[gtk+] GtkGestureMultiPress: reset multi-press sequence if the source device changes

[Matthias Clasen <matthiasc src gnome org>]

commit 3d700515e191986dddb4e5675ef41af8695a472f
Author: Carlos Garnacho <carlosg gnome org>
Date:   Mon Feb 22 22:38:56 2016 +0100

    GtkGestureMultiPress: reset multi-press sequence if the source device changes
    
    This prevents multipress sequences to possibly come from different mice.
    Now the accumulated number of presses will be reset if the device changes
    in the mean time.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=723659

 gtk/gtkgesturemultipress.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkgesturemultipress.c b/gtk/gtkgesturemultipress.c
index 1049eee..ebd01ea 100644
--- a/gtk/gtkgesturemultipress.c
+++ b/gtk/gtkgesturemultipress.c
@@ -46,6 +46,7 @@ typedef struct _GtkGestureMultiPressPrivate GtkGestureMultiPressPrivate;
 struct _GtkGestureMultiPressPrivate
 {
   GdkRectangle rect;
+  GdkDevice *current_device;
   gdouble initial_press_x;
   gdouble initial_press_y;
   guint double_click_timeout_id;
@@ -112,6 +113,7 @@ _gtk_gesture_multi_press_stop (GtkGestureMultiPress *gesture)
   if (priv->n_presses == 0)
     return;
 
+  priv->current_device = NULL;
   priv->current_button = 0;
   priv->n_presses = 0;
   g_signal_emit (gesture, signals[STOPPED], 0);
@@ -196,6 +198,7 @@ gtk_gesture_multi_press_begin (GtkGesture       *gesture,
   guint n_presses, button = 1;
   GdkEventSequence *current;
   const GdkEvent *event;
+  GdkDevice *device;
   gdouble x, y;
 
   if (!gtk_gesture_handles_sequence (gesture, sequence))
@@ -205,6 +208,7 @@ gtk_gesture_multi_press_begin (GtkGesture       *gesture,
   priv = gtk_gesture_multi_press_get_instance_private (multi_press);
   event = gtk_gesture_get_last_event (gesture, sequence);
   current = gtk_gesture_single_get_current_sequence (GTK_GESTURE_SINGLE (gesture));
+  device = gdk_event_get_source_device (event);
 
   if (event->type == GDK_BUTTON_PRESS)
     button = event->button.button;
@@ -218,6 +222,11 @@ gtk_gesture_multi_press_begin (GtkGesture       *gesture,
       priv->current_button != button)
     _gtk_gesture_multi_press_stop (multi_press);
 
+  /* Reset also if the device changed */
+  if (priv->current_device && priv->current_device != device)
+    _gtk_gesture_multi_press_stop (multi_press);
+
+  priv->current_device = device;
   priv->current_button = button;
   _gtk_gesture_multi_press_update_timeout (multi_press);
   gtk_gesture_get_point (gesture, current, &x, &y);