diff options
| -rw-r--r-- | core/jni/android/graphics/Paint.cpp | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/core/jni/android/graphics/Paint.cpp b/core/jni/android/graphics/Paint.cpp index 1844a9870ada..f46f45cc5e5d 100644 --- a/core/jni/android/graphics/Paint.cpp +++ b/core/jni/android/graphics/Paint.cpp @@ -768,6 +768,22 @@ namespace PaintGlue { return false; } + // Returns true if the given string is exact one pair of regional indicators. + static bool isFlag(const jchar* str, size_t length) { + const jchar RI_LEAD_SURROGATE = 0xD83C; + const jchar RI_TRAIL_SURROGATE_MIN = 0xDDE6; + const jchar RI_TRAIL_SURROGATE_MAX = 0xDDFF; + + if (length != 4) { + return false; + } + if (str[0] != RI_LEAD_SURROGATE || str[2] != RI_LEAD_SURROGATE) { + return false; + } + return RI_TRAIL_SURROGATE_MIN <= str[1] && str[1] <= RI_TRAIL_SURROGATE_MAX && + RI_TRAIL_SURROGATE_MIN <= str[3] && str[3] <= RI_TRAIL_SURROGATE_MAX; + } + static jboolean hasGlyph(JNIEnv *env, jclass, jlong paintHandle, jlong typefaceHandle, jint bidiFlags, jstring string) { const Paint* paint = reinterpret_cast<Paint*>(paintHandle); @@ -817,7 +833,26 @@ namespace PaintGlue { // in joining scripts, such as Arabic and Mongolian. return false; } - return nGlyphs > 0 && !layoutContainsNotdef(layout); + + if (nGlyphs == 0 || layoutContainsNotdef(layout)) { + return false; // The collection doesn't have a glyph. + } + + if (nChars == 2 && isFlag(str.get(), str.size())) { + // Some font may have a special glyph for unsupported regional indicator pairs. + // To return false for this case, need to compare the glyph id with the one of ZZ + // since ZZ is reserved for unknown or invalid territory. + // U+1F1FF (REGIONAL INDICATOR SYMBOL LETTER Z) is \uD83C\uDDFF in UTF16. + static const jchar ZZ_FLAG_STR[] = { 0xD83C, 0xDDFF, 0xD83C, 0xDDFF }; + Layout zzLayout; + MinikinUtils::doLayout(&zzLayout, paint, bidiFlags, typeface, ZZ_FLAG_STR, 0, 4, 4); + if (zzLayout.nGlyphs() != 1 || layoutContainsNotdef(zzLayout)) { + // The font collection doesn't have a glyph for unknown flag. Just return true. + return true; + } + return zzLayout.getGlyphId(0) != layout.getGlyphId(0); + } + return true; } static jfloat doRunAdvance(const Paint* paint, Typeface* typeface, const jchar buf[], |