third_party/WebKit/Source/platform/fonts/android/FontCacheAndroid.cpp

   1 /*
   2  * Copyright (c) 2011 Google 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 are
   6  * met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  * copyright notice, this list of conditions and the following disclaimer
  12  * in the documentation and/or other materials provided with the
  13  * distribution.
  14  *     * Neither the name of Google Inc. nor the names of its
  15  * contributors may be used to endorse or promote products derived from
  16  * this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include "config.h"
  32 #include "platform/fonts/FontCache.h"
  33
  34 #include "platform/Language.h"
  35 #include "platform/fonts/SimpleFontData.h"
  36 #include "platform/fonts/FontDescription.h"
  37 #include "platform/fonts/FontFaceCreationParams.h"
  38 #include "platform/text/LocaleToScriptMapping.h"
  39 #include "third_party/skia/include/core/SkTypeface.h"
  40 #include "third_party/skia/include/ports/SkFontMgr.h"
  41
  42 namespace blink {
  43
  44 // SkFontMgr requires script-based locale names, like "zh-Hant" and "zh-Hans",
  45 // instead of "zh-CN" and "zh-TW".
  46 static CString toSkFontMgrLocale(const String& locale)
  47 {
  48     if (!locale.startsWith("zh", TextCaseInsensitive))
  49         return locale.ascii();
  50
  51     switch (localeToScriptCodeForFontSelection(locale)) {
  52     case USCRIPT_SIMPLIFIED_HAN:
  53         return "zh-Hans";
  54     case USCRIPT_TRADITIONAL_HAN:
  55         return "zh-Hant";
  56     default:
  57         return locale.ascii();
  58     }
  59 }
  60
  61 static AtomicString getFamilyNameForCharacter(UChar32 c, const FontDescription& fontDescription)
  62 {
  63     RefPtr<SkFontMgr> fm = adoptRef(SkFontMgr::RefDefault());
  64     const char* bcp47Locales[2];
  65     int localeCount = 0;
  66     CString defaultLocale = toSkFontMgrLocale(defaultLanguage());
  67     bcp47Locales[localeCount++] = defaultLocale.data();
  68     CString fontLocale;
  69     if (!fontDescription.locale().isEmpty()) {
  70         fontLocale = toSkFontMgrLocale(fontDescription.locale());
  71         bcp47Locales[localeCount++] = fontLocale.data();
  72     }
  73     RefPtr<SkTypeface> typeface = adoptRef(fm->matchFamilyStyleCharacter(0, SkFontStyle(), bcp47Locales, localeCount, c));
  74     if (!typeface)
  75         return emptyAtom;
  76
  77     SkString skiaFamilyName;
  78     typeface->getFamilyName(&skiaFamilyName);
  79     return skiaFamilyName.c_str();
  80 }
  81
  82 PassRefPtr<SimpleFontData> FontCache::fallbackFontForCharacter(const FontDescription& fontDescription, UChar32 c, const SimpleFontData*)
  83 {
  84     AtomicString familyName = getFamilyNameForCharacter(c, fontDescription);
  85     if (familyName.isEmpty())
  86         return getLastResortFallbackFont(fontDescription, DoNotRetain);
  87     return fontDataFromFontPlatformData(getFontPlatformData(fontDescription, FontFaceCreationParams(familyName)), DoNotRetain);
  88 }
  89
  90 // static
  91 AtomicString FontCache::getGenericFamilyNameForScript(const AtomicString& familyName, const FontDescription& fontDescription)
  92 {
  93     // This is a hack to use the preferred font for CJK scripts.
  94     // FIXME: Use new Skia API once Android system supports per-family and per-script fallback fonts.
  95     UChar32 examplerChar;
  96     switch (fontDescription.script()) {
  97     case USCRIPT_SIMPLIFIED_HAN:
  98     case USCRIPT_TRADITIONAL_HAN:
  99     case USCRIPT_KATAKANA_OR_HIRAGANA:
 100         examplerChar = 0x4E00; // A common character in Japanese and Chinese.
 101         break;
 102     case USCRIPT_HANGUL:
 103         examplerChar = 0xAC00;
 104         break;
 105     default:
 106         // For other scripts, use the default generic family mapping logic.
 107         return familyName;
 108     }
 109
 110     return getFamilyNameForCharacter(examplerChar, fontDescription);
 111 }
 112
 113 } // namespace blink