adg/adg-style.c

   1 /* ADG - Automatic Drawing Generation
   2  * Copyright (C) 2007,2008,2009 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 Lesser 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  * Lesser 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., 51 Franklin Street, Fifth Floor,
  17  * Boston, MA  02110-1301, USA.
  18  */
  19
  20
  21 /**
  22  * SECTION:style
  23  * @title: AdgStyle
  24  * @short_description: The base class of all styling objects
  25  *
  26  * This is the fundamental abstract class from which all customization object
  27  * must be derived.
  28  */
  29
  30 #include "adg-style.h"
  31 #include "adg-style-private.h"
  32 #include "adg-line-style.h"
  33 #include "adg-font-style.h"
  34 #include "adg-arrow-style.h"
  35 #include "adg-enums.h"
  36 #include "adg-util.h"
  37 #include "adg-intl.h"
  38
  39 #include <string.h>
  40
  41 #define PARENT_CLASS ((GObjectClass *) adg_style_parent_class)
  42
  43
  44 enum {
  45     PROP_0,
  46     PROP_PATTERN
  47 };
  48
  49
  50 static void             get_property    (GObject        *object,
  51                                          guint           prop_id,
  52                                          GValue         *value,
  53                                          GParamSpec     *pspec);
  54 static void             set_property    (GObject        *object,
  55                                          guint           prop_id,
  56                                          const GValue   *value,
  57                                          GParamSpec     *pspec);
  58 static GPtrArray *      get_pool        (void);
  59 static void             apply           (AdgStyle       *style,
  60                                          cairo_t        *cr);
  61 static void             set_pattern     (AdgStyle       *style,
  62                                          AdgPattern     *pattern);
  63
  64
  65 G_DEFINE_ABSTRACT_TYPE(AdgStyle, adg_style, G_TYPE_OBJECT)
  66
  67
  68 static void
  69 adg_style_class_init(AdgStyleClass *klass)
  70 {
  71     GObjectClass *gobject_class;
  72     GParamSpec *param;
  73
  74     gobject_class = (GObjectClass *) klass;
  75
  76     g_type_class_add_private(klass, sizeof(AdgStylePrivate));
  77
  78     gobject_class->get_property = get_property;
  79     gobject_class->set_property = set_property;
  80
  81     klass->get_pool = get_pool;
  82     klass->apply = apply;
  83
  84     param = g_param_spec_boxed("pattern",
  85                                P_("Pattern"),
  86                                P_("The pattern associated to this style"),
  87                                ADG_TYPE_PATTERN, G_PARAM_READWRITE);
  88     g_object_class_install_property(gobject_class, PROP_PATTERN, param);
  89 }
  90
  91 static void
  92 adg_style_init(AdgStyle *style)
  93 {
  94     AdgStylePrivate *priv =
  95         G_TYPE_INSTANCE_GET_PRIVATE(style, ADG_TYPE_STYLE,
  96                                     AdgStylePrivate);
  97
  98     priv->pattern = NULL;
  99
 100     style->priv = priv;
 101 }
 102
 103 static void
 104 get_property(GObject *object,
 105              guint prop_id, GValue *value, GParamSpec *pspec)
 106 {
 107     AdgStyle *style = (AdgStyle *) object;
 108
 109     switch (prop_id) {
 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, const GValue *value, GParamSpec *pspec)
 122 {
 123     AdgStyle *style = (AdgStyle *) object;
 124
 125     switch (prop_id) {
 126     case PROP_PATTERN:
 127         set_pattern(style, g_value_get_boxed(value));
 128         break;
 129     default:
 130         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 131         break;
 132     }
 133 }
 134
 135
 136 /**
 137  * adg_style_register_id:
 138  * @style: an #AdgStyle derived instance
 139  *
 140  * Registers a new style in the internal register.
 141  *
 142  * Return value: the new id associated to this style or %0 on errors
 143  **/
 144 AdgStyleId
 145 adg_style_register_id(AdgStyle *style)
 146 {
 147     GPtrArray *pool;
 148
 149     g_return_val_if_fail(ADG_IS_STYLE(style), 0);
 150
 151     pool = ADG_STYLE_GET_CLASS(style)->get_pool();
 152     g_return_val_if_fail(pool != NULL, 0);
 153
 154     g_ptr_array_add(pool, style);
 155
 156     return pool->len - 1;
 157 }
 158
 159 /**
 160  * adg_style_from_id:
 161  * @type: the style type id
 162  * @id: the id to get
 163  *
 164  * Gets the preregistered style identified by @id of @style family.
 165  *
 166  * Return value: the requested style or %NULL on errors
 167  **/
 168 AdgStyle *
 169 adg_style_from_id(GType type, AdgStyleId id)
 170 {
 171     AdgStyleClass *klass;
 172     GPtrArray *pool;
 173
 174     klass = g_type_class_ref(type);
 175     g_return_val_if_fail(ADG_IS_STYLE_CLASS(klass), NULL);
 176     pool = klass->get_pool();
 177
 178     /* If @type is valid, @klass will be referenced by the pool items */
 179     g_type_class_unref(klass);
 180
 181     if (id > pool->len)
 182         return NULL;
 183
 184     return (AdgStyle *) g_ptr_array_index(pool, id);
 185 }
 186
 187 AdgStyle *
 188 adg_style_get_default(AdgStyleClass *klass)
 189 {
 190     GPtrArray *pool;
 191
 192     g_return_val_if_fail(ADG_IS_STYLE_CLASS(klass), NULL);
 193
 194     pool = klass->get_pool();
 195     return (AdgStyle *) g_ptr_array_index(pool, 0);
 196 }
 197
 198 /**
 199  * adg_style_apply:
 200  * @style: an #AdgStyle derived object
 201  * @cr: the cairo context
 202  *
 203  * Applies @style to @cr so the next rendering will be done accordling to
 204  * this style directives.
 205  **/
 206 void
 207 adg_style_apply(AdgStyle *style, cairo_t *cr)
 208 {
 209     g_return_if_fail(ADG_IS_STYLE(style));
 210     g_return_if_fail(cr != NULL);
 211
 212     return ADG_STYLE_GET_CLASS(style)->apply(style, cr);
 213 }
 214
 215 /**
 216  * adg_style_get_pattern:
 217  * @style: an #AdgStyle object
 218  *
 219  * Gets the pattern binded to this style. The returned pattern refers to
 220  * an internally managed struct that must not be modified or freed.
 221  *
 222  * Return value: the requested pattern or %NULL on no pattern or errors
 223  **/
 224 const AdgPattern *
 225 adg_style_get_pattern(AdgStyle *style)
 226 {
 227     g_return_val_if_fail(ADG_IS_STYLE(style), NULL);
 228
 229     return style->priv->pattern;
 230 }
 231
 232 /**
 233  * adg_style_set_pattern:
 234  * @style: an #AdgStyle object
 235  * @pattern: the new pattern
 236  *
 237  * Sets a new pattern for this style. This operation will release one
 238  * reference on the old pattern (if any) and will add a new reference
 239  * to @pattern.
 240  *
 241  * A %NULL pattern is allowed: it means the previous pattern is kept
 242  * during the rendering process.
 243  **/
 244 void
 245 adg_style_set_pattern(AdgStyle *style, AdgPattern *pattern)
 246 {
 247     g_return_if_fail(ADG_IS_STYLE(style));
 248     g_return_if_fail(pattern != NULL);
 249
 250     set_pattern(style, pattern);
 251     g_object_notify((GObject *) style, "pattern");
 252 }
 253
 254
 255 static GPtrArray *
 256 get_pool(void)
 257 {
 258     g_warning("Uninmplemented get_pool()");
 259     return NULL;
 260 }
 261
 262 static void
 263 apply(AdgStyle *style, cairo_t *cr)
 264 {
 265     if (style->priv->pattern != NULL)
 266         cairo_set_source(cr, style->priv->pattern);
 267 }
 268
 269 static void
 270 set_pattern(AdgStyle *style, AdgPattern *pattern)
 271 {
 272     if (style->priv->pattern != NULL)
 273         cairo_pattern_destroy(style->priv->pattern);
 274
 275     if (pattern != NULL)
 276         cairo_pattern_reference(pattern);
 277
 278     style->priv->pattern = pattern;
 279 }