gtkgesturepan.c 9.72 KB
Newer Older
Carlos Garnacho's avatar
Carlos Garnacho committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
/* GTK - The GIMP Toolkit
 * Copyright (C) 2014, Red Hat, Inc.
 *
 * 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(s): Carlos Garnacho <carlosg@gnome.org>
 */
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

/**
 * SECTION:gtkgesturepan
 * @Short_description: Pan gesture
 * @Title: GtkGesturePan
 *
 * #GtkGesturePan is a #GtkGesture implementation able to recognize
 * pan gestures, those are drags that are locked to happen along one
 * axis. The axis that a #GtkGesturePan handles is defined at
 * construct time, and can be changed through
 * gtk_gesture_pan_set_orientation().
 *
 * When the gesture starts to be recognized, #GtkGesturePan will
 * attempt to determine as early as possible whether the sequence
 * is moving in the expected direction, and denying the sequence if
 * this does not happen.
 *
 * Once a panning gesture along the expected axis is recognized,
Carlos Garnacho's avatar
Carlos Garnacho committed
37
 * the #GtkGesturePan::pan signal will be emitted as input events
38 39 40
 * are received, containing the offset in the given axis.
 */

Carlos Garnacho's avatar
Carlos Garnacho committed
41
#include "config.h"
42 43
#include "gtkgesturepan.h"
#include "gtkgesturepanprivate.h"
Carlos Garnacho's avatar
Carlos Garnacho committed
44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66
#include "gtktypebuiltins.h"
#include "gtkprivate.h"
#include "gtkintl.h"

typedef struct _GtkGesturePanPrivate GtkGesturePanPrivate;

struct _GtkGesturePanPrivate
{
  guint orientation : 2;
  guint panning     : 1;
};

enum {
  PROP_ORIENTATION = 1
};

enum {
  PAN,
  N_SIGNALS
};

static guint signals[N_SIGNALS] = { 0 };

67
G_DEFINE_TYPE_WITH_PRIVATE (GtkGesturePan, gtk_gesture_pan, GTK_TYPE_GESTURE_DRAG)
Carlos Garnacho's avatar
Carlos Garnacho committed
68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106

static void
gtk_gesture_pan_get_property (GObject    *object,
                              guint       prop_id,
                              GValue     *value,
                              GParamSpec *pspec)
{
  GtkGesturePanPrivate *priv;

  priv = gtk_gesture_pan_get_instance_private (GTK_GESTURE_PAN (object));

  switch (prop_id)
    {
    case PROP_ORIENTATION:
      g_value_set_enum (value, priv->orientation);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    }
}

static void
gtk_gesture_pan_set_property (GObject      *object,
                              guint         prop_id,
                              const GValue *value,
                              GParamSpec   *pspec)
{
  switch (prop_id)
    {
    case PROP_ORIENTATION:
      gtk_gesture_pan_set_orientation (GTK_GESTURE_PAN (object),
                                       g_value_get_enum (value));
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    }
}

static void
107 108 109 110
direction_from_offset (gdouble          offset_x,
                       gdouble          offset_y,
                       GtkOrientation   orientation,
                       GtkPanDirection *direction)
Carlos Garnacho's avatar
Carlos Garnacho committed
111
{
112
  if (orientation == GTK_ORIENTATION_HORIZONTAL)
Carlos Garnacho's avatar
Carlos Garnacho committed
113 114 115 116 117 118
    {
      if (offset_x > 0)
        *direction = GTK_PAN_DIRECTION_RIGHT;
      else
        *direction = GTK_PAN_DIRECTION_LEFT;
    }
119
  else if (orientation == GTK_ORIENTATION_VERTICAL)
Carlos Garnacho's avatar
Carlos Garnacho committed
120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140
    {
      if (offset_y > 0)
        *direction = GTK_PAN_DIRECTION_DOWN;
      else
        *direction = GTK_PAN_DIRECTION_UP;
    }
  else
    g_assert_not_reached ();
}

static gboolean
guess_direction (GtkGesturePan   *gesture,
                 gdouble          offset_x,
                 gdouble          offset_y,
                 GtkPanDirection *direction)
{
  gdouble abs_x, abs_y;

  abs_x = ABS (offset_x);
  abs_y = ABS (offset_y);

141
#define FACTOR 2
Carlos Garnacho's avatar
Carlos Garnacho committed
142 143
  if (abs_x > abs_y * FACTOR)
    direction_from_offset (offset_x, offset_y,
144
                           GTK_ORIENTATION_HORIZONTAL, direction);
Carlos Garnacho's avatar
Carlos Garnacho committed
145 146
  else if (abs_y > abs_x * FACTOR)
    direction_from_offset (offset_x, offset_y,
147
                           GTK_ORIENTATION_VERTICAL, direction);
Carlos Garnacho's avatar
Carlos Garnacho committed
148 149 150 151 152 153 154 155 156 157 158 159 160 161 162
  else
    return FALSE;

  return TRUE;
#undef FACTOR
}

static gboolean
check_orientation_matches (GtkGesturePan   *gesture,
                           GtkPanDirection  direction)
{
  GtkGesturePanPrivate *priv = gtk_gesture_pan_get_instance_private (gesture);

  return (((direction == GTK_PAN_DIRECTION_LEFT ||
            direction == GTK_PAN_DIRECTION_RIGHT) &&
163
           priv->orientation == GTK_ORIENTATION_HORIZONTAL) ||
Carlos Garnacho's avatar
Carlos Garnacho committed
164 165
          ((direction == GTK_PAN_DIRECTION_UP ||
            direction == GTK_PAN_DIRECTION_DOWN) &&
166
           priv->orientation == GTK_ORIENTATION_VERTICAL));
Carlos Garnacho's avatar
Carlos Garnacho committed
167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198
}

static void
gtk_gesture_pan_drag_update (GtkGestureDrag *gesture,
                             gdouble         offset_x,
                             gdouble         offset_y)
{
  GtkGesturePanPrivate *priv;
  GtkPanDirection direction;
  GtkGesturePan *pan;
  gdouble offset;

  pan = GTK_GESTURE_PAN (gesture);
  priv = gtk_gesture_pan_get_instance_private (pan);

  if (!priv->panning)
    {
      if (!guess_direction (pan, offset_x, offset_y, &direction))
        return;

      if (!check_orientation_matches (pan, direction))
        {
          gtk_gesture_set_state (GTK_GESTURE (gesture),
                                 GTK_EVENT_SEQUENCE_DENIED);
          return;
        }

      priv->panning = TRUE;
    }
  else
    direction_from_offset (offset_x, offset_y, priv->orientation, &direction);

199
  offset = (priv->orientation == GTK_ORIENTATION_VERTICAL) ?
Carlos Garnacho's avatar
Carlos Garnacho committed
200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226
    ABS (offset_y) : ABS (offset_x);
  g_signal_emit (gesture, signals[PAN], 0, direction, offset);
}

static void
gtk_gesture_pan_drag_end (GtkGestureDrag *gesture,
                          gdouble         offset_x,
                          gdouble         offset_y)
{
  GtkGesturePanPrivate *priv;

  priv = gtk_gesture_pan_get_instance_private (GTK_GESTURE_PAN (gesture));
  priv->panning = FALSE;
}

static void
gtk_gesture_pan_class_init (GtkGesturePanClass *klass)
{
  GtkGestureDragClass *drag_gesture_class = GTK_GESTURE_DRAG_CLASS (klass);
  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  object_class->get_property = gtk_gesture_pan_get_property;
  object_class->set_property = gtk_gesture_pan_set_property;

  drag_gesture_class->drag_update = gtk_gesture_pan_drag_update;
  drag_gesture_class->drag_end = gtk_gesture_pan_drag_end;

227 228 229 230 231 232 233
  /**
   * GtkGesturePan:orientation:
   *
   * The expected orientation of pan gestures.
   *
   * Since: 3.14
   */
Carlos Garnacho's avatar
Carlos Garnacho committed
234 235 236 237 238
  g_object_class_install_property (object_class,
                                   PROP_ORIENTATION,
                                   g_param_spec_enum ("orientation",
                                                      P_("Orientation"),
                                                      P_("Allowed orientations"),
239 240
                                                      GTK_TYPE_ORIENTATION,
                                                      GTK_ORIENTATION_HORIZONTAL,
241 242
                                                      GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY));

243
  /**
Carlos Garnacho's avatar
Carlos Garnacho committed
244
   * GtkGesturePan::pan:
245 246 247 248 249 250 251 252 253
   * @gesture: The object which received the signal
   * @direction: current direction of the pan gesture
   * @offset: Offset along the gesture orientation
   *
   * This signal is emitted once a panning gesture along the
   * expected axis is detected.
   *
   * Since: 3.14
   */
Carlos Garnacho's avatar
Carlos Garnacho committed
254 255 256 257 258 259
  signals[PAN] =
    g_signal_new ("pan",
                  G_TYPE_FROM_CLASS (klass),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (GtkGesturePanClass, pan),
                  NULL, NULL, NULL,
260 261
                  G_TYPE_NONE, 2, GTK_TYPE_PAN_DIRECTION,
                  G_TYPE_DOUBLE);
Carlos Garnacho's avatar
Carlos Garnacho committed
262 263 264 265 266 267 268 269
}

static void
gtk_gesture_pan_init (GtkGesturePan *gesture)
{
  GtkGesturePanPrivate *priv;

  priv = gtk_gesture_pan_get_instance_private (gesture);
270
  priv->orientation = GTK_ORIENTATION_HORIZONTAL;
Carlos Garnacho's avatar
Carlos Garnacho committed
271 272
}

273 274 275 276 277 278 279 280 281 282 283
/**
 * gtk_gesture_pan_new:
 * @widget: a #GtkWidget
 * @orientation: expected orientation
 *
 * Returns a newly created #GtkGesture that recognizes pan gestures.
 *
 * Returns: a newly created #GtkGesturePan
 *
 * Since: 3.14
 **/
Carlos Garnacho's avatar
Carlos Garnacho committed
284
GtkGesture *
285 286
gtk_gesture_pan_new (GtkWidget      *widget,
                     GtkOrientation  orientation)
Carlos Garnacho's avatar
Carlos Garnacho committed
287 288 289 290 291 292 293 294 295
{
  g_return_val_if_fail (GTK_IS_WIDGET (widget), NULL);

  return g_object_new (GTK_TYPE_GESTURE_PAN,
                       "widget", widget,
                       "orientation", orientation,
                       NULL);
}

296 297 298 299 300 301
/**
 * gtk_gesture_pan_get_orientation:
 * @gesture: A #GtkGesturePan
 *
 * Returns the orientation of the pan gestures that this @gesture expects.
 *
302
 * Returns: the expected orientation for pan gestures
303 304 305
 *
 * Since: 3.14
 */
306
GtkOrientation
Carlos Garnacho's avatar
Carlos Garnacho committed
307 308 309 310 311 312 313 314 315 316 317
gtk_gesture_pan_get_orientation (GtkGesturePan *gesture)
{
  GtkGesturePanPrivate *priv;

  g_return_val_if_fail (GTK_IS_GESTURE_PAN (gesture), 0);

  priv = gtk_gesture_pan_get_instance_private (gesture);

  return priv->orientation;
}

318 319 320 321 322 323 324 325 326
/**
 * gtk_gesture_pan_set_orientation:
 * @gesture: A #GtkGesturePan
 * @orientation: expected orientation
 *
 * Sets the orientation to be expected on pan gestures.
 *
 * Since: 3.14
 */
Carlos Garnacho's avatar
Carlos Garnacho committed
327
void
328 329
gtk_gesture_pan_set_orientation (GtkGesturePan  *gesture,
                                 GtkOrientation  orientation)
Carlos Garnacho's avatar
Carlos Garnacho committed
330 331 332 333
{
  GtkGesturePanPrivate *priv;

  g_return_if_fail (GTK_IS_GESTURE_PAN (gesture));
334 335
  g_return_if_fail (orientation == GTK_ORIENTATION_HORIZONTAL ||
                    orientation == GTK_ORIENTATION_VERTICAL);
Carlos Garnacho's avatar
Carlos Garnacho committed
336 337 338 339 340 341 342 343 344

  priv = gtk_gesture_pan_get_instance_private (gesture);

  if (priv->orientation == orientation)
    return;

  priv->orientation = orientation;
  g_object_notify (G_OBJECT (gesture), "orientation");
}