Source/WebCore/layout/formattingContexts/block/BlockFormattingQuirks.cpp - WebKit - Git at Google

 /*
  * 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 "BlockFormattingQuirks.h"

 #if ENABLE(LAYOUT_FORMATTING_CONTEXT)

 #include "BlockFormattingContext.h"
 #include "BlockFormattingGeometry.h"
 #include "BlockMarginCollapse.h"
 #include "LayoutBox.h"
 #include "LayoutBoxGeometry.h"
 #include "LayoutContainerBox.h"
 #include "LayoutInitialContainingBlock.h"
 #include "LayoutState.h"

 namespace WebCore {
 namespace Layout {

 static bool isQuirkContainer(const Box& layoutBox)
 {
     return layoutBox.isBodyBox() || layoutBox.isDocumentBox() || layoutBox.isTableCell();
 }

 BlockFormattingQuirks::BlockFormattingQuirks(const BlockFormattingContext& blockFormattingContext)
     : FormattingQuirks(blockFormattingContext)
 {
 }

 static bool needsStretching(const Box& layoutBox)
 {
     ASSERT(layoutBox.isInFlow());
     // In quirks mode, in-flow body and html stretch to the initial containing block (height: auto only).
     if (!layoutBox.isDocumentBox() && !layoutBox.isBodyBox())
         return false;
     return layoutBox.style().logicalHeight().isAuto();
 }

 std::optional<LayoutUnit> BlockFormattingQuirks::stretchedInFlowHeightIfApplicable(const Box& layoutBox, ContentHeightAndMargin contentHeightAndMargin) const
 {
     ASSERT(layoutState().inQuirksMode());
     if (!needsStretching(layoutBox))
         return { };
     auto& formattingContext = downcast<BlockFormattingContext>(this->formattingContext());
     auto nonCollapsedVerticalMargin = contentHeightAndMargin.nonCollapsedMargin.before + contentHeightAndMargin.nonCollapsedMargin.after;

     if (layoutBox.isDocumentBox()) {
         // Let's stretch the inflow document box(<html>) to the height of the initial containing block (view).
         auto documentBoxContentHeight = formattingContext.geometryForBox(layoutBox.initialContainingBlock(), FormattingContext::EscapeReason::DocumentBoxStretchesToViewportQuirk).contentBoxHeight();
         // Document box's own vertical margin/border/padding values always shrink the content height.
         auto& documentBoxGeometry = formattingContext.geometryForBox(layoutBox);
         documentBoxContentHeight -= nonCollapsedVerticalMargin + documentBoxGeometry.verticalBorder() + documentBoxGeometry.verticalPadding().value_or(0);
         return std::max(contentHeightAndMargin.contentHeight,  documentBoxContentHeight);
     }

     // Here is the quirky part for body box when it stretches all the way to the ICB even when the document box does not (e.g. out-of-flow positioned).
     ASSERT(layoutBox.isBodyBox());
     auto& initialContainingBlock = layoutBox.initialContainingBlock();
     auto& initialContainingBlockGeometry = formattingContext.geometryForBox(initialContainingBlock, FormattingContext::EscapeReason::BodyStretchesToViewportQuirk);
     // Start the content height with the ICB.
     auto bodyBoxContentHeight = initialContainingBlockGeometry.contentBoxHeight();
     // Body box's own border and padding shrink the content height.
     auto& bodyBoxGeometry = formattingContext.geometryForBox(layoutBox);
     bodyBoxContentHeight -= bodyBoxGeometry.verticalBorder() + bodyBoxGeometry.verticalPadding().value_or(0);
     // Body box never collapses its vertical margins with the document box but it might collapse its margin with its descendants.
     auto nonCollapsedMargin = contentHeightAndMargin.nonCollapsedMargin;
     auto marginCollapse = BlockMarginCollapse { formattingContext.layoutState(), formattingContext.formattingState() };
     auto collapsedMargin = marginCollapse.collapsedVerticalValues(layoutBox, nonCollapsedMargin).collapsedValues;
     auto usedVerticalMargin = collapsedMargin.before.value_or(nonCollapsedMargin.before);
     usedVerticalMargin += collapsedMargin.isCollapsedThrough ? nonCollapsedMargin.after : collapsedMargin.after.value_or(nonCollapsedMargin.after);
     bodyBoxContentHeight -= usedVerticalMargin;
     // Document box's padding and border also shrink the body box's content height.
     auto& documentBox = layoutBox.parent();
     auto& documentBoxGeometry = formattingContext.geometryForBox(documentBox, FormattingContext::EscapeReason::BodyStretchesToViewportQuirk);
     bodyBoxContentHeight -= documentBoxGeometry.verticalBorder() + documentBoxGeometry.verticalPadding().value_or(0);
     // However the non-in-flow document box's vertical margins are ignored. They don't affect the body box's content height.
     if (documentBox.isInFlow()) {
         auto& formattingGeometry = formattingContext.formattingGeometry();
         auto precomputeDocumentBoxVerticalMargin = formattingGeometry.computedVerticalMargin(documentBox, formattingGeometry.constraintsForInFlowContent(initialContainingBlock, FormattingContext::EscapeReason::BodyStretchesToViewportQuirk).horizontal());
         bodyBoxContentHeight -= precomputeDocumentBoxVerticalMargin.before.value_or(0) + precomputeDocumentBoxVerticalMargin.after.value_or(0);
     }
     return std::max(contentHeightAndMargin.contentHeight,  bodyBoxContentHeight);
 }

 bool BlockFormattingQuirks::shouldIgnoreCollapsedQuirkMargin(const Box& layoutBox)
 {
     return isQuirkContainer(layoutBox);
 }

 enum class VerticalMargin { Before, After };
 static inline bool hasQuirkMarginToCollapse(const Box& layoutBox, VerticalMargin verticalMargin)
 {
     if (!layoutBox.isInFlow())
         return false;
     auto& style = layoutBox.style();
     return (verticalMargin == VerticalMargin::Before && style.hasMarginBeforeQuirk()) || (verticalMargin == VerticalMargin::After && style.hasMarginAfterQuirk());
 }

 bool BlockFormattingQuirks::shouldCollapseMarginBeforeWithParentMarginBefore(const Box& layoutBox)
 {
     return hasQuirkMarginToCollapse(layoutBox, VerticalMargin::Before) && isQuirkContainer(layoutBox.containingBlock());
 }

 bool BlockFormattingQuirks::shouldCollapseMarginAfterWithParentMarginAfter(const Box& layoutBox)
 {
     return hasQuirkMarginToCollapse(layoutBox, VerticalMargin::After) && isQuirkContainer(layoutBox.containingBlock());
 }

 }
 }

 #endif
	/*
	* 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 "BlockFormattingQuirks.h"

	#if ENABLE(LAYOUT_FORMATTING_CONTEXT)

	#include "BlockFormattingContext.h"
	#include "BlockFormattingGeometry.h"
	#include "BlockMarginCollapse.h"
	#include "LayoutBox.h"
	#include "LayoutBoxGeometry.h"
	#include "LayoutContainerBox.h"
	#include "LayoutInitialContainingBlock.h"
	#include "LayoutState.h"

	namespace WebCore {
	namespace Layout {

	static bool isQuirkContainer(const Box& layoutBox)
	{
	return layoutBox.isBodyBox() \|\| layoutBox.isDocumentBox() \|\| layoutBox.isTableCell();
	}

	BlockFormattingQuirks::BlockFormattingQuirks(const BlockFormattingContext& blockFormattingContext)
	: FormattingQuirks(blockFormattingContext)
	{
	}

	static bool needsStretching(const Box& layoutBox)
	{
	ASSERT(layoutBox.isInFlow());
	// In quirks mode, in-flow body and html stretch to the initial containing block (height: auto only).
	if (!layoutBox.isDocumentBox() && !layoutBox.isBodyBox())
	return false;
	return layoutBox.style().logicalHeight().isAuto();
	}

	std::optional<LayoutUnit> BlockFormattingQuirks::stretchedInFlowHeightIfApplicable(const Box& layoutBox, ContentHeightAndMargin contentHeightAndMargin) const
	{
	ASSERT(layoutState().inQuirksMode());
	if (!needsStretching(layoutBox))
	return { };
	auto& formattingContext = downcast<BlockFormattingContext>(this->formattingContext());
	auto nonCollapsedVerticalMargin = contentHeightAndMargin.nonCollapsedMargin.before + contentHeightAndMargin.nonCollapsedMargin.after;

	if (layoutBox.isDocumentBox()) {
	// Let's stretch the inflow document box(<html>) to the height of the initial containing block (view).
	auto documentBoxContentHeight = formattingContext.geometryForBox(layoutBox.initialContainingBlock(), FormattingContext::EscapeReason::DocumentBoxStretchesToViewportQuirk).contentBoxHeight();
	// Document box's own vertical margin/border/padding values always shrink the content height.
	auto& documentBoxGeometry = formattingContext.geometryForBox(layoutBox);
	documentBoxContentHeight -= nonCollapsedVerticalMargin + documentBoxGeometry.verticalBorder() + documentBoxGeometry.verticalPadding().value_or(0);
	return std::max(contentHeightAndMargin.contentHeight, documentBoxContentHeight);
	}

	// Here is the quirky part for body box when it stretches all the way to the ICB even when the document box does not (e.g. out-of-flow positioned).
	ASSERT(layoutBox.isBodyBox());
	auto& initialContainingBlock = layoutBox.initialContainingBlock();
	auto& initialContainingBlockGeometry = formattingContext.geometryForBox(initialContainingBlock, FormattingContext::EscapeReason::BodyStretchesToViewportQuirk);
	// Start the content height with the ICB.
	auto bodyBoxContentHeight = initialContainingBlockGeometry.contentBoxHeight();
	// Body box's own border and padding shrink the content height.
	auto& bodyBoxGeometry = formattingContext.geometryForBox(layoutBox);
	bodyBoxContentHeight -= bodyBoxGeometry.verticalBorder() + bodyBoxGeometry.verticalPadding().value_or(0);
	// Body box never collapses its vertical margins with the document box but it might collapse its margin with its descendants.
	auto nonCollapsedMargin = contentHeightAndMargin.nonCollapsedMargin;
	auto marginCollapse = BlockMarginCollapse { formattingContext.layoutState(), formattingContext.formattingState() };
	auto collapsedMargin = marginCollapse.collapsedVerticalValues(layoutBox, nonCollapsedMargin).collapsedValues;
	auto usedVerticalMargin = collapsedMargin.before.value_or(nonCollapsedMargin.before);
	usedVerticalMargin += collapsedMargin.isCollapsedThrough ? nonCollapsedMargin.after : collapsedMargin.after.value_or(nonCollapsedMargin.after);
	bodyBoxContentHeight -= usedVerticalMargin;
	// Document box's padding and border also shrink the body box's content height.
	auto& documentBox = layoutBox.parent();
	auto& documentBoxGeometry = formattingContext.geometryForBox(documentBox, FormattingContext::EscapeReason::BodyStretchesToViewportQuirk);
	bodyBoxContentHeight -= documentBoxGeometry.verticalBorder() + documentBoxGeometry.verticalPadding().value_or(0);
	// However the non-in-flow document box's vertical margins are ignored. They don't affect the body box's content height.
	if (documentBox.isInFlow()) {
	auto& formattingGeometry = formattingContext.formattingGeometry();
	auto precomputeDocumentBoxVerticalMargin = formattingGeometry.computedVerticalMargin(documentBox, formattingGeometry.constraintsForInFlowContent(initialContainingBlock, FormattingContext::EscapeReason::BodyStretchesToViewportQuirk).horizontal());
	bodyBoxContentHeight -= precomputeDocumentBoxVerticalMargin.before.value_or(0) + precomputeDocumentBoxVerticalMargin.after.value_or(0);
	}
	return std::max(contentHeightAndMargin.contentHeight, bodyBoxContentHeight);
	}

	bool BlockFormattingQuirks::shouldIgnoreCollapsedQuirkMargin(const Box& layoutBox)
	{
	return isQuirkContainer(layoutBox);
	}

	enum class VerticalMargin { Before, After };
	static inline bool hasQuirkMarginToCollapse(const Box& layoutBox, VerticalMargin verticalMargin)
	{
	if (!layoutBox.isInFlow())
	return false;
	auto& style = layoutBox.style();
	return (verticalMargin == VerticalMargin::Before && style.hasMarginBeforeQuirk()) \|\| (verticalMargin == VerticalMargin::After && style.hasMarginAfterQuirk());
	}

	bool BlockFormattingQuirks::shouldCollapseMarginBeforeWithParentMarginBefore(const Box& layoutBox)
	{
	return hasQuirkMarginToCollapse(layoutBox, VerticalMargin::Before) && isQuirkContainer(layoutBox.containingBlock());
	}

	bool BlockFormattingQuirks::shouldCollapseMarginAfterWithParentMarginAfter(const Box& layoutBox)
	{
	return hasQuirkMarginToCollapse(layoutBox, VerticalMargin::After) && isQuirkContainer(layoutBox.containingBlock());
	}

	}
	}

	#endif