git.sur5r.net Git - glabels/blob - glabels2/src/color.c

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*- */
   2
   3 /*
   4  *  (GLABELS) Label and Business Card Creation program for GNOME
   5  *
   6  *  color.c:  various small utilities for dealing with canvas colors
   7  *
   8  *  Copyright (C) 2002-2007  Jim Evins <evins@snaught.com>.
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to the Free Software
  22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  23  */
  24 #include <config.h>
  25
  26 #include "color.h"
  27
  28 #include <string.h>
  29
  30 /*****************************************************************************/
  31 /* Apply given opacity to given color.                                       */
  32 /*****************************************************************************/
  33 guint
  34 gl_color_set_opacity (guint   color,
  35                       gdouble opacity)
  36 {
  37         guint new_color;
  38
  39         new_color = (color & 0xFFFFFF00) | (((guint)(255.0*opacity)) & 0xFF);
  40
  41         return new_color;
  42 }
  43
  44 /*****************************************************************************/
  45 /* Resolve actual shadow color by adjusting opacity.                         */
  46 /*****************************************************************************/
  47 guint
  48 gl_color_shadow (guint   base_color,
  49                  gdouble opacity,
  50                  guint   object_color)
  51 {
  52         guint color;
  53
  54         color = gl_color_set_opacity (base_color,
  55                                       opacity * GL_COLOR_F_ALPHA (object_color));
  56
  57         return color;
  58 }
  59
  60 /*****************************************************************************/
  61 /* Convert gLabels color into a GdkColor                                     */
  62 /*****************************************************************************/
  63 GdkColor *
  64 gl_color_to_gdk_color (guint color)
  65 {
  66         GdkColor *gdk_color;
  67
  68         gdk_color = g_new0 (GdkColor, 1);
  69
  70         gdk_color->red   = GL_COLOR_F_RED   (color) * 65535;
  71         gdk_color->green = GL_COLOR_F_GREEN (color) * 65535;
  72         gdk_color->blue  = GL_COLOR_F_BLUE  (color) * 65535;
  73
  74         return gdk_color;
  75 }
  76
  77 /*****************************************************************************/
  78 /* Convert GdkColor into a gLabels color                                     */
  79 /*****************************************************************************/
  80 guint
  81 gl_color_from_gdk_color (GdkColor *gdk_color)
  82 {
  83         guint color;
  84
  85         color = GL_COLOR ((gdk_color->red   >>8),
  86                           (gdk_color->green >>8),
  87                           (gdk_color->blue  >>8));
  88
  89         return color;
  90 }
  91
  92 /****************************************************************************/
  93 /* Create a single color node with default color.                           */
  94 /****************************************************************************/
  95 glColorNode *
  96 gl_color_node_new_default (void)
  97 {
  98         glColorNode* color_node;
  99
 100         color_node = g_new0(glColorNode,1);
 101
 102         color_node->field_flag = FALSE;
 103         color_node->color = GL_COLOR_NONE;
 104         color_node->key = NULL;
 105
 106         return color_node;
 107 }
 108
 109 /****************************************************************************/
 110 /* Copy a single color node.                                                 */
 111 /****************************************************************************/
 112 glColorNode *
 113 gl_color_node_dup (glColorNode *src)
 114 {
 115         glColorNode *dst;
 116
 117         if ( src == NULL ) return NULL;
 118
 119         dst = g_new0 (glColorNode, 1);
 120
 121         dst->field_flag = src->field_flag;
 122         if (src->key != NULL)
 123         {
 124                 dst->key = g_strdup (src->key);
 125         }
 126         else
 127         {
 128                 dst->key = NULL;
 129         }
 130         dst->color = src->color;
 131
 132         return dst;
 133 }
 134
 135 /****************************************************************************/
 136 /* Compare 2 color nodes for equality.                                       */
 137 /****************************************************************************/
 138 gboolean
 139 gl_color_node_equal (glColorNode     *color_node1,
 140                      glColorNode     *color_node2)
 141 {
 142         /* First take care of the case of either or both being NULL. */
 143         if ( color_node1 == NULL )
 144         {
 145                 return ( color_node2 == NULL );
 146         }
 147         else
 148         {
 149                 if ( color_node2 == NULL )
 150                 {
 151                         return FALSE;
 152                 }
 153         }
 154
 155         /* Bail if field flags differ. */
 156         if ( color_node1->field_flag != color_node2->field_flag )
 157         {
 158                 return FALSE;
 159         }
 160
 161         /* Now take care of the case of either or both color fields being different. */
 162         if ( color_node1->color != color_node2->color )
 163         {
 164                 return FALSE;
 165         }
 166
 167         /* Then take care of the case of either or both key fields being NULL. */
 168         if ( color_node1->key == NULL )
 169         {
 170                 return ( color_node2->key == NULL );
 171         }
 172         else
 173         {
 174                 if ( color_node2->key == NULL )
 175                 {
 176                         return FALSE;
 177                 }
 178         }
 179
 180         /* Field flags are identical, so now compare the keys. */
 181         return (strcmp (color_node1->key, color_node2->key) == 0);
 182 }
 183
 184 /****************************************************************************/
 185 /* Expand single node into representative color.                            */
 186 /****************************************************************************/
 187 guint
 188 gl_color_node_expand (glColorNode    *color_node,
 189                       glMergeRecord  *record)
 190 {
 191         gchar    *text;
 192         GdkColor *gdk_color;
 193         guint     color;
 194
 195         if (color_node->field_flag)
 196         {
 197                 if (record == NULL)
 198                 {
 199                         return GL_COLOR_NONE;
 200                 }
 201                 else
 202                 {
 203                         text = gl_merge_eval_key (record, color_node->key);
 204                         if (text != NULL)
 205                         {
 206                                 gdk_color = g_new0 (GdkColor, 1);
 207                                 if (gdk_color_parse (text, gdk_color))
 208                                 {
 209                                         color = gl_color_from_gdk_color (gdk_color);
 210                                         g_free (gdk_color);
 211                                         return color;
 212                                 }
 213                                 else
 214                                 {
 215                                         g_free (gdk_color);
 216                                         return GL_COLOR_NONE;
 217                                 }
 218                         }
 219                         else
 220                         {
 221                                 return GL_COLOR_NONE;
 222                         }
 223                 }
 224         }
 225         else
 226         {
 227                 return color_node->color;
 228         }
 229 }
 230
 231 /****************************************************************************/
 232 /* Free a single color node.                                                */
 233 /****************************************************************************/
 234 void
 235 gl_color_node_free (glColorNode **color_node)
 236 {
 237         if ( *color_node == NULL ) return;
 238
 239         g_free ((*color_node)->key);
 240         (*color_node)->key = NULL;
 241         g_free (*color_node);
 242         *color_node = NULL;
 243 }