diff options
| -rw-r--r-- | libs/minikin/LineBreaker.cpp | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/libs/minikin/LineBreaker.cpp b/libs/minikin/LineBreaker.cpp index a832ca2..77374fe 100644 --- a/libs/minikin/LineBreaker.cpp +++ b/libs/minikin/LineBreaker.cpp @@ -17,6 +17,7 @@ #define VERBOSE_DEBUG 0 #include <limits> +#include <unicode/utf16.h> #define LOG_TAG "Minikin" #include <cutils/log.h> @@ -30,6 +31,7 @@ namespace android { const int CHAR_TAB = 0x0009; const uint16_t CHAR_SOFT_HYPHEN = 0x00AD; +const uint16_t CHAR_ZWJ = 0x200D; // Large scores in a hierarchy; we prefer desperate breaks to an overfull line. All these // constants are larger than any reasonable actual width score. @@ -123,6 +125,32 @@ static bool isLineBreakingHyphen(uint16_t c) { c == 0x2E40); // DOUBLE HYPHEN } +/** + * Determine whether a line break at position i within the buffer buf is valid. This + * represents customization beyond the ICU behavior, because plain ICU provides some + * line break opportunities that we don't want. + **/ +static bool isBreakValid(uint16_t codeUnit, const uint16_t* buf, size_t bufEnd, size_t i) { + if (codeUnit == CHAR_SOFT_HYPHEN) { + return false; + } + if (codeUnit == CHAR_ZWJ) { + // Possible emoji ZWJ sequence + uint32_t next_codepoint; + U16_NEXT(buf, i, bufEnd, next_codepoint); + if (next_codepoint == 0x2764 || // HEAVY BLACK HEART + next_codepoint == 0x1F466 || // BOY + next_codepoint == 0x1F467 || // GIRL + next_codepoint == 0x1F468 || // MAN + next_codepoint == 0x1F469 || // WOMAN + next_codepoint == 0x1F48B || // KISS MARK + next_codepoint == 0x1F5E8) { // LEFT SPEECH BUBBLE + return false; + } + } + return true; +} + // Ordinarily, this method measures the text in the range given. However, when paint // is nullptr, it assumes the widths have already been calculated and stored in the // width buffer. @@ -175,8 +203,9 @@ float LineBreaker::addStyleRun(MinikinPaint* paint, const FontCollection* typefa } if (i + 1 == current) { // Override ICU's treatment of soft hyphen as a break opportunity, because we want it - // to be a hyphen break, with penalty and drawing behavior. - if (c != CHAR_SOFT_HYPHEN) { + // to be a hyphen break, with penalty and drawing behavior. Also, suppress line + // breaks within emoji ZWJ sequences. + if (isBreakValid(c, mTextBuf.data(), end, i + 1)) { // TODO: Add a new type of HyphenEdit for breaks whose hyphen already exists, so // we can pass the whole word down to Hyphenator like the soft hyphen case. bool wordEndsInHyphen = isLineBreakingHyphen(c); |