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/*
* Copyright (C) 2020 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 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. AND ITS 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 APPLE INC. OR ITS 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 "FlexFormattingContext.h"
#include "FlexFormattingUtils.h"
#include "FlexRect.h"
#include "InlineRect.h"
#include "LayoutBoxGeometry.h"
#include "LayoutChildIterator.h"
#include "LayoutContext.h"
#include "LayoutState.h"
#include "LengthFunctions.h"
#include "RenderStyleInlines.h"
#include <wtf/FixedVector.h>
#include <wtf/TZoneMallocInlines.h>
namespace WebCore {
namespace Layout {
WTF_MAKE_TZONE_OR_ISO_ALLOCATED_IMPL(FlexFormattingContext);
FlexFormattingContext::FlexFormattingContext(const ElementBox& flexBox, LayoutState& globalLayoutState)
: m_flexBox(flexBox)
, m_globalLayoutState(globalLayoutState)
, m_flexFormattingUtils(*this)
, m_integrationUtils(globalLayoutState)
{
}
void FlexFormattingContext::layout(const ConstraintsForFlexContent& constraints)
{
auto logicalFlexItems = convertFlexItemsToLogicalSpace(constraints);
auto flexItemRects = FlexLayout { *this }.layout(constraints, logicalFlexItems);
setFlexItemsGeometry(logicalFlexItems, flexItemRects, constraints);
positionOutOfFlowChildren();
}
IntrinsicWidthConstraints FlexFormattingContext::computedIntrinsicWidthConstraints()
{
return { };
}
FlexLayout::LogicalFlexItems FlexFormattingContext::convertFlexItemsToLogicalSpace(const ConstraintsForFlexContent& constraints)
{
struct FlexItem {
LogicalFlexItem::MainAxisGeometry mainAxis;
LogicalFlexItem::CrossAxisGeometry crossAxis;
int logicalOrder { 0 };
CheckedPtr<const ElementBox> layoutBox;
};
Vector<FlexItem> flexItemList;
auto flexItemsNeedReordering = false;
auto convertVisualToLogical = [&] {
auto direction = root().style().flexDirection();
auto previousLogicalOrder = std::optional<int> { };
auto isMainAxisParallelWithInlineAxis = FlexFormattingUtils::isMainAxisParallelWithInlineAxis(root());
auto isReversedInCrossAxis = FlexFormattingUtils::areFlexLinesReversedInCrossAxis(root());
for (auto* flexItem = root().firstInFlowChild(); flexItem; flexItem = flexItem->nextInFlowSibling()) {
auto& flexItemGeometry = m_globalLayoutState.geometryForBox(*flexItem);
auto& style = flexItem->style();
auto mainAxis = LogicalFlexItem::MainAxisGeometry { };
auto crossAxis = LogicalFlexItem::CrossAxisGeometry { };
auto propertyValueForLength = [&](auto& propertyValue, auto availableSize) -> std::optional<LayoutUnit> {
if (propertyValue.isFixed())
return LayoutUnit { propertyValue.value() };
if (propertyValue.isSpecified() && availableSize)
return valueForLength(propertyValue, *availableSize);
return { };
};
auto setMainAxisValues = [&] {
auto flexContainerMainInnerSize = constraints.mainAxis().availableSize;
mainAxis.size = propertyValueForLength(isMainAxisParallelWithInlineAxis ? style.width() : style.height(), flexContainerMainInnerSize);
mainAxis.minimumSize = propertyValueForLength(isMainAxisParallelWithInlineAxis ? style.minWidth() : style.minHeight(), flexContainerMainInnerSize);
mainAxis.maximumSize = propertyValueForLength(isMainAxisParallelWithInlineAxis ? style.maxWidth() : style.maxHeight(), flexContainerMainInnerSize);
// Auto keyword retrieves the value of the main size property as the used flex-basis.
// If that value is itself auto, then the used value is content.
mainAxis.definiteFlexBasis = style.flexBasis().isAuto() ? mainAxis.size : propertyValueForLength(style.flexBasis(), flexContainerMainInnerSize);
auto marginStart = [&]() -> std::optional<LayoutUnit> {
if (direction == FlexDirection::Row && !style.marginStart().isAuto())
return flexItemGeometry.marginStart();
if (direction == FlexDirection::RowReverse && !style.marginEnd().isAuto())
return flexItemGeometry.marginEnd();
if (direction == FlexDirection::Column && !style.marginBefore().isAuto())
return flexItemGeometry.marginBefore();
if (direction == FlexDirection::ColumnReverse && !style.marginAfter().isAuto())
return flexItemGeometry.marginAfter();
return { };
};
auto marginEnd = [&]() -> std::optional<LayoutUnit> {
if (direction == FlexDirection::Row && !style.marginEnd().isAuto())
return flexItemGeometry.marginEnd();
if (direction == FlexDirection::RowReverse && !style.marginStart().isAuto())
return flexItemGeometry.marginStart();
if (direction == FlexDirection::Column && !style.marginAfter().isAuto())
return flexItemGeometry.marginAfter();
if (direction == FlexDirection::ColumnReverse && !style.marginBefore().isAuto())
return flexItemGeometry.marginBefore();
return { };
};
auto shouldFlipMargins = isMainAxisParallelWithInlineAxis && root().writingMode().isLineInverted();
mainAxis.marginStart = !shouldFlipMargins ? marginStart() : marginEnd();
mainAxis.marginEnd = !shouldFlipMargins ? marginEnd() : marginStart();
mainAxis.borderAndPadding = isMainAxisParallelWithInlineAxis ? flexItemGeometry.horizontalBorderAndPadding() : flexItemGeometry.verticalBorderAndPadding();
};
setMainAxisValues();
auto setCrossAxisValues = [&] {
auto flexContainerCrossInnerSize = constraints.crossAxis().availableSize;
crossAxis.definiteSize = propertyValueForLength(isMainAxisParallelWithInlineAxis ? style.height() : style.width(), flexContainerCrossInnerSize);
crossAxis.minimumSize = propertyValueForLength(isMainAxisParallelWithInlineAxis ? style.minHeight() : style.minWidth(), flexContainerCrossInnerSize);
crossAxis.maximumSize = propertyValueForLength(isMainAxisParallelWithInlineAxis ? style.maxHeight() : style.maxWidth(), flexContainerCrossInnerSize);
auto marginStart = [&]() -> std::optional<LayoutUnit> {
if (!isReversedInCrossAxis) {
if (direction == FlexDirection::Row || direction == FlexDirection::RowReverse)
return !style.marginBefore().isAuto() ? std::make_optional(flexItemGeometry.marginBefore()) : std::nullopt;
if (direction == FlexDirection::Column || direction == FlexDirection::ColumnReverse)
return !style.marginStart().isAuto() ? std::make_optional(flexItemGeometry.marginStart()) : std::nullopt;
return { };
}
if (direction == FlexDirection::Row || direction == FlexDirection::RowReverse)
return !style.marginAfter().isAuto() ? std::make_optional(flexItemGeometry.marginAfter()) : std::nullopt;
if (direction == FlexDirection::Column || direction == FlexDirection::ColumnReverse)
return !style.marginEnd().isAuto() ? std::make_optional(flexItemGeometry.marginEnd()) : std::nullopt;
return { };
};
auto marginEnd = [&]() -> std::optional<LayoutUnit> {
if (!isReversedInCrossAxis) {
if (direction == FlexDirection::Row || direction == FlexDirection::RowReverse)
return !style.marginAfter().isAuto() ? std::make_optional(flexItemGeometry.marginAfter()) : std::nullopt;
if (direction == FlexDirection::Column || direction == FlexDirection::ColumnReverse)
return !style.marginEnd().isAuto() ? std::make_optional(flexItemGeometry.marginEnd()) : std::nullopt;
return { };
}
if (direction == FlexDirection::Row || direction == FlexDirection::RowReverse)
return !style.marginBefore().isAuto() ? std::make_optional(flexItemGeometry.marginBefore()) : std::nullopt;
if (direction == FlexDirection::Column || direction == FlexDirection::ColumnReverse)
return !style.marginStart().isAuto() ? std::make_optional(flexItemGeometry.marginStart()) : std::nullopt;
return { };
};
auto shouldFlipMargins = !isMainAxisParallelWithInlineAxis && root().writingMode().isLineInverted();
crossAxis.marginStart = !shouldFlipMargins ? marginStart() : marginEnd();
crossAxis.marginEnd = !shouldFlipMargins ? marginEnd() : marginStart();
crossAxis.hasSizeAuto = isMainAxisParallelWithInlineAxis ? style.height().isAuto() : style.width().isAuto();
crossAxis.borderAndPadding = isMainAxisParallelWithInlineAxis ? flexItemGeometry.verticalBorderAndPadding() : flexItemGeometry.horizontalBorderAndPadding();
};
setCrossAxisValues();
auto flexItemOrder = style.order();
flexItemsNeedReordering = flexItemsNeedReordering || flexItemOrder != previousLogicalOrder.value_or(0);
previousLogicalOrder = flexItemOrder;
flexItemList.append({ mainAxis, crossAxis, flexItemOrder, downcast<ElementBox>(flexItem) });
}
};
convertVisualToLogical();
auto reorderFlexItemsIfApplicable = [&] {
if (!flexItemsNeedReordering)
return;
std::stable_sort(flexItemList.begin(), flexItemList.end(), [&] (auto& a, auto& b) {
return a.logicalOrder < b.logicalOrder;
});
};
reorderFlexItemsIfApplicable();
auto logicalFlexItemList = FlexLayout::LogicalFlexItems(flexItemList.size());
for (size_t index = 0; index < flexItemList.size(); ++index) {
auto& flexItem = flexItemList[index];
logicalFlexItemList[index] = { *flexItem.layoutBox
, flexItem.mainAxis
, flexItem.crossAxis
, false
, false
};
}
return logicalFlexItemList;
}
void FlexFormattingContext::setFlexItemsGeometry(const FlexLayout::LogicalFlexItems& logicalFlexItemList, const FlexLayout::LogicalFlexItemRects& logicalRects, const ConstraintsForFlexContent& constraints)
{
auto& flexBoxStyle = root().style();
auto flexDirection = flexBoxStyle.flexDirection();
auto isLeftToRightDirection = flexBoxStyle.writingMode().isLogicalLeftInlineStart();
auto isRowDirection = flexDirection == FlexDirection::Row || flexDirection == FlexDirection::RowReverse;
auto flexContainerContentBoxPosition = LayoutPoint { isRowDirection ? constraints.mainAxis().startPosition : constraints.crossAxis().startPosition, isRowDirection ? constraints.crossAxis().startPosition : constraints.mainAxis().startPosition };
auto flexContainerMainAxisSize = [&] {
if (auto size = constraints.mainAxis().availableSize)
return *size;
// Let's use content size when available size is inf.
auto& lastFlexItem = logicalFlexItemList.last();
auto& lastRect = logicalRects.last();
return lastRect.right() + lastRect.marginRight() + (lastFlexItem.isContentBoxBased() ? geometryForFlexItem(lastFlexItem.layoutBox()).horizontalBorderAndPadding() : 0_lu);
}();
auto flexContainerCrossAxisSize = [&] {
if (auto crossAxisSize = constraints.crossAxis().availableSize)
return *crossAxisSize;
// In case of content size driven height in reversed cross axis direction (content is upside down), the height is just the farthest point with content.
auto maximumHeight = LayoutUnit { };
for (auto& logicalRect : logicalRects)
maximumHeight = std::max(maximumHeight, logicalRect.bottom() + logicalRect.marginBottom());
return maximumHeight;
}();
for (size_t index = 0; index < logicalFlexItemList.size(); ++index) {
auto& logicalFlexItem = logicalFlexItemList[index];
auto& flexItemGeometry = geometryForFlexItem(logicalFlexItem.layoutBox());
auto logicalRect = [&] {
// Note that flex rects are inner size based.
if (flexBoxStyle.flexWrap() != FlexWrap::Reverse)
return logicalRects[index];
auto rect = logicalRects[index];
auto adjustedLogicalBorderBoxTop = flexContainerCrossAxisSize - rect.bottom();
if (logicalFlexItem.isContentBoxBased())
adjustedLogicalBorderBoxTop -= flexDirection == FlexDirection::Row || flexDirection == FlexDirection::RowReverse ? flexItemGeometry.verticalBorderAndPadding() : flexItemGeometry.horizontalBorderAndPadding();
rect.setTop(adjustedLogicalBorderBoxTop);
return rect;
}();
auto borderBoxTop = LayoutUnit { };
auto borderBoxLeft = LayoutUnit { };
if (flexDirection == FlexDirection::Row || flexDirection == FlexDirection::RowReverse) {
borderBoxTop += logicalRect.top();
if (flexDirection == FlexDirection::Row)
borderBoxLeft = logicalRect.left();
else {
borderBoxLeft = flexContainerMainAxisSize - logicalRect.right();
if (logicalFlexItem.isContentBoxBased())
borderBoxLeft -= flexItemGeometry.horizontalBorderAndPadding();
}
} else {
// Let's flip x and y to go from column to row.
borderBoxLeft = logicalRect.top();
if (flexDirection == FlexDirection::Column)
borderBoxTop = logicalRect.left();
else {
borderBoxTop = flexContainerMainAxisSize - logicalRect.right();
if (logicalFlexItem.isContentBoxBased())
borderBoxTop -= flexItemGeometry.verticalBorderAndPadding();
}
}
auto contentBoxWidth = isRowDirection ? logicalRect.width() : logicalRect.height();
auto contentBoxHeight = isRowDirection ? logicalRect.height() : logicalRect.width();
if (!logicalFlexItem.isContentBoxBased()) {
contentBoxWidth -= flexItemGeometry.horizontalBorderAndPadding();
contentBoxHeight -= flexItemGeometry.verticalBorderAndPadding();
}
flexItemGeometry.setContentBoxWidth(contentBoxWidth);
flexItemGeometry.setContentBoxHeight(contentBoxHeight);
if (!isLeftToRightDirection)
borderBoxLeft = (isRowDirection ? flexContainerMainAxisSize : flexContainerCrossAxisSize) - (borderBoxLeft + flexItemGeometry.borderBoxWidth());
flexItemGeometry.setTopLeft({ flexContainerContentBoxPosition.x() + borderBoxLeft, flexContainerContentBoxPosition.y() + borderBoxTop });
}
}
void FlexFormattingContext::positionOutOfFlowChildren()
{
// FIXME: Implement out-of-flow positioning.
for (auto* outOfFlowChild = root().firstOutOfFlowChild(); outOfFlowChild; outOfFlowChild = outOfFlowChild->nextOutOfFlowSibling())
m_globalLayoutState.ensureGeometryForBox(*outOfFlowChild).setTopLeft({ });
}
const BoxGeometry& FlexFormattingContext::geometryForFlexItem(const Box& flexItem) const
{
ASSERT(flexItem.isFlexItem());
return m_globalLayoutState.geometryForBox(flexItem);
}
BoxGeometry& FlexFormattingContext::geometryForFlexItem(const Box& flexItem)
{
ASSERT(flexItem.isFlexItem());
return m_globalLayoutState.ensureGeometryForBox(flexItem);
}
}
}
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