clutter/clutter-swipe-action.c

   1 /*
   2  * Clutter.
   3  *
   4  * An OpenGL based 'interactive canvas' library.
   5  *
   6  * Copyright (C) 2010  Intel Corporation.
   7  * Copyright (C) 2011  Robert Bosch Car Multimedia GmbH.
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library. If not, see <http://www.gnu.org/licenses/>.
  21  *
  22  * Author:
  23  *   Tomeu Vizoso <tomeu.vizoso@collabora.co.uk>
  24  *
  25  * Based on ClutterDragAction, written by:
  26  *   Emmanuele Bassi <ebassi@linux.intel.com>
  27  */
  28
  29 /**
  30  * SECTION:clutter-swipe-action
  31  * @Title: ClutterSwipeAction
  32  * @Short_Description: Action for swipe gestures
  33  *
  34  * #ClutterSwipeAction is a sub-class of #ClutterGestureAction that implements
  35  * the logic for recognizing swipe gestures.
  36  *
  37  * Since: 1.8
  38  */
  39
  40 #ifdef HAVE_CONFIG_H
  41 #include "config.h"
  42 #endif
  43
  44 #include "clutter-swipe-action.h"
  45
  46 #include "clutter-debug.h"
  47 #include "clutter-enum-types.h"
  48 #include "clutter-marshal.h"
  49 #include "clutter-private.h"
  50
  51 struct _ClutterSwipeActionPrivate
  52 {
  53   ClutterSwipeDirection h_direction;
  54   ClutterSwipeDirection v_direction;
  55
  56   int threshold;
  57 };
  58
  59 enum
  60 {
  61   SWEPT,
  62
  63   LAST_SIGNAL
  64 };
  65
  66 static guint swipe_signals[LAST_SIGNAL] = { 0, };
  67
  68 G_DEFINE_TYPE (ClutterSwipeAction, clutter_swipe_action,
  69                CLUTTER_TYPE_GESTURE_ACTION);
  70
  71 static gboolean
  72 gesture_begin (ClutterGestureAction  *action,
  73                ClutterActor          *actor)
  74 {
  75   ClutterSwipeActionPrivate *priv = CLUTTER_SWIPE_ACTION (action)->priv;
  76   ClutterSettings *settings = clutter_settings_get_default ();
  77
  78   /* reset the state at the beginning of a new gesture */
  79   priv->h_direction = 0;
  80   priv->v_direction = 0;
  81
  82   g_object_get (settings, "dnd-drag-threshold", &priv->threshold, NULL);
  83
  84   return TRUE;
  85 }
  86
  87 static gboolean
  88 gesture_progress (ClutterGestureAction *action,
  89                   ClutterActor         *actor)
  90 {
  91   ClutterSwipeActionPrivate *priv = CLUTTER_SWIPE_ACTION (action)->priv;
  92   gfloat press_x, press_y;
  93   gfloat motion_x, motion_y;
  94   gfloat delta_x, delta_y;
  95   ClutterSwipeDirection h_direction = 0, v_direction = 0;
  96
  97   clutter_gesture_action_get_press_coords (action,
  98                                            0,
  99                                            &press_x,
 100                                            &press_y);
 101
 102   clutter_gesture_action_get_motion_coords (action,
 103                                             0,
 104                                             &motion_x,
 105                                             &motion_y);
 106
 107   delta_x = press_x - motion_x;
 108   delta_y = press_y - motion_y;
 109
 110   if (delta_x >= priv->threshold)
 111     h_direction = CLUTTER_SWIPE_DIRECTION_RIGHT;
 112   else if (delta_x < -priv->threshold)
 113     h_direction = CLUTTER_SWIPE_DIRECTION_LEFT;
 114
 115   if (delta_y >= priv->threshold)
 116     v_direction = CLUTTER_SWIPE_DIRECTION_DOWN;
 117   else if (delta_y < -priv->threshold)
 118     v_direction = CLUTTER_SWIPE_DIRECTION_UP;
 119
 120   /* cancel gesture on direction reversal */
 121   if (priv->h_direction == 0)
 122     priv->h_direction = h_direction;
 123
 124   if (priv->v_direction == 0)
 125     priv->v_direction = v_direction;
 126
 127   if (priv->h_direction != h_direction)
 128     return FALSE;
 129
 130   if (priv->v_direction != v_direction)
 131     return FALSE;
 132
 133   return TRUE;
 134 }
 135
 136 static void
 137 gesture_end (ClutterGestureAction *action,
 138              ClutterActor         *actor)
 139 {
 140   ClutterSwipeActionPrivate *priv = CLUTTER_SWIPE_ACTION (action)->priv;
 141   gfloat press_x, press_y;
 142   gfloat release_x, release_y;
 143   ClutterSwipeDirection direction = 0;
 144
 145   clutter_gesture_action_get_press_coords (action,
 146                                            0,
 147                                            &press_x, &press_y);
 148
 149   clutter_gesture_action_get_release_coords (action,
 150                                              0,
 151                                              &release_x, &release_y);
 152
 153   if (release_x - press_x > priv->threshold)
 154     direction |= CLUTTER_SWIPE_DIRECTION_RIGHT;
 155   else if (press_x - release_x > priv->threshold)
 156     direction |= CLUTTER_SWIPE_DIRECTION_LEFT;
 157
 158   if (release_y - press_y > priv->threshold)
 159     direction |= CLUTTER_SWIPE_DIRECTION_DOWN;
 160   else if (press_y - release_y > priv->threshold)
 161     direction |= CLUTTER_SWIPE_DIRECTION_UP;
 162
 163   g_signal_emit (action, swipe_signals[SWEPT], 0, actor, direction);
 164 }
 165
 166 static void
 167 clutter_swipe_action_class_init (ClutterSwipeActionClass *klass)
 168 {
 169   ClutterGestureActionClass *gesture_class =
 170       CLUTTER_GESTURE_ACTION_CLASS (klass);
 171
 172   g_type_class_add_private (klass, sizeof (ClutterSwipeActionPrivate));
 173
 174   gesture_class->gesture_begin = gesture_begin;
 175   gesture_class->gesture_progress = gesture_progress;
 176   gesture_class->gesture_end = gesture_end;
 177
 178   /**
 179    * ClutterSwipeAction::swept:
 180    * @action: the #ClutterSwipeAction that emitted the signal
 181    * @actor: the #ClutterActor attached to the @action
 182    * @direction: the main direction of the swipe gesture
 183    *
 184    * The ::swept signal is emitted when a swipe gesture is recognized on the
 185    * attached actor.
 186    *
 187    * Since: 1.8
 188    */
 189   swipe_signals[SWEPT] =
 190     g_signal_new (I_("swept"),
 191                   G_TYPE_FROM_CLASS (klass),
 192                   G_SIGNAL_RUN_LAST,
 193                   G_STRUCT_OFFSET (ClutterSwipeActionClass, swept),
 194                   NULL, NULL,
 195                   _clutter_marshal_VOID__OBJECT_FLAGS,
 196                   G_TYPE_NONE, 2,
 197                   CLUTTER_TYPE_ACTOR,
 198                   CLUTTER_TYPE_SWIPE_DIRECTION);
 199 }
 200
 201 static void
 202 clutter_swipe_action_init (ClutterSwipeAction *self)
 203 {
 204   self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self, CLUTTER_TYPE_SWIPE_ACTION,
 205                                             ClutterSwipeActionPrivate);
 206 }
 207
 208 /**
 209  * clutter_swipe_action_new:
 210  *
 211  * Creates a new #ClutterSwipeAction instance
 212  *
 213  * Return value: the newly created #ClutterSwipeAction
 214  *
 215  * Since: 1.8
 216  */
 217 ClutterAction *
 218 clutter_swipe_action_new (void)
 219 {
 220   return g_object_new (CLUTTER_TYPE_SWIPE_ACTION, NULL);
 221 }