src/adg/adg-textual.c

   1 /* ADG - Automatic Drawing Generation
   2  * Copyright (C) 2007-2021  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                      g_cclosure_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 <function>set_text</function>
 206  * virtual method is called and the #AdgTextual::text-changed signal
 207  * is emitted.
 208  *
 209  * Since: 1.0
 210  **/
 211 void
 212 adg_textual_set_text(AdgTextual *textual, const gchar *text)
 213 {
 214     AdgTextualIface *iface;
 215     gchar *old_text;
 216
 217     g_return_if_fail(ADG_IS_TEXTUAL(textual));
 218
 219     /* The set_text() method must be defined */
 220     iface = ADG_TEXTUAL_GET_IFACE(textual);
 221     if (iface->set_text == NULL) {
 222         g_warning(_("%s: 'set_text' method not implemented for type '%s'"),
 223                   G_STRLOC, g_type_name(G_OBJECT_TYPE(textual)));
 224         return;
 225     }
 226
 227     old_text = _adg_dup_text(textual, iface);
 228     if (g_strcmp0(text, old_text) != 0) {
 229         iface->set_text(textual, text);
 230         g_signal_emit(textual, _adg_signals[TEXT_CHANGED], 0, old_text);
 231     }
 232
 233     g_free(old_text);
 234 }
 235
 236 /**
 237  * adg_textual_dup_text:
 238  * @textual: an object that implements #AdgTextual
 239  *
 240  * Gets a duplicate of the current text bound to @textual.
 241  *
 242  * Returns: the current text of @textual: free with g_free() when finished
 243  *
 244  * Since: 1.0
 245  **/
 246 gchar *
 247 adg_textual_dup_text(AdgTextual *textual)
 248 {
 249     g_return_val_if_fail(ADG_IS_TEXTUAL(textual), NULL);
 250
 251     return _adg_dup_text(textual, ADG_TEXTUAL_GET_IFACE(textual));
 252 }
 253
 254 /**
 255  * adg_textual_text_changed:
 256  * @textual: an object that implements #AdgTextual
 257  * @old_text: the old text bound to @textual
 258  *
 259  * Emits the #AdgTextual::text-changed signal on @textual.
 260  *
 261  * <note><para>
 262  * This function is only useful when creating a new class that implements
 263  * the #AdgTextual interface.
 264  * </para></note>
 265  *
 266  * Since: 1.0
 267  **/
 268 void
 269 adg_textual_text_changed(AdgTextual *textual, const gchar *old_text)
 270 {
 271     g_return_if_fail(ADG_IS_TEXTUAL(textual));
 272
 273     g_signal_emit(textual, _adg_signals[TEXT_CHANGED], 0, old_text);
 274 }
 275
 276
 277 static gchar *
 278 _adg_dup_text(AdgTextual *textual, AdgTextualIface *iface)
 279 {
 280     if (iface->dup_text == NULL) {
 281         g_warning(_("%s: 'dup_text' method not implemented for type '%s'"),
 282                   G_STRLOC, g_type_name(G_OBJECT_TYPE(textual)));
 283         return NULL;
 284     }
 285
 286     return iface->dup_text(textual);
 287 }