/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Copyright © 2011 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
* Author:
* Emmanuele Bassi <ebassi@linux.intel.com>
*/
/**
* SECTION:clutter-drop-action
* @Title: ClutterDropAction
* @short_description: An action for drop targets
*
* #ClutterDropAction is a #ClutterAction that allows a #ClutterActor
* implementation to control what happens when an actor dragged using
* a #ClutterDragAction crosses the target area or when a dragged actor
* is released (or "dropped") on the target area.
*
* A trivial use of #ClutterDropAction consists in connecting to the
* #ClutterDropAction::drop signal and handling the drop from there,
* for instance:
*
* |[<!-- language="C" -->
* ClutterAction *action = clutter_drop_action ();
*
* g_signal_connect (action, "drop", G_CALLBACK (on_drop), NULL);
* clutter_actor_add_action (an_actor, action);
* ]|
*
* The #ClutterDropAction::can-drop can be used to control whether the
* #ClutterDropAction::drop signal is going to be emitted; returning %FALSE
* from a handler connected to the #ClutterDropAction::can-drop signal will
* cause the #ClutterDropAction::drop signal to be skipped when the input
* device button is released.
*
* It's important to note that #ClutterDropAction will only work with
* actors dragged using #ClutterDragAction.
*
* See [drop-action.c](https://git.gnome.org/browse/clutter/tree/examples/drop-action.c?h=clutter-1.18)
* for an example of how to use #ClutterDropAction.
*
* #ClutterDropAction is available since Clutter 1.8
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "clutter-drop-action.h"
#include "clutter-actor-meta-private.h"
#include "clutter-actor-private.h"
#include "clutter-drag-action.h"
#include "clutter-main.h"
#include "clutter-marshal.h"
#include "clutter-stage-private.h"
struct _ClutterDropActionPrivate
{
ClutterActor *actor;
ClutterActor *stage;
gulong mapped_id;
};
typedef struct _DropTarget {
ClutterActor *stage;
gulong capture_id;
GHashTable *actions;
ClutterDropAction *last_action;
} DropTarget;
enum
{
CAN_DROP,
OVER_IN,
OVER_OUT,
DROP,
DROP_CANCEL,
LAST_SIGNAL
};
static guint drop_signals[LAST_SIGNAL] = { 0, };
G_DEFINE_TYPE_WITH_PRIVATE (ClutterDropAction, clutter_drop_action, CLUTTER_TYPE_ACTION)
static void
drop_target_free (gpointer _data)
{
DropTarget *data = _data;
g_signal_handler_disconnect (data->stage, data->capture_id);
g_hash_table_destroy (data->actions);
g_free (data);
}
static gboolean
on_stage_capture (ClutterStage *stage,
ClutterEvent *event,
gpointer user_data)
{
DropTarget *data = user_data;
gfloat event_x, event_y;
ClutterActor *actor, *drag_actor;
ClutterDropAction *drop_action;
ClutterInputDevice *device;
gboolean was_reactive;
switch (clutter_event_type (event))
{
case CLUTTER_MOTION:
case CLUTTER_BUTTON_RELEASE:
if (clutter_event_type (event) == CLUTTER_MOTION &&
!(clutter_event_get_state (event) & CLUTTER_BUTTON1_MASK))
return CLUTTER_EVENT_PROPAGATE;
if (clutter_event_type (event) == CLUTTER_BUTTON_RELEASE &&
clutter_event_get_button (event) != CLUTTER_BUTTON_PRIMARY)
return CLUTTER_EVENT_PROPAGATE;
device = clutter_event_get_device (event);
drag_actor = _clutter_stage_get_pointer_drag_actor (stage, device);
if (drag_actor == NULL)
return CLUTTER_EVENT_PROPAGATE;
break;
case CLUTTER_TOUCH_UPDATE:
case CLUTTER_TOUCH_END:
drag_actor = _clutter_stage_get_touch_drag_actor (stage,
clutter_event_get_event_sequence (event));
if (drag_actor == NULL)
return CLUTTER_EVENT_PROPAGATE;
break;
default:
return CLUTTER_EVENT_PROPAGATE;
}
clutter_event_get_coords (event, &event_x, &event_y);
/* get the actor under the cursor, excluding the dragged actor; we
* use reactivity because it won't cause any scene invalidation
*/
was_reactive = clutter_actor_get_reactive (drag_actor);
clutter_actor_set_reactive (drag_actor, FALSE);
actor = clutter_stage_get_actor_at_pos (stage, CLUTTER_PICK_REACTIVE,
event_x,
event_y);
if (actor == NULL || actor == CLUTTER_ACTOR (stage))
{
if (data->last_action != NULL)
{
ClutterActorMeta *meta = CLUTTER_ACTOR_META (data->last_action);
g_signal_emit (data->last_action, drop_signals[OVER_OUT], 0,
clutter_actor_meta_get_actor (meta));
data->last_action = NULL;
}
goto out;
}
drop_action = g_hash_table_lookup (data->actions, actor);
if (drop_action == NULL)
{
if (data->last_action != NULL)
{
ClutterActorMeta *meta = CLUTTER_ACTOR_META (data->last_action);
g_signal_emit (data->last_action, drop_signals[OVER_OUT], 0,
clutter_actor_meta_get_actor (meta));
data->last_action = NULL;
}
goto out;
}
else
{
if (data->last_action != drop_action)
{
ClutterActorMeta *meta;
if (data->last_action != NULL)
{
meta = CLUTTER_ACTOR_META (data->last_action);
g_signal_emit (data->last_action, drop_signals[OVER_OUT], 0,
clutter_actor_meta_get_actor (meta));
}
meta = CLUTTER_ACTOR_META (drop_action);
g_signal_emit (drop_action, drop_signals[OVER_IN], 0,
clutter_actor_meta_get_actor (meta));
}
data->last_action = drop_action;
}
out:
if (clutter_event_type (event) == CLUTTER_BUTTON_RELEASE ||
clutter_event_type (event) == CLUTTER_TOUCH_END)
{
if (data->last_action != NULL)
{
ClutterActorMeta *meta = CLUTTER_ACTOR_META (data->last_action);
gboolean can_drop = FALSE;
g_signal_emit (data->last_action, drop_signals[CAN_DROP], 0,
clutter_actor_meta_get_actor (meta),
event_x, event_y,
&can_drop);
if (can_drop)
{
g_signal_emit (data->last_action, drop_signals[DROP], 0,
clutter_actor_meta_get_actor (meta),
event_x, event_y);
}
else
{
g_signal_emit (data->last_action, drop_signals[DROP_CANCEL], 0,
clutter_actor_meta_get_actor (meta),
event_x, event_y);
}
}
data->last_action = NULL;
}
if (drag_actor != NULL)
clutter_actor_set_reactive (drag_actor, was_reactive);
return CLUTTER_EVENT_PROPAGATE;
}
static void
drop_action_register (ClutterDropAction *self)
{
ClutterDropActionPrivate *priv = self->priv;
DropTarget *data;
g_assert (priv->stage != NULL);
data = g_object_get_data (G_OBJECT (priv->stage), "__clutter_drop_targets");
if (data == NULL)
{
data = g_new0 (DropTarget, 1);
data->stage = priv->stage;
data->actions = g_hash_table_new (NULL, NULL);
data->capture_id = g_signal_connect (priv->stage, "captured-event",
G_CALLBACK (on_stage_capture),
data);
g_object_set_data_full (G_OBJECT (priv->stage), "__clutter_drop_targets",
data,
drop_target_free);
}
g_hash_table_replace (data->actions, priv->actor, self);
}
static void
drop_action_unregister (ClutterDropAction *self)
{
ClutterDropActionPrivate *priv = self->priv;
DropTarget *data = NULL;
if (priv->stage != NULL)
data = g_object_get_data (G_OBJECT (priv->stage), "__clutter_drop_targets");
if (data == NULL)
return;
g_hash_table_remove (data->actions, priv->actor);
if (g_hash_table_size (data->actions) == 0)
g_object_set_data (G_OBJECT (data->stage), "__clutter_drop_targets", NULL);
}
static void
on_actor_mapped (ClutterActor *actor,
GParamSpec *pspec,
ClutterDropAction *self)
{
if (clutter_actor_is_mapped (actor))
{
if (self->priv->stage == NULL)
self->priv->stage = clutter_actor_get_stage (actor);
drop_action_register (self);
}
else
drop_action_unregister (self);
}
static void
clutter_drop_action_set_actor (ClutterActorMeta *meta,
ClutterActor *actor)
{
ClutterDropActionPrivate *priv = CLUTTER_DROP_ACTION (meta)->priv;
if (priv->actor != NULL)
{
drop_action_unregister (CLUTTER_DROP_ACTION (meta));
if (priv->mapped_id != 0)
g_signal_handler_disconnect (priv->actor, priv->mapped_id);
priv->stage = NULL;
priv->actor = NULL;
priv->mapped_id = 0;
}
priv->actor = actor;
if (priv->actor != NULL)
{
priv->stage = clutter_actor_get_stage (actor);
priv->mapped_id = g_signal_connect (actor, "notify::mapped",
G_CALLBACK (on_actor_mapped),
meta);
if (priv->stage != NULL)
drop_action_register (CLUTTER_DROP_ACTION (meta));
}
CLUTTER_ACTOR_META_CLASS (clutter_drop_action_parent_class)->set_actor (meta, actor);
}
static gboolean
signal_accumulator (GSignalInvocationHint *ihint,
GValue *return_accu,
const GValue *handler_return,
gpointer user_data)
{
gboolean continue_emission;
continue_emission = g_value_get_boolean (handler_return);
g_value_set_boolean (return_accu, continue_emission);
return continue_emission;
}
static gboolean
clutter_drop_action_real_can_drop (ClutterDropAction *action,
ClutterActor *actor,
gfloat event_x,
gfloat event_y)
{
return TRUE;
}
static void
clutter_drop_action_class_init (ClutterDropActionClass *klass)
{
ClutterActorMetaClass *meta_class = CLUTTER_ACTOR_META_CLASS (klass);
meta_class->set_actor = clutter_drop_action_set_actor;
klass->can_drop = clutter_drop_action_real_can_drop;
/**
* ClutterDropAction::can-drop:
* @action: the #ClutterDropAction that emitted the signal
* @actor: the #ClutterActor attached to the @action
* @event_x: the X coordinate (in stage space) of the drop event
* @event_y: the Y coordinate (in stage space) of the drop event
*
* The ::can-drop signal is emitted when the dragged actor is dropped
* on @actor. The return value of the ::can-drop signal will determine
* whether or not the #ClutterDropAction::drop signal is going to be
* emitted on @action.
*
* The default implementation of #ClutterDropAction returns %TRUE for
* this signal.
*
* Return value: %TRUE if the drop is accepted, and %FALSE otherwise
*
* Since: 1.8
*/
drop_signals[CAN_DROP] =
g_signal_new (I_("can-drop"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (ClutterDropActionClass, can_drop),
signal_accumulator, NULL,
_clutter_marshal_BOOLEAN__OBJECT_FLOAT_FLOAT,
G_TYPE_BOOLEAN, 3,
CLUTTER_TYPE_ACTOR,
G_TYPE_FLOAT,
G_TYPE_FLOAT);
/**
* ClutterDropAction::over-in:
* @action: the #ClutterDropAction that emitted the signal
* @actor: the #ClutterActor attached to the @action
*
* The ::over-in signal is emitted when the dragged actor crosses
* into @actor.
*
* Since: 1.8
*/
drop_signals[OVER_IN] =
g_signal_new (I_("over-in"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (ClutterDropActionClass, over_in),
NULL, NULL,
_clutter_marshal_VOID__OBJECT,
G_TYPE_NONE, 1,
CLUTTER_TYPE_ACTOR);
/**
* ClutterDropAction::over-out:
* @action: the #ClutterDropAction that emitted the signal
* @actor: the #ClutterActor attached to the @action
*
* The ::over-out signal is emitted when the dragged actor crosses
* outside @actor.
*
* Since: 1.8
*/
drop_signals[OVER_OUT] =
g_signal_new (I_("over-out"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (ClutterDropActionClass, over_out),
NULL, NULL,
_clutter_marshal_VOID__OBJECT,
G_TYPE_NONE, 1,
CLUTTER_TYPE_ACTOR);
/**
* ClutterDropAction::drop:
* @action: the #ClutterDropAction that emitted the signal
* @actor: the #ClutterActor attached to the @action
* @event_x: the X coordinate (in stage space) of the drop event
* @event_y: the Y coordinate (in stage space) of the drop event
*
* The ::drop signal is emitted when the dragged actor is dropped
* on @actor. This signal is only emitted if at least an handler of
* #ClutterDropAction::can-drop returns %TRUE.
*
* Since: 1.8
*/
drop_signals[DROP] =
g_signal_new (I_("drop"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (ClutterDropActionClass, drop),
NULL, NULL,
_clutter_marshal_VOID__OBJECT_FLOAT_FLOAT,
G_TYPE_NONE, 3,
CLUTTER_TYPE_ACTOR,
G_TYPE_FLOAT,
G_TYPE_FLOAT);
/**
* ClutterDropAction::drop-cancel:
* @action: the #ClutterDropAction that emitted the signal
* @actor: the #ClutterActor attached to the @action
* @event_x: the X coordinate (in stage space) of the drop event
* @event_y: the Y coordinate (in stage space) of the drop event
*
* The ::drop-cancel signal is emitted when the drop is refused
* by an emission of the #ClutterDropAction::can-drop signal.
*
* After the ::drop-cancel signal is fired the active drag is
* terminated.
*
* Since: 1.12
*/
drop_signals[DROP_CANCEL] =
g_signal_new (I_("drop-cancel"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (ClutterDropActionClass, drop),
NULL, NULL,
_clutter_marshal_VOID__OBJECT_FLOAT_FLOAT,
G_TYPE_NONE, 3,
CLUTTER_TYPE_ACTOR,
G_TYPE_FLOAT,
G_TYPE_FLOAT);
}
static void
clutter_drop_action_init (ClutterDropAction *self)
{
self->priv = clutter_drop_action_get_instance_private (self);
}
/**
* clutter_drop_action_new:
*
* Creates a new #ClutterDropAction.
*
* Use clutter_actor_add_action() to add the action to a #ClutterActor.
*
* Return value: the newly created #ClutterDropAction
*
* Since: 1.8
*/
ClutterAction *
clutter_drop_action_new (void)
{
return g_object_new (CLUTTER_TYPE_DROP_ACTION, NULL);
}