1 /*
2 * Copyright (C) 2006 Apple Computer, Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
14 * its contributors may be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include "config.h"
30 #include "platform/fonts/FontFallbackList.h"
31
32 #include "platform/FontFamilyNames.h"
33 #include "platform/fonts/FontCache.h"
34 #include "platform/fonts/FontDescription.h"
35 #include "platform/fonts/FontFamily.h"
36 #include "platform/fonts/SegmentedFontData.h"
37
38 namespace WebCore {
39
FontFallbackList()40 FontFallbackList::FontFallbackList()
41 : m_pageZero(0)
42 , m_cachedPrimarySimpleFontData(0)
43 , m_fontSelector(nullptr)
44 , m_fontSelectorVersion(0)
45 , m_familyIndex(0)
46 , m_generation(FontCache::fontCache()->generation())
47 , m_pitch(UnknownPitch)
48 , m_hasLoadingFallback(false)
49 {
50 }
51
invalidate(PassRefPtrWillBeRawPtr<FontSelector> fontSelector)52 void FontFallbackList::invalidate(PassRefPtrWillBeRawPtr<FontSelector> fontSelector)
53 {
54 releaseFontData();
55 m_fontList.clear();
56 m_pageZero = 0;
57 m_pages.clear();
58 m_cachedPrimarySimpleFontData = 0;
59 m_familyIndex = 0;
60 m_pitch = UnknownPitch;
61 m_hasLoadingFallback = false;
62 m_fontSelector = fontSelector;
63 m_fontSelectorVersion = m_fontSelector ? m_fontSelector->version() : 0;
64 m_generation = FontCache::fontCache()->generation();
65 m_widthCache.clear();
66 }
67
releaseFontData()68 void FontFallbackList::releaseFontData()
69 {
70 unsigned numFonts = m_fontList.size();
71 for (unsigned i = 0; i < numFonts; ++i) {
72 if (!m_fontList[i]->isCustomFont()) {
73 ASSERT(!m_fontList[i]->isSegmented());
74 FontCache::fontCache()->releaseFontData(static_cast<const SimpleFontData*>(m_fontList[i].get()));
75 }
76 }
77 }
78
determinePitch(const FontDescription & fontDescription) const79 void FontFallbackList::determinePitch(const FontDescription& fontDescription) const
80 {
81 const FontData* fontData = primaryFontData(fontDescription);
82 if (!fontData->isSegmented())
83 m_pitch = static_cast<const SimpleFontData*>(fontData)->pitch();
84 else {
85 const SegmentedFontData* segmentedFontData = static_cast<const SegmentedFontData*>(fontData);
86 unsigned numRanges = segmentedFontData->numRanges();
87 if (numRanges == 1 && segmentedFontData->rangeAt(0).isEntireRange())
88 m_pitch = segmentedFontData->rangeAt(0).fontData()->pitch();
89 else
90 m_pitch = VariablePitch;
91 }
92 }
93
loadingCustomFonts() const94 bool FontFallbackList::loadingCustomFonts() const
95 {
96 if (!m_hasLoadingFallback)
97 return false;
98
99 unsigned numFonts = m_fontList.size();
100 for (unsigned i = 0; i < numFonts; ++i) {
101 if (m_fontList[i]->isLoading())
102 return true;
103 }
104 return false;
105 }
106
shouldSkipDrawing() const107 bool FontFallbackList::shouldSkipDrawing() const
108 {
109 if (!m_hasLoadingFallback)
110 return false;
111
112 unsigned numFonts = m_fontList.size();
113 for (unsigned i = 0; i < numFonts; ++i) {
114 if (m_fontList[i]->shouldSkipDrawing())
115 return true;
116 }
117 return false;
118 }
119
primaryFontData(const FontDescription & fontDescription) const120 const FontData* FontFallbackList::primaryFontData(const FontDescription& fontDescription) const
121 {
122 bool shouldLoadCustomFont = true;
123
124 for (unsigned fontIndex = 0; ; ++fontIndex) {
125 const FontData* fontData = fontDataAt(fontDescription, fontIndex);
126 if (!fontData) {
127 // All fonts are custom fonts and are loading. Return the first FontData.
128 fontData = fontDataAt(fontDescription, 0);
129 if (fontData)
130 return fontData->fontDataForCharacter(' ');
131
132 SimpleFontData* lastResortFallback = FontCache::fontCache()->getLastResortFallbackFont(fontDescription).get();
133 ASSERT(lastResortFallback);
134 return lastResortFallback;
135 }
136
137 if (fontData->isSegmented() && !toSegmentedFontData(fontData)->containsCharacter(' '))
138 continue;
139
140 const SimpleFontData* simpleFontData = fontData->fontDataForCharacter(' ');
141 ASSERT(simpleFontData);
142
143 // When a custom font is loading, we should use the correct fallback font to layout the text.
144 // Here skip the temporary font for the loading custom font which may not act as the correct fallback font.
145 if (!simpleFontData->isLoadingFallback())
146 return fontData;
147
148 // Begin to load the first custom font if needed.
149 if (shouldLoadCustomFont) {
150 shouldLoadCustomFont = false;
151 simpleFontData->customFontData()->beginLoadIfNeeded();
152 }
153 }
154 }
155
getFontData(const FontDescription & fontDescription,int & familyIndex) const156 PassRefPtr<FontData> FontFallbackList::getFontData(const FontDescription& fontDescription, int& familyIndex) const
157 {
158 RefPtr<FontData> result;
159
160 int startIndex = familyIndex;
161 const FontFamily* startFamily = &fontDescription.family();
162 for (int i = 0; startFamily && i < startIndex; i++)
163 startFamily = startFamily->next();
164 const FontFamily* currFamily = startFamily;
165 while (currFamily && !result) {
166 familyIndex++;
167 if (currFamily->family().length()) {
168 if (m_fontSelector)
169 result = m_fontSelector->getFontData(fontDescription, currFamily->family());
170
171 if (!result)
172 result = FontCache::fontCache()->getFontData(fontDescription, currFamily->family());
173 }
174 currFamily = currFamily->next();
175 }
176
177 if (!currFamily)
178 familyIndex = cAllFamiliesScanned;
179
180 if (result || startIndex)
181 return result.release();
182
183 // If it's the primary font that we couldn't find, we try the following. In all other cases, we will
184 // just use per-character system fallback.
185
186 if (m_fontSelector) {
187 // Try the user's preferred standard font.
188 if (RefPtr<FontData> data = m_fontSelector->getFontData(fontDescription, FontFamilyNames::webkit_standard))
189 return data.release();
190 }
191
192 // Still no result. Hand back our last resort fallback font.
193 return FontCache::fontCache()->getLastResortFallbackFont(fontDescription);
194 }
195
196
fontDataAt(const FontDescription & fontDescription,unsigned realizedFontIndex) const197 const FontData* FontFallbackList::fontDataAt(const FontDescription& fontDescription, unsigned realizedFontIndex) const
198 {
199 if (realizedFontIndex < m_fontList.size())
200 return m_fontList[realizedFontIndex].get(); // This fallback font is already in our list.
201
202 // Make sure we're not passing in some crazy value here.
203 ASSERT(realizedFontIndex == m_fontList.size());
204
205 if (m_familyIndex == cAllFamiliesScanned)
206 return 0;
207
208 // Ask the font cache for the font data.
209 // We are obtaining this font for the first time. We keep track of the families we've looked at before
210 // in |m_familyIndex|, so that we never scan the same spot in the list twice. getFontData will adjust our
211 // |m_familyIndex| as it scans for the right font to make.
212 ASSERT(FontCache::fontCache()->generation() == m_generation);
213 RefPtr<FontData> result = getFontData(fontDescription, m_familyIndex);
214 if (result) {
215 m_fontList.append(result);
216 if (result->isLoadingFallback())
217 m_hasLoadingFallback = true;
218 }
219 return result.get();
220 }
221
222 }
223