clutter/clutter-property-transition.c

   1 /*
   2  * Clutter.
   3  *
   4  * An OpenGL based 'interactive canvas' library.
   5  *
   6  * Copyright (C) 2012  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
  22 /**
  23  * SECTION:clutter-property-transition
  24  * @Title: ClutterPropertyTransition
  25  * @Short_Description: Property transitions
  26  *
  27  * #ClutterPropertyTransition is a specialized #ClutterTransition that
  28  * can be used to tween a property of a #ClutterAnimatable instance.
  29  *
  30  * #ClutterPropertyTransition is available since Clutter 1.10
  31  */
  32
  33 #ifdef HAVE_CONFIG_H
  34 #include "config.h"
  35 #endif
  36
  37 #include "clutter-property-transition.h"
  38
  39 #include "clutter-animatable.h"
  40 #include "clutter-debug.h"
  41 #include "clutter-interval.h"
  42 #include "clutter-private.h"
  43 #include "clutter-transition.h"
  44
  45 struct _ClutterPropertyTransitionPrivate
  46 {
  47   char *property_name;
  48
  49   GParamSpec *pspec;
  50 };
  51
  52 enum
  53 {
  54   PROP_0,
  55
  56   PROP_PROPERTY_NAME,
  57
  58   PROP_LAST
  59 };
  60
  61 static GParamSpec *obj_props[PROP_LAST] = { NULL, };
  62
  63 G_DEFINE_TYPE (ClutterPropertyTransition, clutter_property_transition, CLUTTER_TYPE_TRANSITION)
  64
  65 static void
  66 clutter_property_transition_attached (ClutterTransition *transition,
  67                                       ClutterAnimatable *animatable)
  68 {
  69   ClutterPropertyTransition *self = CLUTTER_PROPERTY_TRANSITION (transition);
  70   ClutterPropertyTransitionPrivate *priv = self->priv;
  71
  72   if (priv->property_name == NULL)
  73     return;
  74
  75   priv->pspec = clutter_animatable_find_property (animatable,
  76                                                   priv->property_name);
  77 }
  78
  79 static void
  80 clutter_property_transition_detached (ClutterTransition *transition,
  81                                       ClutterAnimatable *animatable)
  82 {
  83   ClutterPropertyTransition *self = CLUTTER_PROPERTY_TRANSITION (transition);
  84   ClutterPropertyTransitionPrivate *priv = self->priv;
  85
  86   priv->pspec = NULL;
  87 }
  88
  89 static void
  90 clutter_property_transition_compute_value (ClutterTransition *transition,
  91                                            ClutterAnimatable *animatable,
  92                                            ClutterInterval   *interval,
  93                                            gdouble            progress)
  94 {
  95   ClutterPropertyTransition *self = CLUTTER_PROPERTY_TRANSITION (transition);
  96   ClutterPropertyTransitionPrivate *priv = self->priv;
  97   GValue value = G_VALUE_INIT;
  98   gboolean res;
  99
 100   /* if we have a GParamSpec we also have an animatable instance */
 101   if (priv->pspec == NULL)
 102     return;
 103
 104   g_value_init (&value, clutter_interval_get_value_type (interval));
 105
 106   res = clutter_animatable_interpolate_value (animatable,
 107                                               priv->property_name,
 108                                               interval,
 109                                               progress,
 110                                               &value);
 111
 112   if (res)
 113     clutter_animatable_set_final_state (animatable,
 114                                         priv->property_name,
 115                                         &value);
 116
 117   g_value_unset (&value);
 118 }
 119
 120 static void
 121 clutter_property_transition_set_property (GObject      *gobject,
 122                                           guint         prop_id,
 123                                           const GValue *value,
 124                                           GParamSpec   *pspec)
 125 {
 126   ClutterPropertyTransition *self = CLUTTER_PROPERTY_TRANSITION (gobject);
 127
 128   switch (prop_id)
 129     {
 130     case PROP_PROPERTY_NAME:
 131       clutter_property_transition_set_property_name (self,
 132                                                      g_value_get_string (value));
 133       break;
 134
 135     default:
 136       G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
 137     }
 138 }
 139
 140 static void
 141 clutter_property_transition_get_property (GObject    *gobject,
 142                                           guint       prop_id,
 143                                           GValue     *value,
 144                                           GParamSpec *pspec)
 145 {
 146   ClutterPropertyTransitionPrivate *priv = CLUTTER_PROPERTY_TRANSITION (gobject)->priv;
 147
 148   switch (prop_id)
 149     {
 150     case PROP_PROPERTY_NAME:
 151       g_value_set_string (value, priv->property_name);
 152       break;
 153
 154     default:
 155       G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
 156     }
 157 }
 158
 159 static void
 160 clutter_property_transition_finalize (GObject *gobject)
 161 {
 162   ClutterPropertyTransitionPrivate *priv;
 163
 164   priv = CLUTTER_PROPERTY_TRANSITION (gobject)->priv;
 165
 166   g_free (priv->property_name);
 167
 168   G_OBJECT_CLASS (clutter_property_transition_parent_class)->finalize (gobject);
 169 }
 170
 171 static void
 172 clutter_property_transition_class_init (ClutterPropertyTransitionClass *klass)
 173 {
 174   ClutterTransitionClass *transition_class = CLUTTER_TRANSITION_CLASS (klass);
 175   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 176
 177   g_type_class_add_private (klass, sizeof (ClutterPropertyTransitionPrivate));
 178
 179   transition_class->attached = clutter_property_transition_attached;
 180   transition_class->detached = clutter_property_transition_detached;
 181   transition_class->compute_value = clutter_property_transition_compute_value;
 182
 183   gobject_class->set_property = clutter_property_transition_set_property;
 184   gobject_class->get_property = clutter_property_transition_get_property;
 185   gobject_class->finalize = clutter_property_transition_finalize;
 186
 187   /**
 188    * ClutterPropertyTransition:property-name:
 189    *
 190    * The name of the property of a #ClutterAnimatable to animate.
 191    *
 192    * Since: 1.10
 193    */
 194   obj_props[PROP_PROPERTY_NAME] =
 195     g_param_spec_string ("property-name",
 196                          P_("Property Name"),
 197                          P_("The name of the property to animate"),
 198                          NULL,
 199                          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
 200
 201   g_object_class_install_properties (gobject_class, PROP_LAST, obj_props);
 202 }
 203
 204 static void
 205 clutter_property_transition_init (ClutterPropertyTransition *self)
 206 {
 207   self->priv =
 208     G_TYPE_INSTANCE_GET_PRIVATE (self, CLUTTER_TYPE_PROPERTY_TRANSITION,
 209                                  ClutterPropertyTransitionPrivate);
 210 }
 211
 212 /**
 213  * clutter_property_transition_new:
 214  * @property_name: (allow-none): a property of @animatable, or %NULL
 215  *
 216  * Creates a new #ClutterPropertyTransition.
 217  *
 218  * Return value: (transfer full): the newly created #ClutterPropertyTransition.
 219  *   Use g_object_unref() when done
 220  *
 221  * Since: 1.10
 222  */
 223 ClutterTransition *
 224 clutter_property_transition_new (const char *property_name)
 225 {
 226   return g_object_new (CLUTTER_TYPE_PROPERTY_TRANSITION,
 227                        "property-name", property_name,
 228                        NULL);
 229 }
 230
 231 /**
 232  * clutter_property_transition_set_property_name:
 233  * @transition: a #ClutterPropertyTransition
 234  * @property_name: (allow-none): a property name
 235  *
 236  * Sets the #ClutterPropertyTransition:property-name property of @transition.
 237  *
 238  * Since: 1.10
 239  */
 240 void
 241 clutter_property_transition_set_property_name (ClutterPropertyTransition *transition,
 242                                                const char                *property_name)
 243 {
 244   ClutterPropertyTransitionPrivate *priv;
 245   ClutterAnimatable *animatable;
 246
 247   g_return_if_fail (CLUTTER_IS_PROPERTY_TRANSITION (transition));
 248
 249   priv = transition->priv;
 250
 251   if (g_strcmp0 (priv->property_name, property_name) == 0)
 252     return;
 253
 254   g_free (priv->property_name);
 255   priv->property_name = g_strdup (property_name);
 256   priv->pspec = NULL;
 257
 258   animatable =
 259     clutter_transition_get_animatable (CLUTTER_TRANSITION (transition));
 260   if (animatable != NULL)
 261     {
 262       priv->pspec = clutter_animatable_find_property (animatable,
 263                                                       priv->property_name);
 264     }
 265
 266   g_object_notify_by_pspec (G_OBJECT (transition),
 267                             obj_props[PROP_PROPERTY_NAME]);
 268 }
 269
 270 /**
 271  * clutter_property_transition_get_property_name:
 272  * @transition: a #ClutterPropertyTransition
 273  *
 274  * Retrieves the value of the #ClutterPropertyTransition:property-name
 275  * property.
 276  *
 277  * Return value: the name of the property being animated, or %NULL if
 278  *   none is set. The returned string is owned by the @transition and
 279  *   it should not be freed.
 280  *
 281  * Since: 1.10
 282  */
 283 const char *
 284 clutter_property_transition_get_property_name (ClutterPropertyTransition *transition)
 285 {
 286   g_return_val_if_fail (CLUTTER_IS_PROPERTY_TRANSITION (transition), NULL);
 287
 288   return transition->priv->property_name;
 289 }