WebCore/Font.h

   1 /*
   2  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
   3  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
   4  *           (C) 2000 Dirk Mueller (mueller@kde.org)
   5  * Copyright (C) 2003, 2006, 2007 Apple Computer, Inc.
   6  * Copyright (C) 2008 Holger Hans Peter Freyther
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Library General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Library General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Library General Public License
  19  * along with this library; see the file COPYING.LIB.  If not, write to
  20  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21  * Boston, MA 02110-1301, USA.
  22  *
  23  */
  24
  25 #ifndef Font_h
  26 #define Font_h
  27
  28 #include "TextRun.h"
  29 #include "FontDescription.h"
  30 #include "SimpleFontData.h"
  31 #include <wtf/HashMap.h>
  32 #include <wtf/MathExtras.h>
  33
  34 #if PLATFORM(QT)
  35 #include <QFont>
  36 #endif
  37
  38 namespace WebCore {
  39
  40 class FloatPoint;
  41 class FloatRect;
  42 class FontData;
  43 class FontFallbackList;
  44 class FontPlatformData;
  45 class FontSelector;
  46 class GlyphBuffer;
  47 class GlyphPageTreeNode;
  48 class GraphicsContext;
  49 class IntPoint;
  50 class SVGFontElement;
  51
  52 struct GlyphData;
  53
  54 const unsigned defaultUnitsPerEm = 1000;
  55
  56 class Font {
  57 public:
  58     Font();
  59     Font(const FontDescription&, float letterSpacing, float wordSpacing);
  60     // This constructor is only used if the platform wants to start with a native font.
  61     Font(const FontPlatformData&, bool isPrinting);
  62     ~Font();
  63
  64     Font(const Font&);
  65     Font& operator=(const Font&);
  66
  67     bool operator==(const Font& other) const;
  68     bool operator!=(const Font& other) const {
  69         return !(*this == other);
  70     }
  71
  72     const FontDescription& fontDescription() const { return m_fontDescription; }
  73
  74     int pixelSize() const { return fontDescription().computedPixelSize(); }
  75     float size() const { return fontDescription().computedSize(); }
  76
  77     void update(PassRefPtr<FontSelector>) const;
  78
  79     float drawText(GraphicsContext*, const TextRun&, const FloatPoint&, int from = 0, int to = -1) const;
  80
  81     int width(const TextRun& run) const { return lroundf(floatWidth(run)); }
  82     float floatWidth(const TextRun&) const;
  83     float floatWidth(const TextRun& run, int extraCharsAvailable, int& charsConsumed, String& glyphName) const;
  84
  85     int offsetForPosition(const TextRun&, int position, bool includePartialGlyphs) const;
  86     FloatRect selectionRectForText(const TextRun&, const IntPoint&, int h, int from = 0, int to = -1) const;
  87
  88     bool isSmallCaps() const { return m_fontDescription.smallCaps(); }
  89
  90     float wordSpacing() const { return m_wordSpacing; }
  91     float letterSpacing() const { return m_letterSpacing; }
  92     void setWordSpacing(float s) { m_wordSpacing = s; }
  93     void setLetterSpacing(float s) { m_letterSpacing = s; }
  94     bool isFixedPitch() const;
  95     bool isPrinterFont() const { return m_fontDescription.usePrinterFont(); }
  96
  97     FontRenderingMode renderingMode() const { return m_fontDescription.renderingMode(); }
  98
  99     FontFamily& firstFamily() { return m_fontDescription.firstFamily(); }
 100     const FontFamily& family() const { return m_fontDescription.family(); }
 101
 102     bool italic() const { return m_fontDescription.italic(); }
 103     FontWeight weight() const { return m_fontDescription.weight(); }
 104
 105     bool isPlatformFont() const { return m_isPlatformFont; }
 106
 107     // Metrics that we query the FontFallbackList for.
 108     int ascent() const { return primaryFont()->ascent(); }
 109     int descent() const { return primaryFont()->descent(); }
 110     int height() const { return ascent() + descent(); }
 111     int lineSpacing() const { return primaryFont()->lineSpacing(); }
 112     int lineGap() const { return primaryFont()->lineGap(); }
 113     float xHeight() const { return primaryFont()->xHeight(); }
 114     unsigned unitsPerEm() const { return primaryFont()->unitsPerEm(); }
 115     int spaceWidth() const { return (int)ceilf(primaryFont()->m_adjustedSpaceWidth + m_letterSpacing); }
 116     int tabWidth() const { return 8 * spaceWidth(); }
 117
 118     const SimpleFontData* primaryFont() const {
 119         if (!m_cachedPrimaryFont)
 120             cachePrimaryFont();
 121         return m_cachedPrimaryFont;
 122     }
 123
 124     const FontData* fontDataAt(unsigned) const;
 125     const GlyphData& glyphDataForCharacter(UChar32, bool mirror, bool forceSmallCaps = false) const;
 126     // Used for complex text, and does not utilize the glyph map cache.
 127     const FontData* fontDataForCharacters(const UChar*, int length) const;
 128
 129 #if PLATFORM(QT)
 130     QFont font() const;
 131 #endif
 132
 133 private:
 134 #if ENABLE(SVG_FONTS)
 135     void drawTextUsingSVGFont(GraphicsContext*, const TextRun&, const FloatPoint&, int from, int to) const;
 136     float floatWidthUsingSVGFont(const TextRun&) const;
 137     float floatWidthUsingSVGFont(const TextRun&, int extraCharsAvailable, int& charsConsumed, String& glyphName) const;
 138     FloatRect selectionRectForTextUsingSVGFont(const TextRun&, const IntPoint&, int h, int from, int to) const;
 139     int offsetForPositionForTextUsingSVGFont(const TextRun&, int position, bool includePartialGlyphs) const;
 140 #endif
 141
 142 #if USE(FONT_FAST_PATH)
 143     bool canUseGlyphCache(const TextRun&) const;
 144     float drawSimpleText(GraphicsContext*, const TextRun&, const FloatPoint&, int from, int to) const;
 145     void drawGlyphs(GraphicsContext*, const SimpleFontData*, const GlyphBuffer&, int from, int to, const FloatPoint&, bool setColor = true) const;
 146     void drawGlyphBuffer(GraphicsContext*, const GlyphBuffer&, const TextRun&, FloatPoint&) const;
 147     float floatWidthForSimpleText(const TextRun&, GlyphBuffer*) const;
 148     int offsetForPositionForSimpleText(const TextRun&, int position, bool includePartialGlyphs) const;
 149     FloatRect selectionRectForSimpleText(const TextRun&, const IntPoint&, int h, int from, int to) const;
 150 #endif
 151
 152     float drawComplexText(GraphicsContext*, const TextRun&, const FloatPoint&, int from, int to) const;
 153     float floatWidthForComplexText(const TextRun&) const;
 154     int offsetForPositionForComplexText(const TextRun&, int position, bool includePartialGlyphs) const;
 155     FloatRect selectionRectForComplexText(const TextRun&, const IntPoint&, int h, int from, int to) const;
 156     void cachePrimaryFont() const;
 157
 158     friend struct WidthIterator;
 159
 160 public:
 161     bool equalForTextAutoSizing (const Font &other) const {
 162         return (m_fontDescription.equalForTextAutoSizing(other.m_fontDescription) &&
 163                 m_letterSpacing == other.m_letterSpacing &&
 164                 m_wordSpacing == other.m_wordSpacing);
 165     }
 166
 167     // Useful for debugging the different font rendering code paths.
 168 #if USE(FONT_FAST_PATH)
 169     enum CodePath { Auto, Simple, Complex };
 170     static void setCodePath(CodePath);
 171     static CodePath codePath();
 172     static CodePath s_codePath;
 173
 174     static const uint8_t gRoundingHackCharacterTable[256];
 175     static bool isRoundingHackCharacter(UChar32 c)
 176     {
 177         return (((c & ~0xFF) == 0 && gRoundingHackCharacterTable[c]) || c == 0x200e || c == 0x200f);
 178     }
 179 #endif
 180
 181     FontSelector* fontSelector() const;
 182     static bool treatAsSpace(UChar c) { return c == ' ' || c == '\t' || c == '\n' || c == 0x00A0; }
 183     static bool treatAsZeroWidthSpace(UChar c) { return c < 0x20 || (c >= 0x7F && c < 0xA0) || c == 0x200e || c == 0x200f || (c >= 0x202a && c <= 0x202e) || c == 0xFFFC; }
 184
 185 #if ENABLE(SVG_FONTS)
 186     bool isSVGFont() const;
 187     SVGFontElement* svgFont() const;
 188 #endif
 189
 190 private:
 191     FontDescription m_fontDescription;
 192     mutable RefPtr<FontFallbackList> m_fontList;
 193     mutable HashMap<int, GlyphPageTreeNode*> m_pages;
 194     mutable GlyphPageTreeNode* m_pageZero;
 195     mutable const SimpleFontData* m_cachedPrimaryFont;
 196     float m_letterSpacing;
 197     float m_wordSpacing;
 198     bool m_isPlatformFont;
 199 };
 200
 201 }
 202
 203 #endif