1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "chrome/browser/font_family_cache.h" 6 7 #include <map> 8 9 #include "base/prefs/pref_service.h" 10 #include "base/strings/stringprintf.h" 11 #include "base/strings/utf_string_conversions.h" 12 #include "chrome/browser/chrome_notification_types.h" 13 #include "chrome/browser/profiles/profile.h" 14 #include "chrome/common/pref_font_webkit_names.h" 15 #include "chrome/common/pref_names.h" 16 #include "content/public/browser/notification_source.h" 17 18 // Identifies the user data on the profile. 19 const char kFontFamilyCacheKey[] = "FontFamilyCacheKey"; 20 21 FontFamilyCache::FontFamilyCache(Profile* profile) 22 : prefs_(profile->GetPrefs()) { 23 profile_pref_registrar_.Init(profile->GetPrefs()); 24 notification_registrar_.Add(this, 25 chrome::NOTIFICATION_PROFILE_DESTROYED, 26 content::Source<Profile>(profile)); 27 } 28 29 FontFamilyCache::~FontFamilyCache() { 30 } 31 32 void FontFamilyCache::FillFontFamilyMap(Profile* profile, 33 const char* map_name, 34 content::ScriptFontFamilyMap* map) { 35 FontFamilyCache* cache = 36 static_cast<FontFamilyCache*>(profile->GetUserData(&kFontFamilyCacheKey)); 37 if (!cache) { 38 cache = new FontFamilyCache(profile); 39 // The profile takes ownership of |cache|. 40 profile->SetUserData(&kFontFamilyCacheKey, cache); 41 } 42 43 cache->FillFontFamilyMap(map_name, map); 44 } 45 46 void FontFamilyCache::FillFontFamilyMap(const char* map_name, 47 content::ScriptFontFamilyMap* map) { 48 // TODO(falken): Get rid of the brute-force scan over possible 49 // (font family / script) combinations - see http://crbug.com/308095. 50 for (size_t i = 0; i < prefs::kWebKitScriptsForFontFamilyMapsLength; ++i) { 51 const char* script = prefs::kWebKitScriptsForFontFamilyMaps[i]; 52 base::string16 result = FetchAndCacheFont(script, map_name); 53 if (!result.empty()) 54 (*map)[script] = result; 55 } 56 } 57 58 base::string16 FontFamilyCache::FetchFont(const char* script, 59 const char* map_name) { 60 std::string pref_name = base::StringPrintf("%s.%s", map_name, script); 61 std::string font = prefs_->GetString(pref_name.c_str()); 62 base::string16 font16 = base::UTF8ToUTF16(font); 63 64 // Lazily constructs the map if it doesn't already exist. 65 ScriptFontMap& map = font_family_map_[map_name]; 66 map[script] = font16; 67 68 // Register for profile preference changes. 69 profile_pref_registrar_.Add( 70 pref_name.c_str(), 71 base::Bind(&FontFamilyCache::OnPrefsChanged, base::Unretained(this))); 72 return font16; 73 } 74 75 base::string16 FontFamilyCache::FetchAndCacheFont(const char* script, 76 const char* map_name) { 77 FontFamilyMap::const_iterator it = font_family_map_.find(map_name); 78 if (it != font_family_map_.end()) { 79 ScriptFontMap::const_iterator it2 = it->second.find(script); 80 if (it2 != it->second.end()) 81 return it2->second; 82 } 83 84 return FetchFont(script, map_name); 85 } 86 87 // There are ~1000 entries in the cache. Avoid unnecessary object construction, 88 // including std::string. 89 void FontFamilyCache::OnPrefsChanged(const std::string& pref_name) { 90 const size_t delimiter_length = 1; 91 const char delimiter = '.'; 92 for (FontFamilyMap::iterator it = font_family_map_.begin(); 93 it != font_family_map_.end(); 94 ++it) { 95 const char* map_name = it->first; 96 size_t map_name_length = strlen(map_name); 97 98 // If the map name doesn't match, move on. 99 if (pref_name.compare(0, map_name_length, map_name) != 0) 100 continue; 101 102 ScriptFontMap& map = it->second; 103 for (ScriptFontMap::iterator it2 = map.begin(); it2 != map.end(); ++it2) { 104 const char* script = it2->first; 105 size_t script_length = strlen(script); 106 107 // If the length doesn't match, move on. 108 if (pref_name.size() != 109 map_name_length + script_length + delimiter_length) 110 continue; 111 112 // If the script doesn't match, move on. 113 if (pref_name.compare( 114 map_name_length + delimiter_length, script_length, script) != 0) 115 continue; 116 117 // If the delimiter doesn't match, move on. 118 if (pref_name[map_name_length] != delimiter) 119 continue; 120 121 // Clear the cache and the observer. 122 map.erase(it2); 123 profile_pref_registrar_.Remove(pref_name.c_str()); 124 break; 125 } 126 } 127 } 128 129 void FontFamilyCache::Observe(int type, 130 const content::NotificationSource& source, 131 const content::NotificationDetails& details) { 132 DCHECK_EQ(chrome::NOTIFICATION_PROFILE_DESTROYED, type); 133 profile_pref_registrar_.RemoveAll(); 134 } 135