Class PropertyTransition

Markers are unique string identifiers for a given position on the timeline. Once timeline reaches the given progress of its duration, if will emit a ::marker-reached signal for each marker attached to that particular point.

A marker can be removed with clutter_timeline_remove_marker(). The timeline can be advanced to a marker using clutter_timeline_advance_to_marker().

See also: clutter_timeline_add_marker_at_time()

Markers are unique string identifiers for a given position on the timeline. Once timeline reaches the given msecs, it will emit a ::marker-reached signal for each marker attached to that position.

A marker can be removed with clutter_timeline_remove_marker(). The timeline can be advanced to a marker using clutter_timeline_advance_to_marker().

See also: clutter_timeline_add_marker()

The timeline will not emit the #ClutterTimeline::new-frame signal for the given time. The first ::new-frame signal after the call to clutter_timeline_advance() will be emit the skipped markers.

Like clutter_timeline_advance(), this function will not emit the #ClutterTimeline::new-frame for the time where marker_name is set, nor it will emit #ClutterTimeline::marker-reached for marker_name.

Whenever the source_property is changed the target_property is updated using the same value. For instance:

  g_object_bind_property (action, "active", widget, "sensitive", 0);

Will result in the "sensitive" property of the widget #GObject instance to be updated with the same value of the "active" property of the action #GObject instance.

If flags contains %G_BINDING_BIDIRECTIONAL then the binding will be mutual: if target_property on target changes then the source_property on source will be updated as well.

The binding will automatically be removed when either the source or the target instances are finalized. To remove the binding without affecting the source and the target you can just call g_object_unref() on the returned #GBinding instance.

Removing the binding by calling g_object_unref() on it must only be done if the binding, source and target are only used from a single thread and it is clear that both source and target outlive the binding. Especially it is not safe to rely on this if the binding, source or target can be finalized from different threads. Keep another reference to the binding and use g_binding_unbind() instead to be on the safe side.

A #GObject can have multiple bindings.

This function is the language bindings friendly version of g_object_bind_property_full(), using #GClosures instead of function pointers.

The only cloned properties are:

• #ClutterTimeline:duration
• #ClutterTimeline:loop
• #ClutterTimeline:delay
• #ClutterTimeline:direction

This is necessary for accessors that modify multiple properties to prevent premature notification while the object is still being modified.

Repeats start at 0.

This function is only useful inside handlers for the ::new-frame signal, and its behaviour is undefined if the timeline is not playing.

If the #ClutterTimeline:repeat-count property is set to -1, this function will return %G_MAXINT64.

The returned value is to be considered a hint, and it's only valid as long as the timeline hasn't been changed.

The return value of this function is determined by the progress mode set using clutter_timeline_set_progress_mode(), or by the progress function set using clutter_timeline_set_progress_func().

The value can be:

• an empty #GValue initialized by %G_VALUE_INIT, which will be automatically initialized with the expected type of the property (since GLib 2.60)
• a #GValue initialized with the expected type of the property
• a #GValue initialized with a type to which the expected type of the property can be transformed

In general, a copy is made of the property contents and the caller is responsible for freeing the memory by calling g_value_unset().

Note that g_object_get_property() is really intended for language bindings, g_object_get() is much more convenient for C programming.

When possible, eg. when signaling a property change from within the class that registered the property, you should use g_object_notify_by_pspec() instead.

Note that emission of the notify signal may be blocked with g_object_freeze_notify(). In this case, the signal emissions are queued and will be emitted (in reverse order) when g_object_thaw_notify() is called.

This function omits the property name lookup, hence it is faster than g_object_notify().

One way to avoid using g_object_notify() from within the class that registered the properties, and using g_object_notify_by_pspec() instead, is to store the GParamSpec used with g_object_class_install_property() inside a static array, e.g.:

  enum
  {
    PROP_0,
    PROP_FOO,
    PROP_LAST
  };

  static GParamSpec *properties[PROP_LAST];

  static void
  my_object_class_init (MyObjectClass *klass)
  {
    properties[PROP_FOO] = g_param_spec_int ("foo", "Foo", "The foo",
                                             0, 100,
                                             50,
                                             G_PARAM_READWRITE);
    g_object_class_install_property (gobject_class,
                                     PROP_FOO,
                                     properties[PROP_FOO]);
  }

and then notify a change on the "foo" property with:

  g_object_notify_by_pspec (self, properties[PROP_FOO]);

Since GLib 2.56, if GLIB_VERSION_MAX_ALLOWED is 2.56 or greater, the type of object will be propagated to the return type (using the GCC typeof() extension), so any casting the caller needs to do on the return type must be explicit.

In other words, if the object is floating, then this call "assumes ownership" of the floating reference, converting it to a normal reference by clearing the floating flag while leaving the reference count unchanged. If the object is not floating, then this call adds a new normal reference increasing the reference count by one.

Since GLib 2.56, the type of object will be propagated to the return type under the same conditions as for g_object_ref().

This function should only be called from object system implementations.

The transition will acquire a reference to the animatable instance, and will call the #ClutterTransitionClass.attached() virtual function.

If an existing #ClutterAnimatable is attached to transition, the reference will be released, and the #ClutterTransitionClass.detached() virtual function will be called.

Setting the #ClutterTimeline:auto-reverse property to %TRUE is the equivalent of connecting a callback to the #ClutterTimeline::completed signal and changing the direction of the timeline from that callback; for instance, this code:

|[ static void reverse_timeline (ClutterTimeline *timeline) { ClutterTimelineDirection dir = clutter_timeline_get_direction (timeline);

if (dir == CLUTTER_TIMELINE_FORWARD) dir = CLUTTER_TIMELINE_BACKWARD; else dir = CLUTTER_TIMELINE_FORWARD;

clutter_timeline_set_direction (timeline, dir); } ... timeline = clutter_timeline_new (1000); clutter_timeline_set_repeat_count (timeline, -1); g_signal_connect (timeline, "completed", G_CALLBACK (reverse_timeline), NULL);

can be effectively replaced by:

|[
  timeline = clutter_timeline_new (1000);
  clutter_timeline_set_repeat_count (timeline, -1);
  clutter_timeline_set_auto_reverse (timeline);

The cubic bezier curve is between (0, 0) and (1, 1). The X coordinate of the two control points must be in the [ 0, 1 ] range, while the Y coordinate of the two control points can exceed this range.

If the object already had an association with that name, the old association will be destroyed.

Internally, the key is converted to a #GQuark using g_quark_from_string(). This means a copy of key is kept permanently (even after object has been finalized) — so it is recommended to only use a small, bounded set of values for key in your program, to avoid the #GQuark storage growing unbounded.

This is a convenience function that will either create the #ClutterInterval used by transition, or will update it if the #ClutterTransition:interval is already set.

This function will copy the contents of value, so it is safe to call g_value_unset() after it returns.

If transition already has a #ClutterTransition:interval set, then value must hold the same type, or a transformable type, as the interval's #ClutterInterval:value-type property.

This function is meant to be used by language bindings.

This name can be used by user interface designer applications to define a unique name for an object constructable using the UI definition language parsed by #ClutterScript.

The transition will acquire a reference on the interval, sinking the floating flag on it if necessary.

This function is equivalent to calling clutter_timeline_set_repeat_count() with -1 if loop is %TRUE, and with 0 if loop is %FALSE.

If func is not %NULL, the #ClutterTimeline:progress-mode property will be set to %CLUTTER_CUSTOM_MODE.

If func is %NULL, any previously set progress function will be unset, and the #ClutterTimeline:progress-mode property will be set to %CLUTTER_LINEAR.

If count is 0, the timeline never repeats.

If count is -1, the timeline will always repeat until it's stopped.

This is a convenience function that will either create the #ClutterInterval used by transition, or will update it if the #ClutterTransition:interval is already set.

This function will copy the contents of value, so it is safe to call g_value_unset() after it returns.

If transition already has a #ClutterTransition:interval set, then value must hold the same type, or a transformable type, as the interval's #ClutterInterval:value-type property.

This function is meant to be used by language bindings.

void
object_add_to_user_list (GObject     *object,
                         const gchar *new_string)
{
  // the quark, naming the object data
  GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
  // retrieve the old string list
  GList *list = g_object_steal_qdata (object, quark_string_list);

  // prepend new string
  list = g_list_prepend (list, g_strdup (new_string));
  // this changed 'list', so we need to set it again
  g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
}
static void
free_string_list (gpointer data)
{
  GList *node, *list = data;

  for (node = list; node; node = node->next)
    g_free (node->data);
  g_list_free (list);
}

Using g_object_get_qdata() in the above example, instead of g_object_steal_qdata() would have left the destroy function set, and thus the partial string list would have been freed upon g_object_set_qdata_full().

Duplicate notifications for each property are squashed so that at most one #GObject::notify signal is emitted for each property, in the reverse order in which they have been queued.

It is an error to call this function when the freeze count is zero.

If the pointer to the #GObject may be reused in future (for example, if it is an instance variable of another object), it is recommended to clear the pointer to %NULL rather than retain a dangling pointer to a potentially invalid #GObject instance. Use g_clear_object() for this.