clutter/clutter-content.c

   1 /*
   2  * Clutter.
   3  *
   4  * An OpenGL based 'interactive canvas' library.
   5  *
   6  * Copyright (C) 2011  Intel Corporation.
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library. If not, see <http://www.gnu.org/licenses/>.
  20  *
  21  * Author:
  22  *   Emmanuele Bassi <ebassi@linux.intel.com>
  23  */
  24
  25 /**
  26  * SECTION:clutter-content
  27  * @Title: ClutterContent
  28  * @Short_Description: Delegate for painting the content of an actor
  29  *
  30  * #ClutterContent is an interface to implement types responsible for
  31  * painting the content of a #ClutterActor.
  32  *
  33  * Multiple actors can use the same #ClutterContent instance, in order
  34  * to share the resources associated with painting the same content.
  35  *
  36  * #ClutterContent is available since Clutter 1.10.
  37  */
  38
  39 #ifdef HAVE_CONFIG_H
  40 #include "config.h"
  41 #endif
  42
  43 #include "clutter-content-private.h"
  44
  45 #include "clutter-debug.h"
  46 #include "clutter-marshal.h"
  47 #include "clutter-private.h"
  48
  49 typedef struct _ClutterContentIface     ClutterContentInterface;
  50
  51 enum
  52 {
  53   ATTACHED,
  54   DETACHED,
  55
  56   LAST_SIGNAL
  57 };
  58
  59 static GQuark quark_content_actors = 0;
  60
  61 static guint content_signals[LAST_SIGNAL] = { 0, };
  62
  63 G_DEFINE_INTERFACE (ClutterContent, clutter_content, G_TYPE_OBJECT)
  64
  65 static gboolean
  66 clutter_content_real_get_preferred_size (ClutterContent *content,
  67                                          gfloat         *width,
  68                                          gfloat         *height)
  69 {
  70   if (width != NULL)
  71     *width = 0.f;
  72
  73   if (height != NULL)
  74     *height = 0.f;
  75
  76   return FALSE;
  77 }
  78
  79 static void
  80 clutter_content_real_attached (ClutterContent *content,
  81                                ClutterActor   *actor)
  82 {
  83 }
  84
  85 static void
  86 clutter_content_real_detached (ClutterContent *content,
  87                                ClutterActor   *actor)
  88 {
  89 }
  90
  91 static void
  92 clutter_content_real_invalidate (ClutterContent *content)
  93 {
  94 }
  95
  96 static void
  97 clutter_content_real_paint_content (ClutterContent   *content,
  98                                     ClutterActor     *actor,
  99                                     ClutterPaintNode *context)
 100 {
 101 }
 102
 103 static void
 104 clutter_content_default_init (ClutterContentInterface *iface)
 105 {
 106   quark_content_actors = g_quark_from_static_string ("-clutter-content-actors");
 107
 108   iface->get_preferred_size = clutter_content_real_get_preferred_size;
 109   iface->paint_content = clutter_content_real_paint_content;
 110   iface->attached = clutter_content_real_attached;
 111   iface->detached = clutter_content_real_detached;
 112   iface->invalidate = clutter_content_real_invalidate;
 113
 114   /**
 115    * ClutterContent::attached:
 116    * @content: the object that emitted the signal
 117    * @actor: a #ClutterActor
 118    *
 119    * This signal is emitted each time a #ClutterContent implementation is
 120    * assigned to a #ClutterActor.
 121    *
 122    * Since: 1.10
 123    */
 124   content_signals[ATTACHED] =
 125     g_signal_new (I_("attached"),
 126                   G_TYPE_FROM_INTERFACE (iface),
 127                   G_SIGNAL_RUN_FIRST,
 128                   G_STRUCT_OFFSET (ClutterContentIface, attached),
 129                   NULL, NULL,
 130                   _clutter_marshal_VOID__OBJECT,
 131                   G_TYPE_NONE, 1,
 132                   CLUTTER_TYPE_ACTOR);
 133
 134   /**
 135    * ClutterContent::detached:
 136    * @content: the object that emitted the signal
 137    * @actor: a #ClutterActor
 138    *
 139    * This signal is emitted each time a #ClutterContent implementation is
 140    * removed from a #ClutterActor.
 141    *
 142    * Since: 1.10
 143    */
 144   content_signals[DETACHED] =
 145     g_signal_new (I_("detached"),
 146                   G_TYPE_FROM_INTERFACE (iface),
 147                   G_SIGNAL_RUN_FIRST,
 148                   G_STRUCT_OFFSET (ClutterContentIface, detached),
 149                   NULL, NULL,
 150                   _clutter_marshal_VOID__OBJECT,
 151                   G_TYPE_NONE, 1,
 152                   CLUTTER_TYPE_ACTOR);
 153 }
 154
 155 /**
 156  * clutter_content_invalidate:
 157  * @content: a #ClutterContent
 158  *
 159  * Invalidates a #ClutterContent.
 160  *
 161  * This function should be called by #ClutterContent implementations when
 162  * they change the way a the content should be painted regardless of the
 163  * actor state.
 164  *
 165  * Since: 1.10
 166  */
 167 void
 168 clutter_content_invalidate (ClutterContent *content)
 169 {
 170   GHashTable *actors;
 171   GHashTableIter iter;
 172   gpointer key_p, value_p;
 173
 174   g_return_if_fail (CLUTTER_IS_CONTENT (content));
 175
 176   CLUTTER_CONTENT_GET_IFACE (content)->invalidate (content);
 177
 178   actors = g_object_get_qdata (G_OBJECT (content), quark_content_actors);
 179   if (actors == NULL)
 180     return;
 181
 182   g_hash_table_iter_init (&iter, actors);
 183   while (g_hash_table_iter_next (&iter, &key_p, &value_p))
 184     {
 185       ClutterActor *actor = key_p;
 186
 187       g_assert (actor != NULL);
 188
 189       clutter_actor_queue_redraw (actor);
 190     }
 191 }
 192
 193 /*< private >
 194  * _clutter_content_attached:
 195  * @content: a #ClutterContent
 196  * @actor: a #ClutterActor
 197  *
 198  * Attaches @actor to the @content.
 199  *
 200  * This function should be used internally every time a #ClutterActor
 201  * is associated to a #ClutterContent, to set up a backpointer from
 202  * the @content to the @actor.
 203  *
 204  * This function will invoke the #ClutterContentIface.attached() virtual
 205  * function.
 206  */
 207 void
 208 _clutter_content_attached (ClutterContent *content,
 209                            ClutterActor   *actor)
 210 {
 211   GObject *obj = G_OBJECT (content);
 212   GHashTable *actors;
 213
 214   actors = g_object_get_qdata (obj, quark_content_actors);
 215   if (actors == NULL)
 216     {
 217       actors = g_hash_table_new (NULL, NULL);
 218       g_object_set_qdata_full (obj, quark_content_actors,
 219                                actors,
 220                                (GDestroyNotify) g_hash_table_unref);
 221     }
 222
 223   g_hash_table_insert (actors, actor, actor);
 224
 225   g_signal_emit (content, content_signals[ATTACHED], 0, actor);
 226 }
 227
 228 /*< private >
 229  * _clutter_content_detached:
 230  * @content: a #ClutterContent
 231  * @actor: a #ClutterActor
 232  *
 233  * Detaches @actor from @content.
 234  *
 235  * This function should be used internally every time a #ClutterActor
 236  * removes the association with a #ClutterContent.
 237  *
 238  * This function will invoke the #ClutterContentIface.detached() virtual
 239  * function.
 240  */
 241 void
 242 _clutter_content_detached (ClutterContent *content,
 243                            ClutterActor   *actor)
 244 {
 245   GObject *obj = G_OBJECT (content);
 246   GHashTable *actors;
 247
 248   actors = g_object_get_qdata (obj, quark_content_actors);
 249   g_assert (actors != NULL);
 250
 251   g_hash_table_remove (actors, actor);
 252
 253   if (g_hash_table_size (actors) == 0)
 254     g_object_set_qdata (obj, quark_content_actors, NULL);
 255
 256   g_signal_emit (content, content_signals[DETACHED], 0, actor);
 257 }
 258
 259 /*< private >
 260  * _clutter_content_paint_content:
 261  * @content: a #ClutterContent
 262  * @actor: a #ClutterActor
 263  * @context: a #ClutterPaintNode
 264  *
 265  * Creates the render tree for the @content and @actor.
 266  *
 267  * This function will invoke the #ClutterContentIface.paint_content()
 268  * virtual function.
 269  */
 270 void
 271 _clutter_content_paint_content (ClutterContent   *content,
 272                                 ClutterActor     *actor,
 273                                 ClutterPaintNode *node)
 274 {
 275   CLUTTER_CONTENT_GET_IFACE (content)->paint_content (content, actor, node);
 276 }
 277
 278 /**
 279  * clutter_content_get_preferred_size:
 280  * @content: a #ClutterContent
 281  * @width: (out): return location for the natural width of the content
 282  * @height: (out): return location for the natural height of the content
 283  *
 284  * Retrieves the natural size of the @content, if any.
 285  *
 286  * The natural size of a #ClutterContent is defined as the size the content
 287  * would have regardless of the allocation of the actor that is painting it,
 288  * for instance the size of an image data.
 289  *
 290  * Return value: %TRUE if the content has a preferred size, and %FALSE
 291  *   otherwise
 292  *
 293  * Since: 1.10
 294  */
 295 gboolean
 296 clutter_content_get_preferred_size (ClutterContent *content,
 297                                     gfloat         *width,
 298                                     gfloat         *height)
 299 {
 300   g_return_val_if_fail (CLUTTER_IS_CONTENT (content), FALSE);
 301
 302   return CLUTTER_CONTENT_GET_IFACE (content)->get_preferred_size (content,
 303                                                                   width,
 304                                                                   height);
 305 }