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authorRaph Levien <raph@google.com>2015-10-29 21:06:07 (GMT)
committerRaph Levien <raph@google.com>2016-01-13 22:12:56 (GMT)
commit2e98eb6be123ec64070f7524ff24df538695d7c8 (patch)
tree6876504035e9ec5bd739e1ae9d6dada793626470
parent8921cfe226e9b7774810c9711579586b5b227b82 (diff)
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Tailor grapheme boundaries so sequence emoji are one grapheme - DO NOT MERGE
Make it so it's not possible to position the cursor inside an emoji formed by a sequence including zero-width joiners. Bug: 25368653 Change-Id: I67ec0874cd1505f3c82ab91492ffc3d39a52fae6
-rw-r--r--libs/minikin/GraphemeBreak.cpp26
1 files changed, 26 insertions, 0 deletions
diff --git a/libs/minikin/GraphemeBreak.cpp b/libs/minikin/GraphemeBreak.cpp
index f8f386c..56d5b23 100644
--- a/libs/minikin/GraphemeBreak.cpp
+++ b/libs/minikin/GraphemeBreak.cpp
@@ -22,6 +22,19 @@
namespace android {
+// Returns true if the character appears before or after zwj in a zwj emoji sequence. See
+// http://www.unicode.org/emoji/charts/emoji-zwj-sequences.html
+bool isZwjEmoji(uint32_t c) {
+ return (c == 0x2764 // HEAVY BLACK HEART
+ || c == 0x1F468 // MAN
+ || c == 0x1F469 // WOMAN
+ || c == 0x1F48B // KISS MARK
+ || c == 0x1F466 // BOY
+ || c == 0x1F467 // GIRL
+ || c == 0x1F441 // EYE
+ || c == 0x1F5E8); // LEFT SPEECH BUBBLE
+}
+
bool GraphemeBreak::isGraphemeBreak(const uint16_t* buf, size_t start, size_t count,
size_t offset) {
// This implementation closely follows Unicode Standard Annex #29 on
@@ -93,6 +106,19 @@ bool GraphemeBreak::isGraphemeBreak(const uint16_t* buf, size_t start, size_t co
&& u_getIntPropertyValue(c2, UCHAR_GENERAL_CATEGORY) == U_OTHER_LETTER) {
return false;
}
+ // Tailoring: make emoji sequences with ZWJ a single grapheme cluster
+ if (c1 == 0x200D && isZwjEmoji(c2) && offset_back > start) {
+ // look at character before ZWJ to see that both can participate in an emoji zwj sequence
+ uint32_t c0 = 0;
+ U16_PREV(buf, start, offset_back, c0);
+ if (c0 == 0xFE0F && offset_back > start) {
+ // skip over emoji variation selector
+ U16_PREV(buf, start, offset_back, c0);
+ }
+ if (isZwjEmoji(c0)) {
+ return false;
+ }
+ }
// Rule GB10, Any / Any
return true;
}