2012-08-31 13:57:06 +02:00
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/*
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* Copyright (C) 2012, One Laptop Per Child.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*
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* Author(s): Carlos Garnacho <carlos@lanedo.com>
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*/
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#include <math.h>
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#include "sugar-zoom-controller.h"
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typedef struct _SugarZoomControllerPriv SugarZoomControllerPriv;
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enum {
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2012-09-13 14:37:02 +02:00
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SCALE_CHANGED,
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2012-08-31 13:57:06 +02:00
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LAST_SIGNAL
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};
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struct _SugarZoomControllerPriv
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{
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gdouble initial_distance;
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};
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static guint signals[LAST_SIGNAL] = { 0 };
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G_DEFINE_TYPE (SugarZoomController,
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sugar_zoom_controller,
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SUGAR_TYPE_TOUCH_CONTROLLER)
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2012-08-31 13:57:06 +02:00
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static void
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sugar_zoom_controller_init (SugarZoomController *controller)
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{
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controller->_priv = G_TYPE_INSTANCE_GET_PRIVATE (controller,
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SUGAR_TYPE_ZOOM_CONTROLLER,
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SugarZoomControllerPriv);
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}
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static void
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sugar_zoom_controller_finalize (GObject *object)
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{
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G_OBJECT_CLASS (sugar_zoom_controller_parent_class)->finalize (object);
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}
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2012-09-13 14:37:02 +02:00
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static void
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sugar_zoom_controller_constructed (GObject *object)
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2012-08-31 13:57:06 +02:00
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{
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g_object_set (object,
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"min-touches", 2,
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"max-touches", 2,
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NULL);
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2012-08-31 13:57:06 +02:00
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}
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static gboolean
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_sugar_zoom_controller_get_distance (SugarZoomController *controller,
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gdouble *distance)
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{
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SugarZoomControllerPriv *priv;
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2012-09-13 14:37:02 +02:00
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gint x1, y1, x2, y2;
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GList *touches;
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2012-08-31 13:57:06 +02:00
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gdouble dx, dy;
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priv = controller->_priv;
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2012-09-13 14:37:02 +02:00
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if (sugar_touch_controller_get_num_touches (SUGAR_TOUCH_CONTROLLER (controller)) != 2)
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return FALSE;
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2012-09-13 14:37:02 +02:00
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touches = sugar_touch_controller_get_sequences (SUGAR_TOUCH_CONTROLLER (controller));
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sugar_touch_controller_get_coords (SUGAR_TOUCH_CONTROLLER (controller),
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touches->data, &x1, &y1);
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sugar_touch_controller_get_coords (SUGAR_TOUCH_CONTROLLER (controller),
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touches->next->data, &x2, &y2);
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dx = x1 - x2;
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dy = y1 - y2;;
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*distance = sqrt ((dx * dx) + (dy * dy));
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return TRUE;
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}
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static gboolean
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_sugar_zoom_controller_check_emit (SugarZoomController *controller)
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{
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SugarZoomControllerPriv *priv;
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gdouble distance, zoom;
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if (!_sugar_zoom_controller_get_distance (controller, &distance))
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return FALSE;
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priv = controller->_priv;
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if (distance == 0 || priv->initial_distance == 0)
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return FALSE;
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zoom = distance / priv->initial_distance;
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2012-09-13 14:37:18 +02:00
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g_signal_emit (controller, signals[SCALE_CHANGED], 0, zoom);
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2012-08-31 13:57:06 +02:00
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return TRUE;
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}
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SugarEventControllerState
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sugar_zoom_controller_get_state (SugarEventController *controller)
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{
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SugarZoomControllerPriv *priv;
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gint num_touches;
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2012-08-31 13:57:06 +02:00
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priv = SUGAR_ZOOM_CONTROLLER (controller)->_priv;
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2012-09-13 14:37:02 +02:00
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num_touches = sugar_touch_controller_get_num_touches (SUGAR_TOUCH_CONTROLLER (controller));
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2012-08-31 13:57:06 +02:00
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2012-09-13 14:37:02 +02:00
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if (num_touches == 2)
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return SUGAR_EVENT_CONTROLLER_STATE_RECOGNIZED;
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else if (num_touches == 1)
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return SUGAR_EVENT_CONTROLLER_STATE_COLLECTING;
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2012-08-31 13:57:06 +02:00
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return SUGAR_EVENT_CONTROLLER_STATE_NONE;
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}
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2012-09-13 14:37:02 +02:00
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static void
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sugar_zoom_controller_began (SugarEventController *controller)
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2012-08-31 13:57:06 +02:00
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{
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SugarZoomControllerPriv *priv;
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priv = SUGAR_ZOOM_CONTROLLER (controller)->_priv;
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2012-09-13 14:37:02 +02:00
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_sugar_zoom_controller_get_distance (SUGAR_ZOOM_CONTROLLER (controller),
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&priv->initial_distance);
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2012-08-31 13:57:06 +02:00
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g_object_notify (G_OBJECT (controller), "state");
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}
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2012-09-13 14:37:02 +02:00
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static void
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sugar_zoom_controller_updated (SugarEventController *controller)
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{
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_sugar_zoom_controller_check_emit (SUGAR_ZOOM_CONTROLLER (controller));
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}
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2012-08-31 13:57:06 +02:00
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static void
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sugar_zoom_controller_class_init (SugarZoomControllerClass *klass)
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{
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SugarEventControllerClass *controller_class;
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GObjectClass *object_class;
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object_class = G_OBJECT_CLASS (klass);
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object_class->finalize = sugar_zoom_controller_finalize;
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object_class->constructed = sugar_zoom_controller_constructed;
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2012-08-31 13:57:06 +02:00
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controller_class = SUGAR_EVENT_CONTROLLER_CLASS (klass);
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controller_class->get_state = sugar_zoom_controller_get_state;
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2012-09-13 14:37:02 +02:00
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controller_class->began = sugar_zoom_controller_began;
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controller_class->updated = sugar_zoom_controller_updated;
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2012-08-31 13:57:06 +02:00
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2012-08-31 14:23:35 +02:00
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/**
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* SugarZoomController::scale-changed:
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* @controller: the object on which the signal is emitted
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* @scale: Difference with the starting zooming state
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*/
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2012-09-13 14:37:18 +02:00
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signals[SCALE_CHANGED] =
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g_signal_new ("scale-changed",
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SUGAR_TYPE_ZOOM_CONTROLLER,
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G_SIGNAL_RUN_FIRST,
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G_STRUCT_OFFSET (SugarZoomControllerClass, scale_changed),
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NULL, NULL,
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g_cclosure_marshal_VOID__DOUBLE,
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G_TYPE_NONE, 1,
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G_TYPE_DOUBLE);
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g_type_class_add_private (klass, sizeof (SugarZoomControllerPriv));
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}
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SugarEventController *
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sugar_zoom_controller_new (void)
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{
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return g_object_new (SUGAR_TYPE_ZOOM_CONTROLLER, NULL);
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}
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2012-08-31 14:23:35 +02:00
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/**
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* sugar_zoom_controller_get_scale_delta:
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* @controller: a #SugarZoomController
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* @scale: (out) (transfer none): zoom delta
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2012-08-31 14:23:35 +02:00
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*
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* If @controller is on state %SUGAR_EVENT_CONTROLLER_STATE_RECOGNIZED,
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2012-09-13 14:37:18 +02:00
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* this function returns %TRUE and fills in @scale with the zooming
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* difference since the gesture was recognized (hence the starting point
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* is considered 1x).
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*
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* Returns: %TRUE if @controller is recognizing a zoom gesture
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**/
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gboolean
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sugar_zoom_controller_get_scale_delta (SugarZoomController *controller,
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gdouble *scale)
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2012-08-31 13:57:06 +02:00
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{
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SugarZoomControllerPriv *priv;
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gdouble distance;
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g_return_val_if_fail (SUGAR_IS_ZOOM_CONTROLLER (controller), FALSE);
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if (!_sugar_zoom_controller_get_distance (controller, &distance))
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return FALSE;
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priv = controller->_priv;
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2012-09-13 14:37:18 +02:00
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if (scale)
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*scale = distance / priv->initial_distance;
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2012-08-31 13:57:06 +02:00
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return TRUE;
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}
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