demo: Update to gesture widget-level API changes

demos/gtk-demo/gestures.c

@@ -156,7 +156,8 @@ do_gestures (GtkWidget *do_widget)
       gesture = gtk_gesture_swipe_new (drawing_area);
       g_signal_connect (gesture, "swipe",
                         G_CALLBACK (swipe_gesture_swept), drawing_area);
-      gtk_widget_add_gesture (drawing_area, gesture, GTK_PHASE_BUBBLE);
+      gtk_widget_add_controller (drawing_area, GTK_EVENT_CONTROLLER (gesture));
+      g_object_unref (gesture);
 
       /* Long press */
       gesture = gtk_gesture_long_press_new (drawing_area);
@@ -164,19 +165,22 @@ do_gestures (GtkWidget *do_widget)
                         G_CALLBACK (long_press_gesture_pressed), drawing_area);
       g_signal_connect (gesture, "end",
                         G_CALLBACK (long_press_gesture_end), drawing_area);
-      gtk_widget_add_gesture (drawing_area, gesture, GTK_PHASE_BUBBLE);
+      gtk_widget_add_controller (drawing_area, GTK_EVENT_CONTROLLER (gesture));
+      g_object_unref (gesture);
 
       /* Rotate */
       rotate = gesture = gtk_gesture_rotate_new (drawing_area);
       g_signal_connect (gesture, "angle-changed",
                         G_CALLBACK (rotation_angle_changed), drawing_area);
-      gtk_widget_add_gesture (drawing_area, gesture, GTK_PHASE_BUBBLE);
+      gtk_widget_add_controller (drawing_area, GTK_EVENT_CONTROLLER (gesture));
+      g_object_unref (gesture);
 
       /* Zoom */
       zoom = gesture = gtk_gesture_zoom_new (drawing_area);
       g_signal_connect (gesture, "scale-changed",
                         G_CALLBACK (zoom_scale_changed), drawing_area);
-      gtk_widget_add_gesture (drawing_area, gesture, GTK_PHASE_BUBBLE);
+      gtk_widget_add_controller (drawing_area, GTK_EVENT_CONTROLLER (gesture));
+      g_object_unref (gesture);
     }
 
   if (!gtk_widget_get_visible (window))