Fix multi-font ttc rendering for iOS (flutter#3418)

Merged iOS and Android font fallback mechanisms and push font discovery logic into skia

sky/engine/platform/BUILD.gn

@@ -264,17 +264,12 @@ source_set("platform") {
     sources += [ "fonts/apple/FontPlatformDataApple.cpp" ]
   }
 
-  if (is_ios) {
-    deps += [ "//base" ]
-    sources += [ "fonts/apple/FontCacheIOS.mm" ]
-  }
-
   if (is_mac && !is_ios) {
     sources += [ "fonts/apple/FontCacheMac.cpp" ]
   }
 
-  if (is_android) {
-    sources += [ "fonts/android/FontCacheAndroid.cpp" ]
+  if (is_android || is_ios) {
+    sources += [ "fonts/mobile/FontCacheMobile.cpp" ]
   }
 
   if (is_linux && !is_android) {

sky/engine/platform/fonts/FontCache.h

@@ -94,9 +94,7 @@ class PLATFORM_EXPORT FontCache {
     PassRefPtr<OpenTypeVerticalData> getVerticalData(const FontFileKey&, const FontPlatformData&);
 #endif
 
-#if OS(ANDROID)
-    static AtomicString getGenericFamilyNameForScript(const AtomicString& familyName, const FontDescription&);
-#else
+#if !OS(ANDROID) && !OS(IOS)
     struct PlatformFallbackFont {
         String name;
         CString filename;

sky/engine/platform/fonts/android/FontCacheAndroid.cpp → sky/engine/platform/fonts/mobile/FontCacheMobile.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011 Google Inc. All rights reserved.
+ * Copyright (c) 2017 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
@@ -34,21 +34,38 @@
 #include "flutter/sky/engine/platform/fonts/FontDescription.h"
 #include "flutter/sky/engine/platform/fonts/FontFaceCreationParams.h"
 #include "flutter/sky/engine/platform/fonts/SimpleFontData.h"
+#include "flutter/sky/engine/platform/text/LocaleToScriptMapping.h"
 #include "third_party/skia/include/core/SkTypeface.h"
 #include "third_party/skia/include/ports/SkFontMgr.h"
 
 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();
+    }
+}
+
 static AtomicString getFamilyNameForCharacter(UChar32 c, const FontDescription& fontDescription)
 {
     sk_sp<SkFontMgr> fm(SkFontMgr::RefDefault());
     const char* bcp47Locales[2];
     int localeCount = 0;
-    CString defaultLocale = defaultLanguage().ascii();
+    CString defaultLocale = toSkFontMgrLocale(defaultLanguage());
     bcp47Locales[localeCount++] = defaultLocale.data();
     CString fontLocale;
     if (!fontDescription.locale().isEmpty()) {
-        fontLocale = fontDescription.locale().ascii();
+        fontLocale = toSkFontMgrLocale(fontDescription.locale());
         bcp47Locales[localeCount++] = fontLocale.data();
     }
     sk_sp<SkTypeface> typeface(fm->matchFamilyStyleCharacter(0, SkFontStyle(), bcp47Locales, localeCount, c));
@@ -68,27 +85,4 @@ PassRefPtr<SimpleFontData> FontCache::fallbackFontForCharacter(const FontDescrip
     return fontDataFromFontPlatformData(getFontPlatformData(fontDescription, FontFaceCreationParams(familyName)), DoNotRetain);
 }
 
-// static
-AtomicString FontCache::getGenericFamilyNameForScript(const AtomicString& familyName, const FontDescription& fontDescription)
-{
-    // This is a hack to use the preferred font for CJK scripts.
-    // FIXME: Use new Skia API once Android system supports per-family and per-script fallback fonts.
-    UChar32 examplerChar;
-    switch (fontDescription.script()) {
-    case USCRIPT_SIMPLIFIED_HAN:
-    case USCRIPT_TRADITIONAL_HAN:
-    case USCRIPT_KATAKANA_OR_HIRAGANA:
-        examplerChar = 0x4E00; // A common character in Japanese and Chinese.
-        break;
-    case USCRIPT_HANGUL:
-        examplerChar = 0xAC00;
-        break;
-    default:
-        // For other scripts, use the default generic family mapping logic.
-        return familyName;
-    }
-
-    return getFamilyNameForCharacter(examplerChar, fontDescription);
-}
-
 } // namespace blink

sky/engine/platform/fonts/android/FontCacheAndroidTest.cpp → sky/engine/platform/fonts/mobile/FontCacheMobileTest.cpp

@@ -9,7 +9,7 @@
 
 namespace blink {
 
-TEST(FontCacheAndroid, fallbackFontForCharacter)
+TEST(FontCacheMobile, fallbackFontForCharacter)
 {
     // A Latin character in the common locale system font, but not in the
     // Chinese locale-preferred font.

sky/engine/platform/fonts/skia/FontCacheSkia.cpp

@@ -129,7 +129,7 @@ PassRefPtr<SimpleFontData> FontCache::fallbackOnStandardFontStyle(
     return nullptr;
 }
 
-#if !OS(WIN) && !OS(ANDROID)
+#if !OS(WIN) && !OS(ANDROID) && !OS(IOS)
 PassRefPtr<SimpleFontData> FontCache::fallbackFontForCharacter(const FontDescription& fontDescription, UChar32 c, const SimpleFontData*)
 {
     // First try the specified font with standard style & weight.

sky/packages/sky_engine/LICENSE

@@ -9053,6 +9053,36 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 --------------------------------------------------------------------------------
 engine
 
+Copyright (c) 2017 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
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+    * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+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.
+--------------------------------------------------------------------------------
+engine
+
 Copyright 2017 The Chromium Authors. All rights reserved.
 
 Redistribution and use in source and binary forms, with or without