color-selection.c

   1 /*
   2  * Copyright (c) 2018, S. Gilles <sgilles@math.umd.edu>
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software
   5  * for any purpose with or without fee is hereby granted, provided
   6  * that the above copyright notice and this permission notice appear
   7  * in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
  10  * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
  11  * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
  12  * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
  13  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
  14  * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
  15  * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  16  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18 #include <errno.h>
  19 #include <stdint.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24
  25 #include "macros.h"
  26
  27 /*
  28  * I am fully aware of how ugly this file is, which is why it's specially
  29  * split out, so that it can be completely redone one day, when some
  30  * kind of better solution exists.
  31  */
  32 static uint_fast8_t try_kdialog = 1;
  33 static uint_fast8_t try_qarma = 1;
  34 static uint_fast8_t try_yad = 1;
  35 static uint_fast8_t try_zenity = 1;
  36 static uint_fast8_t try_xdialog = 1;
  37 static char *cmd_kdialog = "kdialog --getcolor 2>/dev/null";
  38 static char *cmd_qarma = "qarma --color-selection 2>/dev/null";
  39 static char *cmd_yad = "yad --color 2>/dev/null";
  40 static char *cmd_zenity = "zenity --color-selection 2>/dev/null";
  41 static char *cmd_xdialog = "Xdialog --stdout --colorsel '' 0 0 2>/dev/null";
  42
  43 /* Convert result of fgetc into [0,16), with special case for EOF */
  44 static int
  45 atoh(int c, uint_fast8_t *early_eof)
  46 {
  47         if (c == EOF) {
  48                 *early_eof = 1;
  49         } else if ('0' <= c &&
  50                    c <= '9') {
  51                 return c - '0';
  52         } else if ('a' <= c &&
  53                    c <= 'f') {
  54                 return c - 'a' + 10;
  55         } else if ('A' <= c &&
  56                    c <= 'F') {
  57                 return c - 'A' + 10;
  58         }
  59
  60         return 0;
  61 }
  62
  63 /* Read in #rrggbb, returned by most of these programs */
  64 static int
  65 read_hex(FILE *f, uint32_t *out_argb, uint_fast8_t *out_affirmed)
  66 {
  67         int ret = 0;
  68         int pret = 0;
  69         uint32_t argb = 0;
  70         uint_fast8_t early_eof = 0;
  71         int c = '#';
  72         int n = 0;
  73
  74         /* ignore leading '#', if there are any */
  75         do {
  76                 c = fgetc(f);
  77                 n++;
  78         }        while (n < 128 &&
  79                         !('0' <= c &&
  80                           c <= '9') &&
  81                         !('a' <= c &&
  82                           c <= 'f') &&
  83                         !('A' <= c &&
  84                           c <= 'F'));
  85
  86         /* r */
  87         argb |= atoh(c, &early_eof) << 20;
  88         argb |= atoh(fgetc(f), &early_eof) << 16;
  89
  90         /* g */
  91         argb |= atoh(fgetc(f), &early_eof) << 12;
  92         argb |= atoh(fgetc(f), &early_eof) << 8;
  93
  94         /* b */
  95         argb |= atoh(fgetc(f), &early_eof) << 4;
  96         argb |= atoh(fgetc(f), &early_eof) << 0;
  97         ret = 0;
  98
  99         /* Sometimes, zenity returns #rrrrggggbbbb */
 100         if (early_eof) {
 101                 goto done;
 102         }
 103
 104         if (fgetc(f) == EOF) {
 105                 goto done;
 106         }
 107
 108         if (fgetc(f) == EOF) {
 109                 goto done;
 110         }
 111
 112         /* We are certainly in #rrrrggggbbbb */
 113         argb = (argb & 0xff0000) | ((argb & 0xff) << 8);
 114         argb |= atoh(fgetc(f), &early_eof) << 4;
 115         argb |= atoh(fgetc(f), &early_eof) << 0;
 116 done:
 117         pret = pclose(f);
 118
 119         if (!ret &&
 120             WIFEXITED(pret) &&
 121             WEXITSTATUS(pret) != 127) {
 122                 *out_argb = argb;
 123                 *out_affirmed = !early_eof;
 124         } else {
 125                 ret = 1;
 126                 *out_argb = 0;
 127                 *out_affirmed = 0;
 128         }
 129
 130         return ret;
 131 }
 132
 133 /* Read in rrr ggg bbb, returned by xdialog */
 134 static int
 135 read_spaced(FILE *f, uint32_t *out_argb, uint_fast8_t *out_affirmed)
 136 {
 137         int ret = 0;
 138         int pret = 0;
 139         int c = 0;
 140         int n = 0;
 141         uint_fast8_t r = 0;
 142         uint_fast8_t g = 0;
 143         uint_fast8_t b = 0;
 144         uint_fast8_t s = 0;
 145
 146         /* r */
 147         s = 0;
 148
 149         while (1) {
 150                 n++;
 151                 c = fgetc(f);
 152
 153                 if (c == EOF ||
 154                     n > 128) {
 155                         *out_affirmed = 0;
 156                         goto done;
 157                 } else if (s &&
 158                            (c == ' ' ||
 159                             c == ',')) {
 160                         break;
 161                 } else if ('0' <= c &&
 162                            c <= '9') {
 163                         r = 10 * r + (c - '0');
 164                         s = 1;
 165                 }
 166         }
 167
 168         /* g */
 169         s = 0;
 170
 171         while (1) {
 172                 n++;
 173                 c = fgetc(f);
 174
 175                 if (c == EOF ||
 176                     n > 128) {
 177                         *out_affirmed = 0;
 178                         goto done;
 179                 } else if (s &&
 180                            (c == ' ' ||
 181                             c == ',')) {
 182                         break;
 183                 } else if ('0' <= c &&
 184                            c <= '9') {
 185                         g = 10 * g + (c - '0');
 186                         s = 1;
 187                 }
 188         }
 189
 190         /* b */
 191         s = 0;
 192
 193         while (1) {
 194                 n++;
 195                 c = fgetc(f);
 196
 197                 if (c == EOF ||
 198                     n > 128) {
 199                         *out_affirmed = s;
 200                         break;
 201                 } else if (s &&
 202                            (c == ' ' ||
 203                             c == ',' ||
 204                             c == ')')) {
 205                         *out_affirmed = 1;
 206                         break;
 207                 } else if ('0' <= c &&
 208                            c <= '9') {
 209                         b = 10 * b + (c - '0');
 210                         s = 1;
 211                 }
 212         }
 213
 214         ret = 0;
 215 done:
 216         pret = pclose(f);
 217
 218         if (!ret &&
 219             WIFEXITED(pret) &&
 220             WEXITSTATUS(pret) != 127) {
 221                 *out_argb = (r << 16) | (g << 8) | (b << 0);
 222         } else {
 223                 ret = 1;
 224                 *out_argb = 0;
 225         }
 226
 227         return ret;
 228 }
 229
 230 /* read in EITHER rgb(rrr,ggg,bbb) or #rrggbb */
 231 static int
 232 read_zenity(FILE *f, uint32_t *out_argb, uint_fast8_t *out_affirmed)
 233 {
 234         int c = fgetc(f);
 235
 236         if (c == 'r') {
 237                 /* Probably zenity's rgb(rrr,ggg,bbb,aaa) thing */
 238                 fgetc(f);
 239                 fgetc(f);
 240                 fgetc(f);
 241
 242                 return read_spaced(f, out_argb, out_affirmed);
 243         } else if (c == '#') {
 244                 return read_hex(f, out_argb, out_affirmed);
 245         }
 246
 247         /* This also covers the EOF case */
 248         *out_affirmed = 0;
 249
 250         return 0;
 251 }
 252
 253 int
 254 choose_color(uint32_t *out_color, uint_fast8_t *out_affirmed)
 255 {
 256         uint32_t argb = 0;
 257         uint_fast8_t affirmed = 0;
 258         int ret = ENOTSUP;
 259         FILE *f = 0;
 260
 261         fflush(0);
 262
 263         if (try_kdialog) {
 264                 if ((f = popen(cmd_kdialog, "r"))) {
 265                         if (!(ret = read_hex(f, &argb, &affirmed))) {
 266                                 goto done;
 267                         }
 268                 }
 269
 270                 try_kdialog = 0;
 271         }
 272
 273         if (try_qarma) {
 274                 if ((f = popen(cmd_qarma, "r"))) {
 275                         if (!(ret = read_hex(f, &argb, &affirmed))) {
 276                                 goto done;
 277                         }
 278                 }
 279
 280                 try_qarma = 0;
 281         }
 282
 283         if (try_yad) {
 284                 if ((f = popen(cmd_yad, "r"))) {
 285                         if (!(ret = read_hex(f, &argb, &affirmed))) {
 286                                 goto done;
 287                         }
 288                 }
 289
 290                 try_yad = 0;
 291         }
 292
 293         if (try_zenity) {
 294                 if ((f = popen(cmd_zenity, "r"))) {
 295                         if (!(ret = read_zenity(f, &argb, &affirmed))) {
 296                                 goto done;
 297                         }
 298                 }
 299
 300                 try_zenity = 0;
 301         }
 302
 303         if (try_xdialog) {
 304                 if ((f = popen(cmd_xdialog, "r"))) {
 305                         if (!(ret = read_spaced(f, &argb, &affirmed))) {
 306                                 goto done;
 307                         }
 308                 }
 309
 310                 try_xdialog = 0;
 311         }
 312
 313         ret = ENOTSUP;
 314 done:
 315
 316         if (!ret) {
 317                 *out_color = argb;
 318                 *out_affirmed = affirmed;
 319         }
 320
 321         return ret;
 322 }