blink fonts: Load Android SkFontMgr on Linux.

third_party/WebKit/Source/platform/fonts/skia/FontCacheSkia.cpp

 /*
  * Copyright (c) 2006, 2007, 2008, 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 13 matching lines @@
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "SkFontMgr.h"
 #include "SkStream.h"
 #include "SkTypeface.h"
+#include "platform/Language.h"
 #include "platform/fonts/AlternateFontFamily.h"
 #include "platform/fonts/FontCache.h"
 #include "platform/fonts/FontDescription.h"
 #include "platform/fonts/FontFaceCreationParams.h"
 #include "platform/fonts/SimpleFontData.h"
 #include "public/platform/Platform.h"
 #include "public/platform/linux/WebSandboxSupport.h"
 #include "wtf/Assertions.h"
 #include "wtf/text/AtomicString.h"
 #include "wtf/text/CString.h"
@@ skipping 36 matching lines @@
     SkAutoTUnref<SkFontConfigInterface> fci(SkFontConfigInterface::RefGlobal());
     SkFontConfigInterface::FontIdentity fontIdentity;
     fontIdentity.fID = fontconfigInterfaceId;
     fontIdentity.fTTCIndex = ttcIndex;
     return adoptRef(fci->createTypeface(fontIdentity));
 }
 #endif
 
 namespace blink {
 
+// SkFontMgr requires script-based locale names, like "zh-Hant" and "zh-Hans",
+// instead of "zh-CN" and "zh-TW".
+static CString toSkFontMgrLocale(const String& locale)
+{
+    if (!locale.startsWith("zh", TextCaseInsensitive))
+        return locale.ascii();
+
+    switch (localeToScriptCodeForFontSelection(locale)) {
+    case USCRIPT_SIMPLIFIED_HAN:
+        return "zh-Hans";
+    case USCRIPT_TRADITIONAL_HAN:
+        return "zh-Hant";
+    default:
+        return locale.ascii();
+    }
+}
+
+
+#if OS(ANDROID) || OS(LINUX)
+// This function is called on android or when we are emulating android fonts on linux and the
+// embedder has overriden the default fontManager with WebFontRendering::setSkiaFontMgr.
+// static
+AtomicString FontCache::getFamilyNameForCharacter(SkFontMgr* fm, UChar32 c, const FontDescription& fontDescription)
+{
+    ASSERT(fm);
+
+    const char* bcp47Locales[2];
+    int localeCount = 0;
+    CString defaultLocale = toSkFontMgrLocale(defaultLanguage());
+    bcp47Locales[localeCount++] = defaultLocale.data();
+    CString fontLocale;
+    if (!fontDescription.locale().isEmpty()) {
+        fontLocale = toSkFontMgrLocale(fontDescription.locale());
+        bcp47Locales[localeCount++] = fontLocale.data();
+    }
+    RefPtr<SkTypeface> typeface = adoptRef(fm->matchFamilyStyleCharacter(0, SkFontStyle(), bcp47Locales, localeCount, c));
+    if (!typeface)
+        return emptyAtom;
+
+    SkString skiaFamilyName;
+    typeface->getFamilyName(&skiaFamilyName);
+    return skiaFamilyName.c_str();
+}
+#endif
+
 void FontCache::platformInit()
 {
 }
 
 PassRefPtr<SimpleFontData> FontCache::fallbackOnStandardFontStyle(
     const FontDescription& fontDescription, UChar32 character)
 {
     FontDescription substituteDescription(fontDescription);
     substituteDescription.setStyle(FontStyleNormal);
     substituteDescription.setWeight(FontWeightNormal);
 
     FontFaceCreationParams creationParams(substituteDescription.family().family());
     FontPlatformData* substitutePlatformData = getFontPlatformData(substituteDescription, creationParams);
     if (substitutePlatformData && substitutePlatformData->fontContainsCharacter(character)) {
         FontPlatformData platformData = FontPlatformData(*substitutePlatformData);
         platformData.setSyntheticBold(fontDescription.weight() >= FontWeight600);
         platformData.setSyntheticItalic(fontDescription.style() == FontStyleItalic || fontDescription.style() == FontStyleOblique);
         return fontDataFromFontPlatformData(&platformData, DoNotRetain);
     }
 
     return nullptr;
 }
 
 #if !OS(WIN) && !OS(ANDROID)
 PassRefPtr<SimpleFontData> FontCache::fallbackFontForCharacter(const FontDescription& fontDescription, UChar32 c, const SimpleFontData*)
 {
+#if OS(LINUX)
+    // On linux the m_fontManager is set only if it was provided by the embedder with WebFontRendering::setSkiaFontManager. This is
+    // used to emulate android fonts so we always request the family from the font manager and if none is found, we return
+    // the LastResort fallback font and avoid using FontCache::getFontForCharacter which would use sandbox support to
+    // query the underlying system for the font family.
+    if (m_fontManager) {
+        AtomicString familyName = getFamilyNameForCharacter(m_fontManager.get(), c, fontDescription);
+        if (familyName.isEmpty())
+            return getLastResortFallbackFont(fontDescription, DoNotRetain);
+        return fontDataFromFontPlatformData(getFontPlatformData(fontDescription, FontFaceCreationParams(familyName)), DoNotRetain);
+    }
+#endif
+
     // First try the specified font with standard style & weight.
     if (fontDescription.style() == FontStyleItalic
         || fontDescription.weight() >= FontWeight600) {
         RefPtr<SimpleFontData> fontData = fallbackOnStandardFontStyle(
             fontDescription, c);
         if (fontData)
             return fontData;
     }
 
     FontCache::PlatformFallbackFont fallbackFont;
@@ skipping 144 matching lines @@
     }
 
     if (m_fontManager) {
         return adoptRef(useDirectWrite()
             ? m_fontManager->matchFamilyStyle(name.data(), fontStyle(fontDescription))
             : m_fontManager->legacyCreateTypeface(name.data(), style)
             );
     }
 #endif
 
+#if OS(LINUX)
+    // On linux if the fontManager has been overridden then we should be calling the embedder
+    // provided font Manager rather than calling SkTypeface::CreateFromName which may redirect the
+    // call to the default font Manager.
+    if (m_fontManager)
+        return adoptRef(m_fontManager->legacyCreateTypeface(name.data(), style));
+#endif
+
     // FIXME: Use m_fontManager, SkFontStyle and matchFamilyStyle instead of
     // CreateFromName on all platforms.
     return adoptRef(SkTypeface::CreateFromName(name.data(), static_cast<SkTypeface::Style>(style)));
 }
 
 #if !OS(WIN)
 PassOwnPtr<FontPlatformData> FontCache::createFontPlatformData(const FontDescription& fontDescription,
     const FontFaceCreationParams& creationParams, float fontSize)
 {
     CString name;
     RefPtr<SkTypeface> tf(createTypeface(fontDescription, creationParams, name));
     if (!tf)
         return nullptr;
 
     return adoptPtr(new FontPlatformData(tf,
         name.data(),
         fontSize,
         (fontDescription.weight() >= FontWeight600 && !tf->isBold()) || fontDescription.isSyntheticBold(),
         ((fontDescription.style() == FontStyleItalic || fontDescription.style() == FontStyleOblique) && !tf->isItalic()) || fontDescription.isSyntheticItalic(),
         fontDescription.orientation(),
         fontDescription.useSubpixelPositioning()));
 }
 #endif // !OS(WIN)
 
 } // namespace blink