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:adg-style
  23  * @short_description: The base class of all styling objects
  24  *
  25  * This is the fundamental abstract class for styles.
  26  **/
  27
  28 /**
  29  * AdgStyle:
  30  *
  31  * All fields are private and should not be used directly.
  32  * Use its public methods instead.
  33  **/
  34
  35
  36 #include "adg-style.h"
  37
  38
  39 static void             apply           (AdgStyle       *style,
  40                                          cairo_t        *cr);
  41
  42
  43 G_DEFINE_ABSTRACT_TYPE(AdgStyle, adg_style, G_TYPE_OBJECT);
  44
  45
  46 static void
  47 adg_style_class_init(AdgStyleClass *klass)
  48 {
  49     klass->apply = apply;
  50 }
  51
  52 static void
  53 adg_style_init(AdgStyle *style)
  54 {
  55 }
  56
  57
  58 /**
  59  * adg_style_apply:
  60  * @style: an #AdgStyle derived style
  61  * @cr: the subject cairo context
  62  *
  63  * Applies @style to @cr so the next rendering operations will be done
  64  * accordling to this style directives.
  65  **/
  66 void
  67 adg_style_apply(AdgStyle *style, cairo_t *cr)
  68 {
  69     g_return_if_fail(ADG_IS_STYLE(style));
  70     g_return_if_fail(cr != NULL);
  71
  72     ADG_STYLE_GET_CLASS(style)->apply(style, cr);
  73 }
  74
  75
  76 static void
  77 apply(AdgStyle *style, cairo_t *cr)
  78 {
  79     /* The apply method must be defined */
  80     g_warning("%s: `apply' method not implemented for type `%s'",
  81               G_STRLOC, g_type_name(G_OBJECT_TYPE(style)));
  82 }