Bug 1352977 - Factor out helpers to construct the names for generic- and language-dependent font/font-list preferences. r=masayuki

gfx/thebes/gfxFcPlatformFontList.cpp

@@ -1627,9 +1627,6 @@ gfxFcPlatformFontList::GetStandardFamilyName(const nsAString& aFontName,
     return true;
 }
 
-static const char kFontNamePrefix[] = "font.name.";
-static const char kFontNameListPrefix[] = "font.name-list.";
-
 void
 gfxFcPlatformFontList::AddGenericFonts(mozilla::FontFamilyType aGenericType,
                                        nsIAtom* aLanguage,
@@ -1655,25 +1652,15 @@ gfxFcPlatformFontList::AddGenericFonts(mozilla::FontFamilyType aGenericType,
     if ((!mAlwaysUseFontconfigGenerics && aLanguage) ||
         aLanguage == nsGkAtoms::x_math) {
         nsIAtom* langGroup = GetLangGroup(aLanguage);
-        nsAutoCString langGroupStr;
-        if (langGroup) {
-            langGroup->ToUTF8String(langGroupStr);
-        }
-        nsAutoCString prefFontName(kFontNamePrefix);
-        prefFontName.Append(generic);
-        prefFontName.Append('.');
-        prefFontName.Append(langGroupStr);
-        nsAdoptingString fontlistValue = Preferences::GetString(prefFontName.get());
+        nsAdoptingString fontlistValue =
+            Preferences::GetString(NamePref(generic, langGroup).get());
         if (fontlistValue.IsEmpty()) {
-            nsAutoCString prefFontNameListName(kFontNameListPrefix);
-            prefFontNameListName.Append(generic);
-            prefFontNameListName.Append('.');
-            prefFontNameListName.Append(langGroupStr);
             // The font name list may have two or more family names as comma
             // separated list.  In such case, not matching with generic font
             // name is fine because if the list prefers specific font, we
             // should try to use the pref with complicated path.
-            fontlistValue = Preferences::GetString(prefFontNameListName.get());
+            fontlistValue =
+                 Preferences::GetString(NameListPref(generic, langGroup).get());
         }
         if (fontlistValue) {
             if (!fontlistValue.EqualsLiteral("serif") &&
@@ -1840,6 +1827,8 @@ gfxFcPlatformFontList::FindGenericFamilies(const nsAString& aGeneric,
 bool
 gfxFcPlatformFontList::PrefFontListsUseOnlyGenerics()
 {
+    static const char kFontNamePrefix[] = "font.name.";
+
     bool prefFontsUseOnlyGenerics = true;
     uint32_t count;
     char** names;
@@ -1865,15 +1854,13 @@ gfxFcPlatformFontList::PrefFontListsUseOnlyGenerics()
             const nsDependentCSubstring& langGroup = tokenizer.nextToken();
             nsAdoptingCString fontPrefValue = Preferences::GetCString(names[i]);
             if (fontPrefValue.IsEmpty()) {
-                nsAutoCString nameListPrefName(kFontNameListPrefix);
-                nameListPrefName.Append(generic);
-                nameListPrefName.Append('.');
-                nameListPrefName.Append(langGroup);
                 // The font name list may have two or more family names as comma
                 // separated list.  In such case, not matching with generic font
                 // name is fine because if the list prefers specific font, this
                 // should return false.
-                fontPrefValue = Preferences::GetCString(nameListPrefName.get());
+                fontPrefValue =
+                    Preferences::GetCString(NameListPref(generic,
+                                                         langGroup).get());
             }
 
             if (!langGroup.EqualsLiteral("x-math") &&

gfx/thebes/gfxPlatformFontList.cpp

@@ -803,11 +803,8 @@ gfxPlatformFontList::GetDefaultFontFamily(const nsACString& aLangGroup,
     }
 
     AutoTArray<nsString,4> names;
-    nsAutoCString prefName("font.name-list.");
-    prefName.Append(aGenericFamily);
-    prefName.Append('.');
-    prefName.Append(aLangGroup);
-    gfxFontUtils::AppendPrefsFontList(prefName.get(), names);
+    gfxFontUtils::AppendPrefsFontList(
+        NameListPref(aGenericFamily, aLangGroup).get(), names);
 
     for (nsString& name : names) {
         gfxFontFamily* fontFamily = FindFamily(name);
@@ -869,18 +866,12 @@ gfxPlatformFontList::ResolveGenericFontNames(
     AutoTArray<nsString,4> genericFamilies;
 
     // load family for "font.name.generic.lang"
-    nsAutoCString prefFontName("font.name.");
-    prefFontName.Append(generic);
-    prefFontName.Append('.');
-    prefFontName.Append(langGroupStr);
-    gfxFontUtils::AppendPrefsFontList(prefFontName.get(), genericFamilies);
+    gfxFontUtils::AppendPrefsFontList(
+        NamePref(generic, langGroupStr).get(), genericFamilies);
 
     // load fonts for "font.name-list.generic.lang"
-    nsAutoCString prefFontListName("font.name-list.");
-    prefFontListName.Append(generic);
-    prefFontListName.Append('.');
-    prefFontListName.Append(langGroupStr);
-    gfxFontUtils::AppendPrefsFontList(prefFontListName.get(), genericFamilies);
+    gfxFontUtils::AppendPrefsFontList(
+        NameListPref(generic, langGroupStr).get(), genericFamilies);
 
     nsIAtom* langGroup = GetLangGroupForPrefLang(aPrefLang);
     NS_ASSERTION(langGroup, "null lang group for pref lang");

gfx/thebes/gfxPlatformFontList.h

@@ -273,6 +273,47 @@ protected:
         NS_DECL_NSIMEMORYREPORTER
     };
 
+    template<bool ForNameList>
+    class PrefNameMaker final : public nsAutoCString
+    {
+        void Init(const nsACString& aGeneric, const nsACString& aLangGroup)
+        {
+            Assign(ForNameList ? NS_LITERAL_CSTRING("font.name-list.")
+                               : NS_LITERAL_CSTRING("font.name."));
+            Append(aGeneric);
+            if (!aLangGroup.IsEmpty()) {
+                Append('.');
+                Append(aLangGroup);
+            }
+        }
+
+    public:
+        PrefNameMaker(const nsACString& aGeneric,
+                      const nsACString& aLangGroup)
+        {
+            Init(aGeneric, aLangGroup);
+        }
+
+        PrefNameMaker(const char* aGeneric,
+                      const char* aLangGroup)
+        {
+            Init(nsDependentCString(aGeneric), nsDependentCString(aLangGroup));
+        }
+
+        PrefNameMaker(const char* aGeneric,
+                      nsIAtom* aLangGroup)
+        {
+            if (aLangGroup) {
+                Init(nsDependentCString(aGeneric), nsAtomCString(aLangGroup));
+            } else {
+                Init(nsDependentCString(aGeneric), nsAutoCString());
+            }
+        }
+    };
+
+    typedef PrefNameMaker<false> NamePref;
+    typedef PrefNameMaker<true>  NameListPref;
+
     explicit gfxPlatformFontList(bool aNeedFullnamePostscriptNames = true);
 
     static gfxPlatformFontList *sPlatformFontList;