Check the presence of glyphs when selecting font (#113)

* Check the presence of glyphs when selecting font

* Change default font family name

* Fix coding style

* Cache the glyphs and fonts used when matching fonts

* When matching fonts, if the existing character is a special character, it is checked more.

* Fixed sorting to make emoji fonts go backwards

Signed-off-by: MuHong Byun <[email protected]>

Co-authored-by: Boram Bae <[email protected]>
Co-authored-by: Swift Kim <[email protected]>

Author: 3 people

third_party/txt/src/minikin/FontCollection.cpp

@@ -509,7 +509,9 @@ void FontCollection::itemize(const uint16_t* string,
     if (!shouldContinueRun) {
       const std::shared_ptr<FontFamily>& family = getFamilyForChar(
           ch, isVariationSelector(nextCh) ? nextCh : 0, langListId, variant);
-      if (utf16Pos == 0 || family.get() != lastFamily) {
+      if (utf16Pos == 0 || family.get() != lastFamily ||
+          (!(U_GET_GC_MASK(prevCh) & U_GC_L_MASK) &&
+           (U_GET_GC_MASK(ch) & U_GC_L_MASK))) {
         size_t start = utf16Pos;
         // Workaround for combining marks and emoji modifiers until we implement
         // per-cluster font selection: if a combining mark or an emoji modifier
@@ -528,8 +530,8 @@ void FontCollection::itemize(const uint16_t* string,
           }
           start -= prevChLength;
         }
-        result->push_back(
-            {family->getClosestMatch(style), static_cast<int>(start), 0});
+        result->push_back({family->getClosestMatch(style, ch, variant),
+                           static_cast<int>(start), 0});
         run = &result->back();
         lastFamily = family.get();
       }

third_party/txt/src/minikin/FontFamily.cpp

@@ -146,15 +146,28 @@ static FontFakery computeFakery(FontStyle wanted, FontStyle actual) {
   return FontFakery(isFakeBold, isFakeItalic);
 }
 
-FakedFont FontFamily::getClosestMatch(FontStyle style) const {
+FakedFont FontFamily::getClosestMatch(
+    FontStyle style,
+    uint32_t codepoint /* = 0 */,
+    uint32_t variationSelector /* = 0 */) const {
   const Font* bestFont = nullptr;
-  int bestMatch = 0;
+  int bestMatch = INT_MAX;
   for (size_t i = 0; i < mFonts.size(); i++) {
     const Font& font = mFonts[i];
     int match = computeMatch(font.style, style);
-    if (i == 0 || match < bestMatch) {
-      bestFont = &font;
-      bestMatch = match;
+    bool result = false;
+    if (codepoint != 0) {
+      hb_font_t* hbFont = getHbFontLocked(font.typeface.get());
+      uint32_t unusedGlyph = 0;
+      result =
+          hb_font_get_glyph(hbFont, codepoint, variationSelector, &unusedGlyph);
+      hb_font_destroy(hbFont);
+    }
+    if (codepoint == 0 || (codepoint != 0 && result)) {
+      if (match < bestMatch) {
+        bestFont = &font;
+        bestMatch = match;
+      }
     }
   }
   if (bestFont != nullptr) {

third_party/txt/src/minikin/FontFamily.h

@@ -140,7 +140,9 @@ class FontFamily {
   static bool analyzeStyle(const std::shared_ptr<MinikinFont>& typeface,
                            int* weight,
                            bool* italic);
-  FakedFont getClosestMatch(FontStyle style) const;
+  FakedFont getClosestMatch(FontStyle style,
+                            uint32_t codepoint = 0,
+                            uint32_t variationSelector = 0) const;
 
   uint32_t langId() const { return mLangId; }
   int variant() const { return mVariant; }

third_party/txt/src/txt/font_collection.cc

@@ -245,6 +245,28 @@ void FontCollection::SortSkTypefaces(
   std::sort(
       sk_typefaces.begin(), sk_typefaces.end(),
       [](const sk_sp<SkTypeface>& a, const sk_sp<SkTypeface>& b) {
+        {
+          // A workaround to prevent emoji fonts being selected for normal text
+          // when normal and emojis are mixed at same font family.
+
+          bool a_isEmojiFont = false;
+          bool b_isEmojiFont = false;
+          SkString postScriptName;
+          a->getPostScriptName(&postScriptName);
+          if (postScriptName.contains("Emoji")) {
+            a_isEmojiFont = true;
+          }
+          b->getPostScriptName(&postScriptName);
+          if (postScriptName.contains("Emoji")) {
+            b_isEmojiFont = true;
+          }
+          if (a_isEmojiFont && !b_isEmojiFont) {
+            return false;
+          } else if (!a_isEmojiFont && b_isEmojiFont) {
+            return true;
+          }
+        }
+
         SkFontStyle a_style = a->fontStyle();
         SkFontStyle b_style = b->fontStyle();
 

third_party/txt/src/txt/platform_linux.cc

@@ -13,6 +13,9 @@
 namespace txt {
 
 std::vector<std::string> GetDefaultFontFamilies() {
+#ifdef FLUTTER_USE_FONTCONFIG
+  return {"TizenDefaultFont"};
+#else
   return {
       "SamsungOneUI",
       "SamsungOneUIArabic",
@@ -72,11 +75,12 @@ std::vector<std::string> GetDefaultFontFamilies() {
       "BreezeSansFallback",
       "BreezeColorEmoji",
   };
+#endif
 }
 
 sk_sp<SkFontMgr> GetDefaultFontManager(uint32_t font_initialization_data) {
 #ifdef FLUTTER_USE_FONTCONFIG
-  return SkFontMgr_New_FontConfig(nullptr);
+  return SkFontMgr::RefDefault();
 #else
   return SkFontMgr_New_Custom_Directory("/usr/share/fonts");
 #endif