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/*
* Copyright (C) 2018 Igalia S.L.
*
* 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.
* * Neither the name of Google Inc. nor the names of its
* 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 "GridBaselineAlignment.h"
#include "BaselineAlignmentInlines.h"
#include "RenderBoxInlines.h"
#include "RenderStyleConstants.h"
namespace WebCore {
// This function gives the margin 'over' based on the baseline-axis, since in grid we can have 2-dimensional
// alignment by baseline. In horizontal writing-mode, the row-axis is the horizontal axis. When we use this
// axis to move the grid items so that they are baseline-aligned, we want their "horizontal" margin (right);
// the same will happen when using the column-axis under vertical writing mode, we also want in this case the
// 'right' margin.
LayoutUnit GridBaselineAlignment::marginOverForChild(const RenderBox& child, GridAxis axis) const
{
return isHorizontalBaselineAxis(axis) ? child.marginRight() : child.marginTop();
}
// This function gives the margin 'under' based on the baseline-axis, since in grid we can can 2-dimensional
// alignment by baseline. In horizontal writing-mode, the row-axis is the horizontal axis. When we use this
// axis to move the grid items so that they are baseline-aligned, we want their "horizontal" margin (left);
// the same will happen when using the column-axis under vertical writing mode, we also want in this case the
// 'left' margin.
LayoutUnit GridBaselineAlignment::marginUnderForChild(const RenderBox& child, GridAxis axis) const
{
return isHorizontalBaselineAxis(axis) ? child.marginLeft() : child.marginBottom();
}
LayoutUnit GridBaselineAlignment::logicalAscentForChild(const RenderBox& child, GridAxis baselineAxis, ItemPosition position) const
{
LayoutUnit ascent = ascentForChild(child, baselineAxis, position);
return (isDescentBaselineForChild(child, baselineAxis) || position == ItemPosition::LastBaseline) ? descentForChild(child, ascent, baselineAxis) : ascent;
}
LayoutUnit GridBaselineAlignment::ascentForChild(const RenderBox& child, GridAxis baselineAxis, ItemPosition position) const
{
ASSERT(position == ItemPosition::Baseline || position == ItemPosition::LastBaseline);
LayoutUnit margin = isDescentBaselineForChild(child, baselineAxis) ? marginUnderForChild(child, baselineAxis) : marginOverForChild(child, baselineAxis);
std::optional<LayoutUnit> computedBaselineValue = position == ItemPosition::Baseline ? child.firstLineBaseline() : child.lastLineBaseline();
LayoutUnit baseline(isParallelToBaselineAxisForChild(child, baselineAxis) ? computedBaselineValue.value_or(LayoutUnit(-1)) : LayoutUnit(-1));
// We take border-box's under edge if no valid baseline.
if (baseline == -1) {
ASSERT(!child.needsLayout());
if (isHorizontalBaselineAxis(baselineAxis))
return isFlippedWritingMode(m_blockFlow) ? child.size().width().toInt() + margin : margin;
return child.size().height() + margin;
}
return baseline + margin;
}
LayoutUnit GridBaselineAlignment::descentForChild(const RenderBox& child, LayoutUnit ascent, GridAxis baselineAxis) const
{
ASSERT(!child.needsLayout());
if (isParallelToBaselineAxisForChild(child, baselineAxis))
return child.marginLogicalHeight() + child.logicalHeight() - ascent;
return child.marginLogicalWidth() + child.logicalWidth() - ascent;
}
bool GridBaselineAlignment::isDescentBaselineForChild(const RenderBox& child, GridAxis baselineAxis) const
{
return isHorizontalBaselineAxis(baselineAxis)
&& ((child.style().isFlippedBlocksWritingMode() && !isFlippedWritingMode(m_blockFlow))
|| (child.style().isFlippedLinesWritingMode() && isFlippedWritingMode(m_blockFlow)));
}
bool GridBaselineAlignment::isHorizontalBaselineAxis(GridAxis axis) const
{
return axis == GridRowAxis ? isHorizontalWritingMode(m_blockFlow) : !isHorizontalWritingMode(m_blockFlow);
}
bool GridBaselineAlignment::isOrthogonalChildForBaseline(const RenderBox& child) const
{
return isHorizontalWritingMode(m_blockFlow) != child.isHorizontalWritingMode();
}
bool GridBaselineAlignment::isParallelToBaselineAxisForChild(const RenderBox& child, GridAxis axis) const
{
return axis == GridColumnAxis ? !isOrthogonalChildForBaseline(child) : isOrthogonalChildForBaseline(child);
}
const BaselineGroup& GridBaselineAlignment::baselineGroupForChild(ItemPosition preference, unsigned sharedContext, const RenderBox& child, GridAxis baselineAxis) const
{
ASSERT(isBaselinePosition(preference));
bool isRowAxisContext = baselineAxis == GridColumnAxis;
auto& baselineAlignmentStateMap = isRowAxisContext ? m_rowAxisBaselineAlignmentStates : m_colAxisBaselineAlignmentStates;
auto* baselineAlignmentState = baselineAlignmentStateMap.get(sharedContext);
ASSERT(baselineAlignmentState);
return baselineAlignmentState->sharedGroup(child, preference);
}
void GridBaselineAlignment::updateBaselineAlignmentContext(ItemPosition preference, unsigned sharedContext, const RenderBox& child, GridAxis baselineAxis)
{
ASSERT(isBaselinePosition(preference));
ASSERT(!child.needsLayout());
// Determine Ascent and Descent values of this child with respect to
// its grid container.
LayoutUnit ascent = logicalAscentForChild(child, baselineAxis, preference);
// Looking up for a shared alignment context perpendicular to the
// baseline axis.
bool isRowAxisContext = baselineAxis == GridColumnAxis;
auto& baselineAlignmentStateMap = isRowAxisContext ? m_rowAxisBaselineAlignmentStates : m_colAxisBaselineAlignmentStates;
// Looking for a compatible baseline-sharing group.
if (auto* baselineAlignmentStateSearch = baselineAlignmentStateMap.get(sharedContext))
baselineAlignmentStateSearch->updateSharedGroup(child, preference, ascent);
else
baselineAlignmentStateMap.add(sharedContext, makeUnique<BaselineAlignmentState>(child, preference, ascent));
}
LayoutUnit GridBaselineAlignment::baselineOffsetForChild(ItemPosition preference, unsigned sharedContext, const RenderBox& child, GridAxis baselineAxis) const
{
ASSERT(isBaselinePosition(preference));
auto& group = baselineGroupForChild(preference, sharedContext, child, baselineAxis);
if (group.computeSize() > 1)
return group.maxAscent() - logicalAscentForChild(child, baselineAxis, preference);
return LayoutUnit();
}
void GridBaselineAlignment::clear(GridAxis baselineAxis)
{
if (baselineAxis == GridColumnAxis)
m_rowAxisBaselineAlignmentStates.clear();
else
m_colAxisBaselineAlignmentStates.clear();
}
} // namespace WebCore
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