src/third_party/WebKit/Source/core/css/FontFaceCache.cpp

   1 /*
   2  * Copyright (C) 2007, 2008, 2011 Apple Inc. All rights reserved.
   3  * Copyright (C) 2013 Google Inc. All rights reserved.
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   6  * modification, are permitted provided that the following conditions
   7  * are met:
   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  *
  14  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
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  24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27
  28 #include "config.h"
  29 #include "core/css/FontFaceCache.h"
  30
  31 #include "core/css/CSSFontSelector.h"
  32 #include "core/css/CSSSegmentedFontFace.h"
  33 #include "core/css/CSSValueList.h"
  34 #include "core/css/FontFace.h"
  35 #include "core/css/StyleRule.h"
  36 #include "core/fetch/FontResource.h"
  37 #include "core/fetch/ResourceFetcher.h"
  38 #include "platform/FontFamilyNames.h"
  39 #include "platform/fonts/FontDescription.h"
  40 #include "wtf/text/AtomicString.h"
  41
  42 namespace blink {
  43
  44 FontFaceCache::FontFaceCache()
  45     : m_version(0)
  46 {
  47 }
  48
  49 void FontFaceCache::add(CSSFontSelector* cssFontSelector, const StyleRuleFontFace* fontFaceRule, PassRefPtrWillBeRawPtr<FontFace> prpFontFace)
  50 {
  51     RefPtrWillBeRawPtr<FontFace> fontFace = prpFontFace;
  52     if (!m_styleRuleToFontFace.add(fontFaceRule, fontFace).isNewEntry)
  53         return;
  54     addFontFace(cssFontSelector, fontFace, true);
  55 }
  56
  57 void FontFaceCache::addFontFace(CSSFontSelector* cssFontSelector, PassRefPtrWillBeRawPtr<FontFace> prpFontFace, bool cssConnected)
  58 {
  59     RefPtrWillBeRawPtr<FontFace> fontFace = prpFontFace;
  60
  61     FamilyToTraitsMap::AddResult traitsResult = m_fontFaces.add(fontFace->family(), nullptr);
  62     if (!traitsResult.storedValue->value)
  63         traitsResult.storedValue->value = adoptPtrWillBeNoop(new TraitsMap);
  64
  65     TraitsMap::AddResult segmentedFontFaceResult = traitsResult.storedValue->value->add(fontFace->traits().bitfield(), nullptr);
  66     if (!segmentedFontFaceResult.storedValue->value)
  67         segmentedFontFaceResult.storedValue->value = CSSSegmentedFontFace::create(cssFontSelector, fontFace->traits());
  68
  69     segmentedFontFaceResult.storedValue->value->addFontFace(fontFace, cssConnected);
  70     if (cssConnected)
  71         m_cssConnectedFontFaces.add(fontFace);
  72
  73     ++m_version;
  74 }
  75
  76 void FontFaceCache::remove(const StyleRuleFontFace* fontFaceRule)
  77 {
  78     StyleRuleToFontFace::iterator it = m_styleRuleToFontFace.find(fontFaceRule);
  79     if (it != m_styleRuleToFontFace.end()) {
  80         removeFontFace(it->value.get(), true);
  81         m_styleRuleToFontFace.remove(it);
  82     }
  83 }
  84
  85 void FontFaceCache::removeFontFace(FontFace* fontFace, bool cssConnected)
  86 {
  87     FamilyToTraitsMap::iterator fontFacesIter = m_fontFaces.find(fontFace->family());
  88     if (fontFacesIter == m_fontFaces.end())
  89         return;
  90     TraitsMap* familyFontFaces = fontFacesIter->value.get();
  91
  92     TraitsMap::iterator familyFontFacesIter = familyFontFaces->find(fontFace->traits().bitfield());
  93     if (familyFontFacesIter == familyFontFaces->end())
  94         return;
  95     RefPtrWillBeRawPtr<CSSSegmentedFontFace> segmentedFontFace = familyFontFacesIter->value;
  96
  97     segmentedFontFace->removeFontFace(fontFace);
  98     if (segmentedFontFace->isEmpty()) {
  99         familyFontFaces->remove(familyFontFacesIter);
 100         if (familyFontFaces->isEmpty())
 101             m_fontFaces.remove(fontFacesIter);
 102     }
 103     m_fonts.clear();
 104     if (cssConnected)
 105         m_cssConnectedFontFaces.remove(fontFace);
 106
 107     ++m_version;
 108 }
 109
 110 void FontFaceCache::clearCSSConnected()
 111 {
 112     for (StyleRuleToFontFace::iterator it = m_styleRuleToFontFace.begin(); it != m_styleRuleToFontFace.end(); ++it)
 113         removeFontFace(it->value.get(), true);
 114     m_styleRuleToFontFace.clear();
 115 }
 116
 117 void FontFaceCache::clearAll()
 118 {
 119     if (m_fontFaces.isEmpty())
 120         return;
 121
 122     m_fontFaces.clear();
 123     m_fonts.clear();
 124     m_styleRuleToFontFace.clear();
 125     m_cssConnectedFontFaces.clear();
 126     ++m_version;
 127 }
 128
 129 static inline bool compareFontFaces(CSSSegmentedFontFace* first, CSSSegmentedFontFace* second, FontTraits desiredTraits)
 130 {
 131     const FontTraits& firstTraits = first->traits();
 132     const FontTraits& secondTraits = second->traits();
 133
 134     bool firstHasDesiredVariant = firstTraits.variant() == desiredTraits.variant();
 135     bool secondHasDesiredVariant = secondTraits.variant() == desiredTraits.variant();
 136
 137     if (firstHasDesiredVariant != secondHasDesiredVariant)
 138         return firstHasDesiredVariant;
 139
 140     // We need to check font-variant css property for CSS2.1 compatibility.
 141     if (desiredTraits.variant() == FontVariantSmallCaps) {
 142         // Prefer a font that has indicated that it can only support small-caps to a font that claims to support
 143         // all variants. The specialized font is more likely to be true small-caps and not require synthesis.
 144         bool firstRequiresSmallCaps = firstTraits.variant() == FontVariantSmallCaps;
 145         bool secondRequiresSmallCaps = secondTraits.variant() == FontVariantSmallCaps;
 146         if (firstRequiresSmallCaps != secondRequiresSmallCaps)
 147             return firstRequiresSmallCaps;
 148     }
 149
 150     bool firstHasDesiredStyle = firstTraits.style() == desiredTraits.style();
 151     bool secondHasDesiredStyle = secondTraits.style() == desiredTraits.style();
 152
 153     if (firstHasDesiredStyle != secondHasDesiredStyle)
 154         return firstHasDesiredStyle;
 155
 156     if (desiredTraits.style() == FontStyleItalic) {
 157         // Prefer a font that has indicated that it can only support italics to a font that claims to support
 158         // all styles. The specialized font is more likely to be the one the author wants used.
 159         bool firstRequiresItalics = firstTraits.style() == FontStyleItalic;
 160         bool secondRequiresItalics = secondTraits.style() == FontStyleItalic;
 161         if (firstRequiresItalics != secondRequiresItalics)
 162             return firstRequiresItalics;
 163     }
 164     if (secondTraits.weight() == desiredTraits.weight())
 165         return false;
 166
 167     if (firstTraits.weight() == desiredTraits.weight())
 168         return true;
 169
 170     // http://www.w3.org/TR/2011/WD-css3-fonts-20111004/#font-matching-algorithm says :
 171     //   - If the desired weight is less than 400, weights below the desired weight are checked in descending order followed by weights above the desired weight in ascending order until a match is found.
 172     //   - If the desired weight is greater than 500, weights above the desired weight are checked in ascending order followed by weights below the desired weight in descending order until a match is found.
 173     //   - If the desired weight is 400, 500 is checked first and then the rule for desired weights less than 400 is used.
 174     //   - If the desired weight is 500, 400 is checked first and then the rule for desired weights less than 400 is used.
 175     static const unsigned fallbackRuleSets = 9;
 176     static const unsigned rulesPerSet = 8;
 177     static const FontWeight weightFallbackRuleSets[fallbackRuleSets][rulesPerSet] = {
 178         { FontWeight200, FontWeight300, FontWeight400, FontWeight500, FontWeight600, FontWeight700, FontWeight800, FontWeight900 },
 179         { FontWeight100, FontWeight300, FontWeight400, FontWeight500, FontWeight600, FontWeight700, FontWeight800, FontWeight900 },
 180         { FontWeight200, FontWeight100, FontWeight400, FontWeight500, FontWeight600, FontWeight700, FontWeight800, FontWeight900 },
 181         { FontWeight500, FontWeight300, FontWeight200, FontWeight100, FontWeight600, FontWeight700, FontWeight800, FontWeight900 },
 182         { FontWeight400, FontWeight300, FontWeight200, FontWeight100, FontWeight600, FontWeight700, FontWeight800, FontWeight900 },
 183         { FontWeight700, FontWeight800, FontWeight900, FontWeight500, FontWeight400, FontWeight300, FontWeight200, FontWeight100 },
 184         { FontWeight800, FontWeight900, FontWeight600, FontWeight500, FontWeight400, FontWeight300, FontWeight200, FontWeight100 },
 185         { FontWeight900, FontWeight700, FontWeight600, FontWeight500, FontWeight400, FontWeight300, FontWeight200, FontWeight100 },
 186         { FontWeight800, FontWeight700, FontWeight600, FontWeight500, FontWeight400, FontWeight300, FontWeight200, FontWeight100 }
 187     };
 188
 189     unsigned ruleSetIndex = static_cast<unsigned>(desiredTraits.weight());
 190     ASSERT(ruleSetIndex < fallbackRuleSets);
 191     const FontWeight* weightFallbackRule = weightFallbackRuleSets[ruleSetIndex];
 192     for (unsigned i = 0; i < rulesPerSet; ++i) {
 193         if (secondTraits.weight() == weightFallbackRule[i])
 194             return false;
 195         if (firstTraits.weight() == weightFallbackRule[i])
 196             return true;
 197     }
 198
 199     return false;
 200 }
 201
 202 CSSSegmentedFontFace* FontFaceCache::get(const FontDescription& fontDescription, const AtomicString& family)
 203 {
 204     TraitsMap* familyFontFaces = m_fontFaces.get(family);
 205     if (!familyFontFaces || familyFontFaces->isEmpty())
 206         return 0;
 207
 208     FamilyToTraitsMap::AddResult traitsResult = m_fonts.add(family, nullptr);
 209     if (!traitsResult.storedValue->value)
 210         traitsResult.storedValue->value = adoptPtrWillBeNoop(new TraitsMap);
 211
 212     FontTraits traits = fontDescription.traits();
 213     TraitsMap::AddResult faceResult = traitsResult.storedValue->value->add(traits.bitfield(), nullptr);
 214     if (!faceResult.storedValue->value) {
 215         for (TraitsMap::const_iterator i = familyFontFaces->begin(); i != familyFontFaces->end(); ++i) {
 216             CSSSegmentedFontFace* candidate = i->value.get();
 217             FontTraits candidateTraits = candidate->traits();
 218             if (traits.style() == FontStyleNormal && candidateTraits.style() != FontStyleNormal)
 219                 continue;
 220             if (traits.variant() == FontVariantNormal && candidateTraits.variant() != FontVariantNormal)
 221                 continue;
 222             if (!faceResult.storedValue->value || compareFontFaces(candidate, faceResult.storedValue->value.get(), traits))
 223                 faceResult.storedValue->value = candidate;
 224         }
 225     }
 226     return faceResult.storedValue->value.get();
 227 }
 228
 229 void FontFaceCache::trace(Visitor* visitor)
 230 {
 231 #if ENABLE(OILPAN)
 232     visitor->trace(m_fontFaces);
 233     visitor->trace(m_fonts);
 234     visitor->trace(m_styleRuleToFontFace);
 235     visitor->trace(m_cssConnectedFontFaces);
 236 #endif
 237 }
 238
 239 }