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1 /*
2  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
4  *           (C) 2000 Dirk Mueller (mueller@kde.org)
5  * Copyright (C) 2003, 2006 Apple Inc. All rights reserved.
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Library General Public
9  * License as published by the Free Software Foundation; either
10  * version 2 of the License, or (at your option) any later version.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Library General Public License for more details.
16  *
17  * You should have received a copy of the GNU Library General Public License
18  * along with this library; see the file COPYING.LIB.  If not, write to
19  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
20  * Boston, MA 02110-1301, USA.
21  *
22  */
23 
24 #include "config.h"
25 #include "Font.h"
26 
27 #include "FloatRect.h"
28 #include "FontCache.h"
29 #include "FontFallbackList.h"
30 #include "IntPoint.h"
31 #include "GlyphBuffer.h"
32 #include "WidthIterator.h"
33 #include <wtf/MathExtras.h>
34 #include <wtf/UnusedParam.h>
35 
36 using namespace WTF;
37 using namespace Unicode;
38 
39 namespace WebCore {
40 
41 #if USE(FONT_FAST_PATH)
42 const uint8_t Font::gRoundingHackCharacterTable[256] = {
43     0, 0, 0, 0, 0, 0, 0, 0, 0, 1 /*\t*/, 1 /*\n*/, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
44     1 /*space*/, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 /*-*/, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 /*?*/,
45     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
46     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
47     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
48     1 /*no-break space*/, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
49     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
50     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
51 };
52 
53 Font::CodePath Font::s_codePath = Auto;
54 #endif
55 
56 // ============================================================================================
57 // Font Implementation (Cross-Platform Portion)
58 // ============================================================================================
59 
Font()60 Font::Font()
61     : m_letterSpacing(0)
62     , m_wordSpacing(0)
63     , m_isPlatformFont(false)
64 {
65 }
66 
Font(const FontDescription & fd,short letterSpacing,short wordSpacing)67 Font::Font(const FontDescription& fd, short letterSpacing, short wordSpacing)
68     : m_fontDescription(fd)
69     , m_letterSpacing(letterSpacing)
70     , m_wordSpacing(wordSpacing)
71     , m_isPlatformFont(false)
72 {
73 }
74 
Font(const FontPlatformData & fontData,bool isPrinterFont)75 Font::Font(const FontPlatformData& fontData, bool isPrinterFont)
76     : m_fontList(FontFallbackList::create())
77     , m_letterSpacing(0)
78     , m_wordSpacing(0)
79     , m_isPlatformFont(true)
80 {
81     m_fontDescription.setUsePrinterFont(isPrinterFont);
82     m_fontList->setPlatformFont(fontData);
83 }
84 
Font(const Font & other)85 Font::Font(const Font& other)
86     : m_fontDescription(other.m_fontDescription)
87     , m_fontList(other.m_fontList)
88     , m_letterSpacing(other.m_letterSpacing)
89     , m_wordSpacing(other.m_wordSpacing)
90     , m_isPlatformFont(other.m_isPlatformFont)
91 {
92 }
93 
operator =(const Font & other)94 Font& Font::operator=(const Font& other)
95 {
96     m_fontDescription = other.m_fontDescription;
97     m_fontList = other.m_fontList;
98     m_letterSpacing = other.m_letterSpacing;
99     m_wordSpacing = other.m_wordSpacing;
100     m_isPlatformFont = other.m_isPlatformFont;
101     return *this;
102 }
103 
~Font()104 Font::~Font()
105 {
106 }
107 
operator ==(const Font & other) const108 bool Font::operator==(const Font& other) const
109 {
110     // Our FontData don't have to be checked, since checking the font description will be fine.
111     // FIXME: This does not work if the font was made with the FontPlatformData constructor.
112     if ((m_fontList && m_fontList->loadingCustomFonts()) ||
113         (other.m_fontList && other.m_fontList->loadingCustomFonts()))
114         return false;
115 
116     FontSelector* first = m_fontList ? m_fontList->fontSelector() : 0;
117     FontSelector* second = other.m_fontList ? other.m_fontList->fontSelector() : 0;
118 
119     return first == second
120            && m_fontDescription == other.m_fontDescription
121            && m_letterSpacing == other.m_letterSpacing
122            && m_wordSpacing == other.m_wordSpacing
123            && (m_fontList ? m_fontList->generation() : 0) == (other.m_fontList ? other.m_fontList->generation() : 0);
124 }
125 
primaryFont() const126 const SimpleFontData* Font::primaryFont() const
127 {
128     ASSERT(m_fontList);
129     return m_fontList->primarySimpleFontData(this);
130 }
131 
fontDataAt(unsigned index) const132 const FontData* Font::fontDataAt(unsigned index) const
133 {
134     ASSERT(m_fontList);
135     return m_fontList->fontDataAt(this, index);
136 }
137 
fontDataForCharacters(const UChar * characters,int length) const138 const FontData* Font::fontDataForCharacters(const UChar* characters, int length) const
139 {
140     ASSERT(m_fontList);
141     return m_fontList->fontDataForCharacters(this, characters, length);
142 }
143 
update(PassRefPtr<FontSelector> fontSelector) const144 void Font::update(PassRefPtr<FontSelector> fontSelector) const
145 {
146     // FIXME: It is pretty crazy that we are willing to just poke into a RefPtr, but it ends up
147     // being reasonably safe (because inherited fonts in the render tree pick up the new
148     // style anyway. Other copies are transient, e.g., the state in the GraphicsContext, and
149     // won't stick around long enough to get you in trouble). Still, this is pretty disgusting,
150     // and could eventually be rectified by using RefPtrs for Fonts themselves.
151     if (!m_fontList)
152         m_fontList = FontFallbackList::create();
153     m_fontList->invalidate(fontSelector);
154 }
155 
isFixedPitch() const156 bool Font::isFixedPitch() const
157 {
158     ASSERT(m_fontList);
159     return m_fontList->isFixedPitch(this);
160 }
161 
drawText(GraphicsContext * context,const TextRun & run,const FloatPoint & point,int from,int to) const162 void Font::drawText(GraphicsContext* context, const TextRun& run, const FloatPoint& point, int from, int to) const
163 {
164     // Don't draw anything while we are using custom fonts that are in the process of loading.
165     if (m_fontList && m_fontList->loadingCustomFonts())
166         return;
167 
168     to = (to == -1 ? run.length() : to);
169 
170 #if ENABLE(SVG_FONTS)
171     if (primaryFont()->isSVGFont()) {
172         drawTextUsingSVGFont(context, run, point, from, to);
173         return;
174     }
175 #endif
176 
177 #if USE(FONT_FAST_PATH)
178     if (canUseGlyphCache(run))
179         return drawSimpleText(context, run, point, from, to);
180 #endif
181 
182     return drawComplexText(context, run, point, from, to);
183 }
184 
floatWidth(const TextRun & run,HashSet<const SimpleFontData * > * fallbackFonts) const185 float Font::floatWidth(const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts) const
186 {
187 #if ENABLE(SVG_FONTS)
188     if (primaryFont()->isSVGFont())
189         return floatWidthUsingSVGFont(run);
190 #endif
191 
192 #if USE(FONT_FAST_PATH)
193     if (canUseGlyphCache(run)) {
194         // If the complex text implementation cannot return fallback fonts, avoid
195         // returning them for simple text as well.
196         static bool returnFallbackFonts = canReturnFallbackFontsForComplexText();
197         return floatWidthForSimpleText(run, 0, returnFallbackFonts ? fallbackFonts : 0);
198     }
199 #endif
200 
201     return floatWidthForComplexText(run, fallbackFonts);
202 }
203 
floatWidth(const TextRun & run,int extraCharsAvailable,int & charsConsumed,String & glyphName) const204 float Font::floatWidth(const TextRun& run, int extraCharsAvailable, int& charsConsumed, String& glyphName) const
205 {
206 #if !ENABLE(SVG_FONTS)
207     UNUSED_PARAM(extraCharsAvailable);
208 #else
209     if (primaryFont()->isSVGFont())
210         return floatWidthUsingSVGFont(run, extraCharsAvailable, charsConsumed, glyphName);
211 #endif
212 
213     charsConsumed = run.length();
214     glyphName = "";
215 
216 #if USE(FONT_FAST_PATH)
217     if (canUseGlyphCache(run))
218         return floatWidthForSimpleText(run, 0);
219 #endif
220 
221     return floatWidthForComplexText(run);
222 }
223 
selectionRectForText(const TextRun & run,const IntPoint & point,int h,int from,int to) const224 FloatRect Font::selectionRectForText(const TextRun& run, const IntPoint& point, int h, int from, int to) const
225 {
226 #if ENABLE(SVG_FONTS)
227     if (primaryFont()->isSVGFont())
228         return selectionRectForTextUsingSVGFont(run, point, h, from, to);
229 #endif
230 
231     to = (to == -1 ? run.length() : to);
232 
233 #if USE(FONT_FAST_PATH)
234     if (canUseGlyphCache(run))
235         return selectionRectForSimpleText(run, point, h, from, to);
236 #endif
237 
238     return selectionRectForComplexText(run, point, h, from, to);
239 }
240 
offsetForPosition(const TextRun & run,int x,bool includePartialGlyphs) const241 int Font::offsetForPosition(const TextRun& run, int x, bool includePartialGlyphs) const
242 {
243 #if ENABLE(SVG_FONTS)
244     if (primaryFont()->isSVGFont())
245         return offsetForPositionForTextUsingSVGFont(run, x, includePartialGlyphs);
246 #endif
247 
248 #if USE(FONT_FAST_PATH)
249     if (canUseGlyphCache(run))
250         return offsetForPositionForSimpleText(run, x, includePartialGlyphs);
251 #endif
252 
253     return offsetForPositionForComplexText(run, x, includePartialGlyphs);
254 }
255 
256 #if ENABLE(SVG_FONTS)
isSVGFont() const257 bool Font::isSVGFont() const
258 {
259     return primaryFont()->isSVGFont();
260 }
261 #endif
262 
fontSelector() const263 FontSelector* Font::fontSelector() const
264 {
265     return m_fontList ? m_fontList->fontSelector() : 0;
266 }
267 
normalizeSpaces(const String & string)268 String Font::normalizeSpaces(const String& string)
269 {
270     unsigned length = string.length();
271     Vector<UChar, 256> buffer(length);
272     bool didReplacement = false;
273 
274     for (unsigned i = 0; i < length; ++i) {
275         UChar originalCharacter = string[i];
276         buffer[i] = normalizeSpaces(originalCharacter);
277         if (buffer[i] != originalCharacter)
278             didReplacement = true;
279     }
280 
281     return didReplacement ? String(buffer.data(), length) : string;
282 }
283 
284 static bool shouldUseFontSmoothing = true;
285 
setShouldUseSmoothing(bool shouldUseSmoothing)286 void Font::setShouldUseSmoothing(bool shouldUseSmoothing)
287 {
288     ASSERT(isMainThread());
289     shouldUseFontSmoothing = shouldUseSmoothing;
290 }
291 
shouldUseSmoothing()292 bool Font::shouldUseSmoothing()
293 {
294     return shouldUseFontSmoothing;
295 }
296 
297 }
298