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Diffstat (limited to 'utils/xftwrap.c')
| -rw-r--r-- | utils/xftwrap.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/utils/xftwrap.c b/utils/xftwrap.c new file mode 100644 index 0000000..e880407 --- /dev/null +++ b/utils/xftwrap.c @@ -0,0 +1,206 @@ +/* xftwrap.c --- XftDrawStringUtf8 with multi-line strings. + * xscreensaver, Copyright © 2021 Jamie Zawinski <jwz@jwz.org> + * + * Permission to use, copy, modify, distribute, and sell this software and its + * documentation for any purpose is hereby granted without fee, provided that + * the above copyright notice appear in all copies and that both that + * copyright notice and this permission notice appear in supporting + * documentation. No representations are made about the suitability of this + * software for any purpose. It is provided "as is" without express or + * implied warranty. + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include "utils.h" +#include "xft.h" +#include "xftwrap.h" + +#undef MAX +#undef MIN +#define MAX(a,b) ((a)>(b)?(a):(b)) +#define MIN(a,b) ((a)<(b)?(a):(b)) + + +#ifdef DEBUG +static void +LOG(const char *ss, const char *s, int n) +{ + int i; + fprintf(stderr,"####%s [", ss); + for (i = 0; i < n; i++) fprintf(stderr, "%c", s[i]); + fprintf(stderr,"]\n"); +} +#else +# define LOG(ss,s,n) /**/ +#endif + + +/* Returns a new string word-wrapped to fit in the width in pixels. + */ +char * +xft_word_wrap (Display *dpy, XftFont *font, const char *str, int pixels) +{ + const char *in = str; + char *ret = (char *) malloc (strlen(in) + 2); + char *out = ret; + const char *line_out = out; + char *word_out = 0; + while (1) + { + if (*in == ' ' || *in == '\t' || + *in == '\r' || *in == '\n' || + *in == 0) + { + Bool done = (*in == 0); /* To wrap the *last* word. */ + XGlyphInfo overall; + Bool nl = (*in == '\r' || *in == '\n'); + + if (nl) in++; + while (*in == ' ' || *in == '\t') in++; + in--; + + XftTextExtentsUtf8 (dpy, font, + (FcChar8 *) line_out, + out - line_out, + &overall); + if (overall.width - overall.x >= pixels && + word_out) + { + word_out[0] = '\n'; + line_out = word_out + 1; + word_out = 0; + if (done) break; + *out++ = *in; + } + else + { + if (done) break; + word_out = out; + *out++ = *in; + if (nl) + { + line_out = out + 1; + word_out = 0; + } + } + + if (done) break; + } + else + { + *out++ = *in; + } + in++; + } + + *out = 0; + + return ret; +} + + +/* Like XftTextExtentsUtf8, but handles multi-line strings. + XGlyphInfo will contain the bounding box that encloses all of the text. + Return value is the number of lines in the text, >= 1. + */ +int +XftTextExtentsUtf8_multi (Display *dpy, XftFont *font, + const FcChar8 *str, int len, XGlyphInfo *overall) +{ + int i, start = 0; + int lines = 0; + int line_y = 0; + for (i = 0; i <= len; i++) + { + if (i == len || str[i] == '\r' || str[i] == '\n') + { + XGlyphInfo gi; + XftTextExtentsUtf8 (dpy, font, + str + start, + i - start, + &gi); + if (lines == 0) + *overall = gi; + else + { + /* Find the union of the two bounding boxes, placed at their + respective origins. */ + int ox1, oy1, ox2, oy2; /* bbox of 'overall' */ + int nx1, ny1, nx2, ny2; /* bbox of 'gi' */ + int ux1, uy1, ux2, uy2; /* union */ + + ox1 = overall->x; + oy1 = overall->y; + ox2 = ox1 + overall->width; + oy2 = oy1 + overall->height; + + line_y += font->ascent + font->descent; /* advance origin */ + + nx1 = gi.x; + ny1 = gi.y + line_y; + nx2 = nx1 + gi.width; + ny2 = ny1 + gi.height + line_y; + + ux1 = MIN (ox1, nx1); /* upper left */ + uy1 = MIN (oy1, ny1); + ux2 = MAX (ox2, nx2); /* bottom right */ + uy2 = MAX (oy2, ny2); + + overall->x = ux1; + overall->y = uy1; + overall->width = ux2 - ux1; + overall->height = uy2 - uy1; + } + lines++; + start = i+1; + } + } + + return lines; +} + + +/* Like XftDrawStringUtf8, but handles multi-line strings. + Alignment is 1, 0 or -1 for left, center, right. + */ +void +XftDrawStringUtf8_multi (XftDraw *xftdraw, const XftColor *color, + XftFont *font, int x, int y, const FcChar8 *str, + int len, + int alignment) +{ + Display *dpy = XftDrawDisplay (xftdraw); + int i, start = 0; + int lines = 0; + XGlyphInfo overall; + if (len == 0) return; + + XftTextExtentsUtf8_multi (dpy, font, str, len, &overall); + + for (i = 0; i <= len; i++) + { + if (i == len || str[i] == '\r' || str[i] == '\n') + { + XGlyphInfo gi; + int x2 = x; + XftTextExtentsUtf8 (dpy, font, str + start, i - start, &gi); + switch (alignment) { + case 1: break; + case 0: x2 += (overall.width - gi.width) / 2; break; + case -1: x2 += (overall.width - gi.width); break; + default: abort(); break; + } + + XftDrawStringUtf8 (xftdraw, color, font, x2, y, + str + start, + i - start); + y += font->ascent + font->descent; + lines++; + start = i+1; + } + } +} + |