Initial revision

1 files changed, 366 insertions, 0 deletions

diff --git a/src/colors.c b/src/colors.c
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+/*
+ * File: colors.c
+ *
+ * Copyright (C) 2000-2005 Jorge Arellano Cid <jcid@dillo.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include "colors.h"
+
+#define DEBUG_LEVEL 5
+#include "debug.h"
+#include "msg.h"
+
+/*
+ * If EXTENDED_COLOR is defined, the extended set of named colors is supported.
+ * These colors're not standard but they're supported in most browsers.
+ * NOTE: The colors MUST be in alphabetical order and lower case because the
+ *       code uses a binary search.
+ */
+
+#define EXTENDED_COLOR
+
+static const struct key {
+   char *key;
+   int32_t val;
+} color_keyword [] = {
+#ifdef EXTENDED_COLOR
+   { "aliceblue", 0xf0f8ff},
+   { "antiquewhite", 0xfaebd7},
+#endif
+   { "aqua", 0x00ffff},
+#ifdef EXTENDED_COLOR
+   { "aquamarine", 0x7fffd4},
+   { "azure", 0xf0ffff},
+   { "beige", 0xf5f5dc},
+   { "bisque", 0xffe4c4},
+#endif
+   { "black", 0x000000},
+#ifdef EXTENDED_COLOR
+   { "blanchedalmond", 0xffebcd},
+#endif
+   {"blue", 0x0000ff},
+#ifdef EXTENDED_COLOR
+   { "blueviolet", 0x8a2be2},
+   { "brown", 0xa52a2a},
+   { "burlywood", 0xdeb887},
+   { "cadetblue", 0x5f9ea0},
+   { "chartreuse", 0x7fff00},
+   { "chocolate", 0xd2691e},
+   { "coral", 0xff7f50},
+   { "cornflowerblue", 0x6495ed},
+   { "cornsilk", 0xfff8dc},
+   { "crimson", 0xdc1436},
+   { "cyan", 0x00ffff},
+   { "darkblue", 0x00008b},
+   { "darkcyan", 0x008b8b},
+   { "darkgoldenrod", 0xb8860b},
+   { "darkgray", 0xa9a9a9},
+   { "darkgreen", 0x006400},
+   { "darkkhaki", 0xbdb76b},
+   { "darkmagenta", 0x8b008b},
+   { "darkolivegreen", 0x556b2f},
+   { "darkorange", 0xff8c00},
+   { "darkorchid", 0x9932cc},
+   { "darkred", 0x8b0000},
+   { "darksalmon", 0xe9967a},
+   { "darkseagreen", 0x8fbc8f},
+   { "darkslateblue", 0x483d8b},
+   { "darkslategray", 0x2f4f4f},
+   { "darkturquoise", 0x00ced1},
+   { "darkviolet", 0x9400d3},
+   { "deeppink", 0xff1493},
+   { "deepskyblue", 0x00bfff},
+   { "dimgray", 0x696969},
+   { "dodgerblue", 0x1e90ff},
+   { "firebrick", 0xb22222},
+   { "floralwhite", 0xfffaf0},
+   { "forestgreen", 0x228b22},
+#endif
+   { "fuchsia", 0xff00ff},
+#ifdef EXTENDED_COLOR
+   { "gainsboro", 0xdcdcdc},
+   { "ghostwhite", 0xf8f8ff},
+   { "gold", 0xffd700},
+   { "goldenrod", 0xdaa520},
+#endif
+   { "gray", 0x808080},
+   { "green", 0x008000},
+#ifdef EXTENDED_COLOR
+   { "greenyellow", 0xadff2f},
+   { "honeydew", 0xf0fff0},
+   { "hotpink", 0xff69b4},
+   { "indianred", 0xcd5c5c},
+   { "indigo", 0x4b0082},
+   { "ivory", 0xfffff0},
+   { "khaki", 0xf0e68c},
+   { "lavender", 0xe6e6fa},
+   { "lavenderblush", 0xfff0f5},
+   { "lawngreen", 0x7cfc00},
+   { "lemonchiffon", 0xfffacd},
+   { "lightblue", 0xadd8e6},
+   { "lightcoral", 0xf08080},
+   { "lightcyan", 0xe0ffff},
+   { "lightgoldenrodyellow", 0xfafad2},
+   { "lightgreen", 0x90ee90},
+   { "lightgrey", 0xd3d3d3},
+   { "lightpink", 0xffb6c1},
+   { "lightsalmon", 0xffa07a},
+   { "lightseagreen", 0x20b2aa},
+   { "lightskyblue", 0x87cefa},
+   { "lightslategray", 0x778899},
+   { "lightsteelblue", 0xb0c4de},
+   { "lightyellow", 0xffffe0},
+#endif
+   { "lime", 0x00ff00},
+#ifdef EXTENDED_COLOR
+   { "limegreen", 0x32cd32},
+   { "linen", 0xfaf0e6},
+   { "magenta", 0xff00ff},
+#endif
+   { "maroon", 0x800000},
+#ifdef EXTENDED_COLOR
+   { "mediumaquamarine", 0x66cdaa},
+   { "mediumblue", 0x0000cd},
+   { "mediumorchid", 0xba55d3},
+   { "mediumpurple", 0x9370db},
+   { "mediumseagreen", 0x3cb371},
+   { "mediumslateblue", 0x7b68ee},
+   { "mediumspringgreen", 0x00fa9a},
+   { "mediumturquoise", 0x48d1cc},
+   { "mediumvioletred", 0xc71585},
+   { "midnightblue", 0x191970},
+   { "mintcream", 0xf5fffa},
+   { "mistyrose", 0xffe4e1},
+   { "moccasin", 0xffe4b5},
+   { "navajowhite", 0xffdead},
+#endif
+   { "navy", 0x000080},
+#ifdef EXTENDED_COLOR
+   { "oldlace", 0xfdf5e6},
+#endif
+   { "olive", 0x808000},
+#ifdef EXTENDED_COLOR
+   { "olivedrab", 0x6b8e23},
+   { "orange", 0xffa500},
+   { "orangered", 0xff4500},
+   { "orchid", 0xda70d6},
+   { "palegoldenrod", 0xeee8aa},
+   { "palegreen", 0x98fb98},
+   { "paleturquoise", 0xafeeee},
+   { "palevioletred", 0xdb7093},
+   { "papayawhip", 0xffefd5},
+   { "peachpuff", 0xffdab9},
+   { "peru", 0xcd853f},
+   { "pink", 0xffc0cb},
+   { "plum", 0xdda0dd},
+   { "powderblue", 0xb0e0e6},
+#endif
+   { "purple", 0x800080},
+   { "red", 0xff0000},
+#ifdef EXTENDED_COLOR
+   { "rosybrown", 0xbc8f8f},
+   { "royalblue", 0x4169e1},
+   { "saddlebrown", 0x8b4513},
+   { "salmon", 0xfa8072},
+   { "sandybrown", 0xf4a460},
+   { "seagreen", 0x2e8b57},
+   { "seashell", 0xfff5ee},
+   { "sienna", 0xa0522d},
+#endif
+   { "silver", 0xc0c0c0},
+#ifdef EXTENDED_COLOR
+   { "skyblue", 0x87ceeb},
+   { "slateblue", 0x6a5acd},
+   { "slategray", 0x708090},
+   { "snow", 0xfffafa},
+   { "springgreen", 0x00ff7f},
+   { "steelblue", 0x4682b4},
+   { "tan", 0xd2b48c},
+#endif
+   { "teal", 0x008080},
+#ifdef EXTENDED_COLOR
+   { "thistle", 0xd8bfd8},
+   { "tomato", 0xff6347},
+   { "turquoise", 0x40e0d0},
+   { "violet", 0xee82ee},
+   { "wheat", 0xf5deb3},
+#endif
+   { "white", 0xffffff},
+#ifdef EXTENDED_COLOR
+   { "whitesmoke", 0xf5f5f5},
+#endif
+   { "yellow", 0xffff00},
+#ifdef EXTENDED_COLOR
+   { "yellowgreen", 0x9acd32},
+#endif
+};
+
+#define NCOLORS   (sizeof(color_keyword) / sizeof(struct key))
+
+/*
+ * Parse a color in hex (RRGGBB)
+ *
+ * Return Value:
+ *   parsed color if successful (err = 0),
+ *   default_color on error (err = 1).
+ */
+static int32_t Color_parse_hex (const char *s, int32_t default_color, int *err)
+{
+  int32_t ret_color;
+  char *tail;
+
+  *err = 1;
+  ret_color = strtol(s, &tail, 16);
+  if (tail - s == 6)
+     *err = 0;
+  else
+     ret_color = default_color;
+
+  return ret_color;
+}
+
+/*
+ * Parse the color info from a subtag.
+ * If subtag string begins with # or with 0x simply return the color number
+ * otherwise search one color from the set of named colors.
+ *
+ * Return Value:
+ *    Parsed color if successful,
+ *    default_color (+ error code) on error.
+ */
+int32_t a_Color_parse (const char *subtag, int32_t default_color, int *err)
+{
+   const char *cp;
+   int32_t ret_color;
+   int ret, low, mid, high, st = 1;
+
+   /* skip leading spaces */
+   for (cp = subtag; isspace(*cp); cp++);
+
+   ret_color = default_color;
+   if (*cp == '#') {
+      ret_color = Color_parse_hex(cp + 1, default_color, &st);
+
+   } else if (*cp == '0' && (cp[1] == 'x' || cp[1] == 'X') ) {
+      ret_color = Color_parse_hex(cp + 2, default_color, &st);
+      st = 2;
+
+   } else {
+      /* Binary search */
+      low = 0;
+      high = NCOLORS - 1;
+      while (low <= high) {
+         mid = (low + high) / 2;
+         if ((ret = dStrcasecmp(cp, color_keyword[mid].key)) < 0)
+            high = mid - 1;
+         else if (ret > 0)
+            low = mid + 1;
+         else {
+            ret_color = color_keyword[mid].val;
+            st = 0;
+            break;
+         }
+      }
+
+      if (low > high) {
+         /* try for RRGGBB lacking the leading '#' */
+         ret_color = Color_parse_hex(cp, default_color, &st);
+         st = 1;
+      }
+   }
+
+   DEBUG_MSG(3, "subtag: %s\n", subtag);
+   DEBUG_MSG(3, "color :  %X\n", ret_color);
+
+   *err = st;
+   return ret_color;
+}
+
+#if 0
+/*
+ * Return a "distance" measure (between [0, 10])
+ */
+static int Color_distance(long c1, long c2)
+{
+   return (labs((c1 & 0x0000ff) - (c2 & 0x0000ff)) +
+           labs(((c1 & 0x00ff00) - (c2 & 0x00ff00)) >> 8)  +
+           labs(((c1 & 0xff0000) - (c2 & 0xff0000)) >> 16)) / 75;
+}
+#endif
+
+/*
+ * Return: [0-3]
+ */
+static int Color_distance2(long c1, long c2)
+{
+   return (labs((c1 & 0x0000ff) - (c2 & 0x0000ff)) >= 0x000060) +
+          (labs((c1 & 0x00ff00) - (c2 & 0x00ff00)) >= 0x006000) +
+          (labs((c1 & 0xff0000) - (c2 & 0xff0000)) >= 0x600000);
+}
+
+/*
+ * Return: [0-3] (requires less contrast than distance2)
+ */
+static int Color_distance3(long c1, long c2)
+{
+   return (labs((c1 & 0x0000ff) - (c2 & 0x0000ff)) >= 0x000040) +
+          (labs((c1 & 0x00ff00) - (c2 & 0x00ff00)) >= 0x004000) +
+          (labs((c1 & 0xff0000) - (c2 & 0xff0000)) >= 0x400000);
+}
+
+/*
+ * Return a suitable "visited link" color
+ * Return value:
+ *   if candidate has good contrast with C_txt, C_lnk and C_bg  -> candidate
+ *   else another color (from the internal list)
+ */
+int32_t a_Color_vc(int32_t candidate, int32_t C_txt, int32_t C_lnk, int32_t C_bg)
+{
+                    /* candidate purple    darkcyan  darkmagenta olive   */
+  static int32_t v[] = {0x000000, 0x800080, 0x008b8b, 0x8b008b, 0x808000,
+                    /* darkred   coral     black                        */
+                       0x8b0000, 0xff7f50, 0x000000};
+  int v_size = sizeof(v) / sizeof(v[0]);
+  int i, max_i, score, max_score, d_bg, d_txt, d_lnk;
+
+
+  /* set candidate in the list */
+  v[0] = candidate;
+
+  /* Try to get good overall and individual contrast */
+  max_i = max_score = 0;
+  for (i = 0; i < v_size; ++i) {
+     _MSG("a_Color_vc: [%d]%.6x: %d %d %d\n", i, v[i],
+         Color_distance2(C_txt, v[i]),
+         Color_distance2(C_lnk, v[i]),
+         Color_distance2(C_bg, v[i]));
+
+     /* Tuned with: slashdot.org, paulgraham.com, newsforge.com,
+      *             linuxjournal.com
+      */
+     d_txt = Color_distance2(C_txt, v[i]);
+     d_lnk = Color_distance2(C_lnk, v[i]);
+     d_bg  = Color_distance2(C_bg, v[i]);
+     score = (d_bg >= 2 ? 4 : 2 * d_bg) +
+             (d_txt + d_lnk >= 2 ? 2 : d_txt + d_lnk) +
+             (Color_distance3(C_lnk, v[i]) >= 1 ? 1 : 0);
+     if (score >= 7) {
+        /* enough distance, use this color */
+        max_i = i;
+        break;
+     } else if (score > max_score) {
+        /* keep track of the best candidate so far */
+        max_score = score;
+        max_i = i;
+     }
+  }
+  return v[max_i];
+}