Source/WebCore/rendering/TextPainter.cpp - WebKit - Git at Google

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004-2017 Apple Inc. All rights reserved.
  *
  * 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 "TextPainter.h"

 #include "DisplayListReplayer.h"
 #include "GraphicsContext.h"
 #include "InlineTextBox.h"
 #include "RenderCombineText.h"
 #include "RenderLayer.h"
 #include "ShadowData.h"
 #include <wtf/NeverDestroyed.h>

 namespace WebCore {

 ShadowApplier::ShadowApplier(GraphicsContext& context, const ShadowData* shadow, const FloatRect& textRect, bool lastShadowIterationShouldDrawText, bool opaque, FontOrientation orientation)
     : m_context { context }
     , m_shadow { shadow }
     , m_onlyDrawsShadow { !isLastShadowIteration() || !lastShadowIterationShouldDrawText }
     , m_avoidDrawingShadow { shadowIsCompletelyCoveredByText(opaque) }
     , m_nothingToDraw { shadow && m_avoidDrawingShadow && m_onlyDrawsShadow }
     , m_didSaveContext { false }
 {
     if (!shadow || m_nothingToDraw) {
         m_shadow = nullptr;
         return;
     }

     int shadowX = orientation == Horizontal ? shadow->x() : shadow->y();
     int shadowY = orientation == Horizontal ? shadow->y() : -shadow->x();
     FloatSize shadowOffset(shadowX, shadowY);
     int shadowRadius = shadow->radius();
     const Color& shadowColor = shadow->color();

     // When drawing shadows, we usually clip the context to the area the shadow will reside, and then
     // draw the text itself outside the clipped area (so only the shadow shows up). However, we can
     // often draw the *last* shadow and the text itself in a single call.
     if (m_onlyDrawsShadow) {
         FloatRect shadowRect(textRect);
         shadowRect.inflate(shadow->paintingExtent() + 3 * textRect.height());
         shadowRect.move(shadowOffset);
         context.save();
         context.clip(shadowRect);

         m_didSaveContext = true;
         m_extraOffset = FloatSize(0, 2 * shadowRect.height() + std::max(0.0f, shadowOffset.height()) + shadowRadius);
         shadowOffset -= m_extraOffset;
     }

     if (!m_avoidDrawingShadow)
         context.setShadow(shadowOffset, shadowRadius, shadowColor);
 }

 inline bool ShadowApplier::isLastShadowIteration()
 {
     return m_shadow && !m_shadow->next();
 }

 inline bool ShadowApplier::shadowIsCompletelyCoveredByText(bool textIsOpaque)
 {
     return textIsOpaque && m_shadow && m_shadow->location().isZero() && !m_shadow->radius();
 }

 ShadowApplier::~ShadowApplier()
 {
     if (!m_shadow)
         return;
     if (m_onlyDrawsShadow)
         m_context.restore();
     else if (!m_avoidDrawingShadow)
         m_context.clearShadow();
 }

 TextPainter::TextPainter(GraphicsContext& context)
     : m_context(context)
 {
 }

 void TextPainter::paintTextOrEmphasisMarks(const FontCascade& font, const TextRun& textRun, const AtomicString& emphasisMark,
     float emphasisMarkOffset, const FloatPoint& textOrigin, unsigned startOffset, unsigned endOffset)
 {
     ASSERT(startOffset < endOffset);
     if (!emphasisMark.isEmpty())
         m_context.drawEmphasisMarks(font, textRun, emphasisMark, textOrigin + FloatSize(0, emphasisMarkOffset), startOffset, endOffset);
     else if (startOffset || endOffset < textRun.length() || !m_glyphDisplayList)
         m_context.drawText(font, textRun, textOrigin, startOffset, endOffset);
     else {
         // Replaying back a whole cached glyph run to the GraphicsContext.
         m_context.translate(textOrigin);
         DisplayList::Replayer replayer(m_context, *m_glyphDisplayList);
         replayer.replay();
         m_context.translate(-textOrigin);
     }
     m_glyphDisplayList = nullptr;
 }

 void TextPainter::paintTextWithShadows(const ShadowData* shadow, const FontCascade& font, const TextRun& textRun, const FloatRect& boxRect, const FloatPoint& textOrigin,
     unsigned startOffset, unsigned endOffset, const AtomicString& emphasisMark, float emphasisMarkOffset, bool stroked)
 {
     if (!shadow) {
         paintTextOrEmphasisMarks(font, textRun, emphasisMark, emphasisMarkOffset, textOrigin, startOffset, endOffset);
         return;
     }

     Color fillColor = m_context.fillColor();
     bool opaque = fillColor.isOpaque();
     bool lastShadowIterationShouldDrawText = !stroked && opaque;
     if (!opaque)
         m_context.setFillColor(Color::black);
     while (shadow) {
         ShadowApplier shadowApplier(m_context, shadow, boxRect, lastShadowIterationShouldDrawText, opaque, m_textBoxIsHorizontal ? Horizontal : Vertical);
         if (!shadowApplier.nothingToDraw())
             paintTextOrEmphasisMarks(font, textRun, emphasisMark, emphasisMarkOffset, textOrigin + shadowApplier.extraOffset(), startOffset, endOffset);
         shadow = shadow->next();
     }

     if (!lastShadowIterationShouldDrawText) {
         if (!opaque)
             m_context.setFillColor(fillColor);
         paintTextOrEmphasisMarks(font, textRun, emphasisMark, emphasisMarkOffset, textOrigin, startOffset, endOffset);
     }
 }

 void TextPainter::paintTextAndEmphasisMarksIfNeeded(const TextRun& textRun, const FloatRect& boxRect, const FloatPoint& textOrigin, unsigned startOffset, unsigned endOffset,
     const TextPaintStyle& paintStyle, const ShadowData* shadow)
 {
     if (paintStyle.paintOrder == PaintOrder::Normal) {
         // FIXME: Truncate right-to-left text correctly.
         paintTextWithShadows(shadow, *m_font, textRun, boxRect, textOrigin, startOffset, endOffset, nullAtom(), 0, paintStyle.strokeWidth > 0);
     } else {
         bool paintShadow = true;
         auto textDrawingMode = m_context.textDrawingMode();
         auto paintOrder = RenderStyle::paintTypesForPaintOrder(paintStyle.paintOrder);
         for (auto order : paintOrder) {
             switch (order) {
             case PaintType::Fill:
                 m_context.setTextDrawingMode(textDrawingMode & ~TextModeStroke);
                 paintTextWithShadows(paintShadow ? shadow : nullptr, *m_font, textRun, boxRect, textOrigin, startOffset, endOffset, nullAtom(), 0, false);
                 paintShadow = false;
                 m_context.setTextDrawingMode(textDrawingMode);
                 break;
             case PaintType::Stroke:
                 m_context.setTextDrawingMode(textDrawingMode & ~TextModeFill);
                 paintTextWithShadows(paintShadow ? shadow : nullptr, *m_font, textRun, boxRect, textOrigin, startOffset, endOffset, nullAtom(), 0, paintStyle.strokeWidth > 0);
                 paintShadow = false;
                 m_context.setTextDrawingMode(textDrawingMode);
                 break;
             case PaintType::Markers:
                 continue;
             }
         }
     }

     if (m_emphasisMark.isEmpty())
         return;

     FloatPoint boxOrigin = boxRect.location();
     updateGraphicsContext(m_context, paintStyle, UseEmphasisMarkColor);
     static NeverDestroyed<TextRun> objectReplacementCharacterTextRun(StringView(&objectReplacementCharacter, 1));
     const TextRun& emphasisMarkTextRun = m_combinedText ? objectReplacementCharacterTextRun.get() : textRun;
     FloatPoint emphasisMarkTextOrigin = m_combinedText ? FloatPoint(boxOrigin.x() + boxRect.width() / 2, boxOrigin.y() + m_font->fontMetrics().ascent()) : textOrigin;
     if (m_combinedText)
         m_context.concatCTM(rotation(boxRect, Clockwise));

     // FIXME: Truncate right-to-left text correctly.
     paintTextWithShadows(shadow, m_combinedText ? m_combinedText->originalFont() : *m_font, emphasisMarkTextRun, boxRect, emphasisMarkTextOrigin, startOffset, endOffset,
         m_emphasisMark, m_emphasisMarkOffset, paintStyle.strokeWidth > 0);

     if (m_combinedText)
         m_context.concatCTM(rotation(boxRect, Counterclockwise));
 }

 void TextPainter::paint(const TextRun& textRun, const FloatRect& boxRect, const FloatPoint& textOrigin)
 {
     paintRange(textRun, boxRect, textOrigin, 0, textRun.length());
 }

 void TextPainter::paintRange(const TextRun& textRun, const FloatRect& boxRect, const FloatPoint& textOrigin, unsigned start, unsigned end)
 {
     ASSERT(m_font);
     ASSERT(start < end);

     GraphicsContextStateSaver stateSaver(m_context, m_style.strokeWidth > 0);
     updateGraphicsContext(m_context, m_style);
     paintTextAndEmphasisMarksIfNeeded(textRun, boxRect, textOrigin, start, end, m_style, m_shadow);
 }

 void TextPainter::clearGlyphDisplayLists()
 {
     GlyphDisplayListCache<InlineTextBox>::singleton().clear();
     GlyphDisplayListCache<SimpleLineLayout::Run>::singleton().clear();
 }

 bool TextPainter::shouldUseGlyphDisplayList(const PaintInfo& paintInfo)
 {
     return !paintInfo.context().paintingDisabled() && paintInfo.enclosingSelfPaintingLayer() && paintInfo.enclosingSelfPaintingLayer()->paintingFrequently();
 }

 } // namespace WebCore
	/*
	* (C) 1999 Lars Knoll (knoll@kde.org)
	* (C) 2000 Dirk Mueller (mueller@kde.org)
	* Copyright (C) 2004-2017 Apple Inc. All rights reserved.
	*
	* 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 "TextPainter.h"

	#include "DisplayListReplayer.h"
	#include "GraphicsContext.h"
	#include "InlineTextBox.h"
	#include "RenderCombineText.h"
	#include "RenderLayer.h"
	#include "ShadowData.h"
	#include <wtf/NeverDestroyed.h>

	namespace WebCore {

	ShadowApplier::ShadowApplier(GraphicsContext& context, const ShadowData* shadow, const FloatRect& textRect, bool lastShadowIterationShouldDrawText, bool opaque, FontOrientation orientation)
	: m_context { context }
	, m_shadow { shadow }
	, m_onlyDrawsShadow { !isLastShadowIteration() \|\| !lastShadowIterationShouldDrawText }
	, m_avoidDrawingShadow { shadowIsCompletelyCoveredByText(opaque) }
	, m_nothingToDraw { shadow && m_avoidDrawingShadow && m_onlyDrawsShadow }
	, m_didSaveContext { false }
	{
	if (!shadow \|\| m_nothingToDraw) {
	m_shadow = nullptr;
	return;
	}

	int shadowX = orientation == Horizontal ? shadow->x() : shadow->y();
	int shadowY = orientation == Horizontal ? shadow->y() : -shadow->x();
	FloatSize shadowOffset(shadowX, shadowY);
	int shadowRadius = shadow->radius();
	const Color& shadowColor = shadow->color();

	// When drawing shadows, we usually clip the context to the area the shadow will reside, and then
	// draw the text itself outside the clipped area (so only the shadow shows up). However, we can
	// often draw the last shadow and the text itself in a single call.
	if (m_onlyDrawsShadow) {
	FloatRect shadowRect(textRect);
	shadowRect.inflate(shadow->paintingExtent() + 3 * textRect.height());
	shadowRect.move(shadowOffset);
	context.save();
	context.clip(shadowRect);

	m_didSaveContext = true;
	m_extraOffset = FloatSize(0, 2 * shadowRect.height() + std::max(0.0f, shadowOffset.height()) + shadowRadius);
	shadowOffset -= m_extraOffset;
	}

	if (!m_avoidDrawingShadow)
	context.setShadow(shadowOffset, shadowRadius, shadowColor);
	}

	inline bool ShadowApplier::isLastShadowIteration()
	{
	return m_shadow && !m_shadow->next();
	}

	inline bool ShadowApplier::shadowIsCompletelyCoveredByText(bool textIsOpaque)
	{
	return textIsOpaque && m_shadow && m_shadow->location().isZero() && !m_shadow->radius();
	}

	ShadowApplier::~ShadowApplier()
	{
	if (!m_shadow)
	return;
	if (m_onlyDrawsShadow)
	m_context.restore();
	else if (!m_avoidDrawingShadow)
	m_context.clearShadow();
	}

	TextPainter::TextPainter(GraphicsContext& context)
	: m_context(context)
	{
	}

	void TextPainter::paintTextOrEmphasisMarks(const FontCascade& font, const TextRun& textRun, const AtomicString& emphasisMark,
	float emphasisMarkOffset, const FloatPoint& textOrigin, unsigned startOffset, unsigned endOffset)
	{
	ASSERT(startOffset < endOffset);
	if (!emphasisMark.isEmpty())
	m_context.drawEmphasisMarks(font, textRun, emphasisMark, textOrigin + FloatSize(0, emphasisMarkOffset), startOffset, endOffset);
	else if (startOffset \|\| endOffset < textRun.length() \|\| !m_glyphDisplayList)
	m_context.drawText(font, textRun, textOrigin, startOffset, endOffset);
	else {
	// Replaying back a whole cached glyph run to the GraphicsContext.
	m_context.translate(textOrigin);
	DisplayList::Replayer replayer(m_context, *m_glyphDisplayList);
	replayer.replay();
	m_context.translate(-textOrigin);
	}
	m_glyphDisplayList = nullptr;
	}

	void TextPainter::paintTextWithShadows(const ShadowData* shadow, const FontCascade& font, const TextRun& textRun, const FloatRect& boxRect, const FloatPoint& textOrigin,
	unsigned startOffset, unsigned endOffset, const AtomicString& emphasisMark, float emphasisMarkOffset, bool stroked)
	{
	if (!shadow) {
	paintTextOrEmphasisMarks(font, textRun, emphasisMark, emphasisMarkOffset, textOrigin, startOffset, endOffset);
	return;
	}

	Color fillColor = m_context.fillColor();
	bool opaque = fillColor.isOpaque();
	bool lastShadowIterationShouldDrawText = !stroked && opaque;
	if (!opaque)
	m_context.setFillColor(Color::black);
	while (shadow) {
	ShadowApplier shadowApplier(m_context, shadow, boxRect, lastShadowIterationShouldDrawText, opaque, m_textBoxIsHorizontal ? Horizontal : Vertical);
	if (!shadowApplier.nothingToDraw())
	paintTextOrEmphasisMarks(font, textRun, emphasisMark, emphasisMarkOffset, textOrigin + shadowApplier.extraOffset(), startOffset, endOffset);
	shadow = shadow->next();
	}

	if (!lastShadowIterationShouldDrawText) {
	if (!opaque)
	m_context.setFillColor(fillColor);
	paintTextOrEmphasisMarks(font, textRun, emphasisMark, emphasisMarkOffset, textOrigin, startOffset, endOffset);
	}
	}

	void TextPainter::paintTextAndEmphasisMarksIfNeeded(const TextRun& textRun, const FloatRect& boxRect, const FloatPoint& textOrigin, unsigned startOffset, unsigned endOffset,
	const TextPaintStyle& paintStyle, const ShadowData* shadow)
	{
	if (paintStyle.paintOrder == PaintOrder::Normal) {
	// FIXME: Truncate right-to-left text correctly.
	paintTextWithShadows(shadow, *m_font, textRun, boxRect, textOrigin, startOffset, endOffset, nullAtom(), 0, paintStyle.strokeWidth > 0);
	} else {
	bool paintShadow = true;
	auto textDrawingMode = m_context.textDrawingMode();
	auto paintOrder = RenderStyle::paintTypesForPaintOrder(paintStyle.paintOrder);
	for (auto order : paintOrder) {
	switch (order) {
	case PaintType::Fill:
	m_context.setTextDrawingMode(textDrawingMode & ~TextModeStroke);
	paintTextWithShadows(paintShadow ? shadow : nullptr, *m_font, textRun, boxRect, textOrigin, startOffset, endOffset, nullAtom(), 0, false);
	paintShadow = false;
	m_context.setTextDrawingMode(textDrawingMode);
	break;
	case PaintType::Stroke:
	m_context.setTextDrawingMode(textDrawingMode & ~TextModeFill);
	paintTextWithShadows(paintShadow ? shadow : nullptr, *m_font, textRun, boxRect, textOrigin, startOffset, endOffset, nullAtom(), 0, paintStyle.strokeWidth > 0);
	paintShadow = false;
	m_context.setTextDrawingMode(textDrawingMode);
	break;
	case PaintType::Markers:
	continue;
	}
	}
	}

	if (m_emphasisMark.isEmpty())
	return;

	FloatPoint boxOrigin = boxRect.location();
	updateGraphicsContext(m_context, paintStyle, UseEmphasisMarkColor);
	static NeverDestroyed<TextRun> objectReplacementCharacterTextRun(StringView(&objectReplacementCharacter, 1));
	const TextRun& emphasisMarkTextRun = m_combinedText ? objectReplacementCharacterTextRun.get() : textRun;
	FloatPoint emphasisMarkTextOrigin = m_combinedText ? FloatPoint(boxOrigin.x() + boxRect.width() / 2, boxOrigin.y() + m_font->fontMetrics().ascent()) : textOrigin;
	if (m_combinedText)
	m_context.concatCTM(rotation(boxRect, Clockwise));

	// FIXME: Truncate right-to-left text correctly.
	paintTextWithShadows(shadow, m_combinedText ? m_combinedText->originalFont() : *m_font, emphasisMarkTextRun, boxRect, emphasisMarkTextOrigin, startOffset, endOffset,
	m_emphasisMark, m_emphasisMarkOffset, paintStyle.strokeWidth > 0);

	if (m_combinedText)
	m_context.concatCTM(rotation(boxRect, Counterclockwise));
	}

	void TextPainter::paint(const TextRun& textRun, const FloatRect& boxRect, const FloatPoint& textOrigin)
	{
	paintRange(textRun, boxRect, textOrigin, 0, textRun.length());
	}

	void TextPainter::paintRange(const TextRun& textRun, const FloatRect& boxRect, const FloatPoint& textOrigin, unsigned start, unsigned end)
	{
	ASSERT(m_font);
	ASSERT(start < end);

	GraphicsContextStateSaver stateSaver(m_context, m_style.strokeWidth > 0);
	updateGraphicsContext(m_context, m_style);
	paintTextAndEmphasisMarksIfNeeded(textRun, boxRect, textOrigin, start, end, m_style, m_shadow);
	}

	void TextPainter::clearGlyphDisplayLists()
	{
	GlyphDisplayListCache<InlineTextBox>::singleton().clear();
	GlyphDisplayListCache<SimpleLineLayout::Run>::singleton().clear();
	}

	bool TextPainter::shouldUseGlyphDisplayList(const PaintInfo& paintInfo)
	{
	return !paintInfo.context().paintingDisabled() && paintInfo.enclosingSelfPaintingLayer() && paintInfo.enclosingSelfPaintingLayer()->paintingFrequently();
	}

	} // namespace WebCore