adg/adg-style.c

   1 /* ADG - Automatic Drawing Generation
   2  * Copyright (C) 2007-2008, Nicola Fontana <ntd at entidi.it>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Library General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA  02111-1307, USA.
  18  */
  19
  20
  21 /**
  22  * SECTION:style
  23  * @title: AdgStyle
  24  * @short_description: The base class of all styling objects.
  25  */
  26
  27 #include "adg-style.h"
  28 #include "adg-style-private.h"
  29 #include "adg-line-style.h"
  30 #include "adg-font-style.h"
  31 #include "adg-arrow-style.h"
  32 #include "adg-enums.h"
  33 #include "adg-util.h"
  34 #include "adg-intl.h"
  35
  36 #include <string.h>
  37
  38 #define PARENT_CLASS ((GObjectClass *) adg_style_parent_class)
  39
  40
  41 enum
  42 {
  43   PROP_0,
  44   PROP_PATTERN
  45 };
  46
  47
  48 static void     get_property            (GObject        *object,
  49                                          guint           prop_id,
  50                                          GValue         *value,
  51                                          GParamSpec     *pspec);
  52 static void     set_property            (GObject        *object,
  53                                          guint           prop_id,
  54                                          const GValue   *value,
  55                                          GParamSpec     *pspec);
  56
  57 static void     apply                   (AdgStyle       *style,
  58                                          cairo_t        *cr);
  59 static void     set_pattern             (AdgStyle       *style,
  60                                          AdgPattern     *pattern);
  61
  62
  63 G_DEFINE_ABSTRACT_TYPE (AdgStyle, adg_style, G_TYPE_OBJECT)
  64
  65
  66 static void
  67 adg_style_class_init (AdgStyleClass *klass)
  68 {
  69   GObjectClass *gobject_class;
  70   GParamSpec   *param;
  71
  72   gobject_class = (GObjectClass *) klass;
  73
  74   g_type_class_add_private (klass, sizeof (AdgStylePrivate));
  75
  76   gobject_class->get_property = get_property;
  77   gobject_class->set_property = set_property;
  78
  79   klass->apply = apply;
  80
  81   param = g_param_spec_boxed ("pattern",
  82                               P_("Pattern"),
  83                               P_("The pattern associated to this style"),
  84                               ADG_TYPE_PATTERN,
  85                               G_PARAM_READWRITE);
  86   g_object_class_install_property (gobject_class, PROP_PATTERN, param);
  87 }
  88
  89 static void
  90 adg_style_init (AdgStyle *style)
  91 {
  92   AdgStylePrivate *priv = G_TYPE_INSTANCE_GET_PRIVATE (style, ADG_TYPE_STYLE,
  93                                                        AdgStylePrivate);
  94
  95   priv->pattern = NULL;
  96
  97   style->priv = priv;
  98 }
  99
 100 static void
 101 get_property (GObject    *object,
 102               guint       prop_id,
 103               GValue     *value,
 104               GParamSpec *pspec)
 105 {
 106   AdgStyle *style = (AdgStyle *) object;
 107
 108   switch (prop_id)
 109     {
 110     case PROP_PATTERN:
 111       g_value_set_boxed (value, style->priv->pattern);
 112       break;
 113     default:
 114       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 115       break;
 116     }
 117 }
 118
 119 static void
 120 set_property (GObject      *object,
 121               guint         prop_id,
 122               const GValue *value,
 123               GParamSpec   *pspec)
 124 {
 125   AdgStyle *style = (AdgStyle *) object;
 126
 127   switch (prop_id)
 128     {
 129     case PROP_PATTERN:
 130       set_pattern (style, g_value_get_boxed (value));
 131       break;
 132     default:
 133       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 134       break;
 135     }
 136 }
 137
 138
 139 /**
 140  * adg_style_apply:
 141  * @style: an #AdgStyle derived object
 142  * @cr: the cairo context
 143  *
 144  * Applies @style to @cr so the next rendering will be done accordling to
 145  * this style directives.
 146  **/
 147 void
 148 adg_style_apply (AdgStyle *style,
 149                  cairo_t  *cr)
 150 {
 151   g_return_if_fail (ADG_IS_STYLE (style));
 152   g_return_if_fail (cr != NULL);
 153
 154   return ADG_STYLE_GET_CLASS (style)->apply (style, cr);
 155 }
 156
 157 /**
 158  * adg_style_get_pattern:
 159  * @style: an #AdgStyle object
 160  *
 161  * Gets the pattern binded to this style. The returned pattern refers to
 162  * an internally managed struct that must not be modified or freed.
 163  *
 164  * Return value: the requested pattern or %NULL on no pattern or errors
 165  **/
 166 const AdgPattern *
 167 adg_style_get_pattern (AdgStyle *style)
 168 {
 169   g_return_val_if_fail (ADG_IS_STYLE (style), NULL);
 170
 171   return style->priv->pattern;
 172 }
 173
 174 /**
 175  * adg_style_set_pattern:
 176  * @style: an #AdgStyle object
 177  * @pattern: the new pattern
 178  *
 179  * Sets a new pattern for this style. This operation will release one
 180  * reference on the old pattern (if any) and will add a new reference
 181  * to @pattern.
 182  *
 183  * A %NULL pattern is allowed: it means the previous pattern is kept
 184  * during the rendering process.
 185  **/
 186 void
 187 adg_style_set_pattern (AdgStyle   *style,
 188                        AdgPattern *pattern)
 189 {
 190   g_return_if_fail (ADG_IS_STYLE (style));
 191   g_return_if_fail (pattern != NULL);
 192
 193   set_pattern (style, pattern);
 194   g_object_notify ((GObject *) style, "pattern");
 195 }
 196
 197
 198 static void
 199 apply (AdgStyle *style,
 200        cairo_t  *cr)
 201 {
 202   if (style->priv->pattern != NULL)
 203     cairo_set_source (cr, style->priv->pattern);
 204 }
 205
 206 static void
 207 set_pattern (AdgStyle   *style,
 208              AdgPattern *pattern)
 209 {
 210   if (style->priv->pattern != NULL)
 211     cairo_pattern_destroy (style->priv->pattern);
 212
 213   if (pattern != NULL)
 214     cairo_pattern_reference (pattern);
 215
 216   style->priv->pattern = pattern;
 217 }