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, 2010, 2011 Apple Inc. All rights reserved.
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 "platform/PlatformExport.h"
29 #include "platform/fonts/FontDescription.h"
30 #include "platform/fonts/FontFallbackList.h"
31 #include "platform/fonts/SimpleFontData.h"
32 #include "platform/fonts/TypesettingFeatures.h"
33 #include "platform/text/TextDirection.h"
34 #include "wtf/HashMap.h"
35 #include "wtf/HashSet.h"
36 #include "wtf/MathExtras.h"
37 #include "wtf/unicode/CharacterNames.h"
38
39 // "X11/X.h" defines Complex to 0 and conflicts
40 // with Complex value in CodePath enum.
41 #ifdef Complex
42 #undef Complex
43 #endif
44
45 namespace WebCore {
46
47 class FloatPoint;
48 class FloatRect;
49 class FontData;
50 class FontMetrics;
51 class FontPlatformData;
52 class FontSelector;
53 class GlyphBuffer;
54 class GraphicsContext;
55 class TextLayout;
56 class TextRun;
57 struct TextRunPaintInfo;
58
59 struct GlyphData;
60
61 struct GlyphOverflow {
GlyphOverflowGlyphOverflow62 GlyphOverflow()
63 : left(0)
64 , right(0)
65 , top(0)
66 , bottom(0)
67 , computeBounds(false)
68 {
69 }
70
71 int left;
72 int right;
73 int top;
74 int bottom;
75 bool computeBounds;
76 };
77
78
79 class PLATFORM_EXPORT Font {
80 public:
81 Font();
82 Font(const FontDescription&, float letterSpacing, float wordSpacing);
83 // This constructor is only used if the platform wants to start with a native font.
84 Font(const FontPlatformData&, bool isPrinting, FontSmoothingMode = AutoSmoothing);
85 ~Font();
86
87 Font(const Font&);
88 Font& operator=(const Font&);
89
90 bool operator==(const Font& other) const;
91 bool operator!=(const Font& other) const { return !(*this == other); }
92
fontDescription()93 const FontDescription& fontDescription() const { return m_fontDescription; }
94
pixelSize()95 int pixelSize() const { return fontDescription().computedPixelSize(); }
size()96 float size() const { return fontDescription().computedSize(); }
97
98 void update(PassRefPtr<FontSelector>) const;
99
100 enum CustomFontNotReadyAction { DoNotPaintIfFontNotReady, UseFallbackIfFontNotReady };
101 void drawText(GraphicsContext*, const TextRunPaintInfo&, const FloatPoint&, CustomFontNotReadyAction = DoNotPaintIfFontNotReady) const;
102 void drawEmphasisMarks(GraphicsContext*, const TextRunPaintInfo&, const AtomicString& mark, const FloatPoint&) const;
103
104 float width(const TextRun&, HashSet<const SimpleFontData*>* fallbackFonts = 0, GlyphOverflow* = 0) const;
105 float width(const TextRun&, int& charsConsumed, String& glyphName) const;
106
107 PassOwnPtr<TextLayout> createLayoutForMacComplexText(const TextRun&, unsigned textLength, float xPos, bool collapseWhiteSpace) const;
108 static void deleteLayout(TextLayout*);
109 static float width(TextLayout&, unsigned from, unsigned len, HashSet<const SimpleFontData*>* fallbackFonts = 0);
110
111 int offsetForPosition(const TextRun&, float position, bool includePartialGlyphs) const;
112 FloatRect selectionRectForText(const TextRun&, const FloatPoint&, int h, int from = 0, int to = -1) const;
113
isSmallCaps()114 bool isSmallCaps() const { return m_fontDescription.smallCaps(); }
115
wordSpacing()116 float wordSpacing() const { return m_wordSpacing; }
letterSpacing()117 float letterSpacing() const { return m_letterSpacing; }
setWordSpacing(float s)118 void setWordSpacing(float s) { m_wordSpacing = s; }
setLetterSpacing(float s)119 void setLetterSpacing(float s) { m_letterSpacing = s; }
120 bool isFixedPitch() const;
isPrinterFont()121 bool isPrinterFont() const { return m_fontDescription.usePrinterFont(); }
122
typesettingFeatures()123 TypesettingFeatures typesettingFeatures() const { return static_cast<TypesettingFeatures>(m_typesettingFeatures); }
124
firstFamily()125 FontFamily& firstFamily() { return m_fontDescription.firstFamily(); }
family()126 const FontFamily& family() const { return m_fontDescription.family(); }
127
italic()128 FontItalic italic() const { return m_fontDescription.italic(); }
weight()129 FontWeight weight() const { return m_fontDescription.weight(); }
widthVariant()130 FontWidthVariant widthVariant() const { return m_fontDescription.widthVariant(); }
131
isPlatformFont()132 bool isPlatformFont() const { return m_isPlatformFont; }
133
134 // Metrics that we query the FontFallbackList for.
fontMetrics()135 const FontMetrics& fontMetrics() const { return primaryFont()->fontMetrics(); }
spaceWidth()136 float spaceWidth() const { return primaryFont()->spaceWidth() + m_letterSpacing; }
137 float tabWidth(const SimpleFontData&, unsigned tabSize, float position) const;
tabWidth(unsigned tabSize,float position)138 float tabWidth(unsigned tabSize, float position) const { return tabWidth(*primaryFont(), tabSize, position); }
139
140 int emphasisMarkAscent(const AtomicString&) const;
141 int emphasisMarkDescent(const AtomicString&) const;
142 int emphasisMarkHeight(const AtomicString&) const;
143
144 const SimpleFontData* primaryFont() const;
145 const FontData* fontDataAt(unsigned) const;
146 inline GlyphData glyphDataForCharacter(UChar32 c, bool mirror, FontDataVariant variant = AutoVariant) const
147 {
148 return glyphDataAndPageForCharacter(c, mirror, variant).first;
149 }
150 #if OS(MACOSX)
151 const SimpleFontData* fontDataForCombiningCharacterSequence(const UChar*, size_t length, FontDataVariant) const;
152 #endif
153 std::pair<GlyphData, GlyphPage*> glyphDataAndPageForCharacter(UChar32, bool mirror, FontDataVariant = AutoVariant) const;
154 bool primaryFontHasGlyphForCharacter(UChar32) const;
155
156 static bool isCJKIdeograph(UChar32);
157 static bool isCJKIdeographOrSymbol(UChar32);
158
159 static unsigned expansionOpportunityCount(const LChar*, size_t length, TextDirection, bool& isAfterExpansion);
160 static unsigned expansionOpportunityCount(const UChar*, size_t length, TextDirection, bool& isAfterExpansion);
161
162 static void setShouldUseSmoothing(bool);
163 static bool shouldUseSmoothing();
164
165 enum CodePath { Auto, Simple, Complex, SimpleWithGlyphOverflow };
166 CodePath codePath(const TextRun&) const;
characterRangeCodePath(const LChar *,unsigned)167 static CodePath characterRangeCodePath(const LChar*, unsigned) { return Simple; }
168 static CodePath characterRangeCodePath(const UChar*, unsigned len);
169
170 private:
171 enum ForTextEmphasisOrNot { NotForTextEmphasis, ForTextEmphasis };
172
173 // Returns the initial in-stream advance.
174 float getGlyphsAndAdvancesForSimpleText(const TextRun&, int from, int to, GlyphBuffer&, ForTextEmphasisOrNot = NotForTextEmphasis) const;
175 void drawSimpleText(GraphicsContext*, const TextRunPaintInfo&, const FloatPoint&) const;
176 void drawEmphasisMarksForSimpleText(GraphicsContext*, const TextRunPaintInfo&, const AtomicString& mark, const FloatPoint&) const;
177 void drawGlyphs(GraphicsContext*, const SimpleFontData*, const GlyphBuffer&, unsigned from, unsigned numGlyphs, const FloatPoint&, const FloatRect& textRect) const;
178 void drawGlyphBuffer(GraphicsContext*, const TextRunPaintInfo&, const GlyphBuffer&, const FloatPoint&) const;
179 void drawEmphasisMarks(GraphicsContext*, const TextRunPaintInfo&, const GlyphBuffer&, const AtomicString&, const FloatPoint&) const;
180 float floatWidthForSimpleText(const TextRun&, HashSet<const SimpleFontData*>* fallbackFonts = 0, GlyphOverflow* = 0) const;
181 int offsetForPositionForSimpleText(const TextRun&, float position, bool includePartialGlyphs) const;
182 FloatRect selectionRectForSimpleText(const TextRun&, const FloatPoint&, int h, int from, int to) const;
183
184 bool getEmphasisMarkGlyphData(const AtomicString&, GlyphData&) const;
185
186 static bool canReturnFallbackFontsForComplexText();
187 static bool canExpandAroundIdeographsInComplexText();
188
189 // Returns the initial in-stream advance.
190 float getGlyphsAndAdvancesForComplexText(const TextRun&, int from, int to, GlyphBuffer&, ForTextEmphasisOrNot = NotForTextEmphasis) const;
191 void drawComplexText(GraphicsContext*, const TextRunPaintInfo&, const FloatPoint&) const;
192 void drawEmphasisMarksForComplexText(GraphicsContext*, const TextRunPaintInfo&, const AtomicString& mark, const FloatPoint&) const;
193 float floatWidthForComplexText(const TextRun&, HashSet<const SimpleFontData*>* fallbackFonts = 0, GlyphOverflow* = 0) const;
194 int offsetForPositionForComplexText(const TextRun&, float position, bool includePartialGlyphs) const;
195 FloatRect selectionRectForComplexText(const TextRun&, const FloatPoint&, int h, int from, int to) const;
196
197 friend struct WidthIterator;
198 friend class SVGTextRunRenderingContext;
199
200 public:
201 // Useful for debugging the different font rendering code paths.
202 static void setCodePath(CodePath);
203 static CodePath codePath();
204 static CodePath s_codePath;
205
206 static void setDefaultTypesettingFeatures(TypesettingFeatures);
207 static TypesettingFeatures defaultTypesettingFeatures();
208
209 static const uint8_t s_roundingHackCharacterTable[256];
isRoundingHackCharacter(UChar32 c)210 static bool isRoundingHackCharacter(UChar32 c)
211 {
212 return !(c & ~0xFF) && s_roundingHackCharacterTable[c];
213 }
214
215 FontSelector* fontSelector() const;
treatAsSpace(UChar c)216 static bool treatAsSpace(UChar c) { return c == ' ' || c == '\t' || c == '\n' || c == noBreakSpace; }
treatAsZeroWidthSpace(UChar c)217 static bool treatAsZeroWidthSpace(UChar c) { return treatAsZeroWidthSpaceInComplexScript(c) || c == 0x200c || c == 0x200d; }
treatAsZeroWidthSpaceInComplexScript(UChar c)218 static bool treatAsZeroWidthSpaceInComplexScript(UChar c) { return c < 0x20 || (c >= 0x7F && c < 0xA0) || c == softHyphen || c == zeroWidthSpace || (c >= 0x200e && c <= 0x200f) || (c >= 0x202a && c <= 0x202e) || c == zeroWidthNoBreakSpace || c == objectReplacementCharacter; }
219 static bool canReceiveTextEmphasis(UChar32 c);
220
normalizeSpaces(UChar character)221 static inline UChar normalizeSpaces(UChar character)
222 {
223 if (treatAsSpace(character))
224 return space;
225
226 if (treatAsZeroWidthSpace(character))
227 return zeroWidthSpace;
228
229 return character;
230 }
231
232 static String normalizeSpaces(const LChar*, unsigned length);
233 static String normalizeSpaces(const UChar*, unsigned length);
234
fontList()235 FontFallbackList* fontList() const { return m_fontFallbackList.get(); }
236
237 void willUseFontData() const;
238
239 private:
loadingCustomFonts()240 bool loadingCustomFonts() const
241 {
242 return m_fontFallbackList && m_fontFallbackList->loadingCustomFonts();
243 }
244
computeTypesettingFeatures()245 TypesettingFeatures computeTypesettingFeatures() const
246 {
247 TextRenderingMode textRenderingMode = m_fontDescription.textRenderingMode();
248 TypesettingFeatures features = s_defaultTypesettingFeatures;
249
250 switch (textRenderingMode) {
251 case AutoTextRendering:
252 break;
253 case OptimizeSpeed:
254 features &= ~(Kerning | Ligatures);
255 break;
256 case GeometricPrecision:
257 case OptimizeLegibility:
258 features |= Kerning | Ligatures;
259 break;
260 }
261
262 switch (m_fontDescription.kerning()) {
263 case FontDescription::NoneKerning:
264 features &= ~Kerning;
265 break;
266 case FontDescription::NormalKerning:
267 features |= Kerning;
268 break;
269 case FontDescription::AutoKerning:
270 break;
271 }
272
273 switch (m_fontDescription.commonLigaturesState()) {
274 case FontDescription::DisabledLigaturesState:
275 features &= ~Ligatures;
276 break;
277 case FontDescription::EnabledLigaturesState:
278 features |= Ligatures;
279 break;
280 case FontDescription::NormalLigaturesState:
281 break;
282 }
283
284 return features;
285 }
286
287 static TypesettingFeatures s_defaultTypesettingFeatures;
288
289 FontDescription m_fontDescription;
290 mutable RefPtr<FontFallbackList> m_fontFallbackList;
291 float m_letterSpacing;
292 float m_wordSpacing;
293 bool m_isPlatformFont;
294 mutable unsigned m_typesettingFeatures : 2; // (TypesettingFeatures) Caches values computed from m_fontDescription.
295 };
296
~Font()297 inline Font::~Font()
298 {
299 }
300
primaryFont()301 inline const SimpleFontData* Font::primaryFont() const
302 {
303 ASSERT(m_fontFallbackList);
304 return m_fontFallbackList->primarySimpleFontData(m_fontDescription);
305 }
306
fontDataAt(unsigned index)307 inline const FontData* Font::fontDataAt(unsigned index) const
308 {
309 ASSERT(m_fontFallbackList);
310 return m_fontFallbackList->fontDataAt(m_fontDescription, index);
311 }
312
isFixedPitch()313 inline bool Font::isFixedPitch() const
314 {
315 ASSERT(m_fontFallbackList);
316 return m_fontFallbackList->isFixedPitch(m_fontDescription);
317 }
318
fontSelector()319 inline FontSelector* Font::fontSelector() const
320 {
321 return m_fontFallbackList ? m_fontFallbackList->fontSelector() : 0;
322 }
323
tabWidth(const SimpleFontData & fontData,unsigned tabSize,float position)324 inline float Font::tabWidth(const SimpleFontData& fontData, unsigned tabSize, float position) const
325 {
326 if (!tabSize)
327 return letterSpacing();
328 float tabWidth = tabSize * fontData.spaceWidth() + letterSpacing();
329 return tabWidth - fmodf(position, tabWidth);
330 }
331
332 }
333
334 namespace WTF {
335
336 template <> struct PLATFORM_EXPORT OwnedPtrDeleter<WebCore::TextLayout> {
337 static void deletePtr(WebCore::TextLayout*);
338 };
339
340 }
341
342 #endif
343