Source/WebCore/layout/displaytree/DisplayPainter.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2019 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 "DisplayPainter.h"

 #if ENABLE(LAYOUT_FORMATTING_CONTEXT)

 #include "CachedImage.h"
 #include "Color.h"
 #include "DisplayBox.h"
 #include "GraphicsContext.h"
 #include "InlineFormattingState.h"
 #include "InlineTextItem.h"
 #include "IntRect.h"
 #include "LayoutContainerBox.h"
 #include "LayoutInitialContainingBlock.h"
 #include "LayoutState.h"
 #include "RenderStyle.h"
 #include "TextRun.h"

 namespace WebCore {
 namespace Display {

 static void paintBoxDecoration(GraphicsContext& context, const Box& absoluteDisplayBox, const RenderStyle& style, bool needsMarginPainting)
 {
     auto decorationBoxTopLeft = needsMarginPainting ? absoluteDisplayBox.rectWithMargin().topLeft() : absoluteDisplayBox.topLeft();
     auto decorationBoxSize = needsMarginPainting ? absoluteDisplayBox.rectWithMargin().size() : LayoutSize(absoluteDisplayBox.borderBoxWidth(), absoluteDisplayBox.borderBoxHeight());
     // Background color
     if (style.hasBackground()) {
         context.fillRect({ decorationBoxTopLeft, decorationBoxSize }, style.backgroundColor());
         if (style.hasBackgroundImage()) {
             auto& backgroundLayer = style.backgroundLayers();
             if (backgroundLayer.image() && backgroundLayer.image()->cachedImage() && backgroundLayer.image()->cachedImage()->image())
                 context.drawImage(*backgroundLayer.image()->cachedImage()->image(), { decorationBoxTopLeft, backgroundLayer.image()->cachedImage()->image()->size() });
         }
     }

     // Border
     if (style.hasVisibleBorder()) {

         auto drawBorderSide = [&](auto start, auto end, const auto& borderStyle) {
             if (!borderStyle.width())
                 return;
             if (borderStyle.style() == BorderStyle::None || borderStyle.style() == BorderStyle::Hidden)
                 return;
             context.setStrokeColor(borderStyle.color());
             context.setStrokeThickness(borderStyle.width());
             context.drawLine(start, end);
         };

         context.setFillColor(Color::transparent);

         auto decorationBoxWidth = decorationBoxSize.width();
         auto decorationBoxHeight = decorationBoxSize.height();

         // Top
         {
             auto borderWidth = style.borderTop().width();
             auto start = LayoutPoint { decorationBoxTopLeft };
             auto end = LayoutPoint { start.x() + decorationBoxWidth, start.y() + borderWidth };
             drawBorderSide(start, end, style.borderTop());
         }

         // Right
         {
             auto borderWidth = style.borderRight().width();
             auto start = LayoutPoint { decorationBoxTopLeft.x() + decorationBoxWidth - borderWidth, decorationBoxTopLeft.y() };
             auto end = LayoutPoint { start.x() + borderWidth, decorationBoxTopLeft.y() + decorationBoxHeight };
             drawBorderSide(start, end, style.borderRight());
         }

         // Bottom
         {
             auto borderWidth = style.borderBottom().width();
             auto start = LayoutPoint { decorationBoxTopLeft.x(), decorationBoxTopLeft.y() + decorationBoxHeight - borderWidth };
             auto end = LayoutPoint { start.x() + decorationBoxWidth, start.y() + borderWidth };
             drawBorderSide(start, end, style.borderBottom());
         }

         // Left
         {
             auto borderWidth = style.borderLeft().width();
             auto start = decorationBoxTopLeft;
             auto end = LayoutPoint { start.x() + borderWidth, decorationBoxTopLeft.y() + decorationBoxHeight };
             drawBorderSide(start, end, style.borderLeft());
         }
     }
 }

 static void paintInlineContent(GraphicsContext& context, LayoutPoint absoluteOffset, const Layout::InlineFormattingState& formattingState)
 {
     auto* displayInlineContent = formattingState.displayInlineContent();
     if (!displayInlineContent)
         return;

     auto& displayRuns = displayInlineContent->runs;
     if (displayRuns.isEmpty())
         return;

     for (auto& run : displayRuns) {
         if (auto& textContent = run.textContent()) {
             auto& style = run.style();
             context.setStrokeColor(style.color());
             context.setFillColor(style.color());

             auto absoluteLeft = absoluteOffset.x() + run.left();
             // FIXME: Add non-baseline align painting
             auto& lineBox = displayInlineContent->lineBoxForRun(run);
             auto baselineOffset = absoluteOffset.y() + lineBox.top() + lineBox.baselineOffset();
             auto expansion = run.expansion();
             auto textRun = TextRun { textContent->content(), run.left() - lineBox.left(), expansion.horizontalExpansion, expansion.behavior };
             textRun.setTabSize(!style.collapseWhiteSpace(), style.tabSize());
             context.drawText(style.fontCascade(), textRun, { absoluteLeft, baselineOffset });
         } else if (auto* cachedImage = run.image()) {
             auto runAbsoluteRect = FloatRect { absoluteOffset.x() + run.left(), absoluteOffset.y() + run.top(), run.width(), run.height() };
             context.drawImage(*cachedImage->image(), runAbsoluteRect);
         }
     }
 }

 static Box absoluteDisplayBox(const Layout::LayoutState& layoutState, const Layout::Box& layoutBox)
 {
     // Should never really happen but table code is way too incomplete.
     if (!layoutState.hasDisplayBox(layoutBox))
         return { };
     if (is<Layout::InitialContainingBlock>(layoutBox))
         return layoutState.displayBoxForLayoutBox(layoutBox);

     auto absoluteBox = Box { layoutState.displayBoxForLayoutBox(layoutBox) };
     for (auto* containingBlock = &layoutBox.containingBlock(); !is<Layout::InitialContainingBlock>(*containingBlock); containingBlock = &containingBlock->containingBlock())
         absoluteBox.moveBy(layoutState.displayBoxForLayoutBox(*containingBlock).topLeft());
     return absoluteBox;
 }

 static bool isPaintRootCandidate(const Layout::Box& layoutBox)
 {
     return layoutBox.isPositioned();
 }

 using LayoutBoxList = Vector<const Layout::Box*>;

 enum PaintPhase { Decoration, Content };
 static void paintSubtree(GraphicsContext& context, const Layout::LayoutState& layoutState, const Layout::Box& paintRootBox, const IntRect& dirtyRect, PaintPhase paintPhase)
 {
     auto paint = [&] (auto& layoutBox) {
         if (layoutBox.style().visibility() != Visibility::Visible)
             return;
         if (!layoutState.hasDisplayBox(layoutBox))
             return;
         auto absoluteDisplayBox = Display::absoluteDisplayBox(layoutState, layoutBox);
         if (!dirtyRect.intersects(snappedIntRect(absoluteDisplayBox.rect())))
             return;

         if (paintPhase == PaintPhase::Decoration) {
             if (layoutBox.isAnonymous())
                 return;
             paintBoxDecoration(context, absoluteDisplayBox, layoutBox.style(), layoutBox.isBodyBox());
             return;
         }
         // Only inline content for now.
         if (layoutBox.establishesInlineFormattingContext()) {
             auto& containerBox = downcast<Layout::ContainerBox>(layoutBox);
             paintInlineContent(context, absoluteDisplayBox.topLeft(), layoutState.establishedInlineFormattingState(containerBox));
         }
     };

     paint(paintRootBox);
     if (!is<Layout::ContainerBox>(paintRootBox) || !downcast<Layout::ContainerBox>(paintRootBox).hasChild())
         return;

     LayoutBoxList layoutBoxList;
     layoutBoxList.append(downcast<Layout::ContainerBox>(paintRootBox).firstChild());
     while (!layoutBoxList.isEmpty()) {
         while (true) {
             auto& layoutBox = *layoutBoxList.last();
             if (isPaintRootCandidate(layoutBox))
                 break;
             paint(layoutBox);
             if (!is<Layout::ContainerBox>(layoutBox) || !downcast<Layout::ContainerBox>(layoutBox).hasChild())
                 break;
             layoutBoxList.append(downcast<Layout::ContainerBox>(layoutBox).firstChild());
         }
         while (!layoutBoxList.isEmpty()) {
             auto& layoutBox = *layoutBoxList.takeLast();
             // Stay within.
             if (&layoutBox == &paintRootBox)
                 return;
             if (auto* nextSibling = layoutBox.nextSibling()) {
                 layoutBoxList.append(nextSibling);
                 break;
             }
         }
     }
 }

 static LayoutRect collectPaintRootsAndContentRect(const Layout::LayoutState& layoutState, const Layout::Box& rootLayoutBox, LayoutBoxList& positiveZOrderList, LayoutBoxList& negativeZOrderList)
 {
     auto appendPaintRoot = [&] (const auto& layoutBox) {
         if (layoutBox.style().usedZIndex() < 0) {
             negativeZOrderList.append(&layoutBox);
             return;
         }
         positiveZOrderList.append(&layoutBox);
     };

     auto contentRect = LayoutRect { layoutState.displayBoxForLayoutBox(rootLayoutBox).rect() };

     // Initial BFC is always a paint root.
     appendPaintRoot(rootLayoutBox);
     LayoutBoxList layoutBoxList;
     layoutBoxList.append(&rootLayoutBox);
     while (!layoutBoxList.isEmpty()) {
         while (true) {
             auto& layoutBox = *layoutBoxList.last();
             if (layoutBox.style().visibility() != Visibility::Visible)
                 break;
             if (isPaintRootCandidate(layoutBox))
                 appendPaintRoot(layoutBox);
             if (layoutState.hasDisplayBox(layoutBox))
                 contentRect.uniteIfNonZero(Display::absoluteDisplayBox(layoutState, layoutBox).rect());
             if (!is<Layout::ContainerBox>(layoutBox) || !downcast<Layout::ContainerBox>(layoutBox).hasChild())
                 break;
             layoutBoxList.append(downcast<Layout::ContainerBox>(layoutBox).firstChild());
         }
         while (!layoutBoxList.isEmpty()) {
             auto& layoutBox = *layoutBoxList.takeLast();
             if (auto* nextSibling = layoutBox.nextSibling()) {
                 layoutBoxList.append(nextSibling);
                 break;
             }
         }
     }

     auto compareZIndex = [] (const Layout::Box* a, const Layout::Box* b) {
         return a->style().usedZIndex() < b->style().usedZIndex();
     };

     std::stable_sort(positiveZOrderList.begin(), positiveZOrderList.end(), compareZIndex);
     std::stable_sort(negativeZOrderList.begin(), negativeZOrderList.end(), compareZIndex);
     return contentRect;
 }

 void Painter::paint(const Layout::LayoutState& layoutState, GraphicsContext& context, const IntRect& dirtyRect)
 {
     auto& rootLayoutBox = layoutState.root();
     if (!rootLayoutBox.firstChild())
         return;

     Vector<const Layout::Box*> negativeZOrderList;
     Vector<const Layout::Box*> positiveZOrderList;
     auto contentRect = collectPaintRootsAndContentRect(layoutState, rootLayoutBox, positiveZOrderList, negativeZOrderList);

     // Fill the entire content area.
     context.fillRect(contentRect, Color::white);

     for (auto& paintRootBox : negativeZOrderList) {
         paintSubtree(context, layoutState, *paintRootBox, dirtyRect, PaintPhase::Decoration);
         paintSubtree(context, layoutState, *paintRootBox, dirtyRect, PaintPhase::Content);
     }

     for (auto& paintRootBox : positiveZOrderList) {
         paintSubtree(context, layoutState, *paintRootBox, dirtyRect, PaintPhase::Decoration);
         paintSubtree(context, layoutState, *paintRootBox, dirtyRect, PaintPhase::Content);
     }
 }

 void Painter::paintInlineFlow(const Layout::LayoutState& layoutState, GraphicsContext& context)
 {
     auto& layoutRoot = layoutState.root();

     ASSERT(layoutRoot.establishesInlineFormattingContext());

     paintInlineContent(context, { }, layoutState.establishedInlineFormattingState(layoutRoot));
 }

 }
 }

 #endif
	/*
	* Copyright (C) 2019 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 "DisplayPainter.h"

	#if ENABLE(LAYOUT_FORMATTING_CONTEXT)

	#include "CachedImage.h"
	#include "Color.h"
	#include "DisplayBox.h"
	#include "GraphicsContext.h"
	#include "InlineFormattingState.h"
	#include "InlineTextItem.h"
	#include "IntRect.h"
	#include "LayoutContainerBox.h"
	#include "LayoutInitialContainingBlock.h"
	#include "LayoutState.h"
	#include "RenderStyle.h"
	#include "TextRun.h"

	namespace WebCore {
	namespace Display {

	static void paintBoxDecoration(GraphicsContext& context, const Box& absoluteDisplayBox, const RenderStyle& style, bool needsMarginPainting)
	{
	auto decorationBoxTopLeft = needsMarginPainting ? absoluteDisplayBox.rectWithMargin().topLeft() : absoluteDisplayBox.topLeft();
	auto decorationBoxSize = needsMarginPainting ? absoluteDisplayBox.rectWithMargin().size() : LayoutSize(absoluteDisplayBox.borderBoxWidth(), absoluteDisplayBox.borderBoxHeight());
	// Background color
	if (style.hasBackground()) {
	context.fillRect({ decorationBoxTopLeft, decorationBoxSize }, style.backgroundColor());
	if (style.hasBackgroundImage()) {
	auto& backgroundLayer = style.backgroundLayers();
	if (backgroundLayer.image() && backgroundLayer.image()->cachedImage() && backgroundLayer.image()->cachedImage()->image())
	context.drawImage(*backgroundLayer.image()->cachedImage()->image(), { decorationBoxTopLeft, backgroundLayer.image()->cachedImage()->image()->size() });
	}
	}

	// Border
	if (style.hasVisibleBorder()) {

	auto drawBorderSide = [&](auto start, auto end, const auto& borderStyle) {
	if (!borderStyle.width())
	return;
	if (borderStyle.style() == BorderStyle::None \|\| borderStyle.style() == BorderStyle::Hidden)
	return;
	context.setStrokeColor(borderStyle.color());
	context.setStrokeThickness(borderStyle.width());
	context.drawLine(start, end);
	};

	context.setFillColor(Color::transparent);

	auto decorationBoxWidth = decorationBoxSize.width();
	auto decorationBoxHeight = decorationBoxSize.height();

	// Top
	{
	auto borderWidth = style.borderTop().width();
	auto start = LayoutPoint { decorationBoxTopLeft };
	auto end = LayoutPoint { start.x() + decorationBoxWidth, start.y() + borderWidth };
	drawBorderSide(start, end, style.borderTop());
	}

	// Right
	{
	auto borderWidth = style.borderRight().width();
	auto start = LayoutPoint { decorationBoxTopLeft.x() + decorationBoxWidth - borderWidth, decorationBoxTopLeft.y() };
	auto end = LayoutPoint { start.x() + borderWidth, decorationBoxTopLeft.y() + decorationBoxHeight };
	drawBorderSide(start, end, style.borderRight());
	}

	// Bottom
	{
	auto borderWidth = style.borderBottom().width();
	auto start = LayoutPoint { decorationBoxTopLeft.x(), decorationBoxTopLeft.y() + decorationBoxHeight - borderWidth };
	auto end = LayoutPoint { start.x() + decorationBoxWidth, start.y() + borderWidth };
	drawBorderSide(start, end, style.borderBottom());
	}

	// Left
	{
	auto borderWidth = style.borderLeft().width();
	auto start = decorationBoxTopLeft;
	auto end = LayoutPoint { start.x() + borderWidth, decorationBoxTopLeft.y() + decorationBoxHeight };
	drawBorderSide(start, end, style.borderLeft());
	}
	}
	}

	static void paintInlineContent(GraphicsContext& context, LayoutPoint absoluteOffset, const Layout::InlineFormattingState& formattingState)
	{
	auto* displayInlineContent = formattingState.displayInlineContent();
	if (!displayInlineContent)
	return;

	auto& displayRuns = displayInlineContent->runs;
	if (displayRuns.isEmpty())
	return;

	for (auto& run : displayRuns) {
	if (auto& textContent = run.textContent()) {
	auto& style = run.style();
	context.setStrokeColor(style.color());
	context.setFillColor(style.color());

	auto absoluteLeft = absoluteOffset.x() + run.left();
	// FIXME: Add non-baseline align painting
	auto& lineBox = displayInlineContent->lineBoxForRun(run);
	auto baselineOffset = absoluteOffset.y() + lineBox.top() + lineBox.baselineOffset();
	auto expansion = run.expansion();
	auto textRun = TextRun { textContent->content(), run.left() - lineBox.left(), expansion.horizontalExpansion, expansion.behavior };
	textRun.setTabSize(!style.collapseWhiteSpace(), style.tabSize());
	context.drawText(style.fontCascade(), textRun, { absoluteLeft, baselineOffset });
	} else if (auto* cachedImage = run.image()) {
	auto runAbsoluteRect = FloatRect { absoluteOffset.x() + run.left(), absoluteOffset.y() + run.top(), run.width(), run.height() };
	context.drawImage(*cachedImage->image(), runAbsoluteRect);
	}
	}
	}

	static Box absoluteDisplayBox(const Layout::LayoutState& layoutState, const Layout::Box& layoutBox)
	{
	// Should never really happen but table code is way too incomplete.
	if (!layoutState.hasDisplayBox(layoutBox))
	return { };
	if (is<Layout::InitialContainingBlock>(layoutBox))
	return layoutState.displayBoxForLayoutBox(layoutBox);

	auto absoluteBox = Box { layoutState.displayBoxForLayoutBox(layoutBox) };
	for (auto* containingBlock = &layoutBox.containingBlock(); !is<Layout::InitialContainingBlock>(*containingBlock); containingBlock = &containingBlock->containingBlock())
	absoluteBox.moveBy(layoutState.displayBoxForLayoutBox(*containingBlock).topLeft());
	return absoluteBox;
	}

	static bool isPaintRootCandidate(const Layout::Box& layoutBox)
	{
	return layoutBox.isPositioned();
	}

	using LayoutBoxList = Vector<const Layout::Box*>;

	enum PaintPhase { Decoration, Content };
	static void paintSubtree(GraphicsContext& context, const Layout::LayoutState& layoutState, const Layout::Box& paintRootBox, const IntRect& dirtyRect, PaintPhase paintPhase)
	{
	auto paint = [&] (auto& layoutBox) {
	if (layoutBox.style().visibility() != Visibility::Visible)
	return;
	if (!layoutState.hasDisplayBox(layoutBox))
	return;
	auto absoluteDisplayBox = Display::absoluteDisplayBox(layoutState, layoutBox);
	if (!dirtyRect.intersects(snappedIntRect(absoluteDisplayBox.rect())))
	return;

	if (paintPhase == PaintPhase::Decoration) {
	if (layoutBox.isAnonymous())
	return;
	paintBoxDecoration(context, absoluteDisplayBox, layoutBox.style(), layoutBox.isBodyBox());
	return;
	}
	// Only inline content for now.
	if (layoutBox.establishesInlineFormattingContext()) {
	auto& containerBox = downcast<Layout::ContainerBox>(layoutBox);
	paintInlineContent(context, absoluteDisplayBox.topLeft(), layoutState.establishedInlineFormattingState(containerBox));
	}
	};

	paint(paintRootBox);
	if (!is<Layout::ContainerBox>(paintRootBox) \|\| !downcast<Layout::ContainerBox>(paintRootBox).hasChild())
	return;

	LayoutBoxList layoutBoxList;
	layoutBoxList.append(downcast<Layout::ContainerBox>(paintRootBox).firstChild());
	while (!layoutBoxList.isEmpty()) {
	while (true) {
	auto& layoutBox = *layoutBoxList.last();
	if (isPaintRootCandidate(layoutBox))
	break;
	paint(layoutBox);
	if (!is<Layout::ContainerBox>(layoutBox) \|\| !downcast<Layout::ContainerBox>(layoutBox).hasChild())
	break;
	layoutBoxList.append(downcast<Layout::ContainerBox>(layoutBox).firstChild());
	}
	while (!layoutBoxList.isEmpty()) {
	auto& layoutBox = *layoutBoxList.takeLast();
	// Stay within.
	if (&layoutBox == &paintRootBox)
	return;
	if (auto* nextSibling = layoutBox.nextSibling()) {
	layoutBoxList.append(nextSibling);
	break;
	}
	}
	}
	}

	static LayoutRect collectPaintRootsAndContentRect(const Layout::LayoutState& layoutState, const Layout::Box& rootLayoutBox, LayoutBoxList& positiveZOrderList, LayoutBoxList& negativeZOrderList)
	{
	auto appendPaintRoot = [&] (const auto& layoutBox) {
	if (layoutBox.style().usedZIndex() < 0) {
	negativeZOrderList.append(&layoutBox);
	return;
	}
	positiveZOrderList.append(&layoutBox);
	};

	auto contentRect = LayoutRect { layoutState.displayBoxForLayoutBox(rootLayoutBox).rect() };

	// Initial BFC is always a paint root.
	appendPaintRoot(rootLayoutBox);
	LayoutBoxList layoutBoxList;
	layoutBoxList.append(&rootLayoutBox);
	while (!layoutBoxList.isEmpty()) {
	while (true) {
	auto& layoutBox = *layoutBoxList.last();
	if (layoutBox.style().visibility() != Visibility::Visible)
	break;
	if (isPaintRootCandidate(layoutBox))
	appendPaintRoot(layoutBox);
	if (layoutState.hasDisplayBox(layoutBox))
	contentRect.uniteIfNonZero(Display::absoluteDisplayBox(layoutState, layoutBox).rect());
	if (!is<Layout::ContainerBox>(layoutBox) \|\| !downcast<Layout::ContainerBox>(layoutBox).hasChild())
	break;
	layoutBoxList.append(downcast<Layout::ContainerBox>(layoutBox).firstChild());
	}
	while (!layoutBoxList.isEmpty()) {
	auto& layoutBox = *layoutBoxList.takeLast();
	if (auto* nextSibling = layoutBox.nextSibling()) {
	layoutBoxList.append(nextSibling);
	break;
	}
	}
	}

	auto compareZIndex = [] (const Layout::Box* a, const Layout::Box* b) {
	return a->style().usedZIndex() < b->style().usedZIndex();
	};

	std::stable_sort(positiveZOrderList.begin(), positiveZOrderList.end(), compareZIndex);
	std::stable_sort(negativeZOrderList.begin(), negativeZOrderList.end(), compareZIndex);
	return contentRect;
	}

	void Painter::paint(const Layout::LayoutState& layoutState, GraphicsContext& context, const IntRect& dirtyRect)
	{
	auto& rootLayoutBox = layoutState.root();
	if (!rootLayoutBox.firstChild())
	return;

	Vector<const Layout::Box*> negativeZOrderList;
	Vector<const Layout::Box*> positiveZOrderList;
	auto contentRect = collectPaintRootsAndContentRect(layoutState, rootLayoutBox, positiveZOrderList, negativeZOrderList);

	// Fill the entire content area.
	context.fillRect(contentRect, Color::white);

	for (auto& paintRootBox : negativeZOrderList) {
	paintSubtree(context, layoutState, *paintRootBox, dirtyRect, PaintPhase::Decoration);
	paintSubtree(context, layoutState, *paintRootBox, dirtyRect, PaintPhase::Content);
	}

	for (auto& paintRootBox : positiveZOrderList) {
	paintSubtree(context, layoutState, *paintRootBox, dirtyRect, PaintPhase::Decoration);
	paintSubtree(context, layoutState, *paintRootBox, dirtyRect, PaintPhase::Content);
	}
	}

	void Painter::paintInlineFlow(const Layout::LayoutState& layoutState, GraphicsContext& context)
	{
	auto& layoutRoot = layoutState.root();

	ASSERT(layoutRoot.establishesInlineFormattingContext());

	paintInlineContent(context, { }, layoutState.establishedInlineFormattingState(layoutRoot));
	}

	}
	}

	#endif