DO NOT MERGE Han Preference

Cherry-pick Id8c91ae0be6cad8a7ef77a0cd5803676290986c1 from master.

During font initialization, create a seperate fallback list for each
locale. At runtime, use the fallbacklist associated with the locale
set in the paint object. Fallback files are associated with locales in
fallback_fonts.xml. Multiple files can be associated with the same
locale, ordering within that langauge and apart from that language in
the fallback order is preserved.

This changelist also includes some refactoring, notably of the
functions that call getNextContext().

Change-Id: I121f0e491a522c4a8558a0066b2d8969fb8a3667

3 files changed, 90 insertions, 17 deletions

diff --git a/include/core/SkLanguage.h b/include/core/SkLanguage.h
new file mode 100644
index 0000000..923008e
--- /dev/null
+++ b/include/core/SkLanguage.h
@@ -0,0 +1,70 @@
+
+/*
+ * Copyright 2012 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#ifndef SkLanguage_DEFINED
+#define SkLanguage_DEFINED
+
+#include "SkTypes.h"
+
+#ifdef SK_BUILD_FOR_ANDROID
+
+#include "SkString.h"
+
+struct SkLanguageInfo {
+    SkLanguageInfo(const char* tag) : fTag(tag) { }
+    SkString fTag; //! BCP 47 language identifier
+};
+
+/** \class SkLanguage
+
+    The SkLanguage class represents a human written language, and is used by
+    text draw operations to determine which glyph to draw when drawing
+    characters with variants (ie Han-derived characters).
+*/
+class SkLanguage {
+public:
+    SkLanguage() : fInfo(getInfo("")) { }
+    SkLanguage(const char* tag) : fInfo(getInfo(tag)) { }
+    SkLanguage(const SkLanguage& b) : fInfo(b.fInfo) { }
+
+    /** Gets a BCP 47 language identifier for this SkLanguage.
+        @return a BCP 47 language identifier representing this language
+    */
+    const SkString& getTag() const { return fInfo->fTag; }
+
+    /** Performs BCP 47 fallback to return an SkLanguage one step more general.
+        @return an SkLanguage one step more general
+    */
+    SkLanguage getParent() const;
+
+    bool operator==(const SkLanguage& b) const {
+        return fInfo == b.fInfo;
+    }
+    bool operator!=(const SkLanguage& b) const {
+        return fInfo != b.fInfo;
+    }
+    bool operator<(const SkLanguage& b) const {
+        return fInfo < b.fInfo;
+    }
+    bool operator>(const SkLanguage& b) const {
+        return fInfo > b.fInfo;
+    }
+    SkLanguage& operator=(const SkLanguage& b) {
+        fInfo = b.fInfo;
+        return *this;
+    }
+
+private:
+    const SkLanguageInfo* fInfo;
+
+    static const SkLanguageInfo* getInfo(const char* tag);
+};
+
+#endif // #ifdef SK_BUILD_FOR_ANDROID
+#endif // #ifndef SkLanguage_DEFINED
diff --git a/include/core/SkPaint.h b/include/core/SkPaint.h
index 1715013..d2233f0 100644
--- a/include/core/SkPaint.h
+++ b/include/core/SkPaint.h
@@ -10,11 +10,16 @@
 #ifndef SkPaint_DEFINED
 #define SkPaint_DEFINED
 
+#include "SkTypes.h"
 #include "SkColor.h"
 #include "SkDrawLooper.h"
 #include "SkXfermode.h"
 #include "SkString.h"
 
+#ifdef SK_BUILD_FOR_ANDROID
+#include "SkLanguage.h"
+#endif
+
 class SkAutoGlyphCache;
 class SkColorFilter;
 class SkDescriptor;
@@ -656,15 +661,15 @@ public:
     void    setTextAlign(Align align);
 
 #ifdef SK_BUILD_FOR_ANDROID
-    /** Return the paint's text locale value.
-        @return the paint's text locale value used for drawing text.
+    /** Return the paint's language value used for drawing text.
+        @return the paint's language value used for drawing text.
     */
-    const SkString& getTextLocale() const { return fTextLocale; }
+    const SkLanguage& getLanguage() const { return fLanguage; }
 
-    /** Set the paint's text locale.
-        @param locale set the paint's locale value for drawing text.
+    /** Set the paint's language value used for drawing text.
+        @param language set the paint's language value for drawing text.
     */
-    void    setTextLocale(const SkString& locale);
+    void setLanguage(const SkLanguage& language);
 
 
     enum FontVariant {
@@ -924,7 +929,7 @@ private:
     unsigned        fTextEncoding : 2;  // 3 values
     unsigned        fHinting : 2;
 #ifdef SK_BUILD_FOR_ANDROID
-    SkString        fTextLocale;
+    SkLanguage      fLanguage;
     FontVariant     fFontVariant;
 #endif
 
diff --git a/include/core/SkScalerContext.h b/include/core/SkScalerContext.h
index 33c3c3d..4a0c70d 100644
--- a/include/core/SkScalerContext.h
+++ b/include/core/SkScalerContext.h
@@ -17,6 +17,10 @@
 #include "SkPoint.h"
 #include "SkTypeface.h"
 
+#ifdef SK_BUILD_FOR_ANDROID
+#include "SkLanguage.h"
+#endif
+
 //#define SK_USE_COLOR_LUMINANCE
 
 class SkDescriptor;
@@ -211,6 +215,7 @@ public:
         uint32_t    fLumBits;
 #endif
 #ifdef SK_BUILD_FOR_ANDROID
+        SkLanguage fLanguage;
         SkPaint::FontVariant fFontVariant;
 #endif
         uint8_t     fMaskFormat;
@@ -304,16 +309,7 @@ public:
 #ifdef SK_BUILD_FOR_ANDROID
     // This function must be public for SkTypeface_android.h, but should not be
     // called by other callers
-    SkFontID findTypefaceIdForChar(SkUnichar uni) {
-        SkScalerContext* ctx = this;
-        while (NULL != ctx) {
-            if (ctx->generateCharToGlyph(uni)) {
-                return ctx->fRec.fFontID;
-            }
-            ctx = ctx->getNextContext();
-        }
-        return 0;
-    }
+    SkFontID findTypefaceIdForChar(SkUnichar uni);
 
     unsigned getBaseGlyphCount(SkUnichar charCode);
 #endif
@@ -341,6 +337,8 @@ protected:
     void forceGenerateImageFromPath() { fGenerateImageFromPath = true; }
 
 private:
+    SkScalerContext* getContextFromChar(SkUnichar uni, unsigned& glyphID);
+
     SkPathEffect*   fPathEffect;
     SkMaskFilter*   fMaskFilter;
     SkRasterizer*   fRasterizer;