git.sur5r.net Git - glabels/blob - 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 = NULL;
  67
  68         if ( GL_COLOR_F_ALPHA (color) )
  69         {
  70                 gdk_color = g_new0 (GdkColor, 1);
  71
  72                 gdk_color->red   = GL_COLOR_F_RED   (color) * 65535;
  73                 gdk_color->green = GL_COLOR_F_GREEN (color) * 65535;
  74                 gdk_color->blue  = GL_COLOR_F_BLUE  (color) * 65535;
  75         }
  76
  77         return gdk_color;
  78 }
  79
  80 /*****************************************************************************/
  81 /* Convert GdkColor into a gLabels color                                     */
  82 /*****************************************************************************/
  83 guint
  84 gl_color_from_gdk_color (GdkColor *gdk_color)
  85 {
  86         guint color = GL_COLOR_NONE;
  87
  88         if ( gdk_color )
  89         {
  90                 color = GL_COLOR ((gdk_color->red   >>8),
  91                                   (gdk_color->green >>8),
  92                                   (gdk_color->blue  >>8));
  93         }
  94
  95         return color;
  96 }
  97
  98 /****************************************************************************/
  99 /* Create a single color node with default color.                           */
 100 /****************************************************************************/
 101 glColorNode *
 102 gl_color_node_new_default (void)
 103 {
 104         glColorNode* color_node;
 105
 106         color_node = g_new0(glColorNode,1);
 107
 108         color_node->field_flag = FALSE;
 109         color_node->color = GL_COLOR_NONE;
 110         color_node->key = NULL;
 111
 112         return color_node;
 113 }
 114
 115 /****************************************************************************/
 116 /* Copy a single color node.                                                 */
 117 /****************************************************************************/
 118 glColorNode *
 119 gl_color_node_dup (glColorNode *src)
 120 {
 121         glColorNode *dst;
 122
 123         if ( src == NULL ) return NULL;
 124
 125         dst = g_new0 (glColorNode, 1);
 126
 127         dst->field_flag = src->field_flag;
 128         if (src->key != NULL)
 129         {
 130                 dst->key = g_strdup (src->key);
 131         }
 132         else
 133         {
 134                 dst->key = NULL;
 135         }
 136         dst->color = src->color;
 137
 138         return dst;
 139 }
 140
 141 /****************************************************************************/
 142 /* Compare 2 color nodes for equality.                                       */
 143 /****************************************************************************/
 144 gboolean
 145 gl_color_node_equal (glColorNode     *color_node1,
 146                      glColorNode     *color_node2)
 147 {
 148         /* First take care of the case of either or both being NULL. */
 149         if ( color_node1 == NULL )
 150         {
 151                 return ( color_node2 == NULL );
 152         }
 153         else
 154         {
 155                 if ( color_node2 == NULL )
 156                 {
 157                         return FALSE;
 158                 }
 159         }
 160
 161         /* Bail if field flags differ. */
 162         if ( color_node1->field_flag != color_node2->field_flag )
 163         {
 164                 return FALSE;
 165         }
 166
 167         /* Now take care of the case of either or both color fields being different. */
 168         if ( color_node1->color != color_node2->color )
 169         {
 170                 return FALSE;
 171         }
 172
 173         /* Then take care of the case of either or both key fields being NULL. */
 174         if ( color_node1->key == NULL )
 175         {
 176                 return ( color_node2->key == NULL );
 177         }
 178         else
 179         {
 180                 if ( color_node2->key == NULL )
 181                 {
 182                         return FALSE;
 183                 }
 184         }
 185
 186         /* Field flags are identical, so now compare the keys. */
 187         return (strcmp (color_node1->key, color_node2->key) == 0);
 188 }
 189
 190 /****************************************************************************/
 191 /* Expand single node into representative color.                            */
 192 /****************************************************************************/
 193 guint
 194 gl_color_node_expand (glColorNode    *color_node,
 195                       glMergeRecord  *record)
 196 {
 197         gchar    *text;
 198         GdkColor *gdk_color;
 199         guint     color;
 200
 201         if (color_node->field_flag)
 202         {
 203                 if (record == NULL)
 204                 {
 205                         return GL_COLOR_NONE;
 206                 }
 207                 else
 208                 {
 209                         text = gl_merge_eval_key (record, color_node->key);
 210                         if (text != NULL)
 211                         {
 212                                 gdk_color = g_new0 (GdkColor, 1);
 213                                 if (gdk_color_parse (text, gdk_color))
 214                                 {
 215                                         color = gl_color_from_gdk_color (gdk_color);
 216                                         g_free (gdk_color);
 217                                         return color;
 218                                 }
 219                                 else
 220                                 {
 221                                         g_free (gdk_color);
 222                                         return GL_COLOR_NONE;
 223                                 }
 224                         }
 225                         else
 226                         {
 227                                 return GL_COLOR_NONE;
 228                         }
 229                 }
 230         }
 231         else
 232         {
 233                 return color_node->color;
 234         }
 235 }
 236
 237 /****************************************************************************/
 238 /* Free a single color node.                                                */
 239 /****************************************************************************/
 240 void
 241 gl_color_node_free (glColorNode **color_node)
 242 {
 243         if ( *color_node == NULL ) return;
 244
 245         g_free ((*color_node)->key);
 246         (*color_node)->key = NULL;
 247         g_free (*color_node);
 248         *color_node = NULL;
 249 }