src/adg/adg-textual.c

   1 /* ADG - Automatic Drawing Generation
   2  * Copyright (C) 2007,2008,2009,2010,2011,2012,2013  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-textual
  23  * @Section_Id:AdgTextual
  24  * @title: AdgTextual
  25  * @short_description: An interface for entities that embeds text
  26  *
  27  * The #AdgTextual interface should be implemented by entities that
  28  * can be expressed by text. #AdgToyText is a typical case but also
  29  * more complex entities could implement it.
  30  *
  31  * Since: 1.0
  32  **/
  33
  34 /**
  35  * AdgTextual:
  36  *
  37  * Dummy type of the #AdgTextualIface interface.
  38  *
  39  * Since: 1.0
  40  **/
  41
  42 /**
  43  * AdgTextualIface:
  44  * @set_font_dress: abstract virtual method to change the font dress.
  45  * @get_font_dress: abstract virtual method to get the active font dress.
  46  * @set_text:       abstract virtual method to set a new text.
  47  * @dup_text:       abstract virtual method that returns a duplicate of
  48  *                  the actual text.
  49  * @text_changed:   default signal handler for #AdgTextual::text-changed.
  50  *
  51  * The virtual methods @set_text and @dup_text must be implemented
  52  * by all the types which implement this interface.
  53  *
  54  * Since: 1.0
  55  **/
  56
  57
  58 #include "adg-internal.h"
  59 #include "adg-dress.h"
  60 #include "adg-param-dress.h"
  61
  62 #include "adg-textual.h"
  63
  64
  65 enum {
  66     TEXT_CHANGED,
  67     LAST_SIGNAL
  68 };
  69
  70
  71 static void     _adg_iface_base         (AdgTextualIface *iface);
  72 static gchar *  _adg_dup_text           (AdgTextual      *textual,
  73                                          AdgTextualIface *iface);
  74 static guint    _adg_signals[LAST_SIGNAL] = { 0 };
  75
  76
  77 GType
  78 adg_textual_get_type(void)
  79 {
  80     static GType textual_type = 0;
  81
  82     if (G_UNLIKELY(textual_type == 0)) {
  83         const GTypeInfo textual_info = {
  84             sizeof(AdgTextualIface),
  85             (GBaseInitFunc)      _adg_iface_base,
  86             (GBaseFinalizeFunc)  NULL,
  87             (GClassInitFunc)     NULL,
  88             (GClassFinalizeFunc) NULL,
  89         };
  90         textual_type = g_type_register_static(G_TYPE_INTERFACE, "AdgTextual",
  91                                               &textual_info, 0);
  92         g_type_interface_add_prerequisite(ADG_TYPE_TEXTUAL, G_TYPE_OBJECT);
  93     }
  94
  95     return textual_type;
  96 }
  97
  98 static void
  99 _adg_iface_base(AdgTextualIface *iface)
 100 {
 101     static gboolean initialized = FALSE;
 102     GParamSpec *param;
 103
 104     if (G_LIKELY(initialized))
 105         return;
 106
 107     initialized = TRUE;
 108
 109     param = g_param_spec_string("text",
 110                                 P_("Text"),
 111                                 P_("The text associated to this entity"),
 112                                 NULL,
 113                                 G_PARAM_READWRITE);
 114     g_object_interface_install_property(iface, param);
 115
 116     param = adg_param_spec_dress("font-dress",
 117                                  P_("Font Dress"),
 118                                  P_("The font dress to use for rendering this text"),
 119                                  ADG_DRESS_FONT_TEXT,
 120                                  G_PARAM_READWRITE);
 121     g_object_interface_install_property(iface, param);
 122
 123     /**
 124      * AdgTextual::text-changed:
 125      * @textual: an entity that implements #AdgTextual
 126      * @old_text: the old text
 127      *
 128      * Emitted whenever the text of @textual has been changed.
 129      *
 130      * Since: 1.0
 131      **/
 132     _adg_signals[TEXT_CHANGED] =
 133         g_signal_new("text-changed",
 134                      G_OBJECT_CLASS_TYPE(iface),
 135                      G_SIGNAL_RUN_LAST,
 136                      G_STRUCT_OFFSET(AdgTextualIface, text_changed),
 137                      NULL, NULL,
 138                      adg_marshal_VOID__POINTER,
 139                      G_TYPE_NONE, 1, G_TYPE_POINTER);
 140 }
 141
 142
 143 /**
 144  * adg_textual_set_font_dress:
 145  * @textual: an object that implements #AdgTextual
 146  * @dress: the new dress
 147  *
 148  * Sets the font dress of @textual to @dress.
 149  *
 150  * Since: 1.0
 151  **/
 152 void
 153 adg_textual_set_font_dress(AdgTextual *textual, AdgDress dress)
 154 {
 155     AdgTextualIface *iface;
 156
 157     g_return_if_fail(ADG_IS_TEXTUAL(textual));
 158
 159     /* The set_font_dress() method must be defined */
 160     iface = ADG_TEXTUAL_GET_IFACE(textual);
 161     if (iface->set_font_dress == NULL) {
 162         g_warning(_("%s: `set_font_dress' method not implemented for type `%s'"),
 163                   G_STRLOC, g_type_name(G_OBJECT_TYPE(textual)));
 164         return;
 165     }
 166
 167     iface->set_font_dress(textual, dress);
 168 }
 169
 170 /**
 171  * adg_textual_get_font_dress:
 172  * @textual: an object that implements #AdgTextual
 173  *
 174  * Gets the current font dress of @textual, eventually resolved to
 175  * an #AdgFontStyle before the rendering.
 176  *
 177  * Returns: (transfer none): the current font dress of @textual.
 178  *
 179  * Since: 1.0
 180  **/
 181 AdgDress
 182 adg_textual_get_font_dress(AdgTextual *textual)
 183 {
 184     AdgTextualIface *iface;
 185
 186     g_return_val_if_fail(ADG_IS_TEXTUAL(textual), ADG_DRESS_UNDEFINED);
 187
 188     /* The get_font_dress() method must be defined */
 189     iface = ADG_TEXTUAL_GET_IFACE(textual);
 190     if (iface->get_font_dress == NULL) {
 191         g_warning(_("%s: `get_font_dress' method not implemented for type `%s'"),
 192                   G_STRLOC, g_type_name(G_OBJECT_TYPE(textual)));
 193         return ADG_DRESS_UNDEFINED;
 194     }
 195
 196     return iface->get_font_dress(textual);
 197 }
 198
 199 /**
 200  * adg_textual_set_text:
 201  * @textual: an object that implements #AdgTextual
 202  * @text: the new text to be set
 203  *
 204  * Sets a new text on @textual. If @text is the same as the old text
 205  * no actions are performed, otherwise the set_text() virtual method
 206  * is called and the #AdgTextual::text-changed signal is emitted.
 207  *
 208  * Since: 1.0
 209  **/
 210 void
 211 adg_textual_set_text(AdgTextual *textual, const gchar *text)
 212 {
 213     AdgTextualIface *iface;
 214     gchar *old_text;
 215
 216     g_return_if_fail(ADG_IS_TEXTUAL(textual));
 217
 218     /* The set_text() method must be defined */
 219     iface = ADG_TEXTUAL_GET_IFACE(textual);
 220     if (iface->set_text == NULL) {
 221         g_warning(_("%s: `set_text' method not implemented for type `%s'"),
 222                   G_STRLOC, g_type_name(G_OBJECT_TYPE(textual)));
 223         return;
 224     }
 225
 226     old_text = _adg_dup_text(textual, iface);
 227     if (g_strcmp0(text, old_text) != 0) {
 228         iface->set_text(textual, text);
 229         g_signal_emit(textual, _adg_signals[TEXT_CHANGED], 0, old_text);
 230     }
 231
 232     g_free(old_text);
 233 }
 234
 235 /**
 236  * adg_textual_dup_text:
 237  * @textual: an object that implements #AdgTextual
 238  *
 239  * Gets a duplicate of the current text bound to @textual.
 240  *
 241  * Returns: the current text of @textual: free with g_free() when finished
 242  *
 243  * Since: 1.0
 244  **/
 245 gchar *
 246 adg_textual_dup_text(AdgTextual *textual)
 247 {
 248     g_return_val_if_fail(ADG_IS_TEXTUAL(textual), NULL);
 249
 250     return _adg_dup_text(textual, ADG_TEXTUAL_GET_IFACE(textual));
 251 }
 252
 253 /**
 254  * adg_textual_text_changed:
 255  * @textual: an object that implements #AdgTextual
 256  * @old_text: the old text bound to @textual
 257  *
 258  * Emits the #AdgTextual::text-changed signal on @textual.
 259  *
 260  * <note><para>
 261  * This function is only useful when creating a new class that implements
 262  * the #AdgTextual interface.
 263  * </para></note>
 264  *
 265  * Since: 1.0
 266  **/
 267 void
 268 adg_textual_text_changed(AdgTextual *textual, const gchar *old_text)
 269 {
 270     g_return_if_fail(ADG_IS_TEXTUAL(textual));
 271
 272     g_signal_emit(textual, _adg_signals[TEXT_CHANGED], 0, old_text);
 273 }
 274
 275
 276 static gchar *
 277 _adg_dup_text(AdgTextual *textual, AdgTextualIface *iface)
 278 {
 279     if (iface->dup_text == NULL) {
 280         g_warning(_("%s: `dup_text' method not implemented for type `%s'"),
 281                   G_STRLOC, g_type_name(G_OBJECT_TYPE(textual)));
 282         return NULL;
 283     }
 284
 285     return iface->dup_text(textual);
 286 }