// 25 may 2016 #include "uipriv_windows.hpp" #include "attrstr.hpp" // We could use CharNextW() to generate grapheme cluster boundaries, but it doesn't handle surrogate pairs properly (see http://archives.miloush.net/michkap/archive/2008/12/16/9223301.html). // We could also use Uniscribe (see http://archives.miloush.net/michkap/archive/2005/01/14/352802.html, http://www.catch22.net/tuts/uniscribe-mysteries, http://www.catch22.net/tuts/keyboard-navigation, and https://maxradi.us/documents/uniscribe/), but its rules for buffer sizes is convoluted. // Let's just deal with the CharNextW() bug. int uiprivGraphemesTakesUTF16(void) { return 1; } struct graphemes *uiprivNewGraphemes(void *s, size_t len) { struct graphemes *g; WCHAR *str; size_t *pPTG, *pGTP; g = uiNew(struct graphemes); g->len = 0; str = (WCHAR *) s; while (*str != L'\0') { g->len++; str = CharNextW(str); // no need to worry about surrogates if we're just counting } g->pointsToGraphemes = (size_t *) uiAlloc((len + 1) * sizeof (size_t), "size_t[] (graphemes)"); g->graphemesToPoints = (size_t *) uiAlloc((g->len + 1) * sizeof (size_t), "size_t[] (graphemes)"); pPTG = g->pointsToGraphemes; pGTP = g->graphemesToPoints; str = (WCHAR *) s; while (*str != L'\0') { WCHAR *next, *p; ptrdiff_t nextoff; // as part of the bug, we need to make sure we only call CharNextW() on low halves, otherwise it'll return the same low half forever nextoff = 0; if (IS_HIGH_SURROGATE(*str)) nextoff = 1; next = CharNextW(str + nextoff); if (IS_LOW_SURROGATE(*next)) next--; *pGTP = pPTG - g->pointsToGraphemes; for (p = str; p < next; p++) *pPTG++ = pGTP - g->graphemesToPoints; pGTP++; str = next; } // and handle the last item for the end of the string *pGTP = pPTG - g->pointsToGraphemes; *pPTG = pGTP - g->graphemesToPoints; return g; }