docs: Add custom ClutterActor example which uses composition
This commit is contained in:
Elliot Smith
287
doc/cookbook/examples/cb-button.c
Normal file
287
doc/cookbook/examples/cb-button.c
Normal file
@ -0,0 +1,287 @@
|
||||
#include "cb-button.h"
|
||||
/*
|
||||
* convenience macro for GType implementations; see:
|
||||
* http://library.gnome.org/devel/gobject/2.27/gobject-Type-Information.html#G-DEFINE-TYPE:CAPS
|
||||
*/
|
||||
G_DEFINE_TYPE (CbButton, cb_button, CLUTTER_TYPE_ACTOR);
|
||||
|
||||
/* macro for easy access to the private structure defined in this file */
|
||||
#define CB_BUTTON_GET_PRIVATE(obj) \
|
||||
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), CB_TYPE_BUTTON, CbButtonPrivate))
|
||||
|
||||
/* private structure */
|
||||
struct _CbButtonPrivate
|
||||
{
|
||||
ClutterActor *child;
|
||||
ClutterActor *label;
|
||||
ClutterAction *click_action;
|
||||
gchar *text;
|
||||
};
|
||||
|
||||
/* enum for signals */
|
||||
enum
|
||||
{
|
||||
CLICKED,
|
||||
LAST_SIGNAL
|
||||
};
|
||||
|
||||
/* enum for properties */
|
||||
enum
|
||||
{
|
||||
PROP_0,
|
||||
PROP_TEXT
|
||||
};
|
||||
|
||||
/* signals */
|
||||
static guint cb_button_signals[LAST_SIGNAL] = { 0, };
|
||||
|
||||
static void
|
||||
cb_button_dispose (GObject *gobject)
|
||||
{
|
||||
CbButtonPrivate *priv = CB_BUTTON (gobject)->priv;
|
||||
|
||||
/* we just dispose of the child, and let its dispose()
|
||||
* function deal with its children
|
||||
*/
|
||||
if (priv->child)
|
||||
{
|
||||
clutter_actor_unparent (priv->child);
|
||||
priv->child = NULL;
|
||||
}
|
||||
|
||||
G_OBJECT_CLASS (cb_button_parent_class)->dispose (gobject);
|
||||
}
|
||||
|
||||
static void
|
||||
cb_button_finalize (GObject *gobject)
|
||||
{
|
||||
CbButtonPrivate *priv = CB_BUTTON (gobject)->priv;
|
||||
|
||||
g_free (priv->text);
|
||||
|
||||
G_OBJECT_CLASS (cb_button_parent_class)->finalize (gobject);
|
||||
}
|
||||
|
||||
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;
|
||||
}
|
||||
}
|
||||
|
||||
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;
|
||||
}
|
||||
}
|
||||
|
||||
/* ClutterActor implementation */
|
||||
|
||||
/* 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 */
|
||||
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);
|
||||
}
|
||||
|
||||
/* paint function implementation: just call paint() on the ClutterBox */
|
||||
static void
|
||||
cb_button_paint (ClutterActor *actor)
|
||||
{
|
||||
CbButtonPrivate *priv = CB_BUTTON (actor)->priv;
|
||||
|
||||
clutter_actor_paint (priv->child);
|
||||
}
|
||||
|
||||
/* proxy ClickAction signals so they become signals from the actor */
|
||||
static void
|
||||
cb_button_clicked (ClutterClickAction *action,
|
||||
ClutterActor *actor,
|
||||
gpointer user_data)
|
||||
{
|
||||
g_signal_emit (actor, cb_button_signals[CLICKED], 0);
|
||||
}
|
||||
|
||||
/* GObject class and instance init */
|
||||
static void
|
||||
cb_button_class_init (CbButtonClass *klass)
|
||||
{
|
||||
ClutterActorClass *actor_class = CLUTTER_ACTOR_CLASS (klass);
|
||||
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
|
||||
GParamSpec *pspec;
|
||||
|
||||
gobject_class->dispose = cb_button_dispose;
|
||||
gobject_class->finalize = cb_button_finalize;
|
||||
gobject_class->set_property = cb_button_set_property;
|
||||
gobject_class->get_property = cb_button_get_property;
|
||||
|
||||
actor_class->allocate = cb_button_allocate;
|
||||
actor_class->paint = cb_button_paint;
|
||||
|
||||
g_type_class_add_private (klass, sizeof (CbButtonPrivate));
|
||||
|
||||
pspec = g_param_spec_string ("text",
|
||||
"Text",
|
||||
"Text of the button",
|
||||
NULL,
|
||||
G_PARAM_READWRITE);
|
||||
g_object_class_install_property (gobject_class, PROP_TEXT, pspec);
|
||||
|
||||
cb_button_signals[CLICKED] =
|
||||
g_signal_new ("clicked",
|
||||
G_TYPE_FROM_CLASS (klass),
|
||||
G_SIGNAL_RUN_LAST,
|
||||
G_STRUCT_OFFSET (CbButtonClass, clicked),
|
||||
NULL,
|
||||
NULL,
|
||||
g_cclosure_marshal_VOID__VOID,
|
||||
G_TYPE_NONE,
|
||||
0);
|
||||
}
|
||||
|
||||
static void
|
||||
cb_button_init (CbButton *self)
|
||||
{
|
||||
CbButtonPrivate *priv;
|
||||
ClutterLayoutManager *layout;
|
||||
|
||||
priv = self->priv = CB_BUTTON_GET_PRIVATE (self);
|
||||
|
||||
clutter_actor_set_reactive (CLUTTER_ACTOR (self), TRUE);
|
||||
|
||||
layout = clutter_bin_layout_new (CLUTTER_BIN_ALIGNMENT_CENTER,
|
||||
CLUTTER_BIN_ALIGNMENT_CENTER);
|
||||
|
||||
priv->child = clutter_box_new (layout);
|
||||
|
||||
/* set the parent of the ClutterBox to this instance */
|
||||
clutter_actor_set_parent (priv->child,
|
||||
CLUTTER_ACTOR (self));
|
||||
|
||||
/* add text label to the button */
|
||||
priv->label = g_object_new (CLUTTER_TYPE_TEXT,
|
||||
"line-alignment", PANGO_ALIGN_CENTER,
|
||||
"ellipsize", PANGO_ELLIPSIZE_END,
|
||||
NULL);
|
||||
|
||||
clutter_container_add_actor (CLUTTER_CONTAINER (priv->child),
|
||||
priv->label);
|
||||
|
||||
/* add a ClutterClickAction on this actor, so we can proxy its
|
||||
* "clicked" signal through a signal from this actor
|
||||
*/
|
||||
priv->click_action = clutter_click_action_new ();
|
||||
clutter_actor_add_action (CLUTTER_ACTOR (self), priv->click_action);
|
||||
|
||||
g_signal_connect (priv->click_action,
|
||||
"clicked",
|
||||
G_CALLBACK (cb_button_clicked),
|
||||
NULL);
|
||||
}
|
||||
|
||||
/* public API */
|
||||
|
||||
/* examples of public API functions which wrap functions
|
||||
* on internal actors
|
||||
*/
|
||||
void
|
||||
cb_button_set_text (CbButton *self,
|
||||
const gchar *text)
|
||||
{
|
||||
CbButtonPrivate *priv;
|
||||
|
||||
/* public API should check its arguments;
|
||||
* see also g_return_val_if_fail for functions which
|
||||
* return a value
|
||||
*/
|
||||
g_return_if_fail (CB_IS_BUTTON (self));
|
||||
|
||||
priv = self->priv;
|
||||
|
||||
g_free (priv->text);
|
||||
|
||||
if (text)
|
||||
priv->text = g_strdup (text);
|
||||
else
|
||||
priv->text = g_strdup ("");
|
||||
|
||||
/* call the actual function on the ClutterText inside the layout */
|
||||
clutter_text_set_text (CLUTTER_TEXT (priv->label), priv->text);
|
||||
}
|
||||
|
||||
void
|
||||
cb_button_set_background_color (CbButton *self,
|
||||
const ClutterColor *color)
|
||||
{
|
||||
g_return_if_fail (CB_IS_BUTTON (self));
|
||||
|
||||
clutter_box_set_color (CLUTTER_BOX (self->priv->child), color);
|
||||
}
|
||||
|
||||
void
|
||||
cb_button_set_text_color (CbButton *self,
|
||||
const ClutterColor *color)
|
||||
{
|
||||
g_return_if_fail (CB_IS_BUTTON (self));
|
||||
|
||||
clutter_text_set_color (CLUTTER_TEXT (self->priv->label), color);
|
||||
}
|
||||
|
||||
/* see http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#G-CONST-RETURN:CAPS
|
||||
* for an explanation of G_CONST_RETURN: basically it means that the
|
||||
* return value of this function should not be modified
|
||||
*/
|
||||
G_CONST_RETURN gchar *
|
||||
cb_button_get_text (CbButton *self)
|
||||
{
|
||||
g_return_val_if_fail (CB_IS_BUTTON (self), NULL);
|
||||
|
||||
return self->priv->text;
|
||||
}
|
||||
|
||||
ClutterActor *
|
||||
cb_button_new (void)
|
||||
{
|
||||
return g_object_new (CB_TYPE_BUTTON, NULL);
|
||||
}
|
||||
Reference in New Issue
Block a user