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/*
* Copyright (C) 2018 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 "FormattingContext.h"
#if ENABLE(LAYOUT_FORMATTING_CONTEXT)
#include "DisplayBox.h"
#include "FormattingState.h"
#include "LayoutBox.h"
#include "LayoutContainer.h"
#include "LayoutContext.h"
#include "LayoutDescendantIterator.h"
#include "LayoutState.h"
#include "Logging.h"
#include <wtf/IsoMallocInlines.h>
#include <wtf/text/TextStream.h>
namespace WebCore {
namespace Layout {
WTF_MAKE_ISO_ALLOCATED_IMPL(FormattingContext);
static UsedHorizontalValues::Constraints outOfFlowHorizontalConstraints(const Display::Box& containingBlockGeometry)
{
return UsedHorizontalValues::Constraints { containingBlockGeometry.paddingBoxLeft(), containingBlockGeometry.paddingBoxWidth() };
}
static UsedVerticalValues::Constraints outOfFlowVerticalConstraints(const Display::Box& containingBlockGeometry)
{
return UsedVerticalValues::Constraints { containingBlockGeometry.paddingBoxTop(), containingBlockGeometry.paddingBoxHeight() };
}
FormattingContext::FormattingContext(const Container& formattingContextRoot, FormattingState& formattingState)
: m_root(makeWeakPtr(formattingContextRoot))
, m_formattingState(formattingState)
{
#ifndef NDEBUG
layoutState().registerFormattingContext(*this);
#endif
}
FormattingContext::~FormattingContext()
{
#ifndef NDEBUG
layoutState().deregisterFormattingContext(*this);
#endif
}
LayoutState& FormattingContext::layoutState() const
{
return m_formattingState.layoutState();
}
void FormattingContext::computeOutOfFlowHorizontalGeometry(const Box& layoutBox)
{
auto& containingBlockGeometry = geometryForBox(*layoutBox.containingBlock());
auto containingBlockWidth = containingBlockGeometry.paddingBoxWidth();
auto compute = [&](Optional<LayoutUnit> usedWidth) {
auto usedHorizontalValues = UsedHorizontalValues { outOfFlowHorizontalConstraints(containingBlockGeometry), usedWidth, { } };
auto usedVerticalValues = UsedVerticalValues { outOfFlowVerticalConstraints(containingBlockGeometry), { } };
return geometry().outOfFlowHorizontalGeometry(layoutBox, usedHorizontalValues, usedVerticalValues);
};
auto horizontalGeometry = compute({ });
if (auto maxWidth = geometry().computedValueIfNotAuto(layoutBox.style().logicalMaxWidth(), containingBlockWidth)) {
auto maxHorizontalGeometry = compute(maxWidth);
if (horizontalGeometry.widthAndMargin.width > maxHorizontalGeometry.widthAndMargin.width)
horizontalGeometry = maxHorizontalGeometry;
}
if (auto minWidth = geometry().computedValueIfNotAuto(layoutBox.style().logicalMinWidth(), containingBlockWidth)) {
auto minHorizontalGeometry = compute(minWidth);
if (horizontalGeometry.widthAndMargin.width < minHorizontalGeometry.widthAndMargin.width)
horizontalGeometry = minHorizontalGeometry;
}
auto& displayBox = formattingState().displayBox(layoutBox);
displayBox.setLeft(horizontalGeometry.left + horizontalGeometry.widthAndMargin.usedMargin.start);
displayBox.setContentBoxWidth(horizontalGeometry.widthAndMargin.width);
displayBox.setHorizontalMargin(horizontalGeometry.widthAndMargin.usedMargin);
displayBox.setHorizontalComputedMargin(horizontalGeometry.widthAndMargin.computedMargin);
}
void FormattingContext::computeOutOfFlowVerticalGeometry(const Box& layoutBox)
{
auto compute = [&](auto usedHorizontalValues, auto usedVerticalValues) {
return geometry().outOfFlowVerticalGeometry(layoutBox, usedHorizontalValues, usedVerticalValues);
};
auto& containingBlockGeometry = geometryForBox(*layoutBox.containingBlock());
auto containingBlockHeight = containingBlockGeometry.paddingBoxHeight();
auto usedVerticalValuesForHeight = UsedVerticalValues { outOfFlowVerticalConstraints(containingBlockGeometry), { } };
auto usedHorizontalValues = UsedHorizontalValues { outOfFlowHorizontalConstraints(containingBlockGeometry) };
auto verticalGeometry = compute(usedHorizontalValues, usedVerticalValuesForHeight);
if (auto maxHeight = geometry().computedMaxHeight(layoutBox, containingBlockHeight)) {
auto usedValuesForMaxHeight = UsedVerticalValues { outOfFlowVerticalConstraints(containingBlockGeometry), maxHeight };
auto maxVerticalGeometry = compute(usedHorizontalValues, usedValuesForMaxHeight);
if (verticalGeometry.heightAndMargin.height > maxVerticalGeometry.heightAndMargin.height)
verticalGeometry = maxVerticalGeometry;
}
if (auto minHeight = geometry().computedMinHeight(layoutBox, containingBlockHeight)) {
auto usedValuesForMinHeight = UsedVerticalValues { outOfFlowVerticalConstraints(containingBlockGeometry), minHeight };
auto minVerticalGeometry = compute(usedHorizontalValues, usedValuesForMinHeight);
if (verticalGeometry.heightAndMargin.height < minVerticalGeometry.heightAndMargin.height)
verticalGeometry = minVerticalGeometry;
}
auto& displayBox = formattingState().displayBox(layoutBox);
auto nonCollapsedVerticalMargin = verticalGeometry.heightAndMargin.nonCollapsedMargin;
displayBox.setTop(verticalGeometry.top + nonCollapsedVerticalMargin.before);
displayBox.setContentBoxHeight(verticalGeometry.heightAndMargin.height);
// Margins of absolutely positioned boxes do not collapse
displayBox.setVerticalMargin({ nonCollapsedVerticalMargin, { } });
}
void FormattingContext::computeBorderAndPadding(const Box& layoutBox, Optional<UsedHorizontalValues> usedHorizontalValues)
{
if (!usedHorizontalValues)
usedHorizontalValues = UsedHorizontalValues { UsedHorizontalValues::Constraints { geometryForBox(*layoutBox.containingBlock()) } };
auto& displayBox = formattingState().displayBox(layoutBox);
displayBox.setBorder(geometry().computedBorder(layoutBox));
displayBox.setPadding(geometry().computedPadding(layoutBox, *usedHorizontalValues));
}
void FormattingContext::layoutOutOfFlowContent()
{
LOG_WITH_STREAM(FormattingContextLayout, stream << "Start: layout out-of-flow content -> context: " << &layoutState() << " root: " << &root());
for (auto& outOfFlowBox : formattingState().outOfFlowBoxes()) {
ASSERT(outOfFlowBox->establishesFormattingContext());
computeBorderAndPadding(*outOfFlowBox);
computeOutOfFlowHorizontalGeometry(*outOfFlowBox);
if (is<Container>(*outOfFlowBox)) {
auto& outOfFlowRootContainer = downcast<Container>(*outOfFlowBox);
auto formattingContext = LayoutContext::createFormattingContext(outOfFlowRootContainer, layoutState());
formattingContext->layoutInFlowContent();
computeOutOfFlowVerticalGeometry(outOfFlowRootContainer);
formattingContext->layoutOutOfFlowContent();
} else
computeOutOfFlowVerticalGeometry(*outOfFlowBox);
}
LOG_WITH_STREAM(FormattingContextLayout, stream << "End: layout out-of-flow content -> context: " << &layoutState() << " root: " << &root());
}
static LayoutUnit mapHorizontalPositionToAncestor(const FormattingContext& formattingContext, LayoutUnit horizontalPosition, const Container& containingBlock, const Container& ancestor)
{
// "horizontalPosition" is in the coordinate system of the "containingBlock". -> map from containingBlock to ancestor.
if (&containingBlock == &ancestor)
return horizontalPosition;
ASSERT(containingBlock.isContainingBlockDescendantOf(ancestor));
for (auto* container = &containingBlock; container && container != &ancestor; container = container->containingBlock())
horizontalPosition += formattingContext.geometryForBox(*container).left();
return horizontalPosition;
}
// FIXME: turn these into templates.
LayoutUnit FormattingContext::mapTopToFormattingContextRoot(const Box& layoutBox) const
{
ASSERT(layoutBox.containingBlock());
auto& formattingContextRoot = root();
ASSERT(layoutBox.isContainingBlockDescendantOf(formattingContextRoot));
auto top = geometryForBox(layoutBox).top();
for (auto* container = layoutBox.containingBlock(); container && container != &formattingContextRoot; container = container->containingBlock())
top += geometryForBox(*container).top();
return top;
}
LayoutUnit FormattingContext::mapLeftToFormattingContextRoot(const Box& layoutBox) const
{
ASSERT(layoutBox.containingBlock());
return mapHorizontalPositionToAncestor(*this, geometryForBox(layoutBox).left(), *layoutBox.containingBlock(), root());
}
LayoutUnit FormattingContext::mapRightToFormattingContextRoot(const Box& layoutBox) const
{
ASSERT(layoutBox.containingBlock());
return mapHorizontalPositionToAncestor(*this, geometryForBox(layoutBox).right(), *layoutBox.containingBlock(), root());
}
const Display::Box& FormattingContext::geometryForBox(const Box& layoutBox, Optional<EscapeType> escapeType) const
{
UNUSED_PARAM(escapeType);
#ifndef NDEBUG
auto isOkToAccessDisplayBox = [&] {
// 1. Highly common case of accessing the formatting root's display box itself. This is formatting context escaping in the strict sense, since
// the formatting context root box lives in the parent formatting context.
// This happens e.g. when a block level box box needs to stretch horizontally and checks its containing block for horizontal space (this should probably be limited to reading horizontal constraint values).
if (&layoutBox == &root())
return true;
// 2. Special case when accessing the ICB's display box
if (layoutBox.isInitialContainingBlock()) {
// There has to be a valid reason to access the ICB.
if (!escapeType)
return false;
return *escapeType == EscapeType::AccessParentFormattingContext || *escapeType == EscapeType::AccessAncestorFormattingContext;
}
// 3. Most common case of accessing box/containing block display box within the same formatting context tree.
if (&layoutBox.formattingContextRoot() == &root())
return true;
if (!escapeType)
return false;
// 4. Accessing child formatting context subtree is relatively rare. It happens when e.g a shrink to fit (out-of-flow block level) box checks the content width.
// Checking the content width means to get display boxes from the established formatting context (we try to access display boxes in a child formatting context)
if (*escapeType == EscapeType::AccessChildFormattingContext && &layoutBox.formattingContextRoot().formattingContextRoot() == &root())
return true;
// 5. Float box top/left values are mapped relative to the FloatState's root. Inline formatting contexts(A) inherit floats from parent
// block formatting contexts(B). Floats in these inline formatting contexts(A) need to be mapped to the parent, block formatting context(B).
if (*escapeType == EscapeType::AccessParentFormattingContext && &layoutBox.formattingContextRoot() == &root().formattingContextRoot())
return true;
// 6. Finding the first containing block with fixed height quirk. See Quirks::heightValueOfNearestContainingBlockWithFixedHeight
if (*escapeType == EscapeType::AccessAncestorFormattingContext) {
auto& targetFormattingRoot = layoutBox.formattingContextRoot();
auto* ancestorFormattingContextRoot = &root().formattingContextRoot();
while (true) {
if (&targetFormattingRoot == ancestorFormattingContextRoot)
return true;
if (ancestorFormattingContextRoot->isInitialContainingBlock())
return false;
ancestorFormattingContextRoot = &ancestorFormattingContextRoot->formattingContextRoot();
}
}
return false;
};
#endif
ASSERT(isOkToAccessDisplayBox());
ASSERT(layoutState().hasDisplayBox(layoutBox));
return layoutState().displayBoxForLayoutBox(layoutBox);
}
#ifndef NDEBUG
void FormattingContext::validateGeometryConstraintsAfterLayout() const
{
auto& formattingContextRoot = root();
// FIXME: add a descendantsOfType<> flavor that stops at nested formatting contexts
for (auto& layoutBox : descendantsOfType<Box>(formattingContextRoot)) {
if (&layoutBox.formattingContextRoot() != &formattingContextRoot)
continue;
auto& containingBlockGeometry = geometryForBox(*layoutBox.containingBlock());
auto& boxGeometry = geometryForBox(layoutBox);
// 10.3.3 Block-level, non-replaced elements in normal flow
// 10.3.7 Absolutely positioned, non-replaced elements
if ((layoutBox.isBlockLevelBox() || layoutBox.isOutOfFlowPositioned()) && !layoutBox.replaced()) {
// margin-left + border-left-width + padding-left + width + padding-right + border-right-width + margin-right = width of containing block
auto containingBlockWidth = containingBlockGeometry.contentBoxWidth();
ASSERT(boxGeometry.horizontalMarginBorderAndPadding() + boxGeometry.contentBoxWidth() == containingBlockWidth);
}
// 10.6.4 Absolutely positioned, non-replaced elements
if (layoutBox.isOutOfFlowPositioned() && !layoutBox.replaced()) {
// top + margin-top + border-top-width + padding-top + height + padding-bottom + border-bottom-width + margin-bottom + bottom = height of containing block
auto containingBlockHeight = containingBlockGeometry.contentBoxHeight();
ASSERT(boxGeometry.top() + boxGeometry.marginBefore() + boxGeometry.borderTop() + boxGeometry.paddingTop().valueOr(0) + boxGeometry.contentBoxHeight()
+ boxGeometry.paddingBottom().valueOr(0) + boxGeometry.borderBottom() + boxGeometry.marginAfter() == containingBlockHeight);
}
}
}
#endif
}
}
#endif