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