Source/WebCore/page/PrintContext.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2007-2019 Apple Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */

 #include "config.h"
 #include "PrintContext.h"

 #include "ElementTraversal.h"
 #include "GraphicsContext.h"
 #include "Frame.h"
 #include "FrameView.h"
 #include "LengthBox.h"
 #include "RenderView.h"
 #include "RuntimeEnabledFeatures.h"
 #include "StyleInheritedData.h"
 #include "StyleResolver.h"
 #include "StyleScope.h"
 #include <wtf/text/StringConcatenateNumbers.h>

 namespace WebCore {

 PrintContext::PrintContext(Frame* frame)
     : FrameDestructionObserver(frame)
 {
 }

 PrintContext::~PrintContext()
 {
     if (m_isPrinting)
         end();
 }

 void PrintContext::computePageRects(const FloatRect& printRect, float headerHeight, float footerHeight, float userScaleFactor, float& outPageHeight, bool allowHorizontalTiling)
 {
     if (!frame())
         return;

     auto& frame = *this->frame();
     m_pageRects.clear();
     outPageHeight = 0;

     if (!frame.document() || !frame.view() || !frame.document()->renderView())
         return;

     if (userScaleFactor <= 0) {
         LOG_ERROR("userScaleFactor has bad value %.2f", userScaleFactor);
         return;
     }

     RenderView* view = frame.document()->renderView();
     const IntRect& documentRect = view->documentRect();
     FloatSize pageSize = frame.resizePageRectsKeepingRatio(FloatSize(printRect.width(), printRect.height()), FloatSize(documentRect.width(), documentRect.height()));
     float pageWidth = pageSize.width();
     float pageHeight = pageSize.height();

     outPageHeight = pageHeight; // this is the height of the page adjusted by margins
     pageHeight -= headerHeight + footerHeight;

     if (pageHeight <= 0) {
         LOG_ERROR("pageHeight has bad value %.2f", pageHeight);
         return;
     }

     computePageRectsWithPageSizeInternal(FloatSize(pageWidth / userScaleFactor, pageHeight / userScaleFactor), allowHorizontalTiling);
 }

 FloatBoxExtent PrintContext::computedPageMargin(FloatBoxExtent printMargin)
 {
     if (!frame() || !frame()->document())
         return printMargin;
     if (!RuntimeEnabledFeatures::sharedFeatures().pageAtRuleSupportEnabled())
         return printMargin;
     // FIXME Currently no pseudo class is supported.
     auto style = frame()->document()->styleScope().resolver().styleForPage(0);

     float pixelToPointScaleFactor = 1 / CSSPrimitiveValue::conversionToCanonicalUnitsScaleFactor(CSSUnitType::CSS_PT);
     return { style->marginTop().isAuto() ? printMargin.top() : style->marginTop().value() * pixelToPointScaleFactor,
         style->marginRight().isAuto() ? printMargin.right() : style->marginRight().value() * pixelToPointScaleFactor,
         style->marginBottom().isAuto() ? printMargin.bottom() : style->marginBottom().value() * pixelToPointScaleFactor,
         style->marginLeft().isAuto() ? printMargin.left() : style->marginLeft().value() * pixelToPointScaleFactor };
 }

 FloatSize PrintContext::computedPageSize(FloatSize pageSize, FloatBoxExtent printMargin)
 {
     auto computedMargin = computedPageMargin(printMargin);
     if (computedMargin == printMargin)
         return pageSize;

     auto horizontalMarginDelta = (printMargin.left() - computedMargin.left()) + (printMargin.right() - computedMargin.right());
     auto verticalMarginDelta = (printMargin.top() - computedMargin.top()) + (printMargin.bottom() - computedMargin.bottom());
     return { pageSize.width() + horizontalMarginDelta, pageSize.height() + verticalMarginDelta };
 }

 void PrintContext::computePageRectsWithPageSize(const FloatSize& pageSizeInPixels, bool allowHorizontalTiling)
 {
     m_pageRects.clear();
     computePageRectsWithPageSizeInternal(pageSizeInPixels, allowHorizontalTiling);
 }

 void PrintContext::computePageRectsWithPageSizeInternal(const FloatSize& pageSizeInPixels, bool allowInlineDirectionTiling)
 {
     if (!frame())
         return;

     auto& frame = *this->frame();
     if (!frame.document() || !frame.view() || !frame.document()->renderView())
         return;

     RenderView* view = frame.document()->renderView();

     IntRect docRect = view->documentRect();

     int pageWidth = pageSizeInPixels.width();
     int pageHeight = pageSizeInPixels.height();

     bool isHorizontal = view->style().isHorizontalWritingMode();

     int docLogicalHeight = isHorizontal ? docRect.height() : docRect.width();
     int pageLogicalHeight = isHorizontal ? pageHeight : pageWidth;
     int pageLogicalWidth = isHorizontal ? pageWidth : pageHeight;

     int inlineDirectionStart;
     int inlineDirectionEnd;
     int blockDirectionStart;
     int blockDirectionEnd;
     if (isHorizontal) {
         if (view->style().isFlippedBlocksWritingMode()) {
             blockDirectionStart = docRect.maxY();
             blockDirectionEnd = docRect.y();
         } else {
             blockDirectionStart = docRect.y();
             blockDirectionEnd = docRect.maxY();
         }
         inlineDirectionStart = view->style().isLeftToRightDirection() ? docRect.x() : docRect.maxX();
         inlineDirectionEnd = view->style().isLeftToRightDirection() ? docRect.maxX() : docRect.x();
     } else {
         if (view->style().isFlippedBlocksWritingMode()) {
             blockDirectionStart = docRect.maxX();
             blockDirectionEnd = docRect.x();
         } else {
             blockDirectionStart = docRect.x();
             blockDirectionEnd = docRect.maxX();
         }
         inlineDirectionStart = view->style().isLeftToRightDirection() ? docRect.y() : docRect.maxY();
         inlineDirectionEnd = view->style().isLeftToRightDirection() ? docRect.maxY() : docRect.y();
     }

     unsigned pageCount = ceilf((float)docLogicalHeight / pageLogicalHeight);
     for (unsigned i = 0; i < pageCount; ++i) {
         int pageLogicalTop = blockDirectionEnd > blockDirectionStart ?
                                 blockDirectionStart + i * pageLogicalHeight :
                                 blockDirectionStart - (i + 1) * pageLogicalHeight;
         if (allowInlineDirectionTiling) {
             for (int currentInlinePosition = inlineDirectionStart;
                  inlineDirectionEnd > inlineDirectionStart ? currentInlinePosition < inlineDirectionEnd : currentInlinePosition > inlineDirectionEnd;
                  currentInlinePosition += (inlineDirectionEnd > inlineDirectionStart ? pageLogicalWidth : -pageLogicalWidth)) {
                 int pageLogicalLeft = inlineDirectionEnd > inlineDirectionStart ? currentInlinePosition : currentInlinePosition - pageLogicalWidth;
                 IntRect pageRect(pageLogicalLeft, pageLogicalTop, pageLogicalWidth, pageLogicalHeight);
                 if (!isHorizontal)
                     pageRect = pageRect.transposedRect();
                 m_pageRects.append(pageRect);
             }
         } else {
             int pageLogicalLeft = inlineDirectionEnd > inlineDirectionStart ? inlineDirectionStart : inlineDirectionStart - pageLogicalWidth;
             IntRect pageRect(pageLogicalLeft, pageLogicalTop, pageLogicalWidth, pageLogicalHeight);
             if (!isHorizontal)
                 pageRect = pageRect.transposedRect();
             m_pageRects.append(pageRect);
         }
     }
 }

 void PrintContext::begin(float width, float height)
 {
     if (!frame())
         return;

     auto& frame = *this->frame();
     // This function can be called multiple times to adjust printing parameters without going back to screen mode.
     m_isPrinting = true;

     FloatSize originalPageSize = FloatSize(width, height);
     FloatSize minLayoutSize = frame.resizePageRectsKeepingRatio(originalPageSize, FloatSize(width * minimumShrinkFactor(), height * minimumShrinkFactor()));

     // This changes layout, so callers need to make sure that they don't paint to screen while in printing mode.
     frame.setPrinting(true, minLayoutSize, originalPageSize, maximumShrinkFactor() / minimumShrinkFactor(), AdjustViewSize);
 }

 float PrintContext::computeAutomaticScaleFactor(const FloatSize& availablePaperSize)
 {
     if (!frame())
         return 1;

     auto& frame = *this->frame();
     if (!frame.view())
         return 1;

     bool useViewWidth = true;
     if (frame.document() && frame.document()->renderView())
         useViewWidth = frame.document()->renderView()->style().isHorizontalWritingMode();

     float viewLogicalWidth = useViewWidth ? frame.view()->contentsWidth() : frame.view()->contentsHeight();
     if (viewLogicalWidth < 1)
         return 1;

     float maxShrinkToFitScaleFactor = 1 / maximumShrinkFactor();
     float shrinkToFitScaleFactor = (useViewWidth ? availablePaperSize.width() : availablePaperSize.height()) / viewLogicalWidth;
     return std::max(maxShrinkToFitScaleFactor, shrinkToFitScaleFactor);
 }

 void PrintContext::spoolPage(GraphicsContext& ctx, int pageNumber, float width)
 {
     if (!frame())
         return;

     auto& frame = *this->frame();
     // FIXME: Not correct for vertical text.
     IntRect pageRect = m_pageRects[pageNumber];
     float scale = width / pageRect.width();

     ctx.save();
     ctx.scale(scale);
     ctx.translate(-pageRect.x(), -pageRect.y());
     ctx.clip(pageRect);
     frame.view()->paintContents(ctx, pageRect);
     outputLinkedDestinations(ctx, *frame.document(), pageRect);
     ctx.restore();
 }

 void PrintContext::spoolRect(GraphicsContext& ctx, const IntRect& rect)
 {
     if (!frame())
         return;

     auto& frame = *this->frame();
     // FIXME: Not correct for vertical text.
     ctx.save();
     ctx.translate(-rect.x(), -rect.y());
     ctx.clip(rect);
     frame.view()->paintContents(ctx, rect);
     outputLinkedDestinations(ctx, *frame.document(), rect);
     ctx.restore();
 }

 void PrintContext::end()
 {
     if (!frame())
         return;

     auto& frame = *this->frame();
     ASSERT(m_isPrinting);
     m_isPrinting = false;
     frame.setPrinting(false, FloatSize(), FloatSize(), 0, AdjustViewSize);
     m_linkedDestinations = nullptr;
 }

 static inline RenderBoxModelObject* enclosingBoxModelObject(RenderElement* renderer)
 {
     while (renderer && !is<RenderBoxModelObject>(*renderer))
         renderer = renderer->parent();
     return downcast<RenderBoxModelObject>(renderer);
 }

 int PrintContext::pageNumberForElement(Element* element, const FloatSize& pageSizeInPixels)
 {
     // Make sure the element is not freed during the layout.
     RefPtr<Element> elementRef(element);
     element->document().updateLayout();

     auto* box = enclosingBoxModelObject(element->renderer());
     if (!box)
         return -1;

     Frame* frame = element->document().frame();
     FloatRect pageRect(FloatPoint(0, 0), pageSizeInPixels);
     PrintContext printContext(frame);
     printContext.begin(pageRect.width(), pageRect.height());
     FloatSize scaledPageSize = pageSizeInPixels;
     scaledPageSize.scale(frame->view()->contentsSize().width() / pageRect.width());
     printContext.computePageRectsWithPageSize(scaledPageSize, false);

     int top = roundToInt(box->offsetTop());
     int left = roundToInt(box->offsetLeft());
     size_t pageNumber = 0;
     for (; pageNumber < printContext.pageCount(); pageNumber++) {
         const IntRect& page = printContext.pageRect(pageNumber);
         if (page.x() <= left && left < page.maxX() && page.y() <= top && top < page.maxY())
             return pageNumber;
     }
     return -1;
 }

 void PrintContext::collectLinkedDestinations(Document& document)
 {
     for (Element* child = document.documentElement(); child; child = ElementTraversal::next(*child)) {
         String outAnchorName;
         if (Element* element = child->findAnchorElementForLink(outAnchorName))
             m_linkedDestinations->add(outAnchorName, *element);
     }
 }

 void PrintContext::outputLinkedDestinations(GraphicsContext& graphicsContext, Document& document, const IntRect& pageRect)
 {
     if (!graphicsContext.supportsInternalLinks())
         return;

     if (!m_linkedDestinations) {
         m_linkedDestinations = makeUnique<HashMap<String, Ref<Element>>>();
         collectLinkedDestinations(document);
     }

     for (const auto& it : *m_linkedDestinations) {
         RenderElement* renderer = it.value->renderer();
         if (!renderer)
             continue;

         FloatPoint point = renderer->absoluteAnchorRect().minXMinYCorner();
         point = point.expandedTo(FloatPoint());

         if (!pageRect.contains(roundedIntPoint(point)))
             continue;

         graphicsContext.addDestinationAtPoint(it.key, point);
     }
 }

 String PrintContext::pageProperty(Frame* frame, const char* propertyName, int pageNumber)
 {
     ASSERT(frame);
     ASSERT(frame->document());

     Ref<Frame> protectedFrame(*frame);

     auto& document = *frame->document();
     PrintContext printContext(frame);
     printContext.begin(800); // Any width is OK here.
     document.updateLayout();
     auto style = document.styleScope().resolver().styleForPage(pageNumber);

     // Implement formatters for properties we care about.
     if (!strcmp(propertyName, "margin-left")) {
         if (style->marginLeft().isAuto())
             return "auto"_s;
         return String::number(style->marginLeft().value());
     }
     if (!strcmp(propertyName, "line-height"))
         return String::number(style->lineHeight().value());
     if (!strcmp(propertyName, "font-size"))
         return String::number(style->fontDescription().computedPixelSize());
     if (!strcmp(propertyName, "font-family"))
         return style->fontDescription().firstFamily();
     if (!strcmp(propertyName, "size"))
         return makeString(style->pageSize().width.value(), ' ', style->pageSize().height.value());

     return makeString("pageProperty() unimplemented for: ", propertyName);
 }

 bool PrintContext::isPageBoxVisible(Frame* frame, int pageNumber)
 {
     return frame->document()->isPageBoxVisible(pageNumber);
 }

 String PrintContext::pageSizeAndMarginsInPixels(Frame* frame, int pageNumber, int width, int height, int marginTop, int marginRight, int marginBottom, int marginLeft)
 {
     IntSize pageSize(width, height);
     frame->document()->pageSizeAndMarginsInPixels(pageNumber, pageSize, marginTop, marginRight, marginBottom, marginLeft);

     return makeString('(', pageSize.width(), ", ", pageSize.height(), ") ", marginTop, ' ', marginRight, ' ', marginBottom, ' ', marginLeft);
 }

 bool PrintContext::beginAndComputePageRectsWithPageSize(Frame& frame, const FloatSize& pageSizeInPixels)
 {
     if (!frame.document() || !frame.view() || !frame.document()->renderView())
         return false;

     frame.document()->updateLayout();

     begin(pageSizeInPixels.width(), pageSizeInPixels.height());
     // Account for shrink-to-fit.
     FloatSize scaledPageSize = pageSizeInPixels;
     scaledPageSize.scale(frame.view()->contentsSize().width() / pageSizeInPixels.width());
     computePageRectsWithPageSize(scaledPageSize, false);

     return true;
 }

 int PrintContext::numberOfPages(Frame& frame, const FloatSize& pageSizeInPixels)
 {
     Ref<Frame> protectedFrame(frame);

     PrintContext printContext(&frame);
     if (!printContext.beginAndComputePageRectsWithPageSize(frame, pageSizeInPixels))
         return -1;

     return printContext.pageCount();
 }

 void PrintContext::spoolAllPagesWithBoundaries(Frame& frame, GraphicsContext& graphicsContext, const FloatSize& pageSizeInPixels)
 {
     Ref<Frame> protectedFrame(frame);

     PrintContext printContext(&frame);
     if (!printContext.beginAndComputePageRectsWithPageSize(frame, pageSizeInPixels))
         return;

     const float pageWidth = pageSizeInPixels.width();
     const Vector<IntRect>& pageRects = printContext.pageRects();
     int totalHeight = pageRects.size() * (pageSizeInPixels.height() + 1) - 1;

     // Fill the whole background by white.
     graphicsContext.setFillColor(Color(255, 255, 255));
     graphicsContext.fillRect(FloatRect(0, 0, pageWidth, totalHeight));

     graphicsContext.save();

     int currentHeight = 0;
     for (size_t pageIndex = 0; pageIndex < pageRects.size(); pageIndex++) {
         // Draw a line for a page boundary if this isn't the first page.
         if (pageIndex > 0) {
 #if PLATFORM(COCOA)
             int boundaryLineY = currentHeight;
 #else
             int boundaryLineY = currentHeight - 1;
 #endif
             graphicsContext.save();
             graphicsContext.setStrokeColor(Color(0, 0, 255));
             graphicsContext.setFillColor(Color(0, 0, 255));
             graphicsContext.drawLine(IntPoint(0, boundaryLineY), IntPoint(pageWidth, boundaryLineY));
             graphicsContext.restore();
         }

         graphicsContext.save();
         graphicsContext.translate(0, currentHeight);
         printContext.spoolPage(graphicsContext, pageIndex, pageWidth);
         graphicsContext.restore();

         currentHeight += pageSizeInPixels.height() + 1;
     }

     graphicsContext.restore();
 }

 }
	/*
	* Copyright (C) 2007 Alp Toker <alp@atoker.com>
	* Copyright (C) 2007-2019 Apple Inc.
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Library General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Library General Public License for more details.
	*
	* You should have received a copy of the GNU Library General Public License
	* along with this library; see the file COPYING.LIB. If not, write to
	* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
	* Boston, MA 02110-1301, USA.
	*/

	#include "config.h"
	#include "PrintContext.h"

	#include "ElementTraversal.h"
	#include "GraphicsContext.h"
	#include "Frame.h"
	#include "FrameView.h"
	#include "LengthBox.h"
	#include "RenderView.h"
	#include "RuntimeEnabledFeatures.h"
	#include "StyleInheritedData.h"
	#include "StyleResolver.h"
	#include "StyleScope.h"
	#include <wtf/text/StringConcatenateNumbers.h>

	namespace WebCore {

	PrintContext::PrintContext(Frame* frame)
	: FrameDestructionObserver(frame)
	{
	}

	PrintContext::~PrintContext()
	{
	if (m_isPrinting)
	end();
	}

	void PrintContext::computePageRects(const FloatRect& printRect, float headerHeight, float footerHeight, float userScaleFactor, float& outPageHeight, bool allowHorizontalTiling)
	{
	if (!frame())
	return;

	auto& frame = *this->frame();
	m_pageRects.clear();
	outPageHeight = 0;

	if (!frame.document() \|\| !frame.view() \|\| !frame.document()->renderView())
	return;

	if (userScaleFactor <= 0) {
	LOG_ERROR("userScaleFactor has bad value %.2f", userScaleFactor);
	return;
	}

	RenderView* view = frame.document()->renderView();
	const IntRect& documentRect = view->documentRect();
	FloatSize pageSize = frame.resizePageRectsKeepingRatio(FloatSize(printRect.width(), printRect.height()), FloatSize(documentRect.width(), documentRect.height()));
	float pageWidth = pageSize.width();
	float pageHeight = pageSize.height();

	outPageHeight = pageHeight; // this is the height of the page adjusted by margins
	pageHeight -= headerHeight + footerHeight;

	if (pageHeight <= 0) {
	LOG_ERROR("pageHeight has bad value %.2f", pageHeight);
	return;
	}

	computePageRectsWithPageSizeInternal(FloatSize(pageWidth / userScaleFactor, pageHeight / userScaleFactor), allowHorizontalTiling);
	}

	FloatBoxExtent PrintContext::computedPageMargin(FloatBoxExtent printMargin)
	{
	if (!frame() \|\| !frame()->document())
	return printMargin;
	if (!RuntimeEnabledFeatures::sharedFeatures().pageAtRuleSupportEnabled())
	return printMargin;
	// FIXME Currently no pseudo class is supported.
	auto style = frame()->document()->styleScope().resolver().styleForPage(0);

	float pixelToPointScaleFactor = 1 / CSSPrimitiveValue::conversionToCanonicalUnitsScaleFactor(CSSUnitType::CSS_PT);
	return { style->marginTop().isAuto() ? printMargin.top() : style->marginTop().value() * pixelToPointScaleFactor,
	style->marginRight().isAuto() ? printMargin.right() : style->marginRight().value() * pixelToPointScaleFactor,
	style->marginBottom().isAuto() ? printMargin.bottom() : style->marginBottom().value() * pixelToPointScaleFactor,
	style->marginLeft().isAuto() ? printMargin.left() : style->marginLeft().value() * pixelToPointScaleFactor };
	}

	FloatSize PrintContext::computedPageSize(FloatSize pageSize, FloatBoxExtent printMargin)
	{
	auto computedMargin = computedPageMargin(printMargin);
	if (computedMargin == printMargin)
	return pageSize;

	auto horizontalMarginDelta = (printMargin.left() - computedMargin.left()) + (printMargin.right() - computedMargin.right());
	auto verticalMarginDelta = (printMargin.top() - computedMargin.top()) + (printMargin.bottom() - computedMargin.bottom());
	return { pageSize.width() + horizontalMarginDelta, pageSize.height() + verticalMarginDelta };
	}

	void PrintContext::computePageRectsWithPageSize(const FloatSize& pageSizeInPixels, bool allowHorizontalTiling)
	{
	m_pageRects.clear();
	computePageRectsWithPageSizeInternal(pageSizeInPixels, allowHorizontalTiling);
	}

	void PrintContext::computePageRectsWithPageSizeInternal(const FloatSize& pageSizeInPixels, bool allowInlineDirectionTiling)
	{
	if (!frame())
	return;

	auto& frame = *this->frame();
	if (!frame.document() \|\| !frame.view() \|\| !frame.document()->renderView())
	return;

	RenderView* view = frame.document()->renderView();

	IntRect docRect = view->documentRect();

	int pageWidth = pageSizeInPixels.width();
	int pageHeight = pageSizeInPixels.height();

	bool isHorizontal = view->style().isHorizontalWritingMode();

	int docLogicalHeight = isHorizontal ? docRect.height() : docRect.width();
	int pageLogicalHeight = isHorizontal ? pageHeight : pageWidth;
	int pageLogicalWidth = isHorizontal ? pageWidth : pageHeight;

	int inlineDirectionStart;
	int inlineDirectionEnd;
	int blockDirectionStart;
	int blockDirectionEnd;
	if (isHorizontal) {
	if (view->style().isFlippedBlocksWritingMode()) {
	blockDirectionStart = docRect.maxY();
	blockDirectionEnd = docRect.y();
	} else {
	blockDirectionStart = docRect.y();
	blockDirectionEnd = docRect.maxY();
	}
	inlineDirectionStart = view->style().isLeftToRightDirection() ? docRect.x() : docRect.maxX();
	inlineDirectionEnd = view->style().isLeftToRightDirection() ? docRect.maxX() : docRect.x();
	} else {
	if (view->style().isFlippedBlocksWritingMode()) {
	blockDirectionStart = docRect.maxX();
	blockDirectionEnd = docRect.x();
	} else {
	blockDirectionStart = docRect.x();
	blockDirectionEnd = docRect.maxX();
	}
	inlineDirectionStart = view->style().isLeftToRightDirection() ? docRect.y() : docRect.maxY();
	inlineDirectionEnd = view->style().isLeftToRightDirection() ? docRect.maxY() : docRect.y();
	}

	unsigned pageCount = ceilf((float)docLogicalHeight / pageLogicalHeight);
	for (unsigned i = 0; i < pageCount; ++i) {
	int pageLogicalTop = blockDirectionEnd > blockDirectionStart ?
	blockDirectionStart + i * pageLogicalHeight :
	blockDirectionStart - (i + 1) * pageLogicalHeight;
	if (allowInlineDirectionTiling) {
	for (int currentInlinePosition = inlineDirectionStart;
	inlineDirectionEnd > inlineDirectionStart ? currentInlinePosition < inlineDirectionEnd : currentInlinePosition > inlineDirectionEnd;
	currentInlinePosition += (inlineDirectionEnd > inlineDirectionStart ? pageLogicalWidth : -pageLogicalWidth)) {
	int pageLogicalLeft = inlineDirectionEnd > inlineDirectionStart ? currentInlinePosition : currentInlinePosition - pageLogicalWidth;
	IntRect pageRect(pageLogicalLeft, pageLogicalTop, pageLogicalWidth, pageLogicalHeight);
	if (!isHorizontal)
	pageRect = pageRect.transposedRect();
	m_pageRects.append(pageRect);
	}
	} else {
	int pageLogicalLeft = inlineDirectionEnd > inlineDirectionStart ? inlineDirectionStart : inlineDirectionStart - pageLogicalWidth;
	IntRect pageRect(pageLogicalLeft, pageLogicalTop, pageLogicalWidth, pageLogicalHeight);
	if (!isHorizontal)
	pageRect = pageRect.transposedRect();
	m_pageRects.append(pageRect);
	}
	}
	}

	void PrintContext::begin(float width, float height)
	{
	if (!frame())
	return;

	auto& frame = *this->frame();
	// This function can be called multiple times to adjust printing parameters without going back to screen mode.
	m_isPrinting = true;

	FloatSize originalPageSize = FloatSize(width, height);
	FloatSize minLayoutSize = frame.resizePageRectsKeepingRatio(originalPageSize, FloatSize(width * minimumShrinkFactor(), height * minimumShrinkFactor()));

	// This changes layout, so callers need to make sure that they don't paint to screen while in printing mode.
	frame.setPrinting(true, minLayoutSize, originalPageSize, maximumShrinkFactor() / minimumShrinkFactor(), AdjustViewSize);
	}

	float PrintContext::computeAutomaticScaleFactor(const FloatSize& availablePaperSize)
	{
	if (!frame())
	return 1;

	auto& frame = *this->frame();
	if (!frame.view())
	return 1;

	bool useViewWidth = true;
	if (frame.document() && frame.document()->renderView())
	useViewWidth = frame.document()->renderView()->style().isHorizontalWritingMode();

	float viewLogicalWidth = useViewWidth ? frame.view()->contentsWidth() : frame.view()->contentsHeight();
	if (viewLogicalWidth < 1)
	return 1;

	float maxShrinkToFitScaleFactor = 1 / maximumShrinkFactor();
	float shrinkToFitScaleFactor = (useViewWidth ? availablePaperSize.width() : availablePaperSize.height()) / viewLogicalWidth;
	return std::max(maxShrinkToFitScaleFactor, shrinkToFitScaleFactor);
	}

	void PrintContext::spoolPage(GraphicsContext& ctx, int pageNumber, float width)
	{
	if (!frame())
	return;

	auto& frame = *this->frame();
	// FIXME: Not correct for vertical text.
	IntRect pageRect = m_pageRects[pageNumber];
	float scale = width / pageRect.width();

	ctx.save();
	ctx.scale(scale);
	ctx.translate(-pageRect.x(), -pageRect.y());
	ctx.clip(pageRect);
	frame.view()->paintContents(ctx, pageRect);
	outputLinkedDestinations(ctx, *frame.document(), pageRect);
	ctx.restore();
	}

	void PrintContext::spoolRect(GraphicsContext& ctx, const IntRect& rect)
	{
	if (!frame())
	return;

	auto& frame = *this->frame();
	// FIXME: Not correct for vertical text.
	ctx.save();
	ctx.translate(-rect.x(), -rect.y());
	ctx.clip(rect);
	frame.view()->paintContents(ctx, rect);
	outputLinkedDestinations(ctx, *frame.document(), rect);
	ctx.restore();
	}

	void PrintContext::end()
	{
	if (!frame())
	return;

	auto& frame = *this->frame();
	ASSERT(m_isPrinting);
	m_isPrinting = false;
	frame.setPrinting(false, FloatSize(), FloatSize(), 0, AdjustViewSize);
	m_linkedDestinations = nullptr;
	}

	static inline RenderBoxModelObject* enclosingBoxModelObject(RenderElement* renderer)
	{
	while (renderer && !is<RenderBoxModelObject>(*renderer))
	renderer = renderer->parent();
	return downcast<RenderBoxModelObject>(renderer);
	}

	int PrintContext::pageNumberForElement(Element* element, const FloatSize& pageSizeInPixels)
	{
	// Make sure the element is not freed during the layout.
	RefPtr<Element> elementRef(element);
	element->document().updateLayout();

	auto* box = enclosingBoxModelObject(element->renderer());
	if (!box)
	return -1;

	Frame* frame = element->document().frame();
	FloatRect pageRect(FloatPoint(0, 0), pageSizeInPixels);
	PrintContext printContext(frame);
	printContext.begin(pageRect.width(), pageRect.height());
	FloatSize scaledPageSize = pageSizeInPixels;
	scaledPageSize.scale(frame->view()->contentsSize().width() / pageRect.width());
	printContext.computePageRectsWithPageSize(scaledPageSize, false);

	int top = roundToInt(box->offsetTop());
	int left = roundToInt(box->offsetLeft());
	size_t pageNumber = 0;
	for (; pageNumber < printContext.pageCount(); pageNumber++) {
	const IntRect& page = printContext.pageRect(pageNumber);
	if (page.x() <= left && left < page.maxX() && page.y() <= top && top < page.maxY())
	return pageNumber;
	}
	return -1;
	}

	void PrintContext::collectLinkedDestinations(Document& document)
	{
	for (Element* child = document.documentElement(); child; child = ElementTraversal::next(*child)) {
	String outAnchorName;
	if (Element* element = child->findAnchorElementForLink(outAnchorName))
	m_linkedDestinations->add(outAnchorName, *element);
	}
	}

	void PrintContext::outputLinkedDestinations(GraphicsContext& graphicsContext, Document& document, const IntRect& pageRect)
	{
	if (!graphicsContext.supportsInternalLinks())
	return;

	if (!m_linkedDestinations) {
	m_linkedDestinations = makeUnique<HashMap<String, Ref<Element>>>();
	collectLinkedDestinations(document);
	}

	for (const auto& it : *m_linkedDestinations) {
	RenderElement* renderer = it.value->renderer();
	if (!renderer)
	continue;

	FloatPoint point = renderer->absoluteAnchorRect().minXMinYCorner();
	point = point.expandedTo(FloatPoint());

	if (!pageRect.contains(roundedIntPoint(point)))
	continue;

	graphicsContext.addDestinationAtPoint(it.key, point);
	}
	}

	String PrintContext::pageProperty(Frame* frame, const char* propertyName, int pageNumber)
	{
	ASSERT(frame);
	ASSERT(frame->document());

	Ref<Frame> protectedFrame(*frame);

	auto& document = *frame->document();
	PrintContext printContext(frame);
	printContext.begin(800); // Any width is OK here.
	document.updateLayout();
	auto style = document.styleScope().resolver().styleForPage(pageNumber);

	// Implement formatters for properties we care about.
	if (!strcmp(propertyName, "margin-left")) {
	if (style->marginLeft().isAuto())
	return "auto"_s;
	return String::number(style->marginLeft().value());
	}
	if (!strcmp(propertyName, "line-height"))
	return String::number(style->lineHeight().value());
	if (!strcmp(propertyName, "font-size"))
	return String::number(style->fontDescription().computedPixelSize());
	if (!strcmp(propertyName, "font-family"))
	return style->fontDescription().firstFamily();
	if (!strcmp(propertyName, "size"))
	return makeString(style->pageSize().width.value(), ' ', style->pageSize().height.value());

	return makeString("pageProperty() unimplemented for: ", propertyName);
	}

	bool PrintContext::isPageBoxVisible(Frame* frame, int pageNumber)
	{
	return frame->document()->isPageBoxVisible(pageNumber);
	}

	String PrintContext::pageSizeAndMarginsInPixels(Frame* frame, int pageNumber, int width, int height, int marginTop, int marginRight, int marginBottom, int marginLeft)
	{
	IntSize pageSize(width, height);
	frame->document()->pageSizeAndMarginsInPixels(pageNumber, pageSize, marginTop, marginRight, marginBottom, marginLeft);

	return makeString('(', pageSize.width(), ", ", pageSize.height(), ") ", marginTop, ' ', marginRight, ' ', marginBottom, ' ', marginLeft);
	}

	bool PrintContext::beginAndComputePageRectsWithPageSize(Frame& frame, const FloatSize& pageSizeInPixels)
	{
	if (!frame.document() \|\| !frame.view() \|\| !frame.document()->renderView())
	return false;

	frame.document()->updateLayout();

	begin(pageSizeInPixels.width(), pageSizeInPixels.height());
	// Account for shrink-to-fit.
	FloatSize scaledPageSize = pageSizeInPixels;
	scaledPageSize.scale(frame.view()->contentsSize().width() / pageSizeInPixels.width());
	computePageRectsWithPageSize(scaledPageSize, false);

	return true;
	}

	int PrintContext::numberOfPages(Frame& frame, const FloatSize& pageSizeInPixels)
	{
	Ref<Frame> protectedFrame(frame);

	PrintContext printContext(&frame);
	if (!printContext.beginAndComputePageRectsWithPageSize(frame, pageSizeInPixels))
	return -1;

	return printContext.pageCount();
	}

	void PrintContext::spoolAllPagesWithBoundaries(Frame& frame, GraphicsContext& graphicsContext, const FloatSize& pageSizeInPixels)
	{
	Ref<Frame> protectedFrame(frame);

	PrintContext printContext(&frame);
	if (!printContext.beginAndComputePageRectsWithPageSize(frame, pageSizeInPixels))
	return;

	const float pageWidth = pageSizeInPixels.width();
	const Vector<IntRect>& pageRects = printContext.pageRects();
	int totalHeight = pageRects.size() * (pageSizeInPixels.height() + 1) - 1;

	// Fill the whole background by white.
	graphicsContext.setFillColor(Color(255, 255, 255));
	graphicsContext.fillRect(FloatRect(0, 0, pageWidth, totalHeight));

	graphicsContext.save();

	int currentHeight = 0;
	for (size_t pageIndex = 0; pageIndex < pageRects.size(); pageIndex++) {
	// Draw a line for a page boundary if this isn't the first page.
	if (pageIndex > 0) {
	#if PLATFORM(COCOA)
	int boundaryLineY = currentHeight;
	#else
	int boundaryLineY = currentHeight - 1;
	#endif
	graphicsContext.save();
	graphicsContext.setStrokeColor(Color(0, 0, 255));
	graphicsContext.setFillColor(Color(0, 0, 255));
	graphicsContext.drawLine(IntPoint(0, boundaryLineY), IntPoint(pageWidth, boundaryLineY));
	graphicsContext.restore();
	}

	graphicsContext.save();
	graphicsContext.translate(0, currentHeight);
	printContext.spoolPage(graphicsContext, pageIndex, pageWidth);
	graphicsContext.restore();

	currentHeight += pageSizeInPixels.height() + 1;
	}

	graphicsContext.restore();
	}

	}