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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&, short letterSpacing, short 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 
fontDescription()72     const FontDescription& fontDescription() const { return m_fontDescription; }
73 
pixelSize()74     int pixelSize() const { return fontDescription().computedPixelSize(); }
size()75     float size() const { return fontDescription().computedSize(); }
76 
77     void update(PassRefPtr<FontSelector>) const;
78 
79     void drawText(GraphicsContext*, const TextRun&, const FloatPoint&, int from = 0, int to = -1) const;
80 
81     int width(const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts = 0) const { return lroundf(floatWidth(run, fallbackFonts)); }
82     float floatWidth(const TextRun&, HashSet<const SimpleFontData*>* fallbackFonts = 0) 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 
isSmallCaps()88     bool isSmallCaps() const { return m_fontDescription.smallCaps(); }
89 
wordSpacing()90     short wordSpacing() const { return m_wordSpacing; }
letterSpacing()91     short letterSpacing() const { return m_letterSpacing; }
setWordSpacing(short s)92     void setWordSpacing(short s) { m_wordSpacing = s; }
setLetterSpacing(short s)93     void setLetterSpacing(short s) { m_letterSpacing = s; }
94     bool isFixedPitch() const;
isPrinterFont()95     bool isPrinterFont() const { return m_fontDescription.usePrinterFont(); }
96 
renderingMode()97     FontRenderingMode renderingMode() const { return m_fontDescription.renderingMode(); }
98 
firstFamily()99     FontFamily& firstFamily() { return m_fontDescription.firstFamily(); }
family()100     const FontFamily& family() const { return m_fontDescription.family(); }
101 
italic()102     bool italic() const { return m_fontDescription.italic(); }
weight()103     FontWeight weight() const { return m_fontDescription.weight(); }
104 
isPlatformFont()105     bool isPlatformFont() const { return m_isPlatformFont; }
106 
107     // Metrics that we query the FontFallbackList for.
ascent()108     int ascent() const { return primaryFont()->ascent(); }
descent()109     int descent() const { return primaryFont()->descent(); }
height()110     int height() const { return ascent() + descent(); }
lineSpacing()111     int lineSpacing() const { return primaryFont()->lineSpacing(); }
lineGap()112     int lineGap() const { return primaryFont()->lineGap(); }
xHeight()113     float xHeight() const { return primaryFont()->xHeight(); }
unitsPerEm()114     unsigned unitsPerEm() const { return primaryFont()->unitsPerEm(); }
spaceWidth()115     int spaceWidth() const { return (int)ceilf(primaryFont()->adjustedSpaceWidth() + m_letterSpacing); }
tabWidth()116     int tabWidth() const { return 8 * spaceWidth(); }
117 
118     const SimpleFontData* primaryFont() const;
119     const FontData* fontDataAt(unsigned) const;
120     GlyphData glyphDataForCharacter(UChar32, bool mirror, bool forceSmallCaps = false) const;
121     // Used for complex text, and does not utilize the glyph map cache.
122     const FontData* fontDataForCharacters(const UChar*, int length) const;
123 
124 #if PLATFORM(QT)
125     QFont font() const;
126 #endif
127 
128     static void setShouldUseSmoothing(bool);
129     static bool shouldUseSmoothing();
130 
131 private:
132 #if ENABLE(SVG_FONTS)
133     void drawTextUsingSVGFont(GraphicsContext*, const TextRun&, const FloatPoint&, int from, int to) const;
134     float floatWidthUsingSVGFont(const TextRun&) const;
135     float floatWidthUsingSVGFont(const TextRun&, int extraCharsAvailable, int& charsConsumed, String& glyphName) const;
136     FloatRect selectionRectForTextUsingSVGFont(const TextRun&, const IntPoint&, int h, int from, int to) const;
137     int offsetForPositionForTextUsingSVGFont(const TextRun&, int position, bool includePartialGlyphs) const;
138 #endif
139 
140 #if USE(FONT_FAST_PATH)
141     bool canUseGlyphCache(const TextRun&) const;
142     void drawSimpleText(GraphicsContext*, const TextRun&, const FloatPoint&, int from, int to) const;
143     void drawGlyphs(GraphicsContext*, const SimpleFontData*, const GlyphBuffer&, int from, int to, const FloatPoint&) const;
144     void drawGlyphBuffer(GraphicsContext*, const GlyphBuffer&, const TextRun&, const FloatPoint&) const;
145     float floatWidthForSimpleText(const TextRun&, GlyphBuffer*, HashSet<const SimpleFontData*>* fallbackFonts = 0) const;
146     int offsetForPositionForSimpleText(const TextRun&, int position, bool includePartialGlyphs) const;
147     FloatRect selectionRectForSimpleText(const TextRun&, const IntPoint&, int h, int from, int to) const;
148 
149     static bool canReturnFallbackFontsForComplexText();
150 #endif
151 
152     void drawComplexText(GraphicsContext*, const TextRun&, const FloatPoint&, int from, int to) const;
153     float floatWidthForComplexText(const TextRun&, HashSet<const SimpleFontData*>* fallbackFonts = 0) 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 
157     friend struct WidthIterator;
158 
159 public:
160     // Useful for debugging the different font rendering code paths.
161 #if USE(FONT_FAST_PATH)
162     enum CodePath { Auto, Simple, Complex };
163     static void setCodePath(CodePath);
164     static CodePath codePath();
165     static CodePath s_codePath;
166 
167     static const uint8_t gRoundingHackCharacterTable[256];
isRoundingHackCharacter(UChar32 c)168     static bool isRoundingHackCharacter(UChar32 c)
169     {
170         return (((c & ~0xFF) == 0 && gRoundingHackCharacterTable[c]));
171     }
172 #endif
173 
174     FontSelector* fontSelector() const;
treatAsSpace(UChar c)175     static bool treatAsSpace(UChar c) { return c == ' ' || c == '\t' || c == '\n' || c == 0x00A0; }
treatAsZeroWidthSpace(UChar c)176     static bool treatAsZeroWidthSpace(UChar c) { return c < 0x20 || (c >= 0x7F && c < 0xA0) || c == 0x200e || c == 0x200f || (c >= 0x202a && c <= 0x202e) || c == 0xFFFC; }
177 
178 #if ENABLE(SVG_FONTS)
179     bool isSVGFont() const;
180     SVGFontElement* svgFont() const;
181 #endif
182 
183 private:
184     FontDescription m_fontDescription;
185     mutable RefPtr<FontFallbackList> m_fontList;
186     short m_letterSpacing;
187     short m_wordSpacing;
188     bool m_isPlatformFont;
189 };
190 
191 }
192 
193 #endif
194