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      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 "third_party/skia/include/core/SkTypeface.h"
     39 #include "third_party/skia/include/ports/SkFontMgr.h"
     40 
     41 namespace blink {
     42 
     43 static AtomicString getFamilyNameForCharacter(UChar32 c, const FontDescription& fontDescription)
     44 {
     45     RefPtr<SkFontMgr> fm = adoptRef(SkFontMgr::RefDefault());
     46     const char* bcp47Locales[2];
     47     int localeCount = 0;
     48     CString defaultLocale = defaultLanguage().ascii();
     49     bcp47Locales[localeCount++] = defaultLocale.data();
     50     CString fontLocale;
     51     if (!fontDescription.locale().isEmpty()) {
     52         fontLocale = fontDescription.locale().ascii();
     53         bcp47Locales[localeCount++] = fontLocale.data();
     54     }
     55     RefPtr<SkTypeface> typeface = adoptRef(fm->matchFamilyStyleCharacter(0, SkFontStyle(), bcp47Locales, localeCount, c));
     56     if (!typeface)
     57         return emptyAtom;
     58 
     59     SkString skiaFamilyName;
     60     typeface->getFamilyName(&skiaFamilyName);
     61     return skiaFamilyName.c_str();
     62 }
     63 
     64 PassRefPtr<SimpleFontData> FontCache::fallbackFontForCharacter(const FontDescription& fontDescription, UChar32 c, const SimpleFontData*)
     65 {
     66     AtomicString familyName = getFamilyNameForCharacter(c, fontDescription);
     67     if (familyName.isEmpty())
     68         return getLastResortFallbackFont(fontDescription, DoNotRetain);
     69     return fontDataFromFontPlatformData(getFontPlatformData(fontDescription, FontFaceCreationParams(familyName)), DoNotRetain);
     70 }
     71 
     72 // static
     73 AtomicString FontCache::getGenericFamilyNameForScript(const AtomicString& familyName, const FontDescription& fontDescription)
     74 {
     75     // This is a hack to use the preferred font for CJK scripts.
     76     // FIXME: Use new Skia API once Android system supports per-family and per-script fallback fonts.
     77     UChar32 examplerChar;
     78     switch (fontDescription.script()) {
     79     case USCRIPT_SIMPLIFIED_HAN:
     80     case USCRIPT_TRADITIONAL_HAN:
     81     case USCRIPT_KATAKANA_OR_HIRAGANA:
     82         examplerChar = 0x4E00; // A common character in Japanese and Chinese.
     83         break;
     84     case USCRIPT_HANGUL:
     85         examplerChar = 0xAC00;
     86         break;
     87     default:
     88         // For other scripts, use the default generic family mapping logic.
     89         return familyName;
     90     }
     91 
     92     return getFamilyNameForCharacter(examplerChar, fontDescription);
     93 }
     94 
     95 } // namespace blink
     96