int
main (int argc,
char *argv[])
{
ClutterActor *stage;
ClutterActor *button;
ClutterConstraint *align_x_constraint;
ClutterConstraint *align_y_constraint;
if (clutter_init (&argc, &argv) != CLUTTER_INIT_SUCCESS)
return 1;
stage = clutter_stage_new ();
clutter_actor_set_size (stage, 400, 400);
clutter_stage_set_color (CLUTTER_STAGE (stage), &stage_color);
g_signal_connect (stage, "destroy", G_CALLBACK (clutter_main_quit), NULL);
button = cb_button_new ();
cb_button_set_text (CB_BUTTON (button), "hello");
/* the following is equivalent to the two lines above:
*
* button = g_object_new (CB_TYPE_BUTTON,
* "text", "winkle",
* NULL);
*
* because we defined a set_property function, which can accept
* a PROP_TEXT parameter, GObject can create a button and set one
* or more properties with a single call to g_object_new()
*/
/* note that the size of the button is left to Clutter's size requisition */
cb_button_set_text_color (CB_BUTTON (button), &white_color);
cb_button_set_background_color (CB_BUTTON (button), &yellow_color);
g_signal_connect (button, "clicked", G_CALLBACK (clicked), NULL);
align_x_constraint = clutter_align_constraint_new (stage,
CLUTTER_ALIGN_X_AXIS,
0.5);
align_y_constraint = clutter_align_constraint_new (stage,
CLUTTER_ALIGN_Y_AXIS,
0.5);
clutter_actor_add_constraint (button, align_x_constraint);
clutter_actor_add_constraint (button, align_y_constraint);
clutter_actor_add_child (stage, button);
clutter_actor_show (stage);
clutter_main ();
return EXIT_SUCCESS;
}
/* paint function implementation: just calls paint() on the ClutterBox */
static void
cb_button_paint (ClutterActor *actor)
{
CbButtonPrivate *priv = CB_BUTTON (actor)->priv;
clutter_actor_paint (priv->child);
}
/* use the actor's allocation for the ClutterBox */
static void
cb_button_allocate (ClutterActor *actor,
const ClutterActorBox *box,
ClutterAllocationFlags flags)
{
CbButtonPrivate *priv = CB_BUTTON (actor)->priv;
ClutterActorBox child_box = { 0, };
/* set the allocation for the whole button */
CLUTTER_ACTOR_CLASS (cb_button_parent_class)->allocate (actor, box, flags);
/* make the child (the ClutterBox) fill the parent;
* note that this allocation box is relative to the
* coordinates of the whole button actor, so we can't just
* use the box passed into this function; instead, it
* is adjusted to span the whole of the actor, from its
* top-left corner (0,0) to its bottom-right corner
* (width,height)
*/
child_box.x1 = 0.0;
child_box.y1 = 0.0;
child_box.x2 = clutter_actor_box_get_width (box);
child_box.y2 = clutter_actor_box_get_height (box);
clutter_actor_allocate (priv->child, &child_box, flags);
}
/* from http://mail.gnome.org/archives/gtk-devel-list/2004-July/msg00158.html:
*
* "The finalize method finishes releasing the remaining
* resources just before the object itself will be freed from memory, and
* therefore it will only be called once. The two step process helps break
* cyclic references. Both dispose and finalize must chain up to their
* parent objects by calling their parent's respective methods *after* they
* have disposed or finalized their own members."
*/
static void
cb_button_finalize (GObject *gobject)
{
CbButtonPrivate *priv = CB_BUTTON (gobject)->priv;
g_free (priv->text);
/* call the parent class' finalize() method */
G_OBJECT_CLASS (cb_button_parent_class)->finalize (gobject);
}
static void
cb_button_get_preferred_width (ClutterActor *self,
gfloat for_height,
gfloat *min_width_p,
gfloat *natural_width_p)
{
CbButtonPrivate *priv = CB_BUTTON (self)->priv;
clutter_actor_get_preferred_width (priv->child,
for_height,
min_width_p,
natural_width_p);
*min_width_p += 20.0;
*natural_width_p += 20.0;
}
/* enables objects to be uniformly treated as GObjects;
* also exposes properties so they become scriptable, e.g.
* through ClutterScript
*/
static void
cb_button_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
CbButton *button = CB_BUTTON (gobject);
switch (prop_id)
{
case PROP_TEXT:
cb_button_set_text (button, g_value_get_string (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
/* enables objects to be uniformly treated as GObjects */
static void
cb_button_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
CbButtonPrivate *priv = CB_BUTTON (gobject)->priv;
switch (prop_id)
{
case PROP_TEXT:
g_value_set_string (value, priv->text);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
/* composite actors should implement destroy(), and inside their
* implementation destroy any actors they are composed from;
* in this case, we just destroy the child ClutterBox
*/
static void
cb_button_destroy (ClutterActor *self)
{
CbButtonPrivate *priv = CB_BUTTON (self)->priv;
/* we just destroy the child, and let the child
* deal with destroying _its_ children; note that we have a guard
* here in case the child has already been destroyed
*/
if (priv->child)
{
clutter_actor_destroy (priv->child);
priv->child = NULL;
}
/* chain up to destroy() on the parent ClutterActorClass;
* note that we check the parent class has a destroy() implementation
* before calling it
*/
if (CLUTTER_ACTOR_CLASS (cb_button_parent_class)->destroy)
CLUTTER_ACTOR_CLASS (cb_button_parent_class)->destroy (self);
}