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/*
* Copyright (C) 2011 Apple Inc. All rights reserved.
* Copyright (C) 2013-2017 Igalia S.L.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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 "RenderGrid.h"
#include "GridArea.h"
#include "GridLayoutFunctions.h"
#include "GridPositionsResolver.h"
#include "GridTrackSizingAlgorithm.h"
#include "InspectorInstrumentation.h"
#include "LayoutRepainter.h"
#include "RenderChildIterator.h"
#include "RenderLayer.h"
#include "RenderLayoutState.h"
#include "RenderTreeBuilder.h"
#include "RenderView.h"
#include <cstdlib>
#include <wtf/IsoMallocInlines.h>
namespace WebCore {
WTF_MAKE_ISO_ALLOCATED_IMPL(RenderGrid);
enum TrackSizeRestriction {
AllowInfinity,
ForbidInfinity,
};
RenderGrid::RenderGrid(Element& element, RenderStyle&& style)
: RenderBlock(element, WTFMove(style), 0)
, m_grid(*this)
, m_trackSizingAlgorithm(this, m_grid)
{
// All of our children must be block level.
setChildrenInline(false);
InspectorInstrumentation::nodeLayoutContextChanged(element, this);
}
RenderGrid::~RenderGrid()
{
InspectorInstrumentation::nodeLayoutContextChanged(element(), nullptr);
}
StyleSelfAlignmentData RenderGrid::selfAlignmentForChild(GridAxis axis, const RenderBox& child, const RenderStyle* gridStyle) const
{
return axis == GridRowAxis ? justifySelfForChild(child, StretchingMode::Any, gridStyle) : alignSelfForChild(child, StretchingMode::Any, gridStyle);
}
bool RenderGrid::selfAlignmentChangedToStretch(GridAxis axis, const RenderStyle& oldStyle, const RenderStyle& newStyle, const RenderBox& child) const
{
return selfAlignmentForChild(axis, child, &oldStyle).position() != ItemPosition::Stretch
&& selfAlignmentForChild(axis, child, &newStyle).position() == ItemPosition::Stretch;
}
bool RenderGrid::selfAlignmentChangedFromStretch(GridAxis axis, const RenderStyle& oldStyle, const RenderStyle& newStyle, const RenderBox& child) const
{
return selfAlignmentForChild(axis, child, &oldStyle).position() == ItemPosition::Stretch
&& selfAlignmentForChild(axis, child, &newStyle).position() != ItemPosition::Stretch;
}
void RenderGrid::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
{
RenderBlock::styleDidChange(diff, oldStyle);
if (!oldStyle || diff != StyleDifference::Layout)
return;
const RenderStyle& newStyle = this->style();
if (oldStyle->resolvedAlignItems(selfAlignmentNormalBehavior(this)).position() == ItemPosition::Stretch) {
// Style changes on the grid container implying stretching (to-stretch) or
// shrinking (from-stretch) require the affected items to be laid out again.
// These logic only applies to 'stretch' since the rest of the alignment
// values don't change the size of the box.
// In any case, the items' overrideSize will be cleared and recomputed (if
// necessary) as part of the Grid layout logic, triggered by this style
// change.
for (auto& child : childrenOfType<RenderBox>(*this)) {
if (child.isOutOfFlowPositioned())
continue;
if (selfAlignmentChangedToStretch(GridRowAxis, *oldStyle, newStyle, child)
|| selfAlignmentChangedFromStretch(GridRowAxis, *oldStyle, newStyle, child)
|| selfAlignmentChangedToStretch(GridColumnAxis, *oldStyle, newStyle, child)
|| selfAlignmentChangedFromStretch(GridColumnAxis, *oldStyle, newStyle, child)) {
child.setNeedsLayout();
}
}
}
if (explicitGridDidResize(*oldStyle) || namedGridLinesDefinitionDidChange(*oldStyle) || oldStyle->gridAutoFlow() != style().gridAutoFlow()
|| (style().gridAutoRepeatColumns().size() || style().gridAutoRepeatRows().size()))
dirtyGrid();
}
bool RenderGrid::explicitGridDidResize(const RenderStyle& oldStyle) const
{
return oldStyle.gridColumns().size() != style().gridColumns().size()
|| oldStyle.gridRows().size() != style().gridRows().size()
|| oldStyle.namedGridAreaColumnCount() != style().namedGridAreaColumnCount()
|| oldStyle.namedGridAreaRowCount() != style().namedGridAreaRowCount()
|| oldStyle.gridAutoRepeatColumns().size() != style().gridAutoRepeatColumns().size()
|| oldStyle.gridAutoRepeatRows().size() != style().gridAutoRepeatRows().size();
}
bool RenderGrid::namedGridLinesDefinitionDidChange(const RenderStyle& oldStyle) const
{
return oldStyle.namedGridRowLines() != style().namedGridRowLines()
|| oldStyle.namedGridColumnLines() != style().namedGridColumnLines();
}
// This method optimizes the gutters computation by skiping the available size
// call if gaps are fixed size (it's only needed for percentages).
std::optional<LayoutUnit> RenderGrid::availableSpaceForGutters(GridTrackSizingDirection direction) const
{
bool isRowAxis = direction == ForColumns;
const GapLength& gapLength = isRowAxis ? style().columnGap() : style().rowGap();
if (gapLength.isNormal() || !gapLength.length().isPercentOrCalculated())
return std::nullopt;
return isRowAxis ? availableLogicalWidth() : contentLogicalHeight();
}
void RenderGrid::computeTrackSizesForDefiniteSize(GridTrackSizingDirection direction, LayoutUnit availableSpace)
{
m_trackSizingAlgorithm.setup(direction, numTracks(direction, m_grid), TrackSizing, availableSpace);
m_trackSizingAlgorithm.run();
ASSERT(m_trackSizingAlgorithm.tracksAreWiderThanMinTrackBreadth());
}
void RenderGrid::repeatTracksSizingIfNeeded(LayoutUnit availableSpaceForColumns, LayoutUnit availableSpaceForRows)
{
// In orthogonal flow cases column track's size is determined by using the computed
// row track's size, which it was estimated during the first cycle of the sizing
// algorithm. Hence we need to repeat computeUsedBreadthOfGridTracks for both,
// columns and rows, to determine the final values.
// TODO (lajava): orthogonal flows is just one of the cases which may require
// a new cycle of the sizing algorithm; there may be more. In addition, not all the
// cases with orthogonal flows require this extra cycle; we need a more specific
// condition to detect whether child's min-content contribution has changed or not.
// The complication with repeating the track sizing algorithm for flex max-sizing is that
// it might change a grid item's status of participating in Baseline Alignment for
// a cyclic sizing dependncy case, which should be definitively excluded. See
// https://github.com/w3c/csswg-drafts/issues/3046 for details.
// FIXME: we are avoiding repeating the track sizing algorithm for grid item with baseline alignment
// here in the case of using flex max-sizing functions. We probably also need to investigate whether
// it is applicable for the case of percent-sized rows with indefinite height as well.
if (m_hasAnyOrthogonalItem || m_trackSizingAlgorithm.hasAnyPercentSizedRowsIndefiniteHeight() || (m_trackSizingAlgorithm.hasAnyFlexibleMaxTrackBreadth() && !m_trackSizingAlgorithm.hasAnyBaselineAlignmentItem()) || m_hasAspectRatioBlockSizeDependentItem) {
computeTrackSizesForDefiniteSize(ForColumns, availableSpaceForColumns);
computeContentPositionAndDistributionOffset(ForColumns, m_trackSizingAlgorithm.freeSpace(ForColumns).value(), nonCollapsedTracks(ForColumns));
computeTrackSizesForDefiniteSize(ForRows, availableSpaceForRows);
computeContentPositionAndDistributionOffset(ForRows, m_trackSizingAlgorithm.freeSpace(ForRows).value(), nonCollapsedTracks(ForRows));
}
}
bool RenderGrid::canPerformSimplifiedLayout() const
{
// We cannot perform a simplified layout if we need to position the items and we have some
// positioned items to be laid out.
if (m_grid.needsItemsPlacement() && posChildNeedsLayout())
return false;
return RenderBlock::canPerformSimplifiedLayout();
}
void RenderGrid::layoutBlock(bool relayoutChildren, LayoutUnit)
{
ASSERT(needsLayout());
if (!relayoutChildren && simplifiedLayout())
return;
LayoutRepainter repainter(*this, checkForRepaintDuringLayout());
{
LayoutStateMaintainer statePusher(*this, locationOffset(), hasTransform() || hasReflection() || style().isFlippedBlocksWritingMode());
preparePaginationBeforeBlockLayout(relayoutChildren);
beginUpdateScrollInfoAfterLayoutTransaction();
LayoutSize previousSize = size();
// FIXME: We should use RenderBlock::hasDefiniteLogicalHeight() only but it does not work for positioned stuff.
// FIXME: Consider caching the hasDefiniteLogicalHeight value throughout the layout.
// FIXME: We might need to cache the hasDefiniteLogicalHeight if the call of RenderBlock::hasDefiniteLogicalHeight() causes a relevant performance regression.
bool hasDefiniteLogicalHeight = RenderBlock::hasDefiniteLogicalHeight() || hasOverridingLogicalHeight() || computeContentLogicalHeight(MainOrPreferredSize, style().logicalHeight(), std::nullopt);
m_hasAnyOrthogonalItem = false;
m_hasAspectRatioBlockSizeDependentItem = false;
Vector<RenderBox*> aspectRatioBlockSizeDependentGridItems;
for (auto* child = firstChildBox(); child; child = child->nextSiblingBox()) {
if (child->isOutOfFlowPositioned())
continue;
// Grid's layout logic controls the grid item's override height, hence we need to
// clear any override height set previously, so it doesn't interfere in current layout
// execution. Grid never uses the override width, that's why we don't need to clear it.
child->clearOverridingLogicalHeight();
// We may need to repeat the track sizing in case of any grid item was orthogonal.
if (GridLayoutFunctions::isOrthogonalChild(*this, *child))
m_hasAnyOrthogonalItem = true;
// For a grid item that has an aspect-ratio and block-constraints such as the relative logical height,
// when the grid width is auto, we may need get the real grid width before laying out the item.
if (GridLayoutFunctions::isAspectRatioBlockSizeDependentChild(*child) && (style().logicalWidth().isAuto() || style().logicalWidth().isMinContent() || style().logicalWidth().isMaxContent())) {
aspectRatioBlockSizeDependentGridItems.append(child);
m_hasAspectRatioBlockSizeDependentItem = true;
}
// We keep a cache of items with baseline as alignment values so
// that we only compute the baseline shims for such items. This
// cache is needed for performance related reasons due to the
// cost of evaluating the item's participation in a baseline
// context during the track sizing algorithm.
if (isBaselineAlignmentForChild(*child, GridColumnAxis))
m_trackSizingAlgorithm.cacheBaselineAlignedItem(*child, GridColumnAxis);
if (isBaselineAlignmentForChild(*child, GridRowAxis))
m_trackSizingAlgorithm.cacheBaselineAlignedItem(*child, GridRowAxis);
}
m_baselineItemsCached = true;
resetLogicalHeightBeforeLayoutIfNeeded();
updateLogicalWidth();
// 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 availableSpaceForColumns = availableLogicalWidth();
placeItemsOnGrid(m_trackSizingAlgorithm, availableSpaceForColumns);
m_trackSizingAlgorithm.setAvailableSpace(ForColumns, availableSpaceForColumns);
performGridItemsPreLayout(m_trackSizingAlgorithm);
// 1- First, the track sizing algorithm is used to resolve the sizes of the
// grid columns.
// At this point the logical width is always definite as the above call to
// updateLogicalWidth() properly resolves intrinsic sizes. We cannot do the
// same for heights though because many code paths inside
// updateLogicalHeight() require a previous call to setLogicalHeight() to
// resolve heights properly (like for positioned items for example).
computeTrackSizesForDefiniteSize(ForColumns, availableSpaceForColumns);
// 1.5- Compute Content Distribution offsets for column tracks
computeContentPositionAndDistributionOffset(ForColumns, m_trackSizingAlgorithm.freeSpace(ForColumns).value(), nonCollapsedTracks(ForColumns));
// 2- Next, the track sizing algorithm resolves the sizes of the grid rows,
// using the grid column sizes calculated in the previous step.
bool shouldRecomputeHeight = false;
if (!hasDefiniteLogicalHeight) {
computeTrackSizesForIndefiniteSize(m_trackSizingAlgorithm, ForRows);
if (shouldApplySizeContainment(*this))
shouldRecomputeHeight = true;
} else
computeTrackSizesForDefiniteSize(ForRows, availableLogicalHeight(ExcludeMarginBorderPadding));
LayoutUnit trackBasedLogicalHeight = m_trackSizingAlgorithm.computeTrackBasedSize() + borderAndPaddingLogicalHeight() + scrollbarLogicalHeight();
if (shouldRecomputeHeight)
computeTrackSizesForDefiniteSize(ForRows, trackBasedLogicalHeight);
setLogicalHeight(trackBasedLogicalHeight);
updateLogicalHeight();
// Once grid's indefinite height is resolved, we can compute the
// available free space for Content Alignment.
if (!hasDefiniteLogicalHeight)
m_trackSizingAlgorithm.setFreeSpace(ForRows, logicalHeight() - trackBasedLogicalHeight);
// 2.5- Compute Content Distribution offsets for rows tracks
computeContentPositionAndDistributionOffset(ForRows, m_trackSizingAlgorithm.freeSpace(ForRows).value(), nonCollapsedTracks(ForRows));
if (!aspectRatioBlockSizeDependentGridItems.isEmpty()) {
updateGridAreaForAspectRatioItems(aspectRatioBlockSizeDependentGridItems);
updateLogicalWidth();
}
// 3- If the min-content contribution of any grid items have changed based on the row
// sizes calculated in step 2, steps 1 and 2 are repeated with the new min-content
// contribution (once only).
repeatTracksSizingIfNeeded(availableSpaceForColumns, contentLogicalHeight());
// Grid container should have the minimum height of a line if it's editable. That does not affect track sizing though.
if (hasLineIfEmpty()) {
LayoutUnit minHeightForEmptyLine = borderAndPaddingLogicalHeight()
+ lineHeight(true, isHorizontalWritingMode() ? HorizontalLine : VerticalLine, PositionOfInteriorLineBoxes)
+ scrollbarLogicalHeight();
setLogicalHeight(std::max(logicalHeight(), minHeightForEmptyLine));
}
layoutGridItems();
m_trackSizingAlgorithm.reset();
endAndCommitUpdateScrollInfoAfterLayoutTransaction();
if (size() != previousSize)
relayoutChildren = true;
m_outOfFlowItemColumn.clear();
m_outOfFlowItemRow.clear();
layoutPositionedObjects(relayoutChildren || isDocumentElementRenderer());
computeOverflow(clientLogicalRightAndBottomAfterRepositioning().height());
}
updateLayerTransform();
// Update our scroll information if we're overflow:auto/scroll/hidden now that we know if
// we overflow or not.
updateScrollInfoAfterLayout();
repainter.repaintAfterLayout();
clearNeedsLayout();
m_trackSizingAlgorithm.clearBaselineItemsCache();
m_baselineItemsCached = false;
}
LayoutUnit RenderGrid::gridGap(GridTrackSizingDirection direction, std::optional<LayoutUnit> availableSize) const
{
ASSERT(!availableSize || *availableSize >= 0);
const GapLength& gapLength = direction == ForColumns? style().columnGap() : style().rowGap();
if (gapLength.isNormal())
return 0_lu;
return valueForLength(gapLength.length(), availableSize.value_or(0));
}
LayoutUnit RenderGrid::gridGap(GridTrackSizingDirection direction) const
{
return gridGap(direction, availableSpaceForGutters(direction));
}
LayoutUnit RenderGrid::gridItemOffset(GridTrackSizingDirection direction) const
{
return direction == ForRows ? m_offsetBetweenRows.distributionOffset : m_offsetBetweenColumns.distributionOffset;
}
LayoutUnit RenderGrid::guttersSize(const Grid& grid, GridTrackSizingDirection direction, unsigned startLine, unsigned span, std::optional<LayoutUnit> availableSize) const
{
if (span <= 1)
return { };
LayoutUnit gap = gridGap(direction, availableSize);
// Fast path, no collapsing tracks.
if (!grid.hasAutoRepeatEmptyTracks(direction))
return gap * (span - 1);
// If there are collapsing tracks we need to be sure that gutters are properly collapsed. Apart
// from that, if we have a collapsed track in the edges of the span we're considering, we need
// to move forward (or backwards) in order to know whether the collapsed tracks reach the end of
// the grid (so the gap becomes 0) or there is a non empty track before that.
LayoutUnit gapAccumulator;
unsigned endLine = startLine + span;
for (unsigned line = startLine; line < endLine - 1; ++line) {
if (!grid.isEmptyAutoRepeatTrack(direction, line))
gapAccumulator += gap;
}
// The above loop adds one extra gap for trailing collapsed tracks.
if (gapAccumulator && grid.isEmptyAutoRepeatTrack(direction, endLine - 1)) {
ASSERT(gapAccumulator >= gap);
gapAccumulator -= gap;
}
// If the startLine is the start line of a collapsed track we need to go backwards till we reach
// a non collapsed track. If we find a non collapsed track we need to add that gap.
size_t nonEmptyTracksBeforeStartLine = 0;
if (startLine && grid.isEmptyAutoRepeatTrack(direction, startLine)) {
nonEmptyTracksBeforeStartLine = startLine;
auto begin = grid.autoRepeatEmptyTracks(direction)->begin();
for (auto it = begin; *it != startLine; ++it) {
ASSERT(nonEmptyTracksBeforeStartLine);
--nonEmptyTracksBeforeStartLine;
}
if (nonEmptyTracksBeforeStartLine)
gapAccumulator += gap;
}
// If the endLine is the end line of a collapsed track we need to go forward till we reach a non
// collapsed track. If we find a non collapsed track we need to add that gap.
if (grid.isEmptyAutoRepeatTrack(direction, endLine - 1)) {
unsigned nonEmptyTracksAfterEndLine = grid.numTracks(direction) - endLine;
auto currentEmptyTrack = grid.autoRepeatEmptyTracks(direction)->find(endLine - 1);
auto endEmptyTrack = grid.autoRepeatEmptyTracks(direction)->end();
// HashSet iterators do not implement operator- so we have to manually iterate to know the number of remaining empty tracks.
for (auto it = ++currentEmptyTrack; it != endEmptyTrack; ++it) {
ASSERT(nonEmptyTracksAfterEndLine >= 1);
--nonEmptyTracksAfterEndLine;
}
if (nonEmptyTracksAfterEndLine) {
// We shouldn't count the gap twice if the span starts and ends in a collapsed track bewtween two non-empty tracks.
if (!nonEmptyTracksBeforeStartLine)
gapAccumulator += gap;
} else if (nonEmptyTracksBeforeStartLine) {
// We shouldn't count the gap if the the span starts and ends in a collapsed but there isn't non-empty tracks afterwards (it's at the end of the grid).
gapAccumulator -= gap;
}
}
return gapAccumulator;
}
void RenderGrid::computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const
{
LayoutUnit childMinWidth;
LayoutUnit childMaxWidth;
bool hadExcludedChildren = computePreferredWidthsForExcludedChildren(childMinWidth, childMaxWidth);
Grid grid(const_cast<RenderGrid&>(*this));
GridTrackSizingAlgorithm algorithm(this, grid);
placeItemsOnGrid(algorithm, std::nullopt);
performGridItemsPreLayout(algorithm);
if (m_baselineItemsCached)
algorithm.copyBaselineItemsCache(m_trackSizingAlgorithm, GridRowAxis);
else {
for (auto* child = firstChildBox(); child; child = child->nextSiblingBox()) {
if (child->isOutOfFlowPositioned())
continue;
if (isBaselineAlignmentForChild(*child, GridRowAxis))
algorithm.cacheBaselineAlignedItem(*child, GridRowAxis);
}
}
computeTrackSizesForIndefiniteSize(algorithm, ForColumns, &minLogicalWidth, &maxLogicalWidth);
if (hadExcludedChildren) {
minLogicalWidth = std::max(minLogicalWidth, childMinWidth);
maxLogicalWidth = std::max(maxLogicalWidth, childMaxWidth);
}
LayoutUnit scrollbarWidth = intrinsicScrollbarLogicalWidth();
minLogicalWidth += scrollbarWidth;
maxLogicalWidth += scrollbarWidth;
}
void RenderGrid::computeTrackSizesForIndefiniteSize(GridTrackSizingAlgorithm& algorithm, GridTrackSizingDirection direction, LayoutUnit* minIntrinsicSize, LayoutUnit* maxIntrinsicSize) const
{
const Grid& grid = algorithm.grid();
algorithm.setup(direction, numTracks(direction, grid), IntrinsicSizeComputation, std::nullopt);
algorithm.run();
size_t numberOfTracks = algorithm.tracks(direction).size();
LayoutUnit totalGuttersSize = guttersSize(grid, direction, 0, numberOfTracks, std::nullopt);
if (minIntrinsicSize)
*minIntrinsicSize = algorithm.minContentSize() + totalGuttersSize;
if (maxIntrinsicSize)
*maxIntrinsicSize = algorithm.maxContentSize() + totalGuttersSize;
ASSERT(algorithm.tracksAreWiderThanMinTrackBreadth());
}
unsigned RenderGrid::computeAutoRepeatTracksCount(GridTrackSizingDirection direction, std::optional<LayoutUnit> availableSize) const
{
ASSERT(!availableSize || availableSize.value() != -1);
bool isRowAxis = direction == ForColumns;
const auto& autoRepeatTracks = isRowAxis ? style().gridAutoRepeatColumns() : style().gridAutoRepeatRows();
unsigned autoRepeatTrackListLength = autoRepeatTracks.size();
if (!autoRepeatTrackListLength)
return 0;
bool needsToFulfillMinimumSize = false;
if (!availableSize) {
const Length& maxSize = isRowAxis ? style().logicalMaxWidth() : style().logicalMaxHeight();
std::optional<LayoutUnit> containingBlockAvailableSize;
std::optional<LayoutUnit> availableMaxSize;
if (maxSize.isSpecified()) {
if (maxSize.isPercentOrCalculated())
containingBlockAvailableSize = isRowAxis ? containingBlockLogicalWidthForContent() : containingBlockLogicalHeightForContent(ExcludeMarginBorderPadding);
LayoutUnit maxSizeValue = valueForLength(maxSize, containingBlockAvailableSize.value_or(LayoutUnit()));
availableMaxSize = isRowAxis ? adjustContentBoxLogicalWidthForBoxSizing(maxSizeValue, maxSize.type()) : adjustContentBoxLogicalHeightForBoxSizing(maxSizeValue);
}
const Length& minSize = isRowAxis ? style().logicalMinWidth() : style().logicalMinHeight();
const auto& minSizeForOrthogonalAxis = isRowAxis ? style().logicalMinHeight() : style().logicalMinWidth();
bool shouldComputeMinSizeFromAspectRatio = minSizeForOrthogonalAxis.isSpecified() && !shouldIgnoreAspectRatio();
if (!availableMaxSize && !minSize.isSpecified() && !shouldComputeMinSizeFromAspectRatio)
return autoRepeatTrackListLength;
std::optional<LayoutUnit> availableMinSize;
if (minSize.isSpecified()) {
if (!containingBlockAvailableSize && minSize.isPercentOrCalculated())
containingBlockAvailableSize = isRowAxis ? containingBlockLogicalWidthForContent() : containingBlockLogicalHeightForContent(ExcludeMarginBorderPadding);
LayoutUnit minSizeValue = valueForLength(minSize, containingBlockAvailableSize.value_or(LayoutUnit()));
availableMinSize = isRowAxis ? adjustContentBoxLogicalWidthForBoxSizing(minSizeValue, minSize.type()) : adjustContentBoxLogicalHeightForBoxSizing(minSizeValue);
} else if (shouldComputeMinSizeFromAspectRatio) {
auto [logicalMinWidth, logicalMaxWidth] = computeMinMaxLogicalWidthFromAspectRatio();
availableMinSize = logicalMinWidth;
}
if (!maxSize.isSpecified())
needsToFulfillMinimumSize = true;
availableSize = std::max(availableMinSize.value_or(LayoutUnit()), availableMaxSize.value_or(LayoutUnit()));
}
LayoutUnit autoRepeatTracksSize;
for (auto& autoTrackSize : autoRepeatTracks) {
ASSERT(autoTrackSize.minTrackBreadth().isLength());
ASSERT(!autoTrackSize.minTrackBreadth().isFlex());
bool hasDefiniteMaxTrackSizingFunction = autoTrackSize.maxTrackBreadth().isLength() && !autoTrackSize.maxTrackBreadth().isContentSized();
auto trackLength = hasDefiniteMaxTrackSizingFunction ? autoTrackSize.maxTrackBreadth().length() : autoTrackSize.minTrackBreadth().length();
bool hasDefiniteMinTrackSizingFunction = autoTrackSize.minTrackBreadth().isLength() && !autoTrackSize.minTrackBreadth().isContentSized();
if (hasDefiniteMinTrackSizingFunction && (trackLength.value() < autoTrackSize.minTrackBreadth().length().value()))
trackLength = autoTrackSize.minTrackBreadth().length();
autoRepeatTracksSize += valueForLength(trackLength, availableSize.value());
}
// For the purpose of finding the number of auto-repeated tracks, the UA must floor the track size to a UA-specified
// value to avoid division by zero. It is suggested that this floor be 1px.
autoRepeatTracksSize = std::max<LayoutUnit>(1_lu, autoRepeatTracksSize);
// There will be always at least 1 auto-repeat track, so take it already into account when computing the total track size.
LayoutUnit tracksSize = autoRepeatTracksSize;
auto& trackSizes = isRowAxis ? style().gridColumns() : style().gridRows();
for (const auto& track : trackSizes) {
bool hasDefiniteMaxTrackBreadth = track.maxTrackBreadth().isLength() && !track.maxTrackBreadth().isContentSized();
ASSERT(hasDefiniteMaxTrackBreadth || (track.minTrackBreadth().isLength() && !track.minTrackBreadth().isContentSized()));
tracksSize += valueForLength(hasDefiniteMaxTrackBreadth ? track.maxTrackBreadth().length() : track.minTrackBreadth().length(), availableSize.value());
}
// Add gutters as if auto repeat tracks were only repeated once. Gaps between different repetitions will be added later when
// computing the number of repetitions of the auto repeat().
LayoutUnit gapSize = gridGap(direction, availableSize);
tracksSize += gapSize * (trackSizes.size() + autoRepeatTrackListLength - 1);
LayoutUnit freeSpace = availableSize.value() - tracksSize;
if (freeSpace <= 0)
return autoRepeatTrackListLength;
LayoutUnit autoRepeatSizeWithGap = autoRepeatTracksSize + gapSize * autoRepeatTrackListLength;
unsigned repetitions = 1 + (freeSpace / autoRepeatSizeWithGap).toUnsigned();
freeSpace -= autoRepeatSizeWithGap * (repetitions - 1);
ASSERT(freeSpace >= 0);
// Provided the grid container does not have a definite size or max-size in the relevant axis,
// if the min size is definite then the number of repetitions is the largest possible positive
// integer that fulfills that minimum requirement.
if (needsToFulfillMinimumSize && freeSpace)
++repetitions;
return repetitions * autoRepeatTrackListLength;
}
std::unique_ptr<OrderedTrackIndexSet> RenderGrid::computeEmptyTracksForAutoRepeat(Grid& grid, GridTrackSizingDirection direction) const
{
bool isRowAxis = direction == ForColumns;
if ((isRowAxis && style().gridAutoRepeatColumnsType() != AutoRepeatType::Fit)
|| (!isRowAxis && style().gridAutoRepeatRowsType() != AutoRepeatType::Fit))
return nullptr;
std::unique_ptr<OrderedTrackIndexSet> emptyTrackIndexes;
unsigned insertionPoint = isRowAxis ? style().gridAutoRepeatColumnsInsertionPoint() : style().gridAutoRepeatRowsInsertionPoint();
unsigned firstAutoRepeatTrack = insertionPoint + grid.explicitGridStart(direction);
unsigned lastAutoRepeatTrack = firstAutoRepeatTrack + grid.autoRepeatTracks(direction);
if (!grid.hasGridItems() || shouldApplySizeContainment(*this)) {
emptyTrackIndexes = makeUnique<OrderedTrackIndexSet>();
for (unsigned trackIndex = firstAutoRepeatTrack; trackIndex < lastAutoRepeatTrack; ++trackIndex)
emptyTrackIndexes->add(trackIndex);
} else {
for (unsigned trackIndex = firstAutoRepeatTrack; trackIndex < lastAutoRepeatTrack; ++trackIndex) {
GridIterator iterator(grid, direction, trackIndex);
if (!iterator.nextGridItem()) {
if (!emptyTrackIndexes)
emptyTrackIndexes = makeUnique<OrderedTrackIndexSet>();
emptyTrackIndexes->add(trackIndex);
}
}
}
return emptyTrackIndexes;
}
unsigned RenderGrid::clampAutoRepeatTracks(GridTrackSizingDirection direction, unsigned autoRepeatTracks) const
{
if (!autoRepeatTracks)
return 0;
unsigned insertionPoint = direction == ForColumns ? style().gridAutoRepeatColumnsInsertionPoint() : style().gridAutoRepeatRowsInsertionPoint();
unsigned maxTracks = static_cast<unsigned>(GridPosition::max());
if (!insertionPoint)
return std::min(autoRepeatTracks, maxTracks);
if (insertionPoint >= maxTracks)
return 0;
return std::min(autoRepeatTracks, maxTracks - insertionPoint);
}
// FIXME: We shouldn't have to pass the available logical width as argument. The problem is that
// availableLogicalWidth() does always return a value even if we cannot resolve it like when
// computing the intrinsic size (preferred widths). That's why we pass the responsibility to the
// caller who does know whether the available logical width is indefinite or not.
void RenderGrid::placeItemsOnGrid(GridTrackSizingAlgorithm& algorithm, std::optional<LayoutUnit> availableLogicalWidth) const
{
Grid& grid = algorithm.mutableGrid();
unsigned autoRepeatColumns = computeAutoRepeatTracksCount(ForColumns, availableLogicalWidth);
unsigned autoRepeatRows = computeAutoRepeatTracksCount(ForRows, availableLogicalHeightForPercentageComputation());
autoRepeatRows = clampAutoRepeatTracks(ForRows, autoRepeatRows);
autoRepeatColumns = clampAutoRepeatTracks(ForColumns, autoRepeatColumns);
if (autoRepeatColumns != grid.autoRepeatTracks(ForColumns) || autoRepeatRows != grid.autoRepeatTracks(ForRows)) {
grid.setNeedsItemsPlacement(true);
grid.setAutoRepeatTracks(autoRepeatRows, autoRepeatColumns);
}
if (!grid.needsItemsPlacement())
return;
ASSERT(!grid.hasGridItems());
populateExplicitGridAndOrderIterator(grid);
Vector<RenderBox*> autoMajorAxisAutoGridItems;
Vector<RenderBox*> specifiedMajorAxisAutoGridItems;
for (auto* child = grid.orderIterator().first(); child; child = grid.orderIterator().next()) {
if (grid.orderIterator().shouldSkipChild(*child))
continue;
// Grid items should use the grid area sizes instead of the containing block (grid container)
// sizes, we initialize the overrides here if needed to ensure it.
if (!child->hasOverridingContainingBlockContentLogicalWidth())
child->setOverridingContainingBlockContentLogicalWidth(LayoutUnit());
if (!child->hasOverridingContainingBlockContentLogicalHeight())
child->setOverridingContainingBlockContentLogicalHeight(std::nullopt);
GridArea area = grid.gridItemArea(*child);
if (!area.rows.isIndefinite())
area.rows.translate(grid.explicitGridStart(ForRows));
if (!area.columns.isIndefinite())
area.columns.translate(grid.explicitGridStart(ForColumns));
if (area.rows.isIndefinite() || area.columns.isIndefinite()) {
grid.setGridItemArea(*child, area);
bool majorAxisDirectionIsForColumns = autoPlacementMajorAxisDirection() == ForColumns;
if ((majorAxisDirectionIsForColumns && area.columns.isIndefinite())
|| (!majorAxisDirectionIsForColumns && area.rows.isIndefinite()))
autoMajorAxisAutoGridItems.append(child);
else
specifiedMajorAxisAutoGridItems.append(child);
continue;
}
grid.insert(*child, { area.rows, area.columns });
}
#if ASSERT_ENABLED
if (grid.hasGridItems()) {
ASSERT(grid.numTracks(ForRows) >= GridPositionsResolver::explicitGridRowCount(style(), grid.autoRepeatTracks(ForRows)));
ASSERT(grid.numTracks(ForColumns) >= GridPositionsResolver::explicitGridColumnCount(style(), grid.autoRepeatTracks(ForColumns)));
}
#endif
placeSpecifiedMajorAxisItemsOnGrid(grid, specifiedMajorAxisAutoGridItems);
placeAutoMajorAxisItemsOnGrid(grid, autoMajorAxisAutoGridItems);
// Compute collapsible tracks for auto-fit.
grid.setAutoRepeatEmptyColumns(computeEmptyTracksForAutoRepeat(grid, ForColumns));
grid.setAutoRepeatEmptyRows(computeEmptyTracksForAutoRepeat(grid, ForRows));
grid.setNeedsItemsPlacement(false);
#if ASSERT_ENABLED
for (auto* child = grid.orderIterator().first(); child; child = grid.orderIterator().next()) {
if (grid.orderIterator().shouldSkipChild(*child))
continue;
GridArea area = grid.gridItemArea(*child);
ASSERT(area.rows.isTranslatedDefinite() && area.columns.isTranslatedDefinite());
}
#endif
}
void RenderGrid::performGridItemsPreLayout(const GridTrackSizingAlgorithm& algorithm) const
{
ASSERT(!algorithm.grid().needsItemsPlacement());
// FIXME: We need a way when we are calling this during intrinsic size compuation before performing
// the layout. Maybe using the PreLayout phase ?
for (auto* child = firstChildBox(); child; child = child->nextSiblingBox()) {
if (child->isOutOfFlowPositioned())
continue;
// Orthogonal items should be laid out in order to properly compute content-sized tracks that may depend on item's intrinsic size.
// We also need to properly estimate its grid area size, since it may affect to the baseline shims if such item particiaptes in baseline alignment.
if (GridLayoutFunctions::isOrthogonalChild(*this, *child)) {
updateGridAreaLogicalSize(*child, algorithm.estimatedGridAreaBreadthForChild(*child, ForColumns), algorithm.estimatedGridAreaBreadthForChild(*child, ForRows));
child->layoutIfNeeded();
continue;
}
// We need to layout the item to know whether it must synthesize its
// baseline or not, which may imply a cyclic sizing dependency.
// FIXME: Can we avoid it ?
if (isBaselineAlignmentForChild(*child)) {
updateGridAreaLogicalSize(*child, algorithm.estimatedGridAreaBreadthForChild(*child, ForColumns), algorithm.estimatedGridAreaBreadthForChild(*child, ForRows));
child->layoutIfNeeded();
}
}
}
void RenderGrid::populateExplicitGridAndOrderIterator(Grid& grid) const
{
OrderIteratorPopulator populator(grid.orderIterator());
unsigned explicitRowStart = 0;
unsigned explicitColumnStart = 0;
unsigned autoRepeatRows = grid.autoRepeatTracks(ForRows);
unsigned autoRepeatColumns = grid.autoRepeatTracks(ForColumns);
unsigned maximumRowIndex = GridPositionsResolver::explicitGridRowCount(style(), autoRepeatRows);
unsigned maximumColumnIndex = GridPositionsResolver::explicitGridColumnCount(style(), autoRepeatColumns);
for (RenderBox* child = firstChildBox(); child; child = child->nextSiblingBox()) {
if (!populator.collectChild(*child))
continue;
GridSpan rowPositions = GridPositionsResolver::resolveGridPositionsFromStyle(style(), *child, ForRows, autoRepeatRows);
if (!rowPositions.isIndefinite()) {
explicitRowStart = std::max<int>(explicitRowStart, -rowPositions.untranslatedStartLine());
maximumRowIndex = std::max<int>(maximumRowIndex, rowPositions.untranslatedEndLine());
} else {
// Grow the grid for items with a definite row span, getting the largest such span.
unsigned spanSize = GridPositionsResolver::spanSizeForAutoPlacedItem(*child, ForRows);
maximumRowIndex = std::max(maximumRowIndex, spanSize);
}
GridSpan columnPositions = GridPositionsResolver::resolveGridPositionsFromStyle(style(), *child, ForColumns, autoRepeatColumns);
if (!columnPositions.isIndefinite()) {
explicitColumnStart = std::max<int>(explicitColumnStart, -columnPositions.untranslatedStartLine());
maximumColumnIndex = std::max<int>(maximumColumnIndex, columnPositions.untranslatedEndLine());
} else {
// Grow the grid for items with a definite column span, getting the largest such span.
unsigned spanSize = GridPositionsResolver::spanSizeForAutoPlacedItem(*child, ForColumns);
maximumColumnIndex = std::max(maximumColumnIndex, spanSize);
}
grid.setGridItemArea(*child, { rowPositions, columnPositions });
}
grid.setExplicitGridStart(explicitRowStart, explicitColumnStart);
grid.ensureGridSize(maximumRowIndex + explicitRowStart, maximumColumnIndex + explicitColumnStart);
}
std::unique_ptr<GridArea> RenderGrid::createEmptyGridAreaAtSpecifiedPositionsOutsideGrid(Grid& grid, const RenderBox& gridItem, GridTrackSizingDirection specifiedDirection, const GridSpan& specifiedPositions) const
{
GridTrackSizingDirection crossDirection = specifiedDirection == ForColumns ? ForRows : ForColumns;
const unsigned endOfCrossDirection = grid.numTracks(crossDirection);
unsigned crossDirectionSpanSize = GridPositionsResolver::spanSizeForAutoPlacedItem(gridItem, crossDirection);
GridSpan crossDirectionPositions = GridSpan::translatedDefiniteGridSpan(endOfCrossDirection, endOfCrossDirection + crossDirectionSpanSize);
return makeUnique<GridArea>(specifiedDirection == ForColumns ? crossDirectionPositions : specifiedPositions, specifiedDirection == ForColumns ? specifiedPositions : crossDirectionPositions);
}
void RenderGrid::placeSpecifiedMajorAxisItemsOnGrid(Grid& grid, const Vector<RenderBox*>& autoGridItems) const
{
bool isForColumns = autoPlacementMajorAxisDirection() == ForColumns;
bool isGridAutoFlowDense = style().isGridAutoFlowAlgorithmDense();
// Mapping between the major axis tracks (rows or columns) and the last auto-placed item's position inserted on
// that track. This is needed to implement "sparse" packing for items locked to a given track.
// See http://dev.w3.org/csswg/css-grid/#auto-placement-algorithm
HashMap<unsigned, unsigned, DefaultHash<unsigned>, WTF::UnsignedWithZeroKeyHashTraits<unsigned>> minorAxisCursors;
for (auto& autoGridItem : autoGridItems) {
GridSpan majorAxisPositions = grid.gridItemSpan(*autoGridItem, autoPlacementMajorAxisDirection());
ASSERT(majorAxisPositions.isTranslatedDefinite());
ASSERT(grid.gridItemSpan(*autoGridItem, autoPlacementMinorAxisDirection()).isIndefinite());
unsigned minorAxisSpanSize = GridPositionsResolver::spanSizeForAutoPlacedItem(*autoGridItem, autoPlacementMinorAxisDirection());
unsigned majorAxisInitialPosition = majorAxisPositions.startLine();
GridIterator iterator(grid, autoPlacementMajorAxisDirection(), majorAxisPositions.startLine(), isGridAutoFlowDense ? 0 : minorAxisCursors.get(majorAxisInitialPosition));
std::unique_ptr<GridArea> emptyGridArea = iterator.nextEmptyGridArea(majorAxisPositions.integerSpan(), minorAxisSpanSize);
if (!emptyGridArea)
emptyGridArea = createEmptyGridAreaAtSpecifiedPositionsOutsideGrid(grid, *autoGridItem, autoPlacementMajorAxisDirection(), majorAxisPositions);
grid.insert(*autoGridItem, *emptyGridArea);
if (!isGridAutoFlowDense)
minorAxisCursors.set(majorAxisInitialPosition, isForColumns ? emptyGridArea->rows.startLine() : emptyGridArea->columns.startLine());
}
}
void RenderGrid::placeAutoMajorAxisItemsOnGrid(Grid& grid, const Vector<RenderBox*>& autoGridItems) const
{
AutoPlacementCursor autoPlacementCursor = {0, 0};
bool isGridAutoFlowDense = style().isGridAutoFlowAlgorithmDense();
for (auto& autoGridItem : autoGridItems) {
placeAutoMajorAxisItemOnGrid(grid, *autoGridItem, autoPlacementCursor);
if (isGridAutoFlowDense) {
autoPlacementCursor.first = 0;
autoPlacementCursor.second = 0;
}
}
}
void RenderGrid::placeAutoMajorAxisItemOnGrid(Grid& grid, RenderBox& gridItem, AutoPlacementCursor& autoPlacementCursor) const
{
ASSERT(grid.gridItemSpan(gridItem, autoPlacementMajorAxisDirection()).isIndefinite());
unsigned majorAxisSpanSize = GridPositionsResolver::spanSizeForAutoPlacedItem(gridItem, autoPlacementMajorAxisDirection());
const unsigned endOfMajorAxis = grid.numTracks(autoPlacementMajorAxisDirection());
unsigned majorAxisAutoPlacementCursor = autoPlacementMajorAxisDirection() == ForColumns ? autoPlacementCursor.second : autoPlacementCursor.first;
unsigned minorAxisAutoPlacementCursor = autoPlacementMajorAxisDirection() == ForColumns ? autoPlacementCursor.first : autoPlacementCursor.second;
std::unique_ptr<GridArea> emptyGridArea;
GridSpan minorAxisPositions = grid.gridItemSpan(gridItem, autoPlacementMinorAxisDirection());
if (minorAxisPositions.isTranslatedDefinite()) {
// Move to the next track in major axis if initial position in minor axis is before auto-placement cursor.
if (minorAxisPositions.startLine() < minorAxisAutoPlacementCursor)
majorAxisAutoPlacementCursor++;
if (majorAxisAutoPlacementCursor < endOfMajorAxis) {
GridIterator iterator(grid, autoPlacementMinorAxisDirection(), minorAxisPositions.startLine(), majorAxisAutoPlacementCursor);
emptyGridArea = iterator.nextEmptyGridArea(minorAxisPositions.integerSpan(), majorAxisSpanSize);
}
if (!emptyGridArea)
emptyGridArea = createEmptyGridAreaAtSpecifiedPositionsOutsideGrid(grid, gridItem, autoPlacementMinorAxisDirection(), minorAxisPositions);
} else {
unsigned minorAxisSpanSize = GridPositionsResolver::spanSizeForAutoPlacedItem(gridItem, autoPlacementMinorAxisDirection());
for (unsigned majorAxisIndex = majorAxisAutoPlacementCursor; majorAxisIndex < endOfMajorAxis; ++majorAxisIndex) {
GridIterator iterator(grid, autoPlacementMajorAxisDirection(), majorAxisIndex, minorAxisAutoPlacementCursor);
emptyGridArea = iterator.nextEmptyGridArea(majorAxisSpanSize, minorAxisSpanSize);
if (emptyGridArea) {
// Check that it fits in the minor axis direction, as we shouldn't grow in that direction here (it was already managed in populateExplicitGridAndOrderIterator()).
unsigned minorAxisFinalPositionIndex = autoPlacementMinorAxisDirection() == ForColumns ? emptyGridArea->columns.endLine() : emptyGridArea->rows.endLine();
const unsigned endOfMinorAxis = grid.numTracks(autoPlacementMinorAxisDirection());
if (minorAxisFinalPositionIndex <= endOfMinorAxis)
break;
// Discard empty grid area as it does not fit in the minor axis direction.
// We don't need to create a new empty grid area yet as we might find a valid one in the next iteration.
emptyGridArea = nullptr;
}
// As we're moving to the next track in the major axis we should reset the auto-placement cursor in the minor axis.
minorAxisAutoPlacementCursor = 0;
}
if (!emptyGridArea)
emptyGridArea = createEmptyGridAreaAtSpecifiedPositionsOutsideGrid(grid, gridItem, autoPlacementMinorAxisDirection(), GridSpan::translatedDefiniteGridSpan(0, minorAxisSpanSize));
}
grid.insert(gridItem, *emptyGridArea);
autoPlacementCursor.first = emptyGridArea->rows.startLine();
autoPlacementCursor.second = emptyGridArea->columns.startLine();
}
GridTrackSizingDirection RenderGrid::autoPlacementMajorAxisDirection() const
{
return style().isGridAutoFlowDirectionColumn() ? ForColumns : ForRows;
}
GridTrackSizingDirection RenderGrid::autoPlacementMinorAxisDirection() const
{
return style().isGridAutoFlowDirectionColumn() ? ForRows : ForColumns;
}
void RenderGrid::dirtyGrid()
{
if (m_grid.needsItemsPlacement())
return;
m_grid.setNeedsItemsPlacement(true);
}
Vector<LayoutUnit> RenderGrid::trackSizesForComputedStyle(GridTrackSizingDirection direction) const
{
bool isRowAxis = direction == ForColumns;
auto& positions = isRowAxis ? m_columnPositions : m_rowPositions;
size_t numPositions = positions.size();
LayoutUnit offsetBetweenTracks = isRowAxis ? m_offsetBetweenColumns.distributionOffset : m_offsetBetweenRows.distributionOffset;
Vector<LayoutUnit> tracks;
if (numPositions < 2)
return tracks;
ASSERT(!m_grid.needsItemsPlacement());
bool hasCollapsedTracks = m_grid.hasAutoRepeatEmptyTracks(direction);
LayoutUnit gap = !hasCollapsedTracks ? gridGap(direction) : 0_lu;
tracks.reserveCapacity(numPositions - 1);
for (size_t i = 0; i < numPositions - 2; ++i)
tracks.append(positions[i + 1] - positions[i] - offsetBetweenTracks - gap);
tracks.append(positions[numPositions - 1] - positions[numPositions - 2]);
if (!hasCollapsedTracks)
return tracks;
size_t remainingEmptyTracks = m_grid.autoRepeatEmptyTracks(direction)->size();
size_t lastLine = tracks.size();
gap = gridGap(direction);
for (size_t i = 1; i < lastLine; ++i) {
if (m_grid.isEmptyAutoRepeatTrack(direction, i - 1))
--remainingEmptyTracks;
else {
// Remove the gap between consecutive non empty tracks. Remove it also just once for an
// arbitrary number of empty tracks between two non empty ones.
bool allRemainingTracksAreEmpty = remainingEmptyTracks == (lastLine - i);
if (!allRemainingTracksAreEmpty || !m_grid.isEmptyAutoRepeatTrack(direction, i))
tracks[i - 1] -= gap;
}
}
return tracks;
}
static const StyleContentAlignmentData& contentAlignmentNormalBehaviorGrid()
{
static const StyleContentAlignmentData normalBehavior = {ContentPosition::Normal, ContentDistribution::Stretch};
return normalBehavior;
}
static bool overrideSizeChanged(const RenderBox& child, GridTrackSizingDirection direction, std::optional<LayoutUnit> width, std::optional<LayoutUnit> height)
{
if (direction == ForColumns)
return !child.hasOverridingContainingBlockContentLogicalWidth() || child.overridingContainingBlockContentLogicalWidth() != width;
return !child.hasOverridingContainingBlockContentLogicalHeight() || child.overridingContainingBlockContentLogicalHeight() != height;
}
static bool hasRelativeBlockAxisSize(const RenderGrid& grid, const RenderBox& child)
{
return GridLayoutFunctions::isOrthogonalChild(grid, child) ? child.hasRelativeLogicalWidth() || child.style().logicalWidth().isAuto() : child.hasRelativeLogicalHeight();
}
void RenderGrid::updateGridAreaLogicalSize(RenderBox& child, std::optional<LayoutUnit> width, std::optional<LayoutUnit> height) const
{
// Because the grid area cannot be styled, we don't need to adjust
// the grid breadth to account for 'box-sizing'.
bool gridAreaWidthChanged = overrideSizeChanged(child, ForColumns, width, height);
bool gridAreaHeightChanged = overrideSizeChanged(child, ForRows, width, height);
if (gridAreaWidthChanged || (gridAreaHeightChanged && hasRelativeBlockAxisSize(*this, child)))
child.setNeedsLayout(MarkOnlyThis);
child.setOverridingContainingBlockContentLogicalWidth(width);
child.setOverridingContainingBlockContentLogicalHeight(height);
}
void RenderGrid::updateGridAreaForAspectRatioItems(const Vector<RenderBox*>& autoGridItems)
{
populateGridPositionsForDirection(ForColumns);
populateGridPositionsForDirection(ForRows);
for (auto& autoGridItem : autoGridItems) {
updateGridAreaLogicalSize(*autoGridItem, gridAreaBreadthForChildIncludingAlignmentOffsets(*autoGridItem, ForColumns), gridAreaBreadthForChildIncludingAlignmentOffsets(*autoGridItem, ForRows));
// For an item wtih aspect-ratio, if it has stretch alignment that stretches to the definite row, we also need to transfer the size before laying out the grid item.
if (autoGridItem->hasStretchedLogicalHeight())
applyStretchAlignmentToChildIfNeeded(*autoGridItem);
}
}
void RenderGrid::layoutGridItems()
{
populateGridPositionsForDirection(ForColumns);
populateGridPositionsForDirection(ForRows);
for (RenderBox* child = firstChildBox(); child; child = child->nextSiblingBox()) {
if (m_grid.orderIterator().shouldSkipChild(*child)) {
if (child->isOutOfFlowPositioned())
prepareChildForPositionedLayout(*child);
continue;
}
// Setting the definite grid area's sizes. It may imply that the
// item must perform a layout if its area differs from the one
// used during the track sizing algorithm.
updateGridAreaLogicalSize(*child, gridAreaBreadthForChildIncludingAlignmentOffsets(*child, ForColumns), gridAreaBreadthForChildIncludingAlignmentOffsets(*child, ForRows));
LayoutRect oldChildRect = child->frameRect();
// Stretching logic might force a child layout, so we need to run it before the layoutIfNeeded
// call to avoid unnecessary relayouts. This might imply that child margins, needed to correctly
// determine the available space before stretching, are not set yet.
applyStretchAlignmentToChildIfNeeded(*child);
child->layoutIfNeeded();
// We need pending layouts to be done in order to compute auto-margins properly.
updateAutoMarginsInColumnAxisIfNeeded(*child);
updateAutoMarginsInRowAxisIfNeeded(*child);
setLogicalPositionForChild(*child);
// 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 (!selfNeedsLayout() && child->checkForRepaintDuringLayout())
child->repaintDuringLayoutIfMoved(oldChildRect);
}
}
void RenderGrid::prepareChildForPositionedLayout(RenderBox& child)
{
ASSERT(child.isOutOfFlowPositioned());
child.containingBlock()->insertPositionedObject(child);
RenderLayer* childLayer = child.layer();
// Static position of a positioned child should use the content-box (https://drafts.csswg.org/css-grid/#static-position).
childLayer->setStaticInlinePosition(borderAndPaddingStart());
childLayer->setStaticBlockPosition(borderAndPaddingBefore());
}
bool RenderGrid::hasStaticPositionForChild(const RenderBox& child, GridTrackSizingDirection direction) const
{
return direction == ForColumns ? child.style().hasStaticInlinePosition(isHorizontalWritingMode()) : child.style().hasStaticBlockPosition(isHorizontalWritingMode());
}
void RenderGrid::layoutPositionedObject(RenderBox& child, bool relayoutChildren, bool fixedPositionObjectsOnly)
{
LayoutUnit columnBreadth = gridAreaBreadthForOutOfFlowChild(child, ForColumns);
LayoutUnit rowBreadth = gridAreaBreadthForOutOfFlowChild(child, ForRows);
child.setOverridingContainingBlockContentLogicalWidth(columnBreadth);
child.setOverridingContainingBlockContentLogicalHeight(rowBreadth);
// Mark for layout as we're resetting the position before and we relay in generic layout logic
// for positioned items in order to get the offsets properly resolved.
child.setChildNeedsLayout(MarkOnlyThis);
RenderBlock::layoutPositionedObject(child, relayoutChildren, fixedPositionObjectsOnly);
setLogicalOffsetForChild(child, ForColumns);
setLogicalOffsetForChild(child, ForRows);
}
LayoutUnit RenderGrid::gridAreaBreadthForChildIncludingAlignmentOffsets(const RenderBox& child, GridTrackSizingDirection direction) const
{
// We need the cached value when available because Content Distribution alignment properties
// may have some influence in the final grid area breadth.
const auto& tracks = m_trackSizingAlgorithm.tracks(direction);
const auto& span = m_grid.gridItemSpan(child, direction);
const auto& linePositions = (direction == ForColumns) ? m_columnPositions : m_rowPositions;
LayoutUnit initialTrackPosition = linePositions[span.startLine()];
LayoutUnit finalTrackPosition = linePositions[span.endLine() - 1];
// Track Positions vector stores the 'start' grid line of each track, so we have to add last track's baseSize.
return finalTrackPosition - initialTrackPosition + tracks[span.endLine() - 1].baseSize();
}
void RenderGrid::populateGridPositionsForDirection(GridTrackSizingDirection direction)
{
// Since we add alignment offsets and track gutters, grid lines are not always adjacent. Hence we will have to
// assume from now on that we just store positions of the initial grid lines of each track,
// except the last one, which is the only one considered as a final grid line of a track.
// The grid container's frame elements (border, padding and <content-position> offset) are sensible to the
// inline-axis flow direction. However, column lines positions are 'direction' unaware. This simplification
// allows us to use the same indexes to identify the columns independently on the inline-axis direction.
bool isRowAxis = direction == ForColumns;
auto& tracks = m_trackSizingAlgorithm.tracks(direction);
unsigned numberOfTracks = tracks.size();
unsigned numberOfLines = numberOfTracks + 1;
unsigned lastLine = numberOfLines - 1;
bool hasCollapsedTracks = m_grid.hasAutoRepeatEmptyTracks(direction);
size_t numberOfCollapsedTracks = hasCollapsedTracks ? m_grid.autoRepeatEmptyTracks(direction)->size() : 0;
const auto& offset = direction == ForColumns ? m_offsetBetweenColumns : m_offsetBetweenRows;
auto& positions = isRowAxis ? m_columnPositions : m_rowPositions;
positions.resize(numberOfLines);
auto borderAndPadding = isRowAxis ? borderAndPaddingLogicalLeft() : borderAndPaddingBefore();
#if !PLATFORM(IOS_FAMILY)
// FIXME: Ideally scrollbarLogicalWidth() should return zero in iOS so we don't need this
// (see bug https://webkit.org/b/191857).
// If we are in horizontal writing mode and RTL direction the scrollbar is painted on the left,
// so we need to take into account when computing the position of the columns.
if (isRowAxis && style().isHorizontalWritingMode() && !style().isLeftToRightDirection())
borderAndPadding += scrollbarLogicalWidth();
#endif
positions[0] = borderAndPadding + offset.positionOffset;
if (numberOfLines > 1) {
// If we have collapsed tracks we just ignore gaps here and add them later as we might not
// compute the gap between two consecutive tracks without examining the surrounding ones.
LayoutUnit gap = !hasCollapsedTracks ? gridGap(direction) : 0_lu;
unsigned nextToLastLine = numberOfLines - 2;
for (unsigned i = 0; i < nextToLastLine; ++i)
positions[i + 1] = positions[i] + offset.distributionOffset + tracks[i].baseSize() + gap;
positions[lastLine] = positions[nextToLastLine] + tracks[nextToLastLine].baseSize();
// Adjust collapsed gaps. Collapsed tracks cause the surrounding gutters to collapse (they
// coincide exactly) except on the edges of the grid where they become 0.
if (hasCollapsedTracks) {
gap = gridGap(direction);
unsigned remainingEmptyTracks = numberOfCollapsedTracks;
LayoutUnit offsetAccumulator;
LayoutUnit gapAccumulator;
for (unsigned i = 1; i < lastLine; ++i) {
if (m_grid.isEmptyAutoRepeatTrack(direction, i - 1)) {
--remainingEmptyTracks;
offsetAccumulator += offset.distributionOffset;
} else {
// Add gap between consecutive non empty tracks. Add it also just once for an
// arbitrary number of empty tracks between two non empty ones.
bool allRemainingTracksAreEmpty = remainingEmptyTracks == (lastLine - i);
if (!allRemainingTracksAreEmpty || !m_grid.isEmptyAutoRepeatTrack(direction, i))
gapAccumulator += gap;
}
positions[i] += gapAccumulator - offsetAccumulator;
}
positions[lastLine] += gapAccumulator - offsetAccumulator;
}
}
}
static LayoutUnit computeOverflowAlignmentOffset(OverflowAlignment overflow, LayoutUnit trackSize, LayoutUnit childSize)
{
LayoutUnit offset = trackSize - childSize;
switch (overflow) {
case OverflowAlignment::Safe:
// If overflow is 'safe', we have to make sure we don't overflow the 'start'
// edge (potentially cause some data loss as the overflow is unreachable).
return std::max<LayoutUnit>(0, offset);
case OverflowAlignment::Unsafe:
case OverflowAlignment::Default:
// If we overflow our alignment container and overflow is 'true' (default), we
// ignore the overflow and just return the value regardless (which may cause data
// loss as we overflow the 'start' edge).
return offset;
}
ASSERT_NOT_REACHED();
return 0;
}
LayoutUnit RenderGrid::availableAlignmentSpaceForChildBeforeStretching(LayoutUnit gridAreaBreadthForChild, const RenderBox& child) const
{
// Because we want to avoid multiple layouts, stretching logic might be performed before
// children are laid out, so we can't use the child cached values. Hence, we need to
// compute margins in order to determine the available height before stretching.
GridTrackSizingDirection childBlockFlowDirection = GridLayoutFunctions::flowAwareDirectionForChild(*this, child, ForRows);
return std::max(0_lu, gridAreaBreadthForChild - GridLayoutFunctions::marginLogicalSizeForChild(*this, childBlockFlowDirection, child));
}
StyleSelfAlignmentData RenderGrid::alignSelfForChild(const RenderBox& child, StretchingMode stretchingMode, const RenderStyle* gridStyle) const
{
if (!gridStyle)
gridStyle = &style();
auto normalBehavior = stretchingMode == StretchingMode::Any ? selfAlignmentNormalBehavior(&child) : ItemPosition::Normal;
return child.style().resolvedAlignSelf(gridStyle, normalBehavior);
}
StyleSelfAlignmentData RenderGrid::justifySelfForChild(const RenderBox& child, StretchingMode stretchingMode, const RenderStyle* gridStyle) const
{
if (!gridStyle)
gridStyle = &style();
auto normalBehavior = stretchingMode == StretchingMode::Any ? selfAlignmentNormalBehavior(&child) : ItemPosition::Normal;
return child.style().resolvedJustifySelf(gridStyle, normalBehavior);
}
bool RenderGrid::aspectRatioPrefersInline(const RenderBox& child, bool blockFlowIsColumnAxis)
{
if (!child.style().hasAspectRatio())
return false;
bool hasExplicitInlineStretch = justifySelfForChild(child, StretchingMode::Explicit).position() == ItemPosition::Stretch;
bool hasExplicitBlockStretch = alignSelfForChild(child, StretchingMode::Explicit).position() == ItemPosition::Stretch;
if (!blockFlowIsColumnAxis)
std::swap(hasExplicitInlineStretch, hasExplicitBlockStretch);
return !hasExplicitBlockStretch;
}
// FIXME: This logic is shared by RenderFlexibleBox, so it should be moved to RenderBox.
void RenderGrid::applyStretchAlignmentToChildIfNeeded(RenderBox& child)
{
ASSERT(child.overridingContainingBlockContentLogicalHeight());
ASSERT(child.overridingContainingBlockContentLogicalWidth());
// We clear height and width override values because we will decide now whether it's allowed or
// not, evaluating the conditions which might have changed since the old values were set.
child.clearOverridingLogicalHeight();
child.clearOverridingLogicalWidth();
GridTrackSizingDirection childBlockDirection = GridLayoutFunctions::flowAwareDirectionForChild(*this, child, ForRows);
GridTrackSizingDirection childInlineDirection = GridLayoutFunctions::flowAwareDirectionForChild(*this, child, ForColumns);
bool blockFlowIsColumnAxis = childBlockDirection == ForRows;
bool allowedToStretchChildBlockSize = blockFlowIsColumnAxis ? allowedToStretchChildAlongColumnAxis(child) : allowedToStretchChildAlongRowAxis(child);
if (allowedToStretchChildBlockSize && !aspectRatioPrefersInline(child, blockFlowIsColumnAxis)) {
LayoutUnit stretchedLogicalHeight = availableAlignmentSpaceForChildBeforeStretching(GridLayoutFunctions::overridingContainingBlockContentSizeForChild(child, childBlockDirection).value(), child);
LayoutUnit desiredLogicalHeight = child.constrainLogicalHeightByMinMax(stretchedLogicalHeight, std::nullopt);
child.setOverridingLogicalHeight(desiredLogicalHeight);
// Checking the logical-height of a child isn't enough. Setting an override logical-height
// changes the definiteness, resulting in percentages to resolve differently.
//
// FIXME: Can avoid laying out here in some cases. See https://webkit.org/b/87905.
if (desiredLogicalHeight != child.logicalHeight() || (is<RenderBlock>(child) && downcast<RenderBlock>(child).hasPercentHeightDescendants())) {
child.setLogicalHeight(0_lu);
child.setNeedsLayout(MarkOnlyThis);
}
} else if (!allowedToStretchChildBlockSize && allowedToStretchChildAlongRowAxis(child)) {
LayoutUnit stretchedLogicalWidth = availableAlignmentSpaceForChildBeforeStretching(GridLayoutFunctions::overridingContainingBlockContentSizeForChild(child, childInlineDirection).value(), child);
LayoutUnit desiredLogicalWidth = child.constrainLogicalWidthInFragmentByMinMax(stretchedLogicalWidth, contentWidth(), *this, nullptr);
child.setOverridingLogicalWidth(desiredLogicalWidth);
if (desiredLogicalWidth != child.logicalWidth())
child.setNeedsLayout(MarkOnlyThis);
}
}
// FIXME: This logic is shared by RenderFlexibleBox, so it should be moved to RenderBox.
bool RenderGrid::hasAutoMarginsInColumnAxis(const RenderBox& child) const
{
if (isHorizontalWritingMode())
return child.style().marginTop().isAuto() || child.style().marginBottom().isAuto();
return child.style().marginLeft().isAuto() || child.style().marginRight().isAuto();
}
// FIXME: This logic is shared by RenderFlexibleBox, so it should be moved to RenderBox.
bool RenderGrid::hasAutoMarginsInRowAxis(const RenderBox& child) const
{
if (isHorizontalWritingMode())
return child.style().marginLeft().isAuto() || child.style().marginRight().isAuto();
return child.style().marginTop().isAuto() || child.style().marginBottom().isAuto();
}
// FIXME: This logic is shared by RenderFlexibleBox, so it should be moved to RenderBox.
void RenderGrid::updateAutoMarginsInRowAxisIfNeeded(RenderBox& child)
{
ASSERT(!child.isOutOfFlowPositioned());
const RenderStyle& parentStyle = style();
Length marginStart = child.style().marginStartUsing(&parentStyle);
Length marginEnd = child.style().marginEndUsing(&parentStyle);
LayoutUnit marginLogicalWidth;
// We should only consider computed margins if their specified value isn't
// 'auto', since such computed value may come from a previous layout and may
// be incorrect now.
if (!marginStart.isAuto())
marginLogicalWidth += child.marginStart();
if (!marginEnd.isAuto())
marginLogicalWidth += child.marginEnd();
LayoutUnit availableAlignmentSpace = child.overridingContainingBlockContentLogicalWidth().value() - child.logicalWidth() - marginLogicalWidth;
if (availableAlignmentSpace <= 0)
return;
if (marginStart.isAuto() && marginEnd.isAuto()) {
child.setMarginStart(availableAlignmentSpace / 2, &parentStyle);
child.setMarginEnd(availableAlignmentSpace / 2, &parentStyle);
} else if (marginStart.isAuto()) {
child.setMarginStart(availableAlignmentSpace, &parentStyle);
} else if (marginEnd.isAuto()) {
child.setMarginEnd(availableAlignmentSpace, &parentStyle);
}
}
// FIXME: This logic is shared by RenderFlexibleBox, so it should be moved to RenderBox.
void RenderGrid::updateAutoMarginsInColumnAxisIfNeeded(RenderBox& child)
{
ASSERT(!child.isOutOfFlowPositioned());
const RenderStyle& parentStyle = style();
Length marginBefore = child.style().marginBeforeUsing(&parentStyle);
Length marginAfter = child.style().marginAfterUsing(&parentStyle);
LayoutUnit marginLogicalHeight;
// We should only consider computed margins if their specified value isn't
// 'auto', since such computed value may come from a previous layout and may
// be incorrect now.
if (!marginBefore.isAuto())
marginLogicalHeight += child.marginBefore();
if (!marginAfter.isAuto())
marginLogicalHeight += child.marginAfter();
LayoutUnit availableAlignmentSpace = child.overridingContainingBlockContentLogicalHeight().value() - child.logicalHeight() - marginLogicalHeight;
if (availableAlignmentSpace <= 0)
return;
if (marginBefore.isAuto() && marginAfter.isAuto()) {
child.setMarginBefore(availableAlignmentSpace / 2, &parentStyle);
child.setMarginAfter(availableAlignmentSpace / 2, &parentStyle);
} else if (marginBefore.isAuto()) {
child.setMarginBefore(availableAlignmentSpace, &parentStyle);
} else if (marginAfter.isAuto()) {
child.setMarginAfter(availableAlignmentSpace, &parentStyle);
}
}
bool RenderGrid::isBaselineAlignmentForChild(const RenderBox& child) const
{
return isBaselineAlignmentForChild(child, GridRowAxis) || isBaselineAlignmentForChild(child, GridColumnAxis);
}
bool RenderGrid::isBaselineAlignmentForChild(const RenderBox& child, GridAxis baselineAxis, AllowedBaseLine allowed) const
{
if (child.isOutOfFlowPositioned())
return false;
ItemPosition align = selfAlignmentForChild(baselineAxis, child).position();
bool hasAutoMargins = baselineAxis == GridColumnAxis ? hasAutoMarginsInColumnAxis(child) : hasAutoMarginsInRowAxis(child);
bool isBaseline = allowed == FirstLine ? isFirstBaselinePosition(align) : isBaselinePosition(align);
return isBaseline && !hasAutoMargins;
}
// FIXME: This logic is shared by RenderFlexibleBox, so it might be refactored somehow.
LayoutUnit RenderGrid::baselinePosition(FontBaseline, bool, LineDirectionMode direction, LinePositionMode mode) const
{
ASSERT_UNUSED(mode, mode == PositionOnContainingLine);
auto baseline = firstLineBaseline();
if (!baseline)
return synthesizedBaselineFromBorderBox(*this, direction) + marginLogicalHeight();
return baseline.value() + (direction == HorizontalLine ? marginTop() : marginRight()).toInt();
}
std::optional<LayoutUnit> RenderGrid::firstLineBaseline() const
{
if (isWritingModeRoot() || !m_grid.hasGridItems() || shouldApplyLayoutContainment(*this))
return std::nullopt;
const RenderBox* baselineChild = nullptr;
// Finding the first grid item in grid order.
unsigned numColumns = m_grid.numTracks(ForColumns);
for (size_t column = 0; column < numColumns; column++) {
for (auto& child : m_grid.cell(0, column)) {
ASSERT(child.get());
// If an item participates in baseline alignment, we select such item.
if (isBaselineAlignmentForChild(*child, GridColumnAxis, FirstLine)) {
// FIXME: self-baseline and content-baseline alignment not implemented yet.
baselineChild = child.get();
break;
}
if (!baselineChild)
baselineChild = child.get();
}
}
if (!baselineChild)
return std::nullopt;
auto baseline = GridLayoutFunctions::isOrthogonalChild(*this, *baselineChild) ? std::nullopt : baselineChild->firstLineBaseline();
// We take border-box's bottom if no valid baseline.
if (!baseline) {
// FIXME: We should pass |direction| into firstLineBaseline and stop bailing out if we're a writing
// mode root. This would also fix some cases where the grid is orthogonal to its container.
LineDirectionMode direction = isHorizontalWritingMode() ? HorizontalLine : VerticalLine;
return synthesizedBaselineFromBorderBox(*baselineChild, direction) + logicalTopForChild(*baselineChild);
}
return baseline.value() + baselineChild->logicalTop().toInt();
}
std::optional<LayoutUnit> RenderGrid::inlineBlockBaseline(LineDirectionMode) const
{
return firstLineBaseline();
}
LayoutUnit RenderGrid::columnAxisBaselineOffsetForChild(const RenderBox& child) const
{
return m_trackSizingAlgorithm.baselineOffsetForChild(child, GridColumnAxis);
}
LayoutUnit RenderGrid::rowAxisBaselineOffsetForChild(const RenderBox& child) const
{
return m_trackSizingAlgorithm.baselineOffsetForChild(child, GridRowAxis);
}
GridAxisPosition RenderGrid::columnAxisPositionForChild(const RenderBox& child) const
{
bool hasSameWritingMode = child.style().writingMode() == style().writingMode();
bool childIsLTR = child.style().isLeftToRightDirection();
if (child.isOutOfFlowPositioned() && !hasStaticPositionForChild(child, ForRows))
return GridAxisStart;
switch (alignSelfForChild(child).position()) {
case ItemPosition::SelfStart:
// FIXME: Should we implement this logic in a generic utility function ?
// Aligns the alignment subject to be flush with the edge of the alignment container
// corresponding to the alignment subject's 'start' side in the column axis.
if (GridLayoutFunctions::isOrthogonalChild(*this, child)) {
// If orthogonal writing-modes, self-start will be based on the child's inline-axis
// direction (inline-start), because it's the one parallel to the column axis.
if (style().isFlippedBlocksWritingMode())
return childIsLTR ? GridAxisEnd : GridAxisStart;
return childIsLTR ? GridAxisStart : GridAxisEnd;
}
// self-start is based on the child's block-flow direction. That's why we need to check against the grid container's block-flow direction.
return hasSameWritingMode ? GridAxisStart : GridAxisEnd;
case ItemPosition::SelfEnd:
// FIXME: Should we implement this logic in a generic utility function ?
// Aligns the alignment subject to be flush with the edge of the alignment container
// corresponding to the alignment subject's 'end' side in the column axis.
if (GridLayoutFunctions::isOrthogonalChild(*this, child)) {
// If orthogonal writing-modes, self-end will be based on the child's inline-axis
// direction, (inline-end) because it's the one parallel to the column axis.
if (style().isFlippedBlocksWritingMode())
return childIsLTR ? GridAxisStart : GridAxisEnd;
return childIsLTR ? GridAxisEnd : GridAxisStart;
}
// self-end is based on the child's block-flow direction. That's why we need to check against the grid container's block-flow direction.
return hasSameWritingMode ? GridAxisEnd : GridAxisStart;
case ItemPosition::Left:
// Aligns the alignment subject to be flush with the alignment container's 'line-left' edge.
// The alignment axis (column axis) is always orthogonal to the inline axis, hence this value behaves as 'start'.
return GridAxisStart;
case ItemPosition::Right:
// Aligns the alignment subject to be flush with the alignment container's 'line-right' edge.
// The alignment axis (column axis) is always orthogonal to the inline axis, hence this value behaves as 'start'.
return GridAxisStart;
case ItemPosition::Center:
return GridAxisCenter;
case ItemPosition::FlexStart: // Only used in flex layout, otherwise equivalent to 'start'.
// Aligns the alignment subject to be flush with the alignment container's 'start' edge (block-start) in the column axis.
case ItemPosition::Start:
return GridAxisStart;
case ItemPosition::FlexEnd: // Only used in flex layout, otherwise equivalent to 'end'.
// Aligns the alignment subject to be flush with the alignment container's 'end' edge (block-end) in the column axis.
case ItemPosition::End:
return GridAxisEnd;
case ItemPosition::Stretch:
return GridAxisStart;
case ItemPosition::Baseline:
case ItemPosition::LastBaseline:
// FIXME: Implement the previous values. For now, we always 'start' align the child.
return GridAxisStart;
case ItemPosition::Legacy:
case ItemPosition::Auto:
case ItemPosition::Normal:
break;
}
ASSERT_NOT_REACHED();
return GridAxisStart;
}
GridAxisPosition RenderGrid::rowAxisPositionForChild(const RenderBox& child) const
{
bool hasSameDirection = child.style().direction() == style().direction();
bool gridIsLTR = style().isLeftToRightDirection();
if (child.isOutOfFlowPositioned() && !hasStaticPositionForChild(child, ForColumns))
return GridAxisStart;
switch (justifySelfForChild(child).position()) {
case ItemPosition::SelfStart:
// FIXME: Should we implement this logic in a generic utility function ?
// Aligns the alignment subject to be flush with the edge of the alignment container
// corresponding to the alignment subject's 'start' side in the row axis.
if (GridLayoutFunctions::isOrthogonalChild(*this, child)) {
// If orthogonal writing-modes, self-start will be based on the child's block-axis
// direction, because it's the one parallel to the row axis.
if (child.style().isFlippedBlocksWritingMode())
return gridIsLTR ? GridAxisEnd : GridAxisStart;
return gridIsLTR ? GridAxisStart : GridAxisEnd;
}
// self-start is based on the child's inline-flow direction. That's why we need to check against the grid container's direction.
return hasSameDirection ? GridAxisStart : GridAxisEnd;
case ItemPosition::SelfEnd:
// FIXME: Should we implement this logic in a generic utility function ?
// Aligns the alignment subject to be flush with the edge of the alignment container
// corresponding to the alignment subject's 'end' side in the row axis.
if (GridLayoutFunctions::isOrthogonalChild(*this, child)) {
// If orthogonal writing-modes, self-end will be based on the child's block-axis
// direction, because it's the one parallel to the row axis.
if (child.style().isFlippedBlocksWritingMode())
return gridIsLTR ? GridAxisStart : GridAxisEnd;
return gridIsLTR ? GridAxisEnd : GridAxisStart;
}
// self-end is based on the child's inline-flow direction. That's why we need to check against the grid container's direction.
return hasSameDirection ? GridAxisEnd : GridAxisStart;
case ItemPosition::Left:
// Aligns the alignment subject to be flush with the alignment container's 'line-left' edge.
// We want the physical 'left' side, so we have to take account, container's inline-flow direction.
return gridIsLTR ? GridAxisStart : GridAxisEnd;
case ItemPosition::Right:
// Aligns the alignment subject to be flush with the alignment container's 'line-right' edge.
// We want the physical 'right' side, so we have to take account, container's inline-flow direction.
return gridIsLTR ? GridAxisEnd : GridAxisStart;
case ItemPosition::Center:
return GridAxisCenter;
case ItemPosition::FlexStart: // Only used in flex layout, otherwise equivalent to 'start'.
// Aligns the alignment subject to be flush with the alignment container's 'start' edge (inline-start) in the row axis.
case ItemPosition::Start:
return GridAxisStart;
case ItemPosition::FlexEnd: // Only used in flex layout, otherwise equivalent to 'end'.
// Aligns the alignment subject to be flush with the alignment container's 'end' edge (inline-end) in the row axis.
case ItemPosition::End:
return GridAxisEnd;
case ItemPosition::Stretch:
return GridAxisStart;
case ItemPosition::Baseline:
case ItemPosition::LastBaseline:
// FIXME: Implement the previous values. For now, we always 'start' align the child.
return GridAxisStart;
case ItemPosition::Legacy:
case ItemPosition::Auto:
case ItemPosition::Normal:
break;
}
ASSERT_NOT_REACHED();
return GridAxisStart;
}
LayoutUnit RenderGrid::columnAxisOffsetForChild(const RenderBox& child) const
{
LayoutUnit startOfRow;
LayoutUnit endOfRow;
gridAreaPositionForChild(child, ForRows, startOfRow, endOfRow);
LayoutUnit startPosition = startOfRow + marginBeforeForChild(child);
if (hasAutoMarginsInColumnAxis(child))
return startPosition;
GridAxisPosition axisPosition = columnAxisPositionForChild(child);
switch (axisPosition) {
case GridAxisStart:
return startPosition + columnAxisBaselineOffsetForChild(child);
case GridAxisEnd:
case GridAxisCenter: {
LayoutUnit columnAxisChildSize = GridLayoutFunctions::isOrthogonalChild(*this, child) ? child.logicalWidth() + child.marginLogicalWidth() : child.logicalHeight() + child.marginLogicalHeight();
auto overflow = alignSelfForChild(child).overflow();
LayoutUnit offsetFromStartPosition = computeOverflowAlignmentOffset(overflow, endOfRow - startOfRow, columnAxisChildSize);
return startPosition + (axisPosition == GridAxisEnd ? offsetFromStartPosition : offsetFromStartPosition / 2);
}
}
ASSERT_NOT_REACHED();
return 0;
}
LayoutUnit RenderGrid::rowAxisOffsetForChild(const RenderBox& child) const
{
LayoutUnit startOfColumn;
LayoutUnit endOfColumn;
gridAreaPositionForChild(child, ForColumns, startOfColumn, endOfColumn);
LayoutUnit startPosition = startOfColumn + marginStartForChild(child);
if (hasAutoMarginsInRowAxis(child))
return startPosition;
GridAxisPosition axisPosition = rowAxisPositionForChild(child);
switch (axisPosition) {
case GridAxisStart:
return startPosition + rowAxisBaselineOffsetForChild(child);
case GridAxisEnd:
case GridAxisCenter: {
LayoutUnit rowAxisChildSize = GridLayoutFunctions::isOrthogonalChild(*this, child) ? child.logicalHeight() + child.marginLogicalHeight() : child.logicalWidth() + child.marginLogicalWidth();
auto overflow = justifySelfForChild(child).overflow();
LayoutUnit offsetFromStartPosition = computeOverflowAlignmentOffset(overflow, endOfColumn - startOfColumn, rowAxisChildSize);
return startPosition + (axisPosition == GridAxisEnd ? offsetFromStartPosition : offsetFromStartPosition / 2);
}
}
ASSERT_NOT_REACHED();
return 0;
}
LayoutUnit RenderGrid::resolveAutoStartGridPosition(GridTrackSizingDirection direction) const
{
if (direction == ForRows || style().isLeftToRightDirection())
return 0_lu;
int lastLine = numTracks(ForColumns, m_grid);
ContentPosition position = style().resolvedJustifyContentPosition(contentAlignmentNormalBehaviorGrid());
if (position == ContentPosition::End)
return m_columnPositions[lastLine] - clientLogicalWidth();
if (position == ContentPosition::Start || style().resolvedJustifyContentDistribution(contentAlignmentNormalBehaviorGrid()) == ContentDistribution::Stretch)
return m_columnPositions[0] - borderAndPaddingLogicalLeft();
return 0_lu;
}
LayoutUnit RenderGrid::resolveAutoEndGridPosition(GridTrackSizingDirection direction) const
{
if (direction == ForRows)
return clientLogicalHeight();
if (style().isLeftToRightDirection())
return clientLogicalWidth();
int lastLine = numTracks(ForColumns, m_grid);
ContentPosition position = style().resolvedJustifyContentPosition(contentAlignmentNormalBehaviorGrid());
if (position == ContentPosition::End)
return m_columnPositions[lastLine];
if (position == ContentPosition::Start || style().resolvedJustifyContentDistribution(contentAlignmentNormalBehaviorGrid()) == ContentDistribution::Stretch)
return m_columnPositions[0] - borderAndPaddingLogicalLeft() + clientLogicalWidth();
return clientLogicalWidth();
}
LayoutUnit RenderGrid::gridAreaBreadthForOutOfFlowChild(const RenderBox& child, GridTrackSizingDirection direction)
{
ASSERT(child.isOutOfFlowPositioned());
bool isRowAxis = direction == ForColumns;
GridSpan span = GridPositionsResolver::resolveGridPositionsFromStyle(style(), child, direction, autoRepeatCountForDirection(direction));
if (span.isIndefinite())
return isRowAxis ? clientLogicalWidth() : clientLogicalHeight();
unsigned explicitStart = m_grid.explicitGridStart(direction);
int startLine = span.untranslatedStartLine() + explicitStart;
int endLine = span.untranslatedEndLine() + explicitStart;
int lastLine = numTracks(direction, m_grid);
GridPosition startPosition = direction == ForColumns ? child.style().gridItemColumnStart() : child.style().gridItemRowStart();
GridPosition endPosition = direction == ForColumns ? child.style().gridItemColumnEnd() : child.style().gridItemRowEnd();
bool startIsAuto = startPosition.isAuto() || startLine < 0 || startLine > lastLine;
bool endIsAuto = endPosition.isAuto() || endLine < 0 || endLine > lastLine;
if (startIsAuto && endIsAuto)
return isRowAxis ? clientLogicalWidth() : clientLogicalHeight();
LayoutUnit start;
LayoutUnit end;
auto& positions = isRowAxis ? m_columnPositions : m_rowPositions;
auto& outOfFlowItemLine = isRowAxis ? m_outOfFlowItemColumn : m_outOfFlowItemRow;
LayoutUnit borderEdge = isRowAxis ? (style().isLeftToRightDirection() ? borderLogicalLeft() : borderLogicalRight()) : borderBefore();
if (startIsAuto)
start = resolveAutoStartGridPosition(direction) + borderEdge;
else {
outOfFlowItemLine.set(&child, startLine);
start = positions[startLine];
}
if (endIsAuto)
end = resolveAutoEndGridPosition(direction) + borderEdge;
else {
end = positions[endLine];
// These vectors store line positions including gaps, but we shouldn't consider them for the edges of the grid.
std::optional<LayoutUnit> availableSizeForGutters = availableSpaceForGutters(direction);
if (endLine > 0 && endLine < lastLine) {
ASSERT(!m_grid.needsItemsPlacement());
end -= guttersSize(m_grid, direction, endLine - 1, 2, availableSizeForGutters);
end -= isRowAxis ? m_offsetBetweenColumns.distributionOffset : m_offsetBetweenRows.distributionOffset;
}
}
return std::max(end - start, 0_lu);
}
LayoutUnit RenderGrid::logicalOffsetForOutOfFlowChild(const RenderBox& child, GridTrackSizingDirection direction, LayoutUnit trackBreadth) const
{
ASSERT(child.isOutOfFlowPositioned());
if (hasStaticPositionForChild(child, direction))
return 0_lu;
bool isRowAxis = direction == ForColumns;
bool isFlowAwareRowAxis = GridLayoutFunctions::flowAwareDirectionForChild(*this, child, direction) == ForColumns;
LayoutUnit childPosition = isFlowAwareRowAxis ? child.logicalLeft() : child.logicalTop();
LayoutUnit gridBorder = isRowAxis ? borderLogicalLeft() : borderBefore();
LayoutUnit childMargin = isRowAxis ? child.marginLogicalLeft(&style()) : child.marginBefore(&style());
LayoutUnit offset = childPosition - gridBorder - childMargin;
if (!isRowAxis || style().isLeftToRightDirection())
return offset;
LayoutUnit childBreadth = isFlowAwareRowAxis ? child.logicalWidth() + child.marginLogicalWidth() : child.logicalHeight() + child.marginLogicalHeight();
return trackBreadth - offset - childBreadth;
}
void RenderGrid::gridAreaPositionForOutOfFlowChild(const RenderBox& child, GridTrackSizingDirection direction, LayoutUnit& start, LayoutUnit& end) const
{
ASSERT(child.isOutOfFlowPositioned());
ASSERT(GridLayoutFunctions::hasOverridingContainingBlockContentSizeForChild(child, direction));
LayoutUnit trackBreadth = GridLayoutFunctions::overridingContainingBlockContentSizeForChild(child, direction).value();
bool isRowAxis = direction == ForColumns;
auto& outOfFlowItemLine = isRowAxis ? m_outOfFlowItemColumn : m_outOfFlowItemRow;
start = isRowAxis ? (style().isLeftToRightDirection() ? borderLogicalLeft() : borderLogicalRight()) : borderBefore();
if (auto line = outOfFlowItemLine.get(&child)) {
auto& positions = isRowAxis ? m_columnPositions : m_rowPositions;
start = positions[line.value()];
}
start += logicalOffsetForOutOfFlowChild(child, direction, trackBreadth);
end = start + trackBreadth;
}
void RenderGrid::gridAreaPositionForInFlowChild(const RenderBox& child, GridTrackSizingDirection direction, LayoutUnit& start, LayoutUnit& end) const
{
ASSERT(!child.isOutOfFlowPositioned());
const GridSpan& span = m_grid.gridItemSpan(child, direction);
// FIXME (lajava): This is a common pattern, why not defining a function like
// positions(direction) ?
auto& positions = direction == ForColumns ? m_columnPositions : m_rowPositions;
start = positions[span.startLine()];
end = positions[span.endLine()];
// The 'positions' vector includes distribution offset (because of content
// alignment) and gutters so we need to subtract them to get the actual
// end position for a given track (this does not have to be done for the
// last track as there are no more positions's elements after it, nor for
// collapsed tracks).
if (span.endLine() < positions.size() - 1
&& !(m_grid.hasAutoRepeatEmptyTracks(direction)
&& m_grid.isEmptyAutoRepeatTrack(direction, span.endLine()))) {
end -= gridGap(direction) + gridItemOffset(direction);
}
}
void RenderGrid::gridAreaPositionForChild(const RenderBox& child, GridTrackSizingDirection direction, LayoutUnit& start, LayoutUnit& end) const
{
if (child.isOutOfFlowPositioned())
gridAreaPositionForOutOfFlowChild(child, direction, start, end);
else
gridAreaPositionForInFlowChild(child, direction, start, end);
}
ContentPosition static resolveContentDistributionFallback(ContentDistribution distribution)
{
switch (distribution) {
case ContentDistribution::SpaceBetween:
return ContentPosition::Start;
case ContentDistribution::SpaceAround:
return ContentPosition::Center;
case ContentDistribution::SpaceEvenly:
return ContentPosition::Center;
case ContentDistribution::Stretch:
return ContentPosition::Start;
case ContentDistribution::Default:
return ContentPosition::Normal;
}
ASSERT_NOT_REACHED();
return ContentPosition::Normal;
}
static void contentDistributionOffset(ContentAlignmentData& offset, const LayoutUnit& availableFreeSpace, ContentPosition& fallbackPosition, ContentDistribution distribution, unsigned numberOfGridTracks)
{
if (distribution != ContentDistribution::Default && fallbackPosition == ContentPosition::Normal)
fallbackPosition = resolveContentDistributionFallback(distribution);
// Initialize to an invalid offset.
offset.positionOffset = -1_lu;
offset.distributionOffset = -1_lu;
if (availableFreeSpace <= 0)
return;
LayoutUnit positionOffset;
LayoutUnit distributionOffset;
switch (distribution) {
case ContentDistribution::SpaceBetween:
if (numberOfGridTracks < 2)
return;
distributionOffset = availableFreeSpace / (numberOfGridTracks - 1);
positionOffset = 0_lu;
break;
case ContentDistribution::SpaceAround:
if (numberOfGridTracks < 1)
return;
distributionOffset = availableFreeSpace / numberOfGridTracks;
positionOffset = distributionOffset / 2;
break;
case ContentDistribution::SpaceEvenly:
distributionOffset = availableFreeSpace / (numberOfGridTracks + 1);
positionOffset = distributionOffset;
break;
case ContentDistribution::Stretch:
case ContentDistribution::Default:
return;
default:
ASSERT_NOT_REACHED();
return;
}
offset.positionOffset = positionOffset;
offset.distributionOffset = distributionOffset;
}
StyleContentAlignmentData RenderGrid::contentAlignment(GridTrackSizingDirection direction) const
{
return direction == ForColumns ? style().resolvedJustifyContent(contentAlignmentNormalBehaviorGrid()) : style().resolvedAlignContent(contentAlignmentNormalBehaviorGrid());
}
void RenderGrid::computeContentPositionAndDistributionOffset(GridTrackSizingDirection direction, const LayoutUnit& availableFreeSpace, unsigned numberOfGridTracks)
{
bool isRowAxis = direction == ForColumns;
auto& offset =
isRowAxis ? m_offsetBetweenColumns : m_offsetBetweenRows;
auto contentAlignmentData = contentAlignment(direction);
auto position = contentAlignmentData.position();
// If <content-distribution> value can't be applied, 'position' will become the associated
// <content-position> fallback value.
contentDistributionOffset(offset, availableFreeSpace, position, contentAlignmentData.distribution(), numberOfGridTracks);
if (offset.isValid())
return;
if (availableFreeSpace <= 0 && contentAlignmentData.overflow() == OverflowAlignment::Safe) {
offset.positionOffset = 0_lu;
offset.distributionOffset = 0_lu;
return;
}
LayoutUnit positionOffset;
switch (position) {
case ContentPosition::Left:
ASSERT(isRowAxis);
break;
case ContentPosition::Right:
ASSERT(isRowAxis);
positionOffset = availableFreeSpace;
break;
case ContentPosition::Center:
positionOffset = availableFreeSpace / 2;
break;
case ContentPosition::FlexEnd: // Only used in flex layout, for other layout, it's equivalent to 'end'.
case ContentPosition::End:
if (isRowAxis)
positionOffset = style().isLeftToRightDirection() ? availableFreeSpace : 0_lu;
else
positionOffset = availableFreeSpace;
break;
case ContentPosition::FlexStart: // Only used in flex layout, for other layout, it's equivalent to 'start'.
case ContentPosition::Start:
if (isRowAxis)
positionOffset = style().isLeftToRightDirection() ? 0_lu : availableFreeSpace;
break;
case ContentPosition::Baseline:
case ContentPosition::LastBaseline:
// FIXME: Implement the previous values. For now, we always 'start' align.
// http://webkit.org/b/145566
if (isRowAxis)
positionOffset = style().isLeftToRightDirection() ? 0_lu : availableFreeSpace;
break;
case ContentPosition::Normal:
default:
ASSERT_NOT_REACHED();
return;
}
offset.positionOffset = positionOffset;
offset.distributionOffset = 0_lu;
}
LayoutUnit RenderGrid::translateOutOfFlowRTLCoordinate(const RenderBox& child, LayoutUnit coordinate) const
{
ASSERT(child.isOutOfFlowPositioned());
ASSERT(!style().isLeftToRightDirection());
if (m_outOfFlowItemColumn.get(&child))
return translateRTLCoordinate(coordinate);
return borderLogicalLeft() + borderLogicalRight() + clientLogicalWidth() - coordinate;
}
LayoutUnit RenderGrid::translateRTLCoordinate(LayoutUnit coordinate) const
{
ASSERT(!style().isLeftToRightDirection());
LayoutUnit alignmentOffset = m_columnPositions[0];
LayoutUnit rightGridEdgePosition = m_columnPositions[m_columnPositions.size() - 1];
return rightGridEdgePosition + alignmentOffset - coordinate;
}
// FIXME: SetLogicalPositionForChild has only one caller, consider its refactoring in the future.
void RenderGrid::setLogicalPositionForChild(RenderBox& child) const
{
// "In the positioning phase [...] calculations are performed according to the writing mode of the containing block of the box establishing the
// orthogonal flow." However, 'setLogicalLocation' will only take into account the child's writing-mode, so the position may need to be transposed.
LayoutPoint childLocation(logicalOffsetForChild(child, ForColumns), logicalOffsetForChild(child, ForRows));
child.setLogicalLocation(GridLayoutFunctions::isOrthogonalChild(*this, child) ? childLocation.transposedPoint() : childLocation);
}
void RenderGrid::setLogicalOffsetForChild(RenderBox& child, GridTrackSizingDirection direction) const
{
if (!child.isGridItem() && hasStaticPositionForChild(child, direction))
return;
// 'setLogicalLeft' and 'setLogicalTop' only take into account the child's writing-mode, that's why 'flowAwareDirectionForChild' is needed.
if (GridLayoutFunctions::flowAwareDirectionForChild(*this, child, direction) == ForColumns)
child.setLogicalLeft(logicalOffsetForChild(child, direction));
else
child.setLogicalTop(logicalOffsetForChild(child, direction));
}
LayoutUnit RenderGrid::logicalOffsetForChild(const RenderBox& child, GridTrackSizingDirection direction) const
{
if (direction == ForRows)
return columnAxisOffsetForChild(child);
LayoutUnit rowAxisOffset = rowAxisOffsetForChild(child);
// We stored m_columnPositions's data ignoring the direction, hence we might need now
// to translate positions from RTL to LTR, as it's more convenient for painting.
if (!style().isLeftToRightDirection())
rowAxisOffset = (child.isOutOfFlowPositioned() ? translateOutOfFlowRTLCoordinate(child, rowAxisOffset) : translateRTLCoordinate(rowAxisOffset)) - (GridLayoutFunctions::isOrthogonalChild(*this, child) ? child.logicalHeight() : child.logicalWidth());
return rowAxisOffset;
}
unsigned RenderGrid::nonCollapsedTracks(GridTrackSizingDirection direction) const
{
auto& tracks = m_trackSizingAlgorithm.tracks(direction);
size_t numberOfTracks = tracks.size();
bool hasCollapsedTracks = m_grid.hasAutoRepeatEmptyTracks(direction);
size_t numberOfCollapsedTracks = hasCollapsedTracks ? m_grid.autoRepeatEmptyTracks(direction)->size() : 0;
return numberOfTracks - numberOfCollapsedTracks;
}
unsigned RenderGrid::numTracks(GridTrackSizingDirection direction, const Grid& grid) const
{
// Due to limitations in our internal representation, we cannot know the number of columns from
// m_grid *if* there is no row (because m_grid would be empty). That's why in that case we need
// to get it from the style. Note that we know for sure that there are't any implicit tracks,
// because not having rows implies that there are no "normal" children (out-of-flow children are
// not stored in m_grid).
ASSERT(!grid.needsItemsPlacement());
if (direction == ForRows)
return grid.numTracks(ForRows);
// FIXME: This still requires knowledge about m_grid internals.
return grid.numTracks(ForRows) ? grid.numTracks(ForColumns) : GridPositionsResolver::explicitGridColumnCount(style(), grid.autoRepeatTracks(ForColumns));
}
void RenderGrid::paintChildren(PaintInfo& paintInfo, const LayoutPoint& paintOffset, PaintInfo& forChild, bool usePrintRect)
{
ASSERT(!m_grid.needsItemsPlacement());
for (RenderBox* child = m_grid.orderIterator().first(); child; child = m_grid.orderIterator().next())
paintChild(*child, paintInfo, paintOffset, forChild, usePrintRect, PaintAsInlineBlock);
}
const char* RenderGrid::renderName() const
{
if (isFloating())
return "RenderGrid (floating)";
if (isOutOfFlowPositioned())
return "RenderGrid (positioned)";
if (isAnonymous())
return "RenderGrid (generated)";
if (isRelativelyPositioned())
return "RenderGrid (relative positioned)";
return "RenderGrid";
}
bool RenderGrid::hasAutoSizeInColumnAxis(const RenderBox& child) const
{
if (child.style().hasAspectRatio()) {
// FIXME: should align-items + align-self: auto/justify-items + justify-self: auto be taken into account?
if (isHorizontalWritingMode() == child.isHorizontalWritingMode() && child.style().alignSelf().position() != ItemPosition::Stretch) {
// A non-auto inline size means the same for block size (column axis size) because of the aspect ratio.
if (!child.style().logicalWidth().isAuto())
return false;
} else if (child.style().justifySelf().position() != ItemPosition::Stretch) {
const Length& logicalHeight = child.style().logicalHeight();
if (logicalHeight.isFixed() || (logicalHeight.isPercentOrCalculated() && child.percentageLogicalHeightIsResolvable()))
return false;
}
}
return isHorizontalWritingMode() ? child.style().height().isAuto() : child.style().width().isAuto();
}
bool RenderGrid::hasAutoSizeInRowAxis(const RenderBox& child) const
{
if (child.style().hasAspectRatio()) {
// FIXME: should align-items + align-self: auto/justify-items + justify-self: auto be taken into account?
if (isHorizontalWritingMode() == child.isHorizontalWritingMode() && child.style().justifySelf().position() != ItemPosition::Stretch) {
// A non-auto block size means the same for inline size (row axis size) because of the aspect ratio.
const Length& logicalHeight = child.style().logicalHeight();
if (logicalHeight.isFixed() || (logicalHeight.isPercentOrCalculated() && child.percentageLogicalHeightIsResolvable()))
return false;
} else if (child.style().alignSelf().position() != ItemPosition::Stretch) {
if (!child.style().logicalWidth().isAuto())
return false;
}
}
return isHorizontalWritingMode() ? child.style().width().isAuto() : child.style().height().isAuto();
}
} // namespace WebCore