gtkgesture: Handle touchpad events

These will be mutually exclusive with touch events, so it won't
be possible to trigger gestures through mixed input and whatnot.

The accounting of touchpad events is slightly different, there
will be a single internal PointData struct, stored in the hashtable
with the NULL event sequence/key (same than pointer events in
this regard), just that the events stored will be GdkEventTouchpad*,
so will hold information about all fingers at once.

But this difference is just internal, the GtkGesture API doesn't
make explicit assumptions about the number of points (the closest
to a per-point query API is gtk_gesture_get_sequences()). All
signals emitted just contain the last changed GdkEventSequence,
and API takes GdkEventSequences, so everything is consistent with
sequence=NULL for touchpad events.

gtk/gtkgesture.c

@@ -152,6 +152,7 @@ struct _GtkGesturePrivate
   GList *group_link;
   guint n_points;
   guint recognized : 1;
+  guint touchpad : 1;
 };
 
 static guint signals[N_SIGNALS] = { 0 };
@@ -222,6 +223,42 @@ gtk_gesture_finalize (GObject *object)
   G_OBJECT_CLASS (gtk_gesture_parent_class)->finalize (object);
 }
 
+static guint
+_gtk_gesture_get_n_touchpad_points (GtkGesture *gesture,
+                                    gboolean    only_active)
+{
+  GtkGesturePrivate *priv;
+  PointData *data;
+
+  priv = gtk_gesture_get_instance_private (gesture);
+
+  if (!priv->touchpad)
+    return 0;
+
+  data = g_hash_table_lookup (priv->points, NULL);
+
+  if (!data)
+    return 0;
+
+  if (only_active &&
+      (data->state == GTK_EVENT_SEQUENCE_DENIED ||
+       (data->event->type == GDK_TOUCHPAD_SWIPE &&
+        data->event->touchpad_swipe.phase == GDK_TOUCHPAD_GESTURE_PHASE_END) ||
+       (data->event->type == GDK_TOUCHPAD_PINCH &&
+        data->event->touchpad_pinch.phase == GDK_TOUCHPAD_GESTURE_PHASE_END)))
+    return 0;
+
+  switch (data->event->type)
+    {
+    case GDK_TOUCHPAD_SWIPE:
+      return data->event->touchpad_swipe.n_fingers;
+    case GDK_TOUCHPAD_PINCH:
+      return data->event->touchpad_pinch.n_fingers;
+    default:
+      return 0;
+    }
+}
+
 static guint
 _gtk_gesture_get_n_touch_points (GtkGesture *gesture,
                                  gboolean    only_active)
@@ -252,7 +289,14 @@ static guint
 _gtk_gesture_get_n_physical_points (GtkGesture *gesture,
                                     gboolean    only_active)
 {
-  return _gtk_gesture_get_n_touch_points (gesture, only_active);
+  GtkGesturePrivate *priv;
+
+  priv = gtk_gesture_get_instance_private (gesture);
+
+  if (priv->touchpad)
+    return _gtk_gesture_get_n_touchpad_points (gesture, only_active);
+  else
+    return _gtk_gesture_get_n_touch_points (gesture, only_active);
 }
 
 static gboolean
@@ -428,7 +472,7 @@ _gtk_gesture_update_point (GtkGesture     *gesture,
   GdkWindow *widget_window;
   GtkGesturePrivate *priv;
   GdkDevice *device;
-  gboolean existed;
+  gboolean existed, touchpad;
   PointData *data;
 
   if (!gdk_event_get_coords (event, NULL, NULL))
@@ -445,6 +489,8 @@ _gtk_gesture_update_point (GtkGesture     *gesture,
   if (!widget_window)
     return FALSE;
 
+  touchpad = EVENT_IS_TOUCHPAD_GESTURE (event);
+
   if (add)
     {
       /* If the event happens with the wrong device, or
@@ -456,6 +502,12 @@ _gtk_gesture_update_point (GtkGesture     *gesture,
         return FALSE;
       if (priv->user_window && priv->user_window != widget_window)
         return FALSE;
+
+      /* Make touchpad and touchscreen gestures mutually exclusive */
+      if (touchpad && g_hash_table_size (priv->points) > 0)
+        return FALSE;
+      else if (!touchpad && priv->touchpad)
+        return FALSE;
     }
   else if (!priv->device || !priv->window)
     return FALSE;
@@ -474,6 +526,7 @@ _gtk_gesture_update_point (GtkGesture     *gesture,
         {
           priv->window = widget_window;
           priv->device = device;
+          priv->touchpad = touchpad;
         }
 
       data = g_new0 (PointData, 1);
@@ -511,6 +564,7 @@ _gtk_gesture_check_empty (GtkGesture *gesture)
     {
       priv->window = NULL;
       priv->device = NULL;
+      priv->touchpad = FALSE;
     }
 }
 
@@ -609,7 +663,11 @@ gtk_gesture_handle_event (GtkEventController *controller,
     priv->last_sequence = sequence;
 
   if (event->type == GDK_BUTTON_PRESS ||
-      event->type == GDK_TOUCH_BEGIN)
+      event->type == GDK_TOUCH_BEGIN ||
+      (event->type == GDK_TOUCHPAD_SWIPE &&
+       event->touchpad_swipe.phase == GDK_TOUCHPAD_GESTURE_PHASE_BEGIN) ||
+      (event->type == GDK_TOUCHPAD_PINCH &&
+       event->touchpad_pinch.phase == GDK_TOUCHPAD_GESTURE_PHASE_BEGIN))
     {
       if (_gtk_gesture_update_point (gesture, event, TRUE))
         {
@@ -639,7 +697,11 @@ gtk_gesture_handle_event (GtkEventController *controller,
         }
     }
   else if (event->type == GDK_BUTTON_RELEASE ||
-           event->type == GDK_TOUCH_END)
+           event->type == GDK_TOUCH_END ||
+           (event->type == GDK_TOUCHPAD_SWIPE &&
+            event->touchpad_swipe.phase == GDK_TOUCHPAD_GESTURE_PHASE_END) ||
+           (event->type == GDK_TOUCHPAD_PINCH &&
+            event->touchpad_pinch.phase == GDK_TOUCHPAD_GESTURE_PHASE_END))
     {
       if (_gtk_gesture_update_point (gesture, event, FALSE))
         {
@@ -651,7 +713,11 @@ gtk_gesture_handle_event (GtkEventController *controller,
         }
     }
   else if (event->type == GDK_MOTION_NOTIFY ||
-           event->type == GDK_TOUCH_UPDATE)
+           event->type == GDK_TOUCH_UPDATE ||
+           (event->type == GDK_TOUCHPAD_SWIPE &&
+            event->touchpad_swipe.phase == GDK_TOUCHPAD_GESTURE_PHASE_UPDATE) ||
+           (event->type == GDK_TOUCHPAD_PINCH &&
+            event->touchpad_pinch.phase == GDK_TOUCHPAD_GESTURE_PHASE_UPDATE))
     {
       if (event->type == GDK_MOTION_NOTIFY)
         {
@@ -668,7 +734,16 @@ gtk_gesture_handle_event (GtkEventController *controller,
     }
   else if (event->type == GDK_TOUCH_CANCEL)
     {
-      _gtk_gesture_cancel_sequence (gesture, sequence);
+      if (!priv->touchpad)
+        _gtk_gesture_cancel_sequence (gesture, sequence);
+    }
+  else if ((event->type == GDK_TOUCHPAD_SWIPE &&
+            event->touchpad_swipe.phase == GDK_TOUCHPAD_GESTURE_PHASE_CANCEL) ||
+           (event->type == GDK_TOUCHPAD_PINCH &&
+            event->touchpad_pinch.phase == GDK_TOUCHPAD_GESTURE_PHASE_CANCEL))
+    {
+      if (priv->touchpad)
+        _gtk_gesture_cancel_sequence (gesture, sequence);
     }
   else if (event->type == GDK_GRAB_BROKEN)
     {