Fix Japanese font issue for devices running JB MR1 and higher.

Android JB MR1 is using a new format of /system/etc/fallback_fonts.xml.
This CL preserves backwards compatibility, while also recognizing the
new fallback_fonts.xml format ("lang" attrbiute in <file/>).

NOTE: This CL was originally sumbitted for Chrome on Android (m18)

Review URL: https://codereview.appspot.com/7226053

git-svn-id: http://skia.googlecode.com/svn/trunk@7448 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 41 insertions, 12 deletions

diff --git a/src/ports/FontHostConfiguration_android.cpp b/src/ports/FontHostConfiguration_android.cpp
index aed7001bfe..6d03414b08 100644
--- a/src/ports/FontHostConfiguration_android.cpp
+++ b/src/ports/FontHostConfiguration_android.cpp
@@ -28,13 +28,17 @@
  * can read these variables that are relevant to the current parsing.
  */
 struct FamilyData {
-    FamilyData(XML_Parser *parserRef, SkTDArray<FontFamily*> &familiesRef) :
-            parser(parserRef), families(familiesRef), currentTag(NO_TAG) {};
+    FamilyData(XML_Parser *parserRef, SkTDArray<FontFamily*> &familiesRef, const AndroidLocale &localeRef) :
+            parser(parserRef), families(familiesRef), currentTag(NO_TAG),
+            locale(localeRef), currentFamilyLangMatch(false), familyLangMatchCount(0) {}
 
     XML_Parser *parser;                // The expat parser doing the work
     SkTDArray<FontFamily*> &families;  // The array that each family is put into as it is parsed
     FontFamily *currentFamily;         // The current family being created
     int currentTag;                    // A flag to indicate whether we're in nameset/fileset tags
+    const AndroidLocale &locale;       // The locale to which we compare the "lang" attribute of File.
+    bool currentFamilyLangMatch;       // If currentFamily's File has a "lang" attribute and matches locale.
+    int familyLangMatchCount;          // Number of families containing File which has a "lang" attribute and matches locale.
 };
 
 /**
@@ -90,10 +94,28 @@ void startElementHandler(void *data, const char *tag, const char **atts) {
         familyData->currentTag = NAMESET_TAG;
     } else if (len == 7 && strncmp(tag, "fileset", len) == 0) {
         familyData->currentTag = FILESET_TAG;
-    } else if ((strncmp(tag, "name", len) == 0 && familyData->currentTag == NAMESET_TAG) ||
-            (strncmp(tag, "file", len) == 0 && familyData->currentTag == FILESET_TAG)) {
-        // If it's a Name, parse the text inside
+    } else if (strncmp(tag, "name", len) == 0 && familyData->currentTag == NAMESET_TAG) {
         XML_SetCharacterDataHandler(*familyData->parser, textHandler);
+    } else if (strncmp(tag, "file", len) == 0 && familyData->currentTag == FILESET_TAG) {
+        // From JB MR1, the File tag has a "lang" attribute to specify a language specific font file
+        // and the family entry has higher priority than the others without "lang" attribute.
+        bool includeTheEntry = true;
+        for (int i = 0; atts[i] != NULL; i += 2) {
+            const char* attribute = atts[i];
+            const char* value = atts[i+1];
+            if (strncmp(attribute, "lang", 4) == 0) {
+                if (strcmp(value, familyData->locale.language) == 0) {
+                    // Found matching "lang" attribute. The current Family will have higher priority in the family list.
+                    familyData->currentFamilyLangMatch = true;
+                } else {
+                    // Don't include the entry if "lang" is specified but not matching.
+                    includeTheEntry = false;
+                }
+            }
+        }
+        if (includeTheEntry) {
+            XML_SetCharacterDataHandler(*familyData->parser, textHandler);
+        }
     }
 }
 
@@ -106,7 +128,12 @@ void endElementHandler(void *data, const char *tag) {
     int len = strlen(tag);
     if (strncmp(tag, "family", len)== 0) {
         // Done parsing a Family - store the created currentFamily in the families array
-        *familyData->families.append() = familyData->currentFamily;
+        if (familyData->currentFamilyLangMatch) {
+            *familyData->families.insert(familyData->familyLangMatchCount++) = familyData->currentFamily;
+            familyData->currentFamilyLangMatch = false;
+        } else {
+            *familyData->families.append() = familyData->currentFamily;
+        }
         familyData->currentFamily = NULL;
     } else if (len == 7 && strncmp(tag, "nameset", len)== 0) {
         familyData->currentTag = NO_TAG;
@@ -150,18 +177,16 @@ void getLocale(AndroidLocale &locale)
  *      /system/etc/fallback_fonts-ja.xml
  *      /system/etc/fallback_fonts.xml
  */
-FILE* openLocalizedFile(const char* origname) {
+FILE* openLocalizedFile(const char* origname, const AndroidLocale& locale) {
     FILE* file = 0;
     SkString basename;
     SkString filename;
-    AndroidLocale locale;
 
     basename.set(origname);
     // Remove the .xml suffix. We'll add it back in a moment.
     if (basename.endsWith(".xml")) {
         basename.resize(basename.size()-4);
     }
-    getLocale(locale);
     // Try first with language and region
     filename.printf("%s-%s-%s.xml", basename.c_str(), locale.language, locale.region);
     file = fopen(filename.c_str(), "r");
@@ -183,11 +208,13 @@ FILE* openLocalizedFile(const char* origname) {
  * families array.
  */
 void parseConfigFile(const char *filename, SkTDArray<FontFamily*> &families) {
+    AndroidLocale locale;
+    getLocale(locale);
     XML_Parser parser = XML_ParserCreate(NULL);
-    FamilyData *familyData = new FamilyData(&parser, families);
-    XML_SetUserData(parser, familyData);
+    FamilyData familyData(&parser, families, locale);
+    XML_SetUserData(parser, &familyData);
     XML_SetElementHandler(parser, startElementHandler, endElementHandler);
-    FILE *file = openLocalizedFile(filename);
+    FILE *file = openLocalizedFile(filename, locale);
     // Some of the files we attempt to parse (in particular, /vendor/etc/fallback_fonts.xml)
     // are optional - failure here is okay because one of these optional files may not exist.
     if (file == NULL) {
@@ -203,6 +230,8 @@ void parseConfigFile(const char *filename, SkTDArray<FontFamily*> &families) {
         }
         XML_Parse(parser, buffer, len, done);
     }
+    fclose(file);
+    XML_ParserFree(parser);
 }
 
 void getSystemFontFamilies(SkTDArray<FontFamily*> &fontFamilies) {