svkbd

simple virtual keyboard
git clone git://git.suckless.org/svkbd
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drw.c (10278B)

      1 /* See LICENSE file for copyright and license details. */
      2 #include <stdio.h>
      3 #include <stdlib.h>
      4 #include <string.h>
      5 #include <X11/Xlib.h>
      6 #include <X11/Xft/Xft.h>
      7 
      8 #include "drw.h"
      9 #include "util.h"
     10 
     11 #define UTF_INVALID 0xFFFD
     12 #define UTF_SIZ     4
     13 
     14 static const unsigned char utfbyte[UTF_SIZ + 1] = {0x80,    0, 0xC0, 0xE0, 0xF0};
     15 static const unsigned char utfmask[UTF_SIZ + 1] = {0xC0, 0x80, 0xE0, 0xF0, 0xF8};
     16 static const long utfmin[UTF_SIZ + 1] = {       0,    0,  0x80,  0x800,  0x10000};
     17 static const long utfmax[UTF_SIZ + 1] = {0x10FFFF, 0x7F, 0x7FF, 0xFFFF, 0x10FFFF};
     18 
     19 static long
     20 utf8decodebyte(const char c, size_t *i)
     21 {
     22 	for (*i = 0; *i < (UTF_SIZ + 1); ++(*i))
     23 		if (((unsigned char)c & utfmask[*i]) == utfbyte[*i])
     24 			return (unsigned char)c & ~utfmask[*i];
     25 	return 0;
     26 }
     27 
     28 static size_t
     29 utf8validate(long *u, size_t i)
     30 {
     31 	if (!BETWEEN(*u, utfmin[i], utfmax[i]) || BETWEEN(*u, 0xD800, 0xDFFF))
     32 		*u = UTF_INVALID;
     33 	for (i = 1; *u > utfmax[i]; ++i)
     34 		;
     35 	return i;
     36 }
     37 
     38 static size_t
     39 utf8decode(const char *c, long *u, size_t clen)
     40 {
     41 	size_t i, j, len, type;
     42 	long udecoded;
     43 
     44 	*u = UTF_INVALID;
     45 	if (!clen)
     46 		return 0;
     47 	udecoded = utf8decodebyte(c[0], &len);
     48 	if (!BETWEEN(len, 1, UTF_SIZ))
     49 		return 1;
     50 	for (i = 1, j = 1; i < clen && j < len; ++i, ++j) {
     51 		udecoded = (udecoded << 6) | utf8decodebyte(c[i], &type);
     52 		if (type)
     53 			return j;
     54 	}
     55 	if (j < len)
     56 		return 0;
     57 	*u = udecoded;
     58 	utf8validate(u, len);
     59 
     60 	return len;
     61 }
     62 
     63 Drw *
     64 drw_create(Display *dpy, int screen, Window root, unsigned int w, unsigned int h)
     65 {
     66 	Drw *drw = ecalloc(1, sizeof(Drw));
     67 
     68 	drw->dpy = dpy;
     69 	drw->screen = screen;
     70 	drw->root = root;
     71 	drw->w = w;
     72 	drw->h = h;
     73 	drw->drawable = XCreatePixmap(dpy, root, w, h, DefaultDepth(dpy, screen));
     74 	drw->gc = XCreateGC(dpy, root, 0, NULL);
     75 	XSetLineAttributes(dpy, drw->gc, 1, LineSolid, CapButt, JoinMiter);
     76 
     77 	return drw;
     78 }
     79 
     80 void
     81 drw_resize(Drw *drw, unsigned int w, unsigned int h)
     82 {
     83 	if (!drw)
     84 		return;
     85 
     86 	drw->w = w;
     87 	drw->h = h;
     88 	if (drw->drawable)
     89 		XFreePixmap(drw->dpy, drw->drawable);
     90 	drw->drawable = XCreatePixmap(drw->dpy, drw->root, w, h, DefaultDepth(drw->dpy, drw->screen));
     91 }
     92 
     93 void
     94 drw_free(Drw *drw)
     95 {
     96 	XFreePixmap(drw->dpy, drw->drawable);
     97 	XFreeGC(drw->dpy, drw->gc);
     98 	drw_fontset_free(drw->fonts);
     99 	free(drw);
    100 }
    101 
    102 /* This function is an implementation detail. Library users should use
    103  * drw_fontset_create instead.
    104  */
    105 static Fnt *
    106 xfont_create(Drw *drw, const char *fontname, FcPattern *fontpattern)
    107 {
    108 	Fnt *font;
    109 	XftFont *xfont = NULL;
    110 	FcPattern *pattern = NULL;
    111 
    112 	if (fontname) {
    113 		/* Using the pattern found at font->xfont->pattern does not yield the
    114 		 * same substitution results as using the pattern returned by
    115 		 * FcNameParse; using the latter results in the desired fallback
    116 		 * behaviour whereas the former just results in missing-character
    117 		 * rectangles being drawn, at least with some fonts. */
    118 		if (!(xfont = XftFontOpenName(drw->dpy, drw->screen, fontname))) {
    119 			fprintf(stderr, "error, cannot load font from name: '%s'\n", fontname);
    120 			return NULL;
    121 		}
    122 		if (!(pattern = FcNameParse((FcChar8 *) fontname))) {
    123 			fprintf(stderr, "error, cannot parse font name to pattern: '%s'\n", fontname);
    124 			XftFontClose(drw->dpy, xfont);
    125 			return NULL;
    126 		}
    127 	} else if (fontpattern) {
    128 		if (!(xfont = XftFontOpenPattern(drw->dpy, fontpattern))) {
    129 			fprintf(stderr, "error, cannot load font from pattern.\n");
    130 			return NULL;
    131 		}
    132 	} else {
    133 		die("no font specified.");
    134 	}
    135 
    136 	/* Do not allow using color fonts. This is a workaround for a BadLength
    137 	 * error from Xft with color glyphs. Modelled on the Xterm workaround. See
    138 	 * https://bugzilla.redhat.com/show_bug.cgi?id=1498269
    139 	 * https://lists.suckless.org/dev/1701/30932.html
    140 	 * https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=916349
    141 	 * and lots more all over the internet.
    142 	 */
    143 	FcBool iscol;
    144 	if(FcPatternGetBool(xfont->pattern, FC_COLOR, 0, &iscol) == FcResultMatch && iscol) {
    145 		XftFontClose(drw->dpy, xfont);
    146 		return NULL;
    147 	}
    148 
    149 	font = ecalloc(1, sizeof(Fnt));
    150 	font->xfont = xfont;
    151 	font->pattern = pattern;
    152 	font->h = xfont->ascent + xfont->descent;
    153 	font->dpy = drw->dpy;
    154 
    155 	return font;
    156 }
    157 
    158 static void
    159 xfont_free(Fnt *font)
    160 {
    161 	if (!font)
    162 		return;
    163 	if (font->pattern)
    164 		FcPatternDestroy(font->pattern);
    165 	XftFontClose(font->dpy, font->xfont);
    166 	free(font);
    167 }
    168 
    169 Fnt*
    170 drw_fontset_create(Drw* drw, const char *fonts[], size_t fontcount)
    171 {
    172 	Fnt *cur, *ret = NULL;
    173 	size_t i;
    174 
    175 	if (!drw || !fonts)
    176 		return NULL;
    177 
    178 	for (i = 1; i <= fontcount; i++) {
    179 		if ((cur = xfont_create(drw, fonts[fontcount - i], NULL))) {
    180 			cur->next = ret;
    181 			ret = cur;
    182 		}
    183 	}
    184 	return (drw->fonts = ret);
    185 }
    186 
    187 void
    188 drw_fontset_free(Fnt *font)
    189 {
    190 	if (font) {
    191 		drw_fontset_free(font->next);
    192 		xfont_free(font);
    193 	}
    194 }
    195 
    196 void
    197 drw_clr_create(Drw *drw, Clr *dest, const char *clrname)
    198 {
    199 	if (!drw || !dest || !clrname)
    200 		return;
    201 
    202 	if (!XftColorAllocName(drw->dpy, DefaultVisual(drw->dpy, drw->screen),
    203 	                       DefaultColormap(drw->dpy, drw->screen),
    204 	                       clrname, dest))
    205 		die("error, cannot allocate color '%s'", clrname);
    206 }
    207 
    208 /* Wrapper to create color schemes. The caller has to call free(3) on the
    209  * returned color scheme when done using it. */
    210 Clr *
    211 drw_scm_create(Drw *drw, const char *clrnames[], size_t clrcount)
    212 {
    213 	size_t i;
    214 	Clr *ret;
    215 
    216 	/* need at least two colors for a scheme */
    217 	if (!drw || !clrnames || clrcount < 2 || !(ret = ecalloc(clrcount, sizeof(XftColor))))
    218 		die("error, cannot create color scheme (drw=%d) (clrcount=%d)", drw, clrcount);
    219 
    220 	for (i = 0; i < clrcount; i++)
    221 		drw_clr_create(drw, &ret[i], clrnames[i]);
    222 	return ret;
    223 }
    224 
    225 void
    226 drw_setfontset(Drw *drw, Fnt *set)
    227 {
    228 	if (drw)
    229 		drw->fonts = set;
    230 }
    231 
    232 void
    233 drw_setscheme(Drw *drw, Clr *scm)
    234 {
    235 	if (drw)
    236 		drw->scheme = scm;
    237 }
    238 
    239 void
    240 drw_rect(Drw *drw, int x, int y, unsigned int w, unsigned int h, int filled, int invert)
    241 {
    242 	if (!drw || !drw->scheme)
    243 		return;
    244 	XSetForeground(drw->dpy, drw->gc, invert ? drw->scheme[ColBg].pixel : drw->scheme[ColFg].pixel);
    245 	if (filled)
    246 		XFillRectangle(drw->dpy, drw->drawable, drw->gc, x, y, w, h);
    247 	else
    248 		XDrawRectangle(drw->dpy, drw->drawable, drw->gc, x, y, w - 1, h - 1);
    249 }
    250 
    251 int
    252 drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lpad, const char *text, int invert)
    253 {
    254 	char buf[1024];
    255 	int ty;
    256 	unsigned int ew;
    257 	XftDraw *d = NULL;
    258 	Fnt *usedfont, *curfont, *nextfont;
    259 	size_t i, len;
    260 	int utf8strlen, utf8charlen, render = x || y || w || h;
    261 	long utf8codepoint = 0;
    262 	const char *utf8str;
    263 	FcCharSet *fccharset;
    264 	FcPattern *fcpattern;
    265 	FcPattern *match;
    266 	XftResult result;
    267 	int charexists = 0;
    268 
    269 	if (!drw || (render && !drw->scheme) || !text || !drw->fonts)
    270 		return 0;
    271 
    272 	if (!render) {
    273 		w = ~w;
    274 	} else {
    275 		XSetForeground(drw->dpy, drw->gc, drw->scheme[invert ? ColFg : ColBg].pixel);
    276 		XFillRectangle(drw->dpy, drw->drawable, drw->gc, x, y, w, h);
    277 		d = XftDrawCreate(drw->dpy, drw->drawable,
    278 		                  DefaultVisual(drw->dpy, drw->screen),
    279 		                  DefaultColormap(drw->dpy, drw->screen));
    280 		x += lpad;
    281 		w -= lpad;
    282 	}
    283 
    284 	usedfont = drw->fonts;
    285 	while (1) {
    286 		utf8strlen = 0;
    287 		utf8str = text;
    288 		nextfont = NULL;
    289 		while (*text) {
    290 			utf8charlen = utf8decode(text, &utf8codepoint, UTF_SIZ);
    291 			for (curfont = drw->fonts; curfont; curfont = curfont->next) {
    292 				charexists = charexists || XftCharExists(drw->dpy, curfont->xfont, utf8codepoint);
    293 				if (charexists) {
    294 					if (curfont == usedfont) {
    295 						utf8strlen += utf8charlen;
    296 						text += utf8charlen;
    297 					} else {
    298 						nextfont = curfont;
    299 					}
    300 					break;
    301 				}
    302 			}
    303 
    304 			if (!charexists || nextfont)
    305 				break;
    306 			else
    307 				charexists = 0;
    308 		}
    309 
    310 		if (utf8strlen) {
    311 			drw_font_getexts(usedfont, utf8str, utf8strlen, &ew, NULL);
    312 			/* shorten text if necessary */
    313 			for (len = MIN(utf8strlen, sizeof(buf) - 1); len && ew > w; len--)
    314 				drw_font_getexts(usedfont, utf8str, len, &ew, NULL);
    315 
    316 			if (len) {
    317 				memcpy(buf, utf8str, len);
    318 				buf[len] = '\0';
    319 				if (len < utf8strlen)
    320 					for (i = len; i && i > len - 3; buf[--i] = '.')
    321 						; /* NOP */
    322 
    323 				if (render) {
    324 					ty = y + (h - usedfont->h) / 2 + usedfont->xfont->ascent;
    325 					XftDrawStringUtf8(d, &drw->scheme[invert ? ColBg : ColFg],
    326 					                  usedfont->xfont, x, ty, (XftChar8 *)buf, len);
    327 				}
    328 				x += ew;
    329 				w -= ew;
    330 			}
    331 		}
    332 
    333 		if (!*text) {
    334 			break;
    335 		} else if (nextfont) {
    336 			charexists = 0;
    337 			usedfont = nextfont;
    338 		} else {
    339 			/* Regardless of whether or not a fallback font is found, the
    340 			 * character must be drawn. */
    341 			charexists = 1;
    342 
    343 			fccharset = FcCharSetCreate();
    344 			FcCharSetAddChar(fccharset, utf8codepoint);
    345 
    346 			if (!drw->fonts->pattern) {
    347 				/* Refer to the comment in xfont_create for more information. */
    348 				die("the first font in the cache must be loaded from a font string.");
    349 			}
    350 
    351 			fcpattern = FcPatternDuplicate(drw->fonts->pattern);
    352 			FcPatternAddCharSet(fcpattern, FC_CHARSET, fccharset);
    353 			FcPatternAddBool(fcpattern, FC_SCALABLE, FcTrue);
    354 			FcPatternAddBool(fcpattern, FC_COLOR, FcFalse);
    355 
    356 			FcConfigSubstitute(NULL, fcpattern, FcMatchPattern);
    357 			FcDefaultSubstitute(fcpattern);
    358 			match = XftFontMatch(drw->dpy, drw->screen, fcpattern, &result);
    359 
    360 			FcCharSetDestroy(fccharset);
    361 			FcPatternDestroy(fcpattern);
    362 
    363 			if (match) {
    364 				usedfont = xfont_create(drw, NULL, match);
    365 				if (usedfont && XftCharExists(drw->dpy, usedfont->xfont, utf8codepoint)) {
    366 					for (curfont = drw->fonts; curfont->next; curfont = curfont->next)
    367 						; /* NOP */
    368 					curfont->next = usedfont;
    369 				} else {
    370 					xfont_free(usedfont);
    371 					usedfont = drw->fonts;
    372 				}
    373 			}
    374 		}
    375 	}
    376 	if (d)
    377 		XftDrawDestroy(d);
    378 
    379 	return x + (render ? w : 0);
    380 }
    381 
    382 void
    383 drw_map(Drw *drw, Window win, int x, int y, unsigned int w, unsigned int h)
    384 {
    385 	if (!drw)
    386 		return;
    387 
    388 	XCopyArea(drw->dpy, drw->drawable, win, drw->gc, x, y, w, h, x, y);
    389 }
    390 
    391 void
    392 drw_sync(Drw *drw)
    393 {
    394 	XSync(drw->dpy, False);
    395 }
    396 
    397 unsigned int
    398 drw_fontset_getwidth(Drw *drw, const char *text)
    399 {
    400 	if (!drw || !drw->fonts || !text)
    401 		return 0;
    402 	return drw_text(drw, 0, 0, 0, 0, 0, text, 0);
    403 }
    404 
    405 void
    406 drw_font_getexts(Fnt *font, const char *text, unsigned int len, unsigned int *w, unsigned int *h)
    407 {
    408 	XGlyphInfo ext;
    409 
    410 	if (!font || !text)
    411 		return;
    412 
    413 	XftTextExtentsUtf8(font->dpy, font->xfont, (XftChar8 *)text, len, &ext);
    414 	if (w)
    415 		*w = ext.xOff;
    416 	if (h)
    417 		*h = font->h;
    418 }