diff options
Diffstat (limited to 'src/character.c')
| -rw-r--r-- | src/character.c | 112 |
1 files changed, 90 insertions, 22 deletions
diff --git a/src/character.c b/src/character.c index a599a0355f4..38a81d36b09 100644 --- a/src/character.c +++ b/src/character.c @@ -34,6 +34,7 @@ along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. */ #include "lisp.h" #include "character.h" #include "buffer.h" +#include "frame.h" #include "dispextern.h" #include "composite.h" #include "disptab.h" @@ -321,28 +322,41 @@ strwidth (const char *str, ptrdiff_t len) return c_string_width ((const unsigned char *) str, len, -1, NULL, NULL); } -/* Return width of Lisp string STRING when displayed in the current - buffer. The width is measured by how many columns it occupies on - the screen while paying attention to compositions. If PRECISION > - 0, return the width of longest substring that doesn't exceed - PRECISION, and set number of characters and bytes of the substring - in *NCHARS and *NBYTES respectively. */ +/* Return width of a (substring of a) Lisp string STRING when + displayed in the current buffer. The width is measured by how many + columns it occupies on the screen while paying attention to + compositions. If PRECISION > 0, return the width of longest + substring that doesn't exceed PRECISION, and set number of + characters and bytes of the substring in *NCHARS and *NBYTES + respectively. FROM and TO are zero-based character indices that + define the substring of STRING to consider. If AUTO_COMP is + non-zero, account for automatic compositions in STRING. */ ptrdiff_t -lisp_string_width (Lisp_Object string, ptrdiff_t precision, - ptrdiff_t *nchars, ptrdiff_t *nbytes) +lisp_string_width (Lisp_Object string, ptrdiff_t from, ptrdiff_t to, + ptrdiff_t precision, ptrdiff_t *nchars, ptrdiff_t *nbytes, + bool auto_comp) { - ptrdiff_t len = SCHARS (string); /* This set multibyte to 0 even if STRING is multibyte when it contains only ascii and eight-bit-graphic, but that's intentional. */ - bool multibyte = len < SBYTES (string); - unsigned char *str = SDATA (string); - ptrdiff_t i = 0, i_byte = 0; + bool multibyte = SCHARS (string) < SBYTES (string); + ptrdiff_t i = from, i_byte = from ? string_char_to_byte (string, from) : 0; + ptrdiff_t from_byte = i_byte; ptrdiff_t width = 0; struct Lisp_Char_Table *dp = buffer_display_table (); +#ifdef HAVE_WINDOW_SYSTEM + struct frame *f = + (FRAMEP (selected_frame) && FRAME_LIVE_P (XFRAME (selected_frame))) + ? XFRAME (selected_frame) + : NULL; + int font_width = -1; + Lisp_Object default_font, frame_font; +#endif - while (i < len) + eassert (precision <= 0 || (nchars && nbytes)); + + while (i < to) { ptrdiff_t chars, bytes, thiswidth; Lisp_Object val; @@ -357,9 +371,53 @@ lisp_string_width (Lisp_Object string, ptrdiff_t precision, chars = end - i; bytes = string_char_to_byte (string, end) - i_byte; } +#ifdef HAVE_WINDOW_SYSTEM + else if (auto_comp + && f && FRAME_WINDOW_P (f) + && multibyte + && find_automatic_composition (i, -1, i, &ignore, + &end, &val, string) + && end > i) + { + int j; + for (j = 0; j < LGSTRING_GLYPH_LEN (val); j++) + if (NILP (LGSTRING_GLYPH (val, j))) + break; + + int pixelwidth = composition_gstring_width (val, 0, j, NULL); + + /* The below is somewhat expensive, so compute it only once + for the entire loop, and only if needed. */ + if (font_width < 0) + { + font_width = FRAME_COLUMN_WIDTH (f); + default_font = Fface_font (Qdefault, Qnil, Qnil); + frame_font = Fframe_parameter (Qnil, Qfont); + + if (STRINGP (default_font) && STRINGP (frame_font) + && (SCHARS (default_font) != SCHARS (frame_font) + || SBYTES (default_font) != SBYTES (frame_font) + || memcmp (SDATA (default_font), SDATA (frame_font), + SBYTES (default_font)))) + { + Lisp_Object font_info = Ffont_info (default_font, Qnil); + if (VECTORP (font_info)) + { + font_width = XFIXNUM (AREF (font_info, 11)); + if (font_width <= 0) + font_width = XFIXNUM (AREF (font_info, 10)); + } + } + } + thiswidth = (double) pixelwidth / font_width + 0.5; + chars = end - i; + bytes = string_char_to_byte (string, end) - i_byte; + } +#endif /* HAVE_WINDOW_SYSTEM */ else { int c; + unsigned char *str = SDATA (string); if (multibyte) { @@ -375,8 +433,8 @@ lisp_string_width (Lisp_Object string, ptrdiff_t precision, if (0 < precision && precision - width < thiswidth) { - *nchars = i; - *nbytes = i_byte; + *nchars = i - from; + *nbytes = i_byte - from_byte; return width; } if (INT_ADD_WRAPV (thiswidth, width, &width)) @@ -387,27 +445,37 @@ lisp_string_width (Lisp_Object string, ptrdiff_t precision, if (precision > 0) { - *nchars = i; - *nbytes = i_byte; + *nchars = i - from; + *nbytes = i_byte - from_byte; } return width; } -DEFUN ("string-width", Fstring_width, Sstring_width, 1, 1, 0, +DEFUN ("string-width", Fstring_width, Sstring_width, 1, 3, 0, doc: /* Return width of STRING when displayed in the current buffer. Width is measured by how many columns it occupies on the screen. +Optional arguments FROM and TO specify the substring of STRING to +consider, and are interpreted as in `substring'. + When calculating width of a multibyte character in STRING, only the base leading-code is considered; the validity of the following bytes is not checked. Tabs in STRING are always -taken to occupy `tab-width' columns. -usage: (string-width STRING) */) - (Lisp_Object str) +taken to occupy `tab-width' columns. The effect of faces and fonts +used for non-Latin and other unusual characters (such as emoji) is +ignored as well, as are display properties and invisible text. +For these reasons, the results are not generally reliable; +for accurate dimensions of text as it will be displayed, +use `window-text-pixel-size' instead. +usage: (string-width STRING &optional FROM TO) */) + (Lisp_Object str, Lisp_Object from, Lisp_Object to) { Lisp_Object val; + ptrdiff_t ifrom, ito; CHECK_STRING (str); - XSETFASTINT (val, lisp_string_width (str, -1, NULL, NULL)); + validate_subarray (str, from, to, SCHARS (str), &ifrom, &ito); + XSETFASTINT (val, lisp_string_width (str, ifrom, ito, -1, NULL, NULL, true)); return val; } |