mutter/clutter/clutter-rotate-action.c
Emmanuele Bassi 8cb326dc54 Explicitly set the trigger edge in GestureAction subclasses
Each GestureAction subclass has its own trigger edge handling, so we
want to be resilient in case of changes in the super-class.

https://bugzilla.gnome.org/show_bug.cgi?id=710227
2013-12-05 15:20:39 +00:00

241 lines
7.0 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Copyright (C) 2012 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:
* Lionel Landwerlin <lionel.g.landwerlin@linux.intel.com>
*/
/**
* SECTION:clutter-rotate-action
* @Title: ClutterRotateAction
* @Short_Description: Action to rotate an actor
*
* #ClutterRotateAction is a sub-class of #ClutterGestureAction that implements
* the logic for recognizing rotate gestures using two touch points.
*
* Since: 1.12
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <math.h>
#include "clutter-rotate-action.h"
#include "clutter-debug.h"
#include "clutter-enum-types.h"
#include "clutter-gesture-action-private.h"
#include "clutter-marshal.h"
#include "clutter-private.h"
struct _ClutterRotateActionPrivate
{
gfloat initial_vector[2];
gdouble initial_vector_norm;
gdouble initial_rotation;
};
enum
{
ROTATE,
LAST_SIGNAL
};
static guint rotate_signals[LAST_SIGNAL] = { 0, };
G_DEFINE_TYPE_WITH_PRIVATE (ClutterRotateAction, clutter_rotate_action, CLUTTER_TYPE_GESTURE_ACTION)
static gboolean
clutter_rotate_action_real_rotate (ClutterRotateAction *action,
ClutterActor *actor,
gdouble angle)
{
clutter_actor_set_rotation_angle (actor,
CLUTTER_Z_AXIS,
action->priv->initial_rotation + angle);
return TRUE;
}
static gboolean
clutter_rotate_action_gesture_begin (ClutterGestureAction *action,
ClutterActor *actor)
{
ClutterRotateActionPrivate *priv = CLUTTER_ROTATE_ACTION (action)->priv;
gfloat p1[2], p2[2];
/* capture initial vector */
clutter_gesture_action_get_motion_coords (action, 0, &p1[0], &p1[1]);
clutter_gesture_action_get_motion_coords (action, 1, &p2[0], &p2[1]);
priv->initial_vector[0] = p2[0] - p1[0];
priv->initial_vector[1] = p2[1] - p1[1];
priv->initial_vector_norm =
sqrt (priv->initial_vector[0] * priv->initial_vector[0] +
priv->initial_vector[1] * priv->initial_vector[1]);
priv->initial_rotation = clutter_actor_get_rotation_angle (actor, CLUTTER_Z_AXIS);
return TRUE;
}
static gboolean
clutter_rotate_action_gesture_progress (ClutterGestureAction *action,
ClutterActor *actor)
{
ClutterRotateActionPrivate *priv = CLUTTER_ROTATE_ACTION (action)->priv;
gfloat p1[2], p2[2];
gfloat vector[2];
gboolean retval;
/* capture current vector */
clutter_gesture_action_get_motion_coords (action, 0, &p1[0], &p1[1]);
clutter_gesture_action_get_motion_coords (action, 1, &p2[0], &p2[1]);
vector[0] = p2[0] - p1[0];
vector[1] = p2[1] - p1[1];
if ((vector[0] == priv->initial_vector[0]) &&
(vector[1] == priv->initial_vector[1]))
{
g_signal_emit (action, rotate_signals[ROTATE], 0,
actor, (gdouble) 0.0,
&retval);
}
else
{
gfloat mult[2];
gfloat norm;
gdouble angle;
/* Computes angle between the 2 initial touch points and the
current position of the 2 touch points. */
norm = sqrt (vector[0] * vector[0] + vector[1] * vector[1]);
norm = (priv->initial_vector[0] * vector[0] +
priv->initial_vector[1] * vector[1]) / (priv->initial_vector_norm * norm);
if ((norm >= -1.0) && (norm <= 1.0))
angle = acos (norm);
else
angle = 0;
/* The angle given is comprise between 0 and 180 degrees, we
need some logic on top to get a value between 0 and 360. */
mult[0] = priv->initial_vector[0] * vector[1] -
priv->initial_vector[1] * vector[0];
mult[1] = priv->initial_vector[1] * vector[0] -
priv->initial_vector[0] * vector[1];
if (mult[0] < 0)
angle = -angle;
/* Convert radians to degrees */
angle = angle * 180.0 / G_PI;
g_signal_emit (action, rotate_signals[ROTATE], 0,
actor, angle,
&retval);
}
return TRUE;
}
static void
clutter_rotate_action_gesture_cancel (ClutterGestureAction *action,
ClutterActor *actor)
{
gboolean retval;
g_signal_emit (action, rotate_signals[ROTATE], 0,
actor, (gdouble) 0.0,
&retval);
}
static void
clutter_rotate_action_class_init (ClutterRotateActionClass *klass)
{
ClutterGestureActionClass *gesture_class =
CLUTTER_GESTURE_ACTION_CLASS (klass);
klass->rotate = clutter_rotate_action_real_rotate;
gesture_class->gesture_begin = clutter_rotate_action_gesture_begin;
gesture_class->gesture_progress = clutter_rotate_action_gesture_progress;
gesture_class->gesture_cancel = clutter_rotate_action_gesture_cancel;
/**
* ClutterRotateAction::rotate:
* @action: the #ClutterRotateAction that emitted the signal
* @actor: the #ClutterActor attached to the @action
* @angle: the difference of angle of rotation between the initial
* rotation and the current rotation
*
* The ::rotate signal is emitted when a rotate gesture is
* recognized on the attached actor and when the gesture is
* cancelled (in this case with an angle value of 0).
*
* Return value: %TRUE if the rotation should continue, and %FALSE if
* the rotation should be cancelled.
*
* Since: 1.12
*/
rotate_signals[ROTATE] =
g_signal_new (I_("rotate"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (ClutterRotateActionClass, rotate),
_clutter_boolean_continue_accumulator, NULL,
_clutter_marshal_BOOLEAN__OBJECT_DOUBLE,
G_TYPE_BOOLEAN, 2,
CLUTTER_TYPE_ACTOR,
G_TYPE_DOUBLE);
}
static void
clutter_rotate_action_init (ClutterRotateAction *self)
{
ClutterGestureAction *gesture;
self->priv = clutter_rotate_action_get_instance_private (self);
gesture = CLUTTER_GESTURE_ACTION (self);
clutter_gesture_action_set_n_touch_points (gesture, 2);
clutter_gesture_action_set_threshold_trigger_edge (gesture, CLUTTER_GESTURE_TRIGGER_EDGE_NONE);
}
/**
* clutter_rotate_action_new:
*
* Creates a new #ClutterRotateAction instance
*
* Return value: the newly created #ClutterRotateAction
*
* Since: 1.12
*/
ClutterAction *
clutter_rotate_action_new (void)
{
return g_object_new (CLUTTER_TYPE_ROTATE_ACTION, NULL);
}