third_party/WebKit/Source/platform/fonts/Font.h - chromium/src - Git at Google

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2007, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Holger Hans Peter Freyther
  *
  * 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.
  *
  */

 #ifndef Font_h
 #define Font_h

 #include "platform/LayoutUnit.h"
 #include "platform/PlatformExport.h"
 #include "platform/fonts/FontDescription.h"
 #include "platform/fonts/FontFallbackList.h"
 #include "platform/fonts/FontFallbackPriority.h"
 #include "platform/fonts/SimpleFontData.h"
 #include "platform/text/TabSize.h"
 #include "platform/text/TextDirection.h"
 #include "platform/text/TextPath.h"
 #include "wtf/Allocator.h"
 #include "wtf/HashMap.h"
 #include "wtf/HashSet.h"
 #include "wtf/MathExtras.h"
 #include "wtf/text/CharacterNames.h"

 class SkCanvas;
 class SkPaint;
 struct SkPoint;

 namespace blink {

 struct CharacterRange;
 class FloatPoint;
 class FloatRect;
 class FontFallbackIterator;
 class FontData;
 class FontMetrics;
 class FontSelector;
 class GlyphBuffer;
 class TextRun;
 struct TextRunPaintInfo;

 struct GlyphData;

 class PLATFORM_EXPORT Font {
   DISALLOW_NEW();

  public:
   Font();
   Font(const FontDescription&);
   ~Font();

   Font(const Font&);
   Font& operator=(const Font&);

   bool operator==(const Font& other) const;
   bool operator!=(const Font& other) const { return !(*this == other); }

   const FontDescription& getFontDescription() const {
     return m_fontDescription;
   }

   void update(FontSelector*) const;

   enum CustomFontNotReadyAction {
     DoNotPaintIfFontNotReady,
     UseFallbackIfFontNotReady
   };
   bool drawText(SkCanvas*,
                 const TextRunPaintInfo&,
                 const FloatPoint&,
                 float deviceScaleFactor,
                 const SkPaint&) const;
   bool drawBidiText(SkCanvas*,
                     const TextRunPaintInfo&,
                     const FloatPoint&,
                     CustomFontNotReadyAction,
                     float deviceScaleFactor,
                     const SkPaint&) const;
   void drawEmphasisMarks(SkCanvas*,
                          const TextRunPaintInfo&,
                          const AtomicString& mark,
                          const FloatPoint&,
                          float deviceScaleFactor,
                          const SkPaint&) const;

   // Glyph bounds will be the minimum rect containing all glyph strokes, in
   // coordinates using (<text run x position>, <baseline position>) as the
   // origin.
   float width(const TextRun&,
               HashSet<const SimpleFontData*>* fallbackFonts = nullptr,
               FloatRect* glyphBounds = nullptr) const;

   int offsetForPosition(const TextRun&,
                         float position,
                         bool includePartialGlyphs) const;
   FloatRect selectionRectForText(const TextRun&,
                                  const FloatPoint&,
                                  int h,
                                  int from = 0,
                                  int to = -1,
                                  bool accountForGlyphBounds = false) const;
   CharacterRange getCharacterRange(const TextRun&,
                                    unsigned from,
                                    unsigned to) const;
   Vector<CharacterRange> individualCharacterRanges(const TextRun&) const;

   // Metrics that we query the FontFallbackList for.
   const FontMetrics& getFontMetrics() const {
     RELEASE_ASSERT(primaryFont());
     return primaryFont()->getFontMetrics();
   }
   float spaceWidth() const {
     return primaryFont()->spaceWidth() + getFontDescription().letterSpacing();
   }
   float tabWidth(const SimpleFontData&, const TabSize&, float position) const;
   float tabWidth(const TabSize& tabSize, float position) const {
     return tabWidth(*primaryFont(), tabSize, position);
   }

   int emphasisMarkAscent(const AtomicString&) const;
   int emphasisMarkDescent(const AtomicString&) const;
   int emphasisMarkHeight(const AtomicString&) const;

   const SimpleFontData* primaryFont() const;
   const FontData* fontDataAt(unsigned) const;

   GlyphData glyphDataForCharacter(UChar32&,
                                   bool mirror,
                                   bool normalizeSpace = false,
                                   FontDataVariant = AutoVariant) const;
   CodePath codePath(const TextRunPaintInfo&) const;

   // Whether the font supports shaping word by word instead of shaping the
   // full run in one go. Allows better caching for fonts where space cannot
   // participate in kerning and/or ligatures.
   bool canShapeWordByWord() const;

   void setCanShapeWordByWordForTesting(bool b) {
     m_canShapeWordByWord = b;
     m_shapeWordByWordComputed = true;
   }

  private:
   enum ForTextEmphasisOrNot { NotForTextEmphasis, ForTextEmphasis };

   // Returns the total advance.
   float buildGlyphBuffer(const TextRunPaintInfo&,
                          GlyphBuffer&,
                          const GlyphData* emphasisData = nullptr) const;
   void drawGlyphBuffer(SkCanvas*,
                        const SkPaint&,
                        const TextRunPaintInfo&,
                        const GlyphBuffer&,
                        const FloatPoint&,
                        float deviceScaleFactor) const;
   float floatWidthForSimpleText(
       const TextRun&,
       HashSet<const SimpleFontData*>* fallbackFonts = 0,
       FloatRect* glyphBounds = 0) const;
   int offsetForPositionForSimpleText(const TextRun&,
                                      float position,
                                      bool includePartialGlyphs) const;
   FloatRect selectionRectForSimpleText(const TextRun&,
                                        const FloatPoint&,
                                        int h,
                                        int from,
                                        int to,
                                        bool accountForGlyphBounds) const;

   bool getEmphasisMarkGlyphData(const AtomicString&, GlyphData&) const;

   float floatWidthForComplexText(const TextRun&,
                                  HashSet<const SimpleFontData*>* fallbackFonts,
                                  FloatRect* glyphBounds) const;
   int offsetForPositionForComplexText(const TextRun&,
                                       float position,
                                       bool includePartialGlyphs) const;
   FloatRect selectionRectForComplexText(const TextRun&,
                                         const FloatPoint&,
                                         int h,
                                         int from,
                                         int to) const;

   bool computeCanShapeWordByWord() const;

   friend struct SimpleShaper;

  public:
   FontSelector* getFontSelector() const;
   PassRefPtr<FontFallbackIterator> createFontFallbackIterator(
       FontFallbackPriority) const;

   void willUseFontData(const String& text) const;

   bool loadingCustomFonts() const;
   bool isFallbackValid() const;

  private:
   bool shouldSkipDrawing() const {
     return m_fontFallbackList && m_fontFallbackList->shouldSkipDrawing();
   }

   FontDescription m_fontDescription;
   mutable RefPtr<FontFallbackList> m_fontFallbackList;
   mutable unsigned m_canShapeWordByWord : 1;
   mutable unsigned m_shapeWordByWordComputed : 1;

   // For accessing buildGlyphBuffer and retrieving fonts used in rendering a
   // node.
   friend class InspectorCSSAgent;
 };

 inline Font::~Font() {}

 inline const SimpleFontData* Font::primaryFont() const {
   ASSERT(m_fontFallbackList);
   return m_fontFallbackList->primarySimpleFontData(m_fontDescription);
 }

 inline const FontData* Font::fontDataAt(unsigned index) const {
   ASSERT(m_fontFallbackList);
   return m_fontFallbackList->fontDataAt(m_fontDescription, index);
 }

 inline FontSelector* Font::getFontSelector() const {
   return m_fontFallbackList ? m_fontFallbackList->getFontSelector() : 0;
 }

 inline float Font::tabWidth(const SimpleFontData& fontData,
                             const TabSize& tabSize,
                             float position) const {
   float baseTabWidth = tabSize.getPixelSize(fontData.spaceWidth());
   if (!baseTabWidth)
     return getFontDescription().letterSpacing();
   float distanceToTabStop = baseTabWidth - fmodf(position, baseTabWidth);

   // Let the minimum width be the half of the space width so that it's always
   // recognizable.  if the distance to the next tab stop is less than that,
   // advance an additional tab stop.
   if (distanceToTabStop < fontData.spaceWidth() / 2)
     distanceToTabStop += baseTabWidth;

   return distanceToTabStop;
 }

 }  // namespace blink

 #endif
	/*
	* Copyright (C) 2000 Lars Knoll (knoll@kde.org)
	* (C) 2000 Antti Koivisto (koivisto@kde.org)
	* (C) 2000 Dirk Mueller (mueller@kde.org)
	* Copyright (C) 2003, 2006, 2007, 2010, 2011 Apple Inc. All rights reserved.
	* Copyright (C) 2008 Holger Hans Peter Freyther
	*
	* 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.
	*
	*/

	#ifndef Font_h
	#define Font_h

	#include "platform/LayoutUnit.h"
	#include "platform/PlatformExport.h"
	#include "platform/fonts/FontDescription.h"
	#include "platform/fonts/FontFallbackList.h"
	#include "platform/fonts/FontFallbackPriority.h"
	#include "platform/fonts/SimpleFontData.h"
	#include "platform/text/TabSize.h"
	#include "platform/text/TextDirection.h"
	#include "platform/text/TextPath.h"
	#include "wtf/Allocator.h"
	#include "wtf/HashMap.h"
	#include "wtf/HashSet.h"
	#include "wtf/MathExtras.h"
	#include "wtf/text/CharacterNames.h"

	class SkCanvas;
	class SkPaint;
	struct SkPoint;

	namespace blink {

	struct CharacterRange;
	class FloatPoint;
	class FloatRect;
	class FontFallbackIterator;
	class FontData;
	class FontMetrics;
	class FontSelector;
	class GlyphBuffer;
	class TextRun;
	struct TextRunPaintInfo;

	struct GlyphData;

	class PLATFORM_EXPORT Font {
	DISALLOW_NEW();

	public:
	Font();
	Font(const FontDescription&);
	~Font();

	Font(const Font&);
	Font& operator=(const Font&);

	bool operator==(const Font& other) const;
	bool operator!=(const Font& other) const { return !(*this == other); }

	const FontDescription& getFontDescription() const {
	return m_fontDescription;
	}

	void update(FontSelector*) const;

	enum CustomFontNotReadyAction {
	DoNotPaintIfFontNotReady,
	UseFallbackIfFontNotReady
	};
	bool drawText(SkCanvas*,
	const TextRunPaintInfo&,
	const FloatPoint&,
	float deviceScaleFactor,
	const SkPaint&) const;
	bool drawBidiText(SkCanvas*,
	const TextRunPaintInfo&,
	const FloatPoint&,
	CustomFontNotReadyAction,
	float deviceScaleFactor,
	const SkPaint&) const;
	void drawEmphasisMarks(SkCanvas*,
	const TextRunPaintInfo&,
	const AtomicString& mark,
	const FloatPoint&,
	float deviceScaleFactor,
	const SkPaint&) const;

	// Glyph bounds will be the minimum rect containing all glyph strokes, in
	// coordinates using (<text run x position>, <baseline position>) as the
	// origin.
	float width(const TextRun&,
	HashSet<const SimpleFontData> fallbackFonts = nullptr,
	FloatRect* glyphBounds = nullptr) const;

	int offsetForPosition(const TextRun&,
	float position,
	bool includePartialGlyphs) const;
	FloatRect selectionRectForText(const TextRun&,
	const FloatPoint&,
	int h,
	int from = 0,
	int to = -1,
	bool accountForGlyphBounds = false) const;
	CharacterRange getCharacterRange(const TextRun&,
	unsigned from,
	unsigned to) const;
	Vector<CharacterRange> individualCharacterRanges(const TextRun&) const;

	// Metrics that we query the FontFallbackList for.
	const FontMetrics& getFontMetrics() const {
	RELEASE_ASSERT(primaryFont());
	return primaryFont()->getFontMetrics();
	}
	float spaceWidth() const {
	return primaryFont()->spaceWidth() + getFontDescription().letterSpacing();
	}
	float tabWidth(const SimpleFontData&, const TabSize&, float position) const;
	float tabWidth(const TabSize& tabSize, float position) const {
	return tabWidth(*primaryFont(), tabSize, position);
	}

	int emphasisMarkAscent(const AtomicString&) const;
	int emphasisMarkDescent(const AtomicString&) const;
	int emphasisMarkHeight(const AtomicString&) const;

	const SimpleFontData* primaryFont() const;
	const FontData* fontDataAt(unsigned) const;

	GlyphData glyphDataForCharacter(UChar32&,
	bool mirror,
	bool normalizeSpace = false,
	FontDataVariant = AutoVariant) const;
	CodePath codePath(const TextRunPaintInfo&) const;

	// Whether the font supports shaping word by word instead of shaping the
	// full run in one go. Allows better caching for fonts where space cannot
	// participate in kerning and/or ligatures.
	bool canShapeWordByWord() const;

	void setCanShapeWordByWordForTesting(bool b) {
	m_canShapeWordByWord = b;
	m_shapeWordByWordComputed = true;
	}

	private:
	enum ForTextEmphasisOrNot { NotForTextEmphasis, ForTextEmphasis };

	// Returns the total advance.
	float buildGlyphBuffer(const TextRunPaintInfo&,
	GlyphBuffer&,
	const GlyphData* emphasisData = nullptr) const;
	void drawGlyphBuffer(SkCanvas*,
	const SkPaint&,
	const TextRunPaintInfo&,
	const GlyphBuffer&,
	const FloatPoint&,
	float deviceScaleFactor) const;
	float floatWidthForSimpleText(
	const TextRun&,
	HashSet<const SimpleFontData> fallbackFonts = 0,
	FloatRect* glyphBounds = 0) const;
	int offsetForPositionForSimpleText(const TextRun&,
	float position,
	bool includePartialGlyphs) const;
	FloatRect selectionRectForSimpleText(const TextRun&,
	const FloatPoint&,
	int h,
	int from,
	int to,
	bool accountForGlyphBounds) const;

	bool getEmphasisMarkGlyphData(const AtomicString&, GlyphData&) const;

	float floatWidthForComplexText(const TextRun&,
	HashSet<const SimpleFontData> fallbackFonts,
	FloatRect* glyphBounds) const;
	int offsetForPositionForComplexText(const TextRun&,
	float position,
	bool includePartialGlyphs) const;
	FloatRect selectionRectForComplexText(const TextRun&,
	const FloatPoint&,
	int h,
	int from,
	int to) const;

	bool computeCanShapeWordByWord() const;

	friend struct SimpleShaper;

	public:
	FontSelector* getFontSelector() const;
	PassRefPtr<FontFallbackIterator> createFontFallbackIterator(
	FontFallbackPriority) const;

	void willUseFontData(const String& text) const;

	bool loadingCustomFonts() const;
	bool isFallbackValid() const;

	private:
	bool shouldSkipDrawing() const {
	return m_fontFallbackList && m_fontFallbackList->shouldSkipDrawing();
	}

	FontDescription m_fontDescription;
	mutable RefPtr<FontFallbackList> m_fontFallbackList;
	mutable unsigned m_canShapeWordByWord : 1;
	mutable unsigned m_shapeWordByWordComputed : 1;

	// For accessing buildGlyphBuffer and retrieving fonts used in rendering a
	// node.
	friend class InspectorCSSAgent;
	};

	inline Font::~Font() {}

	inline const SimpleFontData* Font::primaryFont() const {
	ASSERT(m_fontFallbackList);
	return m_fontFallbackList->primarySimpleFontData(m_fontDescription);
	}

	inline const FontData* Font::fontDataAt(unsigned index) const {
	ASSERT(m_fontFallbackList);
	return m_fontFallbackList->fontDataAt(m_fontDescription, index);
	}

	inline FontSelector* Font::getFontSelector() const {
	return m_fontFallbackList ? m_fontFallbackList->getFontSelector() : 0;
	}

	inline float Font::tabWidth(const SimpleFontData& fontData,
	const TabSize& tabSize,
	float position) const {
	float baseTabWidth = tabSize.getPixelSize(fontData.spaceWidth());
	if (!baseTabWidth)
	return getFontDescription().letterSpacing();
	float distanceToTabStop = baseTabWidth - fmodf(position, baseTabWidth);

	// Let the minimum width be the half of the space width so that it's always
	// recognizable. if the distance to the next tab stop is less than that,
	// advance an additional tab stop.
	if (distanceToTabStop < fontData.spaceWidth() / 2)
	distanceToTabStop += baseTabWidth;

	return distanceToTabStop;
	}

	} // namespace blink

	#endif