Paint.hasGlyph should return false on unsupported flags.
By Noto font update, now it has a special glyph for unsupported flags.
Paint.hasGlyph should return false in this case even if it has a glyph.
Bug: 27999343
Change-Id: Icbd31db83d945d66de1477aa888275f6c0ef79b0
diff --git a/core/jni/android/graphics/Paint.cpp b/core/jni/android/graphics/Paint.cpp
index 1844a98..f46f45c 100644
--- a/core/jni/android/graphics/Paint.cpp
+++ b/core/jni/android/graphics/Paint.cpp
@@ -768,6 +768,22 @@
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 @@
// 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[],