgression::Reverse;
if (oldProgressionIsReversed != newProgressionIsReversed) {
multiColumnFlow()->setProgressionIsReversed(newProgressionIsReversed);
needsLayout = true;
}
if (needsLayout)
setNeedsLayoutAndPrefWidthsRecalc();
}
LayoutUnit RenderBlockFlow::computedColumnWidth() const
{
if (multiColumnFlow())
return multiColumnFlow()->computedColumnWidth();
return contentLogicalWidth();
}
unsigned RenderBlockFlow::computedColumnCount() const
{
if (multiColumnFlow())
return multiColumnFlow()->computedColumnCount();
return 1;
}
bool RenderBlockFlow::isTopLayoutOverflowAllowed() const
{
bool hasTopOverflow = RenderBlock::isTopLayoutOverflowAllowed();
if (!multiColumnFlow() || style().columnProgression() == ColumnProgression::Normal)
return hasTopOverflow;
if (!(isHorizontalWritingMode() ^ !style().hasInlineColumnAxis()))
hasTopOverflow = !hasTopOverflow;
return hasTopOverflow;
}
bool RenderBlockFlow::isLeftLayoutOverflowAllowed() const
{
bool hasLeftOverflow = RenderBlock::isLeftLayoutOverflowAllowed();
if (!multiColumnFlow() || style().columnProgression() == ColumnProgression::Normal)
return hasLeftOverflow;
if (isHorizontalWritingMode() ^ !style().hasInlineColumnAxis())
hasLeftOverflow = !hasLeftOverflow;
return hasLeftOverflow;
}
struct InlineMinMaxIterator {
/* InlineMinMaxIterator is a class that will iterate over all render 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.
*/
const RenderBlockFlow& parent;
RenderObject* current;
bool endOfInline;
bool initial;
InlineMinMaxIterator(const RenderBlockFlow& p)
: parent(p)
, current(nullptr)
, endOfInline(false)
, initial(true)
{ }
RenderObject* next();
};
RenderObject* InlineMinMaxIterator::next()
{
RenderObject* result = nullptr;
bool oldEndOfInline = endOfInline;
endOfInline = false;
do {
if (!oldEndOfInline && (current && !current->isFloating() && !current->isReplaced() && !current->isOutOfFlowPositioned()))
result = current->firstChildSlow();
else if (initial) {
result = parent.firstChild();
initial = false;
}
if (!result) {
// We hit the end of our inline. (It was empty, e.g., <span></span>.)
if (!oldEndOfInline && current && current->isRenderInline()) {
result = current;
endOfInline = true;
break;
}
while (current && current != &parent) {
result = current->nextSibling();
if (result)
break;
current = current->parent();
if (current && current != &parent && current->isRenderInline()) {
result = current;
endOfInline = true;
break;
}
}
}
if (!result)
break;
if (!result->isOutOfFlowPositioned() && (result->isTextOrLineBreak() || result->isFloating() || result->isReplaced() || result->isRenderInline()))
break;
current = result;
result = nullptr;
} while (current || current == &parent);
// Update our position.
current = result;
return result;
}
static LayoutUnit getBPMWidth(LayoutUnit childValue, Length cssUnit)
{
if (cssUnit.type() != Auto)
return (cssUnit.isFixed() ? LayoutUnit(cssUnit.value()) : childValue);
return 0;
}
static LayoutUnit getBorderPaddingMargin(const RenderBoxModelObject& child, bool endOfInline)
{
const RenderStyle& childStyle = child.style();
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(float& inlineMax, float& inlineMin, RenderObject* trailingSpaceChild)
{
if (is<RenderText>(trailingSpaceChild)) {
// Collapse away the trailing space at the end of a block.
RenderText& renderText = downcast<RenderText>(*trailingSpaceChild);
const UChar space = ' ';
const FontCascade& font = renderText.style().fontCascade(); // FIXME: This ignores first-line.
float spaceWidth = font.width(RenderBlock::constructTextRun(&space, 1, renderText.style()));
inlineMax -= spaceWidth + font.wordSpacing();
if (inlineMin > inlineMax)
inlineMin = inlineMax;
}
}
static inline LayoutUnit preferredWidth(LayoutUnit preferredWidth, float result)
{
return std::max(preferredWidth, LayoutUnit::fromFloatCeil(result));
}
void RenderBlockFlow::computeInlinePreferredLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const
{
float inlineMax = 0;
float inlineMin = 0;
const RenderStyle& styleToUse = style();
RenderBlock* containingBlock = this->containingBlock();
LayoutUnit cw = containingBlock ? containingBlock->contentLogicalWidth() : 0_lu;
// 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;
RenderObject* 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 renderings).
// Not supporting the quirk has caused us to mis-render some real sites. (See Bugzilla 10517.)
bool allowImagesToBreak = !document().inQuirksMode() || !isTableCell() || !styleToUse.logicalWidth().isIntrinsicOrAuto();
bool 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);
RenderObject* prevFloat = 0;
bool isPrevChildInlineFlow = false;
bool shouldBreakLineAfterText = false;
bool canHangPunctuationAtStart = styleToUse.hangingPunctuation().contains(HangingPunctuation::First);
bool canHangPunctuationAtEnd = styleToUse.hangingPunctuation().contains(HangingPunctuation::Last);
RenderText* lastText = nullptr;
bool addedStartPunctuationHang = false;
while (RenderObject* child = childIterator.next()) {
bool autoWrap = child->isReplaced() ? child->parent()->style().autoWrap() :
child->style().autoWrap();
if (!child->isBR()) {
// Step One: determine whether or not we need to 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 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 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 RenderStyle& childStyle = child->style();
float childMin = 0;
float childMax = 0;
if (!child->isText()) {
if (child->isLineBreakOpportunity()) {
minLogicalWidth = preferredWidth(minLogicalWidth, inlineMin);
inlineMin = 0;
continue;
}
// Case (1) and (2). Inline replaced and inline flow elements.
if (is<RenderInline>(*child)) {
// Add in padding/border/margin from the appropriate side of
// the element.
float bpm = getBorderPaddingMargin(downcast<RenderInline>(*child), childIterator.endOfInline);
childMin += bpm;
childMax += bpm;
inlineMin += childMin;
inlineMax += childMax;
child->setPreferredLogicalWidthsDirty(false);
} else {
// Inline replaced elts add in their margins to their min/max values.
if (!child->isFloating())
lastText = nullptr;
LayoutUnit margins;
Length startMargin = childStyle.marginStart();
Length endMargin = childStyle.marginEnd();
if (startMargin.isFixed())
margins += LayoutUnit::fromFloatCeil(startMargin.value());
if (endMargin.isFixed())
margins += LayoutUnit::fromFloatCeil(endMargin.value());
childMin += margins.ceilToFloat();
childMax += margins.ceilToFloat();
}
}
if (!is<RenderInline>(*child) && !is<RenderText>(*child)) {
// Case (2). Inline replaced elements and floats.
// Terminate the current line as far as minwidth is concerned.
LayoutUnit childMinPreferredLogicalWidth, childMaxPreferredLogicalWidth;
computeChildPreferredLogicalWidths(*child, childMinPreferredLogicalWidth, childMaxPreferredLogicalWidth);
childMin += childMinPreferredLogicalWidth.ceilToFloat();
childMax += childMaxPreferredLogicalWidth.ceilToFloat();
bool clearPreviousFloat;
if (child->isFloating()) {
clearPreviousFloat = (prevFloat
&& ((prevFloat->style().floating() == Float::Left && (childStyle.clear() == Clear::Left || childStyle.clear() == Clear::Both))
|| (prevFloat->style().floating() == Float::Right && (childStyle.clear() == Clear::Right || childStyle.clear() == Clear::Both))));
prevFloat = child;
} else
clearPreviousFloat = false;
bool canBreakReplacedElement = !child->isImage() || allowImagesToBreak;
if (((canBreakReplacedElement && (autoWrap || oldAutoWrap) && (!isPrevChildInlineFlow || shouldBreakLineAfterText)) || clearPreviousFloat)) {
minLogicalWidth = preferredWidth(minLogicalWidth, inlineMin);
inlineMin = 0;
}
// If we're supposed to clear the previous float, then terminate maxwidth as well.
if (clearPreviousFloat) {
maxLogicalWidth = preferredWidth(maxLogicalWidth, inlineMax);
inlineMax = 0;
}
// Add in text-indent. This is added in only once.
if (!addedTextIndent && !child->isFloating()) {
LayoutUnit ceiledIndent { textIndent.ceilToFloat() };
childMin += ceiledIndent;
childMax += ceiledIndent;
if (childMin < 0)
textIndent = LayoutUnit::fromFloatCeil(childMin);
else
addedTextIndent = true;
}
if (canHangPunctuationAtStart && !addedStartPunctuationHang && !child->isFloating())
addedStartPunctuationHang = true;
// Add our width to the max.
inlineMax += std::max<float>(0, childMax);
if ((!autoWrap || !canBreakReplacedElement || (isPrevChildInlineFlow && !shouldBreakLineAfterText))) {
if (child->isFloating())
minLogicalWidth = preferredWidth(minLogicalWidth, childMin);
else
inlineMin += childMin;
} else {
// Now check our line.
minLogicalWidth = preferredWidth(minLogicalWidth, childMin);
// Now start a new line.
inlineMin = 0;
}
if (autoWrap && canBreakReplacedElement && isPrevChildInlineFlow) {
minLogicalWidth = preferredWidth(minLogicalWidth, inlineMin);
inlineMin = 0;
}
// We are no longer stripping whitespace at the start of a line.
if (!child->isFloating()) {
stripFrontSpaces = false;
trailingSpaceChild = nullptr;
lastText = nullptr;
}
} else if (is<RenderText>(*child)) {
// Case (3). Text.
RenderText& renderText = downcast<RenderText>(*child);
if (renderText.style().hasTextCombine() && renderText.isCombineText())
downcast<RenderCombineText>(renderText).combineTextIfNeeded();
// 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 strippingBeginWS = stripFrontSpaces;
auto widths = renderText.trimmedPreferredWidths(inlineMax, stripFrontSpaces);
childMin = widths.min;
childMax = widths.max;
// This text object will not be rendered, but it may still provide a breaking opportunity.
if (!widths.hasBreak && !childMax) {
if (autoWrap && (widths.beginWS || widths.endWS)) {
minLogicalWidth = preferredWidth(minLogicalWidth, inlineMin);
inlineMin = 0;
}
continue;
}
lastText = &renderText;
if (stripFrontSpaces)
trailingSpaceChild = child;
else
trailingSpaceChild = 0;
// Add in text-indent. This is added in only once.
float ti = 0;
if (!addedTextIndent || hasRemainingNegativeTextIndent) {
ti = textIndent.ceilToFloat();
childMin += ti;
widths.beginMin += 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;
widths.beginMax += ti;
addedTextIndent = true;
}
if (childMin < 0) {
textIndent = childMin;
hasRemainingNegativeTextIndent = true;
}
}
// See if we have a hanging punctuation situation at the start.
if (canHangPunctuationAtStart && !addedStartPunctuationHang) {
unsigned startIndex = strippingBeginWS ? renderText.firstCharacterIndexStrippingSpaces() : 0;
float hangStartWidth = renderText.hangablePunctuationStartWidth(startIndex);
childMin -= hangStartWidth;
widths.beginMin -= hangStartWidth;
childMax -= hangStartWidth;
widths.beginMax -= hangStartWidth;
addedStartPunctuationHang = 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 (!widths.hasBreakableChar)
inlineMin += childMin;
else {
// We have a breakable character. Now we need to know if
// we start and end with whitespace.
if (widths.beginWS) {
// End the current line.
minLogicalWidth = preferredWidth(minLogicalWidth, inlineMin);
} else {
inlineMin += widths.beginMin;
minLogicalWidth = preferredWidth(minLogicalWidth, inlineMin);
childMin -= ti;
}
inlineMin = childMin;
if (widths.endWS) {
// We end in whitespace, which means we can end our current line.
minLogicalWidth = preferredWidth(minLogicalWidth, inlineMin);
inlineMin = 0;
shouldBreakLineAfterText = false;
} else {
minLogicalWidth = preferredWidth(minLogicalWidth, inlineMin);
inlineMin = widths.endMin;
shouldBreakLineAfterText = true;
}
}
if (widths.hasBreak) {
inlineMax += widths.beginMax;
maxLogicalWidth = preferredWidth(maxLogicalWidth, inlineMax);
maxLogicalWidth = preferredWidth(maxLogicalWidth, childMax);
inlineMax = widths.endMax;
addedTextIndent = true;
addedStartPunctuationHang = true;
} else
inlineMax += std::max<float>(0, childMax);
}
// Ignore spaces after a list marker.
if (child->isListMarker())
stripFrontSpaces = true;
} else {
minLogicalWidth = preferredWidth(minLogicalWidth, inlineMin);
maxLogicalWidth = preferredWidth(maxLogicalWidth, inlineMax);
inlineMin = inlineMax = 0;
stripFrontSpaces = true;
trailingSpaceChild = 0;
addedTextIndent = true;
addedStartPunctuationHang = true;
}
if (!child->isText() && child->isRenderInline())
isPrevChildInlineFlow = true;
else
isPrevChildInlineFlow = false;
oldAutoWrap = autoWrap;
}
if (styleToUse.collapseWhiteSpace())
stripTrailingSpace(inlineMax, inlineMin, trailingSpaceChild);
if (canHangPunctuationAtEnd && lastText && lastText->text().length() > 0) {
unsigned endIndex = trailingSpaceChild == lastText ? lastText->lastCharacterIndexStrippingSpaces() : lastText->text().length() - 1;
float endHangWidth = lastText->hangablePunctuationEndWidth(endIndex);
inlineMin -= endHangWidth;
inlineMax -= endHangWidth;
}
minLogicalWidth = preferredWidth(minLogicalWidth, inlineMin);
maxLogicalWidth = preferredWidth(maxLogicalWidth, inlineMax);
}
}
// namespace WebCore