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/*
* Copyright (C) 2011 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
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* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "core/rendering/RenderFlexibleBox.h"
#include "core/frame/UseCounter.h"
#include "core/paint/BlockPainter.h"
#include "core/rendering/RenderLayer.h"
#include "core/rendering/RenderView.h"
#include "core/rendering/TextAutosizer.h"
#include "core/rendering/style/RenderStyle.h"
#include "platform/LengthFunctions.h"
#include "wtf/MathExtras.h"
#include <limits>
namespace blink {
struct RenderFlexibleBox::LineContext {
LineContext(LayoutUnit crossAxisOffset, LayoutUnit crossAxisExtent, size_t numberOfChildren, LayoutUnit maxAscent)
: crossAxisOffset(crossAxisOffset)
, crossAxisExtent(crossAxisExtent)
, numberOfChildren(numberOfChildren)
, maxAscent(maxAscent)
{
}
LayoutUnit crossAxisOffset;
LayoutUnit crossAxisExtent;
size_t numberOfChildren;
LayoutUnit maxAscent;
};
struct RenderFlexibleBox::Violation {
Violation(RenderBox* child, LayoutUnit childSize)
: child(child)
, childSize(childSize)
{
}
RenderBox* child;
LayoutUnit childSize;
};
RenderFlexibleBox::RenderFlexibleBox(Element* element)
: RenderBlock(element)
, m_orderIterator(this)
, m_numberOfInFlowChildrenOnFirstLine(-1)
{
ASSERT(!childrenInline());
}
RenderFlexibleBox::~RenderFlexibleBox()
{
}
RenderFlexibleBox* RenderFlexibleBox::createAnonymous(Document* document)
{
RenderFlexibleBox* renderer = new RenderFlexibleBox(0);
renderer->setDocumentForAnonymous(document);
return renderer;
}
const char* RenderFlexibleBox::renderName() const
{
return "RenderFlexibleBox";
}
void RenderFlexibleBox::computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const
{
// FIXME: We're ignoring flex-basis here and we shouldn't. We can't start honoring it though until
// the flex shorthand stops setting it to 0.
// See https://bugs.webkit.org/show_bug.cgi?id=116117 and http://crbug.com/240765.
for (RenderBox* child = firstChildBox(); child; child = child->nextSiblingBox()) {
if (child->isOutOfFlowPositioned())
continue;
LayoutUnit margin = marginIntrinsicLogicalWidthForChild(child);
bool hasOrthogonalWritingMode = child->isHorizontalWritingMode() != isHorizontalWritingMode();
LayoutUnit minPreferredLogicalWidth = hasOrthogonalWritingMode ? child->logicalHeight() : child->minPreferredLogicalWidth();
LayoutUnit maxPreferredLogicalWidth = hasOrthogonalWritingMode ? child->logicalHeight() : child->maxPreferredLogicalWidth();
minPreferredLogicalWidth += margin;
maxPreferredLogicalWidth += margin;
if (!isColumnFlow()) {
maxLogicalWidth += maxPreferredLogicalWidth;
if (isMultiline()) {
// For multiline, the min preferred width is if you put a break between each item.
minLogicalWidth = std::max(minLogicalWidth, minPreferredLogicalWidth);
} else
minLogicalWidth += minPreferredLogicalWidth;
} else {
minLogicalWidth = std::max(minPreferredLogicalWidth, minLogicalWidth);
maxLogicalWidth = std::max(maxPreferredLogicalWidth, maxLogicalWidth);
}
}
maxLogicalWidth = std::max(minLogicalWidth, maxLogicalWidth);
LayoutUnit scrollbarWidth = instrinsicScrollbarLogicalWidth();
maxLogicalWidth += scrollbarWidth;
minLogicalWidth += scrollbarWidth;
}
static int synthesizedBaselineFromContentBox(const RenderBox& box, LineDirectionMode direction)
{
return direction == HorizontalLine ? box.borderTop() + box.paddingTop() + box.contentHeight() : box.borderRight() + box.paddingRight() + box.contentWidth();
}
int RenderFlexibleBox::baselinePosition(FontBaseline, bool, LineDirectionMode direction, LinePositionMode mode) const
{
ASSERT(mode == PositionOnContainingLine);
int baseline = firstLineBoxBaseline();
if (baseline == -1)
baseline = synthesizedBaselineFromContentBox(*this, direction);
return beforeMarginInLineDirection(direction) + baseline;
}
int RenderFlexibleBox::firstLineBoxBaseline() const
{
if (isWritingModeRoot() || m_numberOfInFlowChildrenOnFirstLine <= 0)
return -1;
RenderBox* baselineChild = 0;
int childNumber = 0;
for (RenderBox* child = m_orderIterator.first(); child; child = m_orderIterator.next()) {
if (child->isOutOfFlowPositioned())
continue;
if (alignmentForChild(*child) == ItemPositionBaseline && !hasAutoMarginsInCrossAxis(*child)) {
baselineChild = child;
break;
}
if (!baselineChild)
baselineChild = child;
++childNumber;
if (childNumber == m_numberOfInFlowChildrenOnFirstLine)
break;
}
if (!baselineChild)
return -1;
if (!isColumnFlow() && hasOrthogonalFlow(*baselineChild))
return crossAxisExtentForChild(*baselineChild) + baselineChild->logicalTop();
if (isColumnFlow() && !hasOrthogonalFlow(*baselineChild))
return mainAxisExtentForChild(*baselineChild) + baselineChild->logicalTop();
int baseline = baselineChild->firstLineBoxBaseline();
if (baseline == -1) {
// FIXME: We should pass |direction| into firstLineBoxBaseline and stop bailing out if we're a writing mode root.
// This would also fix some cases where the flexbox is orthogonal to its container.
LineDirectionMode direction = isHorizontalWritingMode() ? HorizontalLine : VerticalLine;
return synthesizedBaselineFromContentBox(*baselineChild, direction) + baselineChild->logicalTop();
}
return baseline + baselineChild->logicalTop();
}
int RenderFlexibleBox::inlineBlockBaseline(LineDirectionMode direction) const
{
int baseline = firstLineBoxBaseline();
if (baseline != -1)
return baseline;
int marginAscent = direction == HorizontalLine ? marginTop() : marginRight();
return synthesizedBaselineFromContentBox(*this, direction) + marginAscent;
}
void RenderFlexibleBox::removeChild(RenderObject* child)
{
RenderBlock::removeChild(child);
m_intrinsicSizeAlongMainAxis.remove(child);
}
void RenderFlexibleBox::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
{
RenderBlock::styleDidChange(diff, oldStyle);
if (oldStyle && oldStyle->alignItems() == ItemPositionStretch && diff.needsFullLayout()) {
// Flex items that were previously stretching need to be relayed out so we can compute new available cross axis space.
// This is only necessary for stretching since other alignment values don't change the size of the box.
for (RenderBox* child = firstChildBox(); child; child = child->nextSiblingBox()) {
ItemPosition previousAlignment = RenderStyle::resolveAlignment(oldStyle, child->style(), ItemPositionStretch);
if (previousAlignment == ItemPositionStretch && previousAlignment != RenderStyle::resolveAlignment(style(), child->style(), ItemPositionStretch))
child->setChildNeedsLayout(MarkOnlyThis);
}
}
}
void RenderFlexibleBox::layoutBlock(bool relayoutChildren)
{
ASSERT(needsLayout());
if (!relayoutChildren && simplifiedLayout())
return;
if (updateLogicalWidthAndColumnWidth())
relayoutChildren = true;
LayoutUnit previousHeight = logicalHeight();
setLogicalHeight(borderAndPaddingLogicalHeight() + scrollbarLogicalHeight());
{
TextAutosizer::LayoutScope textAutosizerLayoutScope(this);
LayoutState state(*this, locationOffset());
m_numberOfInFlowChildrenOnFirstLine = -1;
RenderBlock::startDelayUpdateScrollInfo();
prepareOrderIteratorAndMargins();
ChildFrameRects oldChildRects;
appendChildFrameRects(oldChildRects);
layoutFlexItems(relayoutChildren);
RenderBlock::finishDelayUpdateScrollInfo();
if (logicalHeight() != previousHeight)
relayoutChildren = true;
layoutPositionedObjects(relayoutChildren || isDocumentElement());
// FIXME: css3/flexbox/repaint-rtl-column.html seems to issue paint invalidations for more overflow than it needs to.
computeOverflow(clientLogicalBottomAfterRepositioning());
}
updateLayerTransformAfterLayout();
// Update our scroll information if we're overflow:auto/scroll/hidden now that we know if
// we overflow or not.
updateScrollInfoAfterLayout();
clearNeedsLayout();
}
void RenderFlexibleBox::appendChildFrameRects(ChildFrameRects& childFrameRects)
{
for (RenderBox* child = m_orderIterator.first(); child; child = m_orderIterator.next()) {
if (!child->isOutOfFlowPositioned())
childFrameRects.append(child->frameRect());
}
}
void RenderFlexibleBox::paintChildren(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
BlockPainter::paintChildrenOfFlexibleBox(*this, paintInfo, paintOffset);
}
void RenderFlexibleBox::repositionLogicalHeightDependentFlexItems(Vector<LineContext>& lineContexts)
{
LayoutUnit crossAxisStartEdge = lineContexts.isEmpty() ? LayoutUnit() : lineContexts[0].crossAxisOffset;
alignFlexLines(lineContexts);
alignChildren(lineContexts);
if (style()->flexWrap() == FlexWrapReverse)
flipForWrapReverse(lineContexts, crossAxisStartEdge);
// direction:rtl + flex-direction:column means the cross-axis direction is flipped.
flipForRightToLeftColumn();
}
LayoutUnit RenderFlexibleBox::clientLogicalBottomAfterRepositioning()
{
LayoutUnit maxChildLogicalBottom = 0;
for (RenderBox* child = firstChildBox(); child; child = child->nextSiblingBox()) {
if (child->isOutOfFlowPositioned())
continue;
LayoutUnit childLogicalBottom = logicalTopForChild(child) + logicalHeightForChild(child) + marginAfterForChild(child);
maxChildLogicalBottom = std::max(maxChildLogicalBottom, childLogicalBottom);
}
return std::max(clientLogicalBottom(), maxChildLogicalBottom + paddingAfter());
}
bool RenderFlexibleBox::hasOrthogonalFlow(RenderBox& child) const
{
// FIXME: If the child is a flexbox, then we need to check isHorizontalFlow.
return isHorizontalFlow() != child.isHorizontalWritingMode();
}
bool RenderFlexibleBox::isColumnFlow() const
{
return style()->isColumnFlexDirection();
}
bool RenderFlexibleBox::isHorizontalFlow() const
{
if (isHorizontalWritingMode())
return !isColumnFlow();
return isColumnFlow();
}
bool RenderFlexibleBox::isLeftToRightFlow() const
{
if (isColumnFlow())
return style()->writingMode() == TopToBottomWritingMode || style()->writingMode() == LeftToRightWritingMode;
return style()->isLeftToRightDirection() ^ (style()->flexDirection() == FlowRowReverse);
}
bool RenderFlexibleBox::isMultiline() const
{
return style()->flexWrap() != FlexNoWrap;
}
Length RenderFlexibleBox::flexBasisForChild(RenderBox& child) const
{
Length flexLength = child.style()->flexBasis();
if (flexLength.isAuto())
flexLength = isHorizontalFlow() ? child.style()->width() : child.style()->height();
return flexLength;
}
LayoutUnit RenderFlexibleBox::crossAxisExtentForChild(RenderBox& child) const
{
return isHorizontalFlow() ? child.height() : child.width();
}
static inline LayoutUnit constrainedChildIntrinsicContentLogicalHeight(RenderBox& child)
{
LayoutUnit childIntrinsicContentLogicalHeight = child.intrinsicContentLogicalHeight();
return child.constrainLogicalHeightByMinMax(childIntrinsicContentLogicalHeight + child.borderAndPaddingLogicalHeight(), childIntrinsicContentLogicalHeight);
}
LayoutUnit RenderFlexibleBox::childIntrinsicHeight(RenderBox& child) const
{
if (child.isHorizontalWritingMode() && needToStretchChildLogicalHeight(child))
return constrainedChildIntrinsicContentLogicalHeight(child);
return child.height();
}
LayoutUnit RenderFlexibleBox::childIntrinsicWidth(RenderBox& child) const
{
if (!child.isHorizontalWritingMode() && needToStretchChildLogicalHeight(child))
return constrainedChildIntrinsicContentLogicalHeight(child);
return child.width();
}
LayoutUnit RenderFlexibleBox::crossAxisIntrinsicExtentForChild(RenderBox& child) const
{
return isHorizontalFlow() ? childIntrinsicHeight(child) : childIntrinsicWidth(child);
}
LayoutUnit RenderFlexibleBox::mainAxisExtentForChild(RenderBox& child) const
{
return isHorizontalFlow() ? child.width() : child.height();
}
LayoutUnit RenderFlexibleBox::crossAxisExtent() const
{
return isHorizontalFlow() ? height() : width();
}
LayoutUnit RenderFlexibleBox::mainAxisExtent() const
{
return isHorizontalFlow() ? width() : height();
}
LayoutUnit RenderFlexibleBox::crossAxisContentExtent() const
{
return isHorizontalFlow() ? contentHeight() : contentWidth();
}
LayoutUnit RenderFlexibleBox::mainAxisContentExtent(LayoutUnit contentLogicalHeight)
{
if (isColumnFlow()) {
LogicalExtentComputedValues computedValues;
LayoutUnit borderPaddingAndScrollbar = borderAndPaddingLogicalHeight() + scrollbarLogicalHeight();
LayoutUnit borderBoxLogicalHeight = contentLogicalHeight + borderPaddingAndScrollbar;
computeLogicalHeight(borderBoxLogicalHeight, logicalTop(), computedValues);
if (computedValues.m_extent == LayoutUnit::max())
return computedValues.m_extent;
return std::max(LayoutUnit(0), computedValues.m_extent - borderPaddingAndScrollbar);
}
return contentLogicalWidth();
}
LayoutUnit RenderFlexibleBox::computeMainAxisExtentForChild(RenderBox& child, SizeType sizeType, const Length& size)
{
// FIXME: This is wrong for orthogonal flows. It should use the flexbox's writing-mode, not the child's in order
// to figure out the logical height/width.
if (isColumnFlow()) {
// We don't have to check for "auto" here - computeContentLogicalHeight will just return -1 for that case anyway.
if (size.isIntrinsic())
child.layoutIfNeeded();
return child.computeContentLogicalHeight(size, child.logicalHeight() - child.borderAndPaddingLogicalHeight()) + child.scrollbarLogicalHeight();
}
return child.computeLogicalWidthUsing(sizeType, size, contentLogicalWidth(), this) - child.borderAndPaddingLogicalWidth();
}
WritingMode RenderFlexibleBox::transformedWritingMode() const
{
WritingMode mode = style()->writingMode();
if (!isColumnFlow())
return mode;
switch (mode) {
case TopToBottomWritingMode:
case BottomToTopWritingMode:
return style()->isLeftToRightDirection() ? LeftToRightWritingMode : RightToLeftWritingMode;
case LeftToRightWritingMode:
case RightToLeftWritingMode:
return style()->isLeftToRightDirection() ? TopToBottomWritingMode : BottomToTopWritingMode;
}
ASSERT_NOT_REACHED();
return TopToBottomWritingMode;
}
LayoutUnit RenderFlexibleBox::flowAwareBorderStart() const
{
if (isHorizontalFlow())
return isLeftToRightFlow() ? borderLeft() : borderRight();
return isLeftToRightFlow() ? borderTop() : borderBottom();
}
LayoutUnit RenderFlexibleBox::flowAwareBorderEnd() const
{
if (isHorizontalFlow())
return isLeftToRightFlow() ? borderRight() : borderLeft();
return isLeftToRightFlow() ? borderBottom() : borderTop();
}
LayoutUnit RenderFlexibleBox::flowAwareBorderBefore() const
{
switch (transformedWritingMode()) {
case TopToBottomWritingMode:
return borderTop();
case BottomToTopWritingMode:
return borderBottom();
case LeftToRightWritingMode:
return borderLeft();
case RightToLeftWritingMode:
return borderRight();
}
ASSERT_NOT_REACHED();
return borderTop();
}
LayoutUnit RenderFlexibleBox::flowAwareBorderAfter() const
{
switch (transformedWritingMode()) {
case TopToBottomWritingMode:
return borderBottom();
case BottomToTopWritingMode:
return borderTop();
case LeftToRightWritingMode:
return borderRight();
case RightToLeftWritingMode:
return borderLeft();
}
ASSERT_NOT_REACHED();
return borderTop();
}
LayoutUnit RenderFlexibleBox::flowAwarePaddingStart() const
{
if (isHorizontalFlow())
return isLeftToRightFlow() ? paddingLeft() : paddingRight();
return isLeftToRightFlow() ? paddingTop() : paddingBottom();
}
LayoutUnit RenderFlexibleBox::flowAwarePaddingEnd() const
{
if (isHorizontalFlow())
return isLeftToRightFlow() ? paddingRight() : paddingLeft();
return isLeftToRightFlow() ? paddingBottom() : paddingTop();
}
LayoutUnit RenderFlexibleBox::flowAwarePaddingBefore() const
{
switch (transformedWritingMode()) {
case TopToBottomWritingMode:
return paddingTop();
case BottomToTopWritingMode:
return paddingBottom();
case LeftToRightWritingMode:
return paddingLeft();
case RightToLeftWritingMode:
return paddingRight();
}
ASSERT_NOT_REACHED();
return paddingTop();
}
LayoutUnit RenderFlexibleBox::flowAwarePaddingAfter() const
{
switch (transformedWritingMode()) {
case TopToBottomWritingMode:
return paddingBottom();
case BottomToTopWritingMode:
return paddingTop();
case LeftToRightWritingMode:
return paddingRight();
case RightToLeftWritingMode:
return paddingLeft();
}
ASSERT_NOT_REACHED();
return paddingTop();
}
LayoutUnit RenderFlexibleBox::flowAwareMarginStartForChild(RenderBox& child) const
{
if (isHorizontalFlow())
return isLeftToRightFlow() ? child.marginLeft() : child.marginRight();
return isLeftToRightFlow() ? child.marginTop() : child.marginBottom();
}
LayoutUnit RenderFlexibleBox::flowAwareMarginEndForChild(RenderBox& child) const
{
if (isHorizontalFlow())
return isLeftToRightFlow() ? child.marginRight() : child.marginLeft();
return isLeftToRightFlow() ? child.marginBottom() : child.marginTop();
}
LayoutUnit RenderFlexibleBox::flowAwareMarginBeforeForChild(RenderBox& child) const
{
switch (transformedWritingMode()) {
case TopToBottomWritingMode:
return child.marginTop();
case BottomToTopWritingMode:
return child.marginBottom();
case LeftToRightWritingMode:
return child.marginLeft();
case RightToLeftWritingMode:
return child.marginRight();
}
ASSERT_NOT_REACHED();
return marginTop();
}
LayoutUnit RenderFlexibleBox::crossAxisMarginExtentForChild(RenderBox& child) const
{
return isHorizontalFlow() ? child.marginHeight() : child.marginWidth();
}
LayoutUnit RenderFlexibleBox::crossAxisScrollbarExtent() const
{
return isHorizontalFlow() ? horizontalScrollbarHeight() : verticalScrollbarWidth();
}
LayoutUnit RenderFlexibleBox::crossAxisScrollbarExtentForChild(RenderBox& child) const
{
return isHorizontalFlow() ? child.horizontalScrollbarHeight() : child.verticalScrollbarWidth();
}
LayoutPoint RenderFlexibleBox::flowAwareLocationForChild(RenderBox& child) const
{
return isHorizontalFlow() ? child.location() : child.location().transposedPoint();
}
void RenderFlexibleBox::setFlowAwareLocationForChild(RenderBox& child, const LayoutPoint& location)
{
if (isHorizontalFlow())
child.setLocation(location);
else
child.setLocation(location.transposedPoint());
}
LayoutUnit RenderFlexibleBox::mainAxisBorderAndPaddingExtentForChild(RenderBox& child) const
{
return isHorizontalFlow() ? child.borderAndPaddingWidth() : child.borderAndPaddingHeight();
}
static inline bool preferredMainAxisExtentDependsOnLayout(const Length& flexBasis, bool hasInfiniteLineLength)
{
return flexBasis.isAuto() || (flexBasis.isPercent() && hasInfiniteLineLength);
}
bool RenderFlexibleBox::childPreferredMainAxisContentExtentRequiresLayout(RenderBox& child, bool hasInfiniteLineLength) const
{
return preferredMainAxisExtentDependsOnLayout(flexBasisForChild(child), hasInfiniteLineLength) && hasOrthogonalFlow(child);
}
LayoutUnit RenderFlexibleBox::preferredMainAxisContentExtentForChild(RenderBox& child, bool hasInfiniteLineLength, bool relayoutChildren)
{
child.clearOverrideSize();
if (child.isImage() || child.isVideo() || child.isCanvas())
UseCounter::count(document(), UseCounter::AspectRatioFlexItem);
Length flexBasis = flexBasisForChild(child);
if (preferredMainAxisExtentDependsOnLayout(flexBasis, hasInfiniteLineLength)) {
LayoutUnit mainAxisExtent;
if (hasOrthogonalFlow(child)) {
if (child.needsLayout() || relayoutChildren || !m_intrinsicSizeAlongMainAxis.contains(&child)) {
m_intrinsicSizeAlongMainAxis.remove(&child);
child.forceChildLayout();
m_intrinsicSizeAlongMainAxis.set(&child, child.logicalHeight());
}
mainAxisExtent = m_intrinsicSizeAlongMainAxis.get(&child);
} else {
mainAxisExtent = child.maxPreferredLogicalWidth();
}
ASSERT(mainAxisExtent - mainAxisBorderAndPaddingExtentForChild(child) >= 0);
return mainAxisExtent - mainAxisBorderAndPaddingExtentForChild(child);
}
return std::max(LayoutUnit(0), computeMainAxisExtentForChild(child, MainOrPreferredSize, flexBasis));
}
void RenderFlexibleBox::layoutFlexItems(bool relayoutChildren)
{
Vector<LineContext> lineContexts;
OrderedFlexItemList orderedChildren;
LayoutUnit sumFlexBaseSize;
double totalFlexGrow;
double totalWeightedFlexShrink;
LayoutUnit sumHypotheticalMainSize;
Vector<LayoutUnit, 16> childSizes;
m_orderIterator.first();
LayoutUnit crossAxisOffset = flowAwareBorderBefore() + flowAwarePaddingBefore();
bool hasInfiniteLineLength = false;
while (computeNextFlexLine(orderedChildren, sumFlexBaseSize, totalFlexGrow, totalWeightedFlexShrink, sumHypotheticalMainSize, hasInfiniteLineLength, relayoutChildren)) {
LayoutUnit containerMainInnerSize = mainAxisContentExtent(sumHypotheticalMainSize);
LayoutUnit availableFreeSpace = containerMainInnerSize - sumFlexBaseSize;
FlexSign flexSign = (sumHypotheticalMainSize < containerMainInnerSize) ? PositiveFlexibility : NegativeFlexibility;
InflexibleFlexItemSize inflexibleItems;
childSizes.reserveCapacity(orderedChildren.size());
while (!resolveFlexibleLengths(flexSign, orderedChildren, availableFreeSpace, totalFlexGrow, totalWeightedFlexShrink, inflexibleItems, childSizes, hasInfiniteLineLength)) {
ASSERT(totalFlexGrow >= 0 && totalWeightedFlexShrink >= 0);
ASSERT(inflexibleItems.size() > 0);
}
layoutAndPlaceChildren(crossAxisOffset, orderedChildren, childSizes, availableFreeSpace, relayoutChildren, lineContexts, hasInfiniteLineLength);
}
if (hasLineIfEmpty()) {
// Even if computeNextFlexLine returns true, the flexbox might not have
// a line because all our children might be out of flow positioned.
// Instead of just checking if we have a line, make sure the flexbox
// has at least a line's worth of height to cover this case.
LayoutUnit minHeight = borderAndPaddingLogicalHeight()
+ lineHeight(true, isHorizontalWritingMode() ? HorizontalLine : VerticalLine, PositionOfInteriorLineBoxes)
+ scrollbarLogicalHeight();
if (height() < minHeight)
setLogicalHeight(minHeight);
}
updateLogicalHeight();
repositionLogicalHeightDependentFlexItems(lineContexts);
}
LayoutUnit RenderFlexibleBox::autoMarginOffsetInMainAxis(const OrderedFlexItemList& children, LayoutUnit& availableFreeSpace)
{
if (availableFreeSpace <= 0)
return 0;
int numberOfAutoMargins = 0;
bool isHorizontal = isHorizontalFlow();
for (size_t i = 0; i < children.size(); ++i) {
RenderBox* child = children[i];
if (child->isOutOfFlowPositioned())
continue;
if (isHorizontal) {
if (child->style()->marginLeft().isAuto())
++numberOfAutoMargins;
if (child->style()->marginRight().isAuto())
++numberOfAutoMargins;
} else {
if (child->style()->marginTop().isAuto())
++numberOfAutoMargins;
if (child->style()->marginBottom().isAuto())
++numberOfAutoMargins;
}
}
if (!numberOfAutoMargins)
return 0;
LayoutUnit sizeOfAutoMargin = availableFreeSpace / numberOfAutoMargins;
availableFreeSpace = 0;
return sizeOfAutoMargin;
}
void RenderFlexibleBox::updateAutoMarginsInMainAxis(RenderBox& child, LayoutUnit autoMarginOffset)
{
ASSERT(autoMarginOffset >= 0);
if (isHorizontalFlow()) {
if (child.style()->marginLeft().isAuto())
child.setMarginLeft(autoMarginOffset);
if (child.style()->marginRight().isAuto())
child.setMarginRight(autoMarginOffset);
} else {
if (child.style()->marginTop().isAuto())
child.setMarginTop(autoMarginOffset);
if (child.style()->marginBottom().isAuto())
child.setMarginBottom(autoMarginOffset);
}
}
bool RenderFlexibleBox::hasAutoMarginsInCrossAxis(RenderBox& child) const
{
if (isHorizontalFlow())
return child.style()->marginTop().isAuto() || child.style()->marginBottom().isAuto();
return child.style()->marginLeft().isAuto() || child.style()->marginRight().isAuto();
}
LayoutUnit RenderFlexibleBox::availableAlignmentSpaceForChild(LayoutUnit lineCrossAxisExtent, RenderBox& child)
{
ASSERT(!child.isOutOfFlowPositioned());
LayoutUnit childCrossExtent = crossAxisMarginExtentForChild(child) + crossAxisExtentForChild(child);
return lineCrossAxisExtent - childCrossExtent;
}
LayoutUnit RenderFlexibleBox::availableAlignmentSpaceForChildBeforeStretching(LayoutUnit lineCrossAxisExtent, RenderBox& child)
{
ASSERT(!child.isOutOfFlowPositioned());
LayoutUnit childCrossExtent = crossAxisMarginExtentForChild(child) + crossAxisIntrinsicExtentForChild(child);
return lineCrossAxisExtent - childCrossExtent;
}
bool RenderFlexibleBox::updateAutoMarginsInCrossAxis(RenderBox& child, LayoutUnit availableAlignmentSpace)
{
ASSERT(!child.isOutOfFlowPositioned());
ASSERT(availableAlignmentSpace >= 0);
bool isHorizontal = isHorizontalFlow();
Length topOrLeft = isHorizontal ? child.style()->marginTop() : child.style()->marginLeft();
Length bottomOrRight = isHorizontal ? child.style()->marginBottom() : child.style()->marginRight();
if (topOrLeft.isAuto() && bottomOrRight.isAuto()) {
adjustAlignmentForChild(child, availableAlignmentSpace / 2);
if (isHorizontal) {
child.setMarginTop(availableAlignmentSpace / 2);
child.setMarginBottom(availableAlignmentSpace / 2);
} else {
child.setMarginLeft(availableAlignmentSpace / 2);
child.setMarginRight(availableAlignmentSpace / 2);
}
return true;
}
bool shouldAdjustTopOrLeft = true;
if (isColumnFlow() && !child.style()->isLeftToRightDirection()) {
// For column flows, only make this adjustment if topOrLeft corresponds to the "before" margin,
// so that flipForRightToLeftColumn will do the right thing.
shouldAdjustTopOrLeft = false;
}
if (!isColumnFlow() && child.style()->slowIsFlippedBlocksWritingMode()) {
// If we are a flipped writing mode, we need to adjust the opposite side. This is only needed
// for row flows because this only affects the block-direction axis.
shouldAdjustTopOrLeft = false;
}
if (topOrLeft.isAuto()) {
if (shouldAdjustTopOrLeft)
adjustAlignmentForChild(child, availableAlignmentSpace);
if (isHorizontal)
child.setMarginTop(availableAlignmentSpace);
else
child.setMarginLeft(availableAlignmentSpace);
return true;
}
if (bottomOrRight.isAuto()) {
if (!shouldAdjustTopOrLeft)
adjustAlignmentForChild(child, availableAlignmentSpace);
if (isHorizontal)
child.setMarginBottom(availableAlignmentSpace);
else
child.setMarginRight(availableAlignmentSpace);
return true;
}
return false;
}
LayoutUnit RenderFlexibleBox::marginBoxAscentForChild(RenderBox& child)
{
LayoutUnit ascent = child.firstLineBoxBaseline();
if (ascent == -1)
ascent = crossAxisExtentForChild(child);
return ascent + flowAwareMarginBeforeForChild(child);
}
LayoutUnit RenderFlexibleBox::computeChildMarginValue(Length margin)
{
// When resolving the margins, we use the content size for resolving percent and calc (for percents in calc expressions) margins.
// Fortunately, percent margins are always computed with respect to the block's width, even for margin-top and margin-bottom.
LayoutUnit availableSize = contentLogicalWidth();
return minimumValueForLength(margin, availableSize);
}
void RenderFlexibleBox::prepareOrderIteratorAndMargins()
{
OrderIteratorPopulator populator(m_orderIterator);
for (RenderBox* child = firstChildBox(); child; child = child->nextSiblingBox()) {
populator.collectChild(child);
if (child->isOutOfFlowPositioned())
continue;
// Before running the flex algorithm, 'auto' has a margin of 0.
// Also, if we're not auto sizing, we don't do a layout that computes the start/end margins.
if (isHorizontalFlow()) {
child->setMarginLeft(computeChildMarginValue(child->style()->marginLeft()));
child->setMarginRight(computeChildMarginValue(child->style()->marginRight()));
} else {
child->setMarginTop(computeChildMarginValue(child->style()->marginTop()));
child->setMarginBottom(computeChildMarginValue(child->style()->marginBottom()));
}
}
}
LayoutUnit RenderFlexibleBox::adjustChildSizeForMinAndMax(RenderBox& child, LayoutUnit childSize)
{
Length max = isHorizontalFlow() ? child.style()->maxWidth() : child.style()->maxHeight();
if (max.isSpecifiedOrIntrinsic()) {
LayoutUnit maxExtent = computeMainAxisExtentForChild(child, MaxSize, max);
if (maxExtent != -1 && childSize > maxExtent)
childSize = maxExtent;
}
Length min = isHorizontalFlow() ? child.style()->minWidth() : child.style()->minHeight();
LayoutUnit minExtent = 0;
if (min.isSpecifiedOrIntrinsic())
minExtent = computeMainAxisExtentForChild(child, MinSize, min);
return std::max(childSize, minExtent);
}
bool RenderFlexibleBox::computeNextFlexLine(OrderedFlexItemList& orderedChildren, LayoutUnit& sumFlexBaseSize, double& totalFlexGrow, double& totalWeightedFlexShrink, LayoutUnit& sumHypotheticalMainSize, bool& hasInfiniteLineLength, bool relayoutChildren)
{
orderedChildren.clear();
sumFlexBaseSize = 0;
totalFlexGrow = totalWeightedFlexShrink = 0;
sumHypotheticalMainSize = 0;
if (!m_orderIterator.currentChild())
return false;
LayoutUnit lineBreakLength = mainAxisContentExtent(LayoutUnit::max());
hasInfiniteLineLength = lineBreakLength == LayoutUnit::max();
bool lineHasInFlowItem = false;
for (RenderBox* child = m_orderIterator.currentChild(); child; child = m_orderIterator.next()) {
if (child->isOutOfFlowPositioned()) {
orderedChildren.append(child);
continue;
}
LayoutUnit childMainAxisExtent = preferredMainAxisContentExtentForChild(*child, hasInfiniteLineLength, relayoutChildren);
LayoutUnit childMainAxisMarginBorderPadding = mainAxisBorderAndPaddingExtentForChild(*child)
+ (isHorizontalFlow() ? child->marginWidth() : child->marginHeight());
LayoutUnit childFlexBaseSize = childMainAxisExtent + childMainAxisMarginBorderPadding;
LayoutUnit childMinMaxAppliedMainAxisExtent = adjustChildSizeForMinAndMax(*child, childMainAxisExtent);
LayoutUnit childHypotheticalMainSize = childMinMaxAppliedMainAxisExtent + childMainAxisMarginBorderPadding;
if (isMultiline() && sumHypotheticalMainSize + childHypotheticalMainSize > lineBreakLength && lineHasInFlowItem)
break;
orderedChildren.append(child);
lineHasInFlowItem = true;
sumFlexBaseSize += childFlexBaseSize;
totalFlexGrow += child->style()->flexGrow();
totalWeightedFlexShrink += child->style()->flexShrink() * childMainAxisExtent;
sumHypotheticalMainSize += childHypotheticalMainSize;
}
return true;
}
void RenderFlexibleBox::freezeViolations(const Vector<Violation>& violations, LayoutUnit& availableFreeSpace, double& totalFlexGrow, double& totalWeightedFlexShrink, InflexibleFlexItemSize& inflexibleItems, bool hasInfiniteLineLength)
{
for (size_t i = 0; i < violations.size(); ++i) {
RenderBox* child = violations[i].child;
LayoutUnit childSize = violations[i].childSize;
LayoutUnit preferredChildSize = preferredMainAxisContentExtentForChild(*child, hasInfiniteLineLength);
availableFreeSpace -= childSize - preferredChildSize;
totalFlexGrow -= child->style()->flexGrow();
totalWeightedFlexShrink -= child->style()->flexShrink() * preferredChildSize;
inflexibleItems.set(child, childSize);
}
}
// Returns true if we successfully ran the algorithm and sized the flex items.
bool RenderFlexibleBox::resolveFlexibleLengths(FlexSign flexSign, const OrderedFlexItemList& children, LayoutUnit& availableFreeSpace, double& totalFlexGrow, double& totalWeightedFlexShrink, InflexibleFlexItemSize& inflexibleItems, Vector<LayoutUnit, 16>& childSizes, bool hasInfiniteLineLength)
{
childSizes.resize(0);
LayoutUnit totalViolation = 0;
LayoutUnit usedFreeSpace = 0;
Vector<Violation> minViolations;
Vector<Violation> maxViolations;
for (size_t i = 0; i < children.size(); ++i) {
RenderBox* child = children[i];
if (child->isOutOfFlowPositioned()) {
childSizes.append(0);
continue;
}
if (inflexibleItems.contains(child))
childSizes.append(inflexibleItems.get(child));
else {
LayoutUnit preferredChildSize = preferredMainAxisContentExtentForChild(*child, hasInfiniteLineLength);
LayoutUnit childSize = preferredChildSize;
double extraSpace = 0;
if (availableFreeSpace > 0 && totalFlexGrow > 0 && flexSign == PositiveFlexibility && std::isfinite(totalFlexGrow))
extraSpace = availableFreeSpace * child->style()->flexGrow() / totalFlexGrow;
else if (availableFreeSpace < 0 && totalWeightedFlexShrink > 0 && flexSign == NegativeFlexibility && std::isfinite(totalWeightedFlexShrink))
extraSpace = availableFreeSpace * child->style()->flexShrink() * preferredChildSize / totalWeightedFlexShrink;
if (std::isfinite(extraSpace))
childSize += LayoutUnit::fromFloatRound(extraSpace);
LayoutUnit adjustedChildSize = adjustChildSizeForMinAndMax(*child, childSize);
childSizes.append(adjustedChildSize);
usedFreeSpace += adjustedChildSize - preferredChildSize;
LayoutUnit violation = adjustedChildSize - childSize;
if (violation > 0)
minViolations.append(Violation(child, adjustedChildSize));
else if (violation < 0)
maxViolations.append(Violation(child, adjustedChildSize));
totalViolation += violation;
}
}
if (totalViolation)
freezeViolations(totalViolation < 0 ? maxViolations : minViolations, availableFreeSpace, totalFlexGrow, totalWeightedFlexShrink, inflexibleItems, hasInfiniteLineLength);
else
availableFreeSpace -= usedFreeSpace;
return !totalViolation;
}
static LayoutUnit initialJustifyContentOffset(LayoutUnit availableFreeSpace, ContentPosition justifyContent, ContentDistributionType justifyContentDistribution, unsigned numberOfChildren)
{
if (justifyContent == ContentPositionFlexEnd)
return availableFreeSpace;
if (justifyContent == ContentPositionCenter)
return availableFreeSpace / 2;
if (justifyContentDistribution == ContentDistributionSpaceAround) {
if (availableFreeSpace > 0 && numberOfChildren)
return availableFreeSpace / (2 * numberOfChildren);
else
return availableFreeSpace / 2;
}
return 0;
}
static LayoutUnit justifyContentSpaceBetweenChildren(LayoutUnit availableFreeSpace, ContentDistributionType justifyContentDistribution, unsigned numberOfChildren)
{
if (availableFreeSpace > 0 && numberOfChildren > 1) {
if (justifyContentDistribution == ContentDistributionSpaceBetween)
return availableFreeSpace / (numberOfChildren - 1);
if (justifyContentDistribution == ContentDistributionSpaceAround)
return availableFreeSpace / numberOfChildren;
}
return 0;
}
void RenderFlexibleBox::setLogicalOverrideSize(RenderBox& child, LayoutUnit childPreferredSize)
{
if (hasOrthogonalFlow(child))
child.setOverrideLogicalContentHeight(childPreferredSize - child.borderAndPaddingLogicalHeight());
else
child.setOverrideLogicalContentWidth(childPreferredSize - child.borderAndPaddingLogicalWidth());
}
void RenderFlexibleBox::prepareChildForPositionedLayout(RenderBox& child, LayoutUnit mainAxisOffset, LayoutUnit crossAxisOffset, PositionedLayoutMode layoutMode)
{
ASSERT(child.isOutOfFlowPositioned());
child.containingBlock()->insertPositionedObject(&child);
RenderLayer* childLayer = child.layer();
LayoutUnit inlinePosition = isColumnFlow() ? crossAxisOffset : mainAxisOffset;
if (layoutMode == FlipForRowReverse && style()->flexDirection() == FlowRowReverse)
inlinePosition = mainAxisExtent() - mainAxisOffset;
childLayer->setStaticInlinePosition(inlinePosition);
LayoutUnit staticBlockPosition = isColumnFlow() ? mainAxisOffset : crossAxisOffset;
if (childLayer->staticBlockPosition() != staticBlockPosition) {
childLayer->setStaticBlockPosition(staticBlockPosition);
if (child.style()->hasStaticBlockPosition(style()->isHorizontalWritingMode()))
child.setChildNeedsLayout(MarkOnlyThis);
}
}
ItemPosition RenderFlexibleBox::alignmentForChild(RenderBox& child) const
{
ItemPosition align = RenderStyle::resolveAlignment(style(), child.style(), ItemPositionStretch);
if (align == ItemPositionBaseline && hasOrthogonalFlow(child))
align = ItemPositionFlexStart;
if (style()->flexWrap() == FlexWrapReverse) {
if (align == ItemPositionFlexStart)
align = ItemPositionFlexEnd;
else if (align == ItemPositionFlexEnd)
align = ItemPositionFlexStart;
}
return align;
}
size_t RenderFlexibleBox::numberOfInFlowPositionedChildren(const OrderedFlexItemList& children) const
{
size_t count = 0;
for (size_t i = 0; i < children.size(); ++i) {
RenderBox* child = children[i];
if (!child->isOutOfFlowPositioned())
++count;
}
return count;
}
void RenderFlexibleBox::resetAutoMarginsAndLogicalTopInCrossAxis(RenderBox& child)
{
if (hasAutoMarginsInCrossAxis(child)) {
child.updateLogicalHeight();
if (isHorizontalFlow()) {
if (child.style()->marginTop().isAuto())
child.setMarginTop(0);
if (child.style()->marginBottom().isAuto())
child.setMarginBottom(0);
} else {
if (child.style()->marginLeft().isAuto())
child.setMarginLeft(0);
if (child.style()->marginRight().isAuto())
child.setMarginRight(0);
}
}
}
bool RenderFlexibleBox::needToStretchChildLogicalHeight(RenderBox& child) const
{
if (alignmentForChild(child) != ItemPositionStretch)
return false;
return isHorizontalFlow() && child.style()->height().isAuto();
}
void RenderFlexibleBox::layoutAndPlaceChildren(LayoutUnit& crossAxisOffset, const OrderedFlexItemList& children, const Vector<LayoutUnit, 16>& childSizes, LayoutUnit availableFreeSpace, bool relayoutChildren, Vector<LineContext>& lineContexts, bool hasInfiniteLineLength)
{
ASSERT(childSizes.size() == children.size());
size_t numberOfChildrenForJustifyContent = numberOfInFlowPositionedChildren(children);
LayoutUnit autoMarginOffset = autoMarginOffsetInMainAxis(children, availableFreeSpace);
LayoutUnit mainAxisOffset = flowAwareBorderStart() + flowAwarePaddingStart();
mainAxisOffset += initialJustifyContentOffset(availableFreeSpace, style()->justifyContent(), style()->justifyContentDistribution(), numberOfChildrenForJustifyContent);
if (style()->flexDirection() == FlowRowReverse)
mainAxisOffset += isHorizontalFlow() ? verticalScrollbarWidth() : horizontalScrollbarHeight();
LayoutUnit totalMainExtent = mainAxisExtent();
LayoutUnit maxAscent = 0, maxDescent = 0; // Used when align-items: baseline.
LayoutUnit maxChildCrossAxisExtent = 0;
size_t seenInFlowPositionedChildren = 0;
bool shouldFlipMainAxis = !isColumnFlow() && !isLeftToRightFlow();
for (size_t i = 0; i < children.size(); ++i) {
RenderBox* child = children[i];
if (child->isOutOfFlowPositioned()) {
prepareChildForPositionedLayout(*child, mainAxisOffset, crossAxisOffset, FlipForRowReverse);
continue;
}
// FIXME Investigate if this can be removed based on other flags. crbug.com/370010
child->setMayNeedPaintInvalidation(true);
LayoutUnit childPreferredSize = childSizes[i] + mainAxisBorderAndPaddingExtentForChild(*child);
setLogicalOverrideSize(*child, childPreferredSize);
if (childPreferredSize != mainAxisExtentForChild(*child)) {
child->setChildNeedsLayout(MarkOnlyThis);
} else {
// To avoid double applying margin changes in updateAutoMarginsInCrossAxis, we reset the margins here.
resetAutoMarginsAndLogicalTopInCrossAxis(*child);
}
// We may have already forced relayout for orthogonal flowing children in preferredMainAxisContentExtentForChild.
bool forceChildRelayout = relayoutChildren && !childPreferredMainAxisContentExtentRequiresLayout(*child, hasInfiniteLineLength);
updateBlockChildDirtyBitsBeforeLayout(forceChildRelayout, child);
child->layoutIfNeeded();
updateAutoMarginsInMainAxis(*child, autoMarginOffset);
LayoutUnit childCrossAxisMarginBoxExtent;
if (alignmentForChild(*child) == ItemPositionBaseline && !hasAutoMarginsInCrossAxis(*child)) {
LayoutUnit ascent = marginBoxAscentForChild(*child);
LayoutUnit descent = (crossAxisMarginExtentForChild(*child) + crossAxisExtentForChild(*child)) - ascent;
maxAscent = std::max(maxAscent, ascent);
maxDescent = std::max(maxDescent, descent);
childCrossAxisMarginBoxExtent = maxAscent + maxDescent;
} else {
childCrossAxisMarginBoxExtent = crossAxisIntrinsicExtentForChild(*child) + crossAxisMarginExtentForChild(*child) + crossAxisScrollbarExtentForChild(*child);
}
if (!isColumnFlow())
setLogicalHeight(std::max(logicalHeight(), crossAxisOffset + flowAwareBorderAfter() + flowAwarePaddingAfter() + childCrossAxisMarginBoxExtent + crossAxisScrollbarExtent()));
maxChildCrossAxisExtent = std::max(maxChildCrossAxisExtent, childCrossAxisMarginBoxExtent);
mainAxisOffset += flowAwareMarginStartForChild(*child);
LayoutUnit childMainExtent = mainAxisExtentForChild(*child);
// In an RTL column situation, this will apply the margin-right/margin-end on the left.
// This will be fixed later in flipForRightToLeftColumn.
LayoutPoint childLocation(shouldFlipMainAxis ? totalMainExtent - mainAxisOffset - childMainExtent : mainAxisOffset,
crossAxisOffset + flowAwareMarginBeforeForChild(*child));
// FIXME: Supporting layout deltas.
setFlowAwareLocationForChild(*child, childLocation);
mainAxisOffset += childMainExtent + flowAwareMarginEndForChild(*child);
++seenInFlowPositionedChildren;
if (seenInFlowPositionedChildren < numberOfChildrenForJustifyContent)
mainAxisOffset += justifyContentSpaceBetweenChildren(availableFreeSpace, style()->justifyContentDistribution(), numberOfChildrenForJustifyContent);
}
if (isColumnFlow())
setLogicalHeight(mainAxisOffset + flowAwareBorderEnd() + flowAwarePaddingEnd() + scrollbarLogicalHeight());
if (style()->flexDirection() == FlowColumnReverse) {
// We have to do an extra pass for column-reverse to reposition the flex items since the start depends
// on the height of the flexbox, which we only know after we've positioned all the flex items.
updateLogicalHeight();
layoutColumnReverse(children, crossAxisOffset, availableFreeSpace);
}
if (m_numberOfInFlowChildrenOnFirstLine == -1)
m_numberOfInFlowChildrenOnFirstLine = seenInFlowPositionedChildren;
lineContexts.append(LineContext(crossAxisOffset, maxChildCrossAxisExtent, children.size(), maxAscent));
crossAxisOffset += maxChildCrossAxisExtent;
}
void RenderFlexibleBox::layoutColumnReverse(const OrderedFlexItemList& children, LayoutUnit crossAxisOffset, LayoutUnit availableFreeSpace)
{
// This is similar to the logic in layoutAndPlaceChildren, except we place the children
// starting from the end of the flexbox. We also don't need to layout anything since we're
// just moving the children to a new position.
size_t numberOfChildrenForJustifyContent = numberOfInFlowPositionedChildren(children);
LayoutUnit mainAxisOffset = logicalHeight() - flowAwareBorderEnd() - flowAwarePaddingEnd();
mainAxisOffset -= initialJustifyContentOffset(availableFreeSpace, style()->justifyContent(), style()->justifyContentDistribution(), numberOfChildrenForJustifyContent);
mainAxisOffset -= isHorizontalFlow() ? verticalScrollbarWidth() : horizontalScrollbarHeight();
size_t seenInFlowPositionedChildren = 0;
for (size_t i = 0; i < children.size(); ++i) {
RenderBox* child = children[i];
if (child->isOutOfFlowPositioned()) {
child->layer()->setStaticBlockPosition(mainAxisOffset);
continue;
}
mainAxisOffset -= mainAxisExtentForChild(*child) + flowAwareMarginEndForChild(*child);
setFlowAwareLocationForChild(*child, LayoutPoint(mainAxisOffset, crossAxisOffset + flowAwareMarginBeforeForChild(*child)));
mainAxisOffset -= flowAwareMarginStartForChild(*child);
++seenInFlowPositionedChildren;
if (seenInFlowPositionedChildren < numberOfChildrenForJustifyContent)
mainAxisOffset -= justifyContentSpaceBetweenChildren(availableFreeSpace, style()->justifyContentDistribution(), numberOfChildrenForJustifyContent);
}
}
static LayoutUnit initialAlignContentOffset(LayoutUnit availableFreeSpace, EAlignContent alignContent, unsigned numberOfLines)
{
if (numberOfLines <= 1)
return 0;
if (alignContent == AlignContentFlexEnd)
return availableFreeSpace;
if (alignContent == AlignContentCenter)
return availableFreeSpace / 2;
if (alignContent == AlignContentSpaceAround) {
if (availableFreeSpace > 0 && numberOfLines)
return availableFreeSpace / (2 * numberOfLines);
if (availableFreeSpace < 0)
return availableFreeSpace / 2;
}
return 0;
}
static LayoutUnit alignContentSpaceBetweenChildren(LayoutUnit availableFreeSpace, EAlignContent alignContent, unsigned numberOfLines)
{
if (availableFreeSpace > 0 && numberOfLines > 1) {
if (alignContent == AlignContentSpaceBetween)
return availableFreeSpace / (numberOfLines - 1);
if (alignContent == AlignContentSpaceAround || alignContent == AlignContentStretch)
return availableFreeSpace / numberOfLines;
}
return 0;
}
void RenderFlexibleBox::alignFlexLines(Vector<LineContext>& lineContexts)
{
// If we have a single line flexbox or a multiline line flexbox with only one flex line,
// the line height is all the available space.
// For flex-direction: row, this means we need to use the height, so we do this after calling updateLogicalHeight.
if (lineContexts.size() == 1) {
lineContexts[0].crossAxisExtent = crossAxisContentExtent();
return;
}
if (style()->alignContent() == AlignContentFlexStart)
return;
LayoutUnit availableCrossAxisSpace = crossAxisContentExtent();
for (size_t i = 0; i < lineContexts.size(); ++i)
availableCrossAxisSpace -= lineContexts[i].crossAxisExtent;
RenderBox* child = m_orderIterator.first();
LayoutUnit lineOffset = initialAlignContentOffset(availableCrossAxisSpace, style()->alignContent(), lineContexts.size());
for (unsigned lineNumber = 0; lineNumber < lineContexts.size(); ++lineNumber) {
lineContexts[lineNumber].crossAxisOffset += lineOffset;
for (size_t childNumber = 0; childNumber < lineContexts[lineNumber].numberOfChildren; ++childNumber, child = m_orderIterator.next())
adjustAlignmentForChild(*child, lineOffset);
if (style()->alignContent() == AlignContentStretch && availableCrossAxisSpace > 0)
lineContexts[lineNumber].crossAxisExtent += availableCrossAxisSpace / static_cast<unsigned>(lineContexts.size());
lineOffset += alignContentSpaceBetweenChildren(availableCrossAxisSpace, style()->alignContent(), lineContexts.size());
}
}
void RenderFlexibleBox::adjustAlignmentForChild(RenderBox& child, LayoutUnit delta)
{
if (child.isOutOfFlowPositioned()) {
LayoutUnit staticInlinePosition = child.layer()->staticInlinePosition();
LayoutUnit staticBlockPosition = child.layer()->staticBlockPosition();
LayoutUnit mainAxis = isColumnFlow() ? staticBlockPosition : staticInlinePosition;
LayoutUnit crossAxis = isColumnFlow() ? staticInlinePosition : staticBlockPosition;
crossAxis += delta;
prepareChildForPositionedLayout(child, mainAxis, crossAxis, NoFlipForRowReverse);
return;
}
setFlowAwareLocationForChild(child, flowAwareLocationForChild(child) + LayoutSize(0, delta));
}
void RenderFlexibleBox::alignChildren(const Vector<LineContext>& lineContexts)
{
// Keep track of the space between the baseline edge and the after edge of the box for each line.
Vector<LayoutUnit> minMarginAfterBaselines;
RenderBox* child = m_orderIterator.first();
for (size_t lineNumber = 0; lineNumber < lineContexts.size(); ++lineNumber) {
LayoutUnit minMarginAfterBaseline = LayoutUnit::max();
LayoutUnit lineCrossAxisExtent = lineContexts[lineNumber].crossAxisExtent;
LayoutUnit maxAscent = lineContexts[lineNumber].maxAscent;
for (size_t childNumber = 0; childNumber < lineContexts[lineNumber].numberOfChildren; ++childNumber, child = m_orderIterator.next()) {
ASSERT(child);
if (child->isOutOfFlowPositioned()) {
if (style()->flexWrap() == FlexWrapReverse)
adjustAlignmentForChild(*child, lineCrossAxisExtent);
continue;
}
if (updateAutoMarginsInCrossAxis(*child, std::max(LayoutUnit(0), availableAlignmentSpaceForChild(lineCrossAxisExtent, *child))))
continue;
switch (alignmentForChild(*child)) {
case ItemPositionAuto:
ASSERT_NOT_REACHED();
break;
case ItemPositionStretch: {
applyStretchAlignmentToChild(*child, lineCrossAxisExtent);
// Since wrap-reverse flips cross start and cross end, strech children should be aligned with the cross end.
if (style()->flexWrap() == FlexWrapReverse)
adjustAlignmentForChild(*child, availableAlignmentSpaceForChild(lineCrossAxisExtent, *child));
break;
}
case ItemPositionFlexStart:
break;
case ItemPositionFlexEnd:
adjustAlignmentForChild(*child, availableAlignmentSpaceForChild(lineCrossAxisExtent, *child));
break;
case ItemPositionCenter:
adjustAlignmentForChild(*child, availableAlignmentSpaceForChild(lineCrossAxisExtent, *child) / 2);
break;
case ItemPositionBaseline: {
// FIXME: If we get here in columns, we want the use the descent, except we currently can't get the ascent/descent of orthogonal children.
// https://bugs.webkit.org/show_bug.cgi?id=98076
LayoutUnit ascent = marginBoxAscentForChild(*child);
LayoutUnit startOffset = maxAscent - ascent;
adjustAlignmentForChild(*child, startOffset);
if (style()->flexWrap() == FlexWrapReverse)
minMarginAfterBaseline = std::min(minMarginAfterBaseline, availableAlignmentSpaceForChild(lineCrossAxisExtent, *child) - startOffset);
break;
}
case ItemPositionLastBaseline:
case ItemPositionSelfStart:
case ItemPositionSelfEnd:
case ItemPositionStart:
case ItemPositionEnd:
case ItemPositionLeft:
case ItemPositionRight:
// FIXME: File a bug about implementing that. The extended grammar
// is not enabled by default so we shouldn't hit this codepath.
ASSERT_NOT_REACHED();
break;
}
}
minMarginAfterBaselines.append(minMarginAfterBaseline);
}
if (style()->flexWrap() != FlexWrapReverse)
return;
// wrap-reverse flips the cross axis start and end. For baseline alignment, this means we
// need to align the after edge of baseline elements with the after edge of the flex line.
child = m_orderIterator.first();
for (size_t lineNumber = 0; lineNumber < lineContexts.size(); ++lineNumber) {
LayoutUnit minMarginAfterBaseline = minMarginAfterBaselines[lineNumber];
for (size_t childNumber = 0; childNumber < lineContexts[lineNumber].numberOfChildren; ++childNumber, child = m_orderIterator.next()) {
ASSERT(child);
if (alignmentForChild(*child) == ItemPositionBaseline && !hasAutoMarginsInCrossAxis(*child) && minMarginAfterBaseline)
adjustAlignmentForChild(*child, minMarginAfterBaseline);
}
}
}
void RenderFlexibleBox::applyStretchAlignmentToChild(RenderBox& child, LayoutUnit lineCrossAxisExtent)
{
if (!isColumnFlow() && child.style()->logicalHeight().isAuto()) {
// FIXME: If the child has orthogonal flow, then it already has an override height set, so use it.
if (!hasOrthogonalFlow(child)) {
LayoutUnit heightBeforeStretching = needToStretchChildLogicalHeight(child) ? constrainedChildIntrinsicContentLogicalHeight(child) : child.logicalHeight();
LayoutUnit stretchedLogicalHeight = heightBeforeStretching + availableAlignmentSpaceForChildBeforeStretching(lineCrossAxisExtent, child);
ASSERT(!child.needsLayout());
LayoutUnit desiredLogicalHeight = child.constrainLogicalHeightByMinMax(stretchedLogicalHeight, heightBeforeStretching - child.borderAndPaddingLogicalHeight());
// FIXME: Can avoid laying out here in some cases. See https://webkit.org/b/87905.
bool childNeedsRelayout = desiredLogicalHeight != child.logicalHeight();
if (childNeedsRelayout || !child.hasOverrideHeight())
child.setOverrideLogicalContentHeight(desiredLogicalHeight - child.borderAndPaddingLogicalHeight());
if (childNeedsRelayout) {
child.setLogicalHeight(0);
child.forceChildLayout();
}
}
} else if (isColumnFlow() && child.style()->logicalWidth().isAuto()) {
// FIXME: If the child doesn't have orthogonal flow, then it already has an override width set, so use it.
if (hasOrthogonalFlow(child)) {
LayoutUnit childWidth = std::max<LayoutUnit>(0, lineCrossAxisExtent - crossAxisMarginExtentForChild(child));
childWidth = child.constrainLogicalWidthByMinMax(childWidth, childWidth, this);
if (childWidth != child.logicalWidth()) {
child.setOverrideLogicalContentWidth(childWidth - child.borderAndPaddingLogicalWidth());
child.forceChildLayout();
}
}
}
}
void RenderFlexibleBox::flipForRightToLeftColumn()
{
if (style()->isLeftToRightDirection() || !isColumnFlow())
return;
LayoutUnit crossExtent = crossAxisExtent();
for (RenderBox* child = m_orderIterator.first(); child; child = m_orderIterator.next()) {
if (child->isOutOfFlowPositioned())
continue;
LayoutPoint location = flowAwareLocationForChild(*child);
// For vertical flows, setFlowAwareLocationForChild will transpose x and y,
// so using the y axis for a column cross axis extent is correct.
location.setY(crossExtent - crossAxisExtentForChild(*child) - location.y());
setFlowAwareLocationForChild(*child, location);
}
}
void RenderFlexibleBox::flipForWrapReverse(const Vector<LineContext>& lineContexts, LayoutUnit crossAxisStartEdge)
{
LayoutUnit contentExtent = crossAxisContentExtent();
RenderBox* child = m_orderIterator.first();
for (size_t lineNumber = 0; lineNumber < lineContexts.size(); ++lineNumber) {
for (size_t childNumber = 0; childNumber < lineContexts[lineNumber].numberOfChildren; ++childNumber, child = m_orderIterator.next()) {
ASSERT(child);
LayoutUnit lineCrossAxisExtent = lineContexts[lineNumber].crossAxisExtent;
LayoutUnit originalOffset = lineContexts[lineNumber].crossAxisOffset - crossAxisStartEdge;
LayoutUnit newOffset = contentExtent - originalOffset - lineCrossAxisExtent;
adjustAlignmentForChild(*child, newOffset - originalOffset);
}
}
}
}