Move cursor tracker ownership to the backend

Let the backend initialize the cursor tracker, and change all call
sites to get the cursor tracker from the backend instead of from the
screen. It wasn't associated with the screen anyway, so the API was
missleading.

https://bugzilla.gnome.org/show_bug.cgi?id=777732

src/backends/meta-backend-private.h

@@ -116,6 +116,7 @@ ClutterBackend * meta_backend_get_clutter_backend (MetaBackend *backend);
 MetaIdleMonitor * meta_backend_get_idle_monitor (MetaBackend *backend,
                                                  int          device_id);
 MetaMonitorManager * meta_backend_get_monitor_manager (MetaBackend *backend);
+MetaCursorTracker * meta_backend_get_cursor_tracker (MetaBackend *backend);
 MetaCursorRenderer * meta_backend_get_cursor_renderer (MetaBackend *backend);
 MetaRenderer * meta_backend_get_renderer (MetaBackend *backend);
 MetaEgl * meta_backend_get_egl (MetaBackend *backend);

src/backends/meta-backend.c

@@ -62,6 +62,7 @@ meta_get_backend (void)
 struct _MetaBackendPrivate
 {
   MetaMonitorManager *monitor_manager;
+  MetaCursorTracker *cursor_tracker;
   MetaCursorRenderer *cursor_renderer;
   MetaInputSettings *input_settings;
   MetaRenderer *renderer;
@@ -246,7 +247,8 @@ on_device_removed (ClutterDeviceManager *device_manager,
    */
   if (backend->current_device_id == device_id)
     {
-      MetaCursorTracker *cursor_tracker = meta_cursor_tracker_get_for_screen (NULL);
+      MetaBackendPrivate *priv = meta_backend_get_instance_private (backend);
+      MetaCursorTracker *cursor_tracker = priv->cursor_tracker;
       gboolean has_touchscreen, has_pointing_device;
       ClutterInputDeviceType device_type;
 
@@ -319,7 +321,7 @@ meta_backend_real_post_init (MetaBackend *backend)
         has_touchscreen |= device_is_slave_touchscreen (device);
       }
 
-    cursor_tracker = meta_cursor_tracker_get_for_screen (NULL);
+    cursor_tracker = priv->cursor_tracker;
     meta_cursor_tracker_set_pointer_visible (cursor_tracker, !has_touchscreen);
 
     g_slist_free (devices);
@@ -424,6 +426,8 @@ meta_backend_initable_init (GInitable     *initable,
       return FALSE;
     }
 
+  priv->cursor_tracker = g_object_new (META_TYPE_CURSOR_TRACKER, NULL);
+
   return TRUE;
 }
 
@@ -466,6 +470,14 @@ meta_backend_get_monitor_manager (MetaBackend *backend)
   return priv->monitor_manager;
 }
 
+MetaCursorTracker *
+meta_backend_get_cursor_tracker (MetaBackend *backend)
+{
+  MetaBackendPrivate *priv = meta_backend_get_instance_private (backend);
+
+  return priv->cursor_tracker;
+}
+
 /**
  * meta_backend_get_cursor_renderer: (skip)
  */
@@ -582,8 +594,8 @@ meta_backend_get_stage (MetaBackend *backend)
 static gboolean
 update_last_device (MetaBackend *backend)
 {
-  MetaCursorTracker *cursor_tracker = meta_cursor_tracker_get_for_screen (NULL);
   MetaBackendPrivate *priv = meta_backend_get_instance_private (backend);
+  MetaCursorTracker *cursor_tracker = priv->cursor_tracker;
   ClutterInputDeviceType device_type;
   ClutterDeviceManager *manager;
   ClutterInputDevice *device;

src/backends/meta-cursor-tracker.c

@@ -130,14 +130,6 @@ meta_cursor_tracker_class_init (MetaCursorTrackerClass *klass)
                                           G_TYPE_NONE, 0);
 }
 
-static MetaCursorTracker *
-meta_cursor_tracker_new (void)
-{
-  return g_object_new (META_TYPE_CURSOR_TRACKER, NULL);
-}
-
-static MetaCursorTracker *_cursor_tracker;
-
 /**
  * meta_cursor_tracker_get_for_screen:
  * @screen: the #MetaScreen
@@ -149,10 +141,12 @@ static MetaCursorTracker *_cursor_tracker;
 MetaCursorTracker *
 meta_cursor_tracker_get_for_screen (MetaScreen *screen)
 {
-  if (!_cursor_tracker)
+  MetaBackend *backend = meta_get_backend ();
-    _cursor_tracker = meta_cursor_tracker_new ();
+  MetaCursorTracker *tracker = meta_backend_get_cursor_tracker (backend);
 
-  return _cursor_tracker;
+  g_assert (tracker);
+
+  return tracker;
 }
 
 static void

src/backends/native/meta-backend-native.c

@@ -318,7 +318,7 @@ meta_backend_native_warp_pointer (MetaBackend *backend,
 {
   ClutterDeviceManager *manager = clutter_device_manager_get_default ();
   ClutterInputDevice *device = clutter_device_manager_get_core_device (manager, CLUTTER_POINTER_DEVICE);
-  MetaCursorTracker *tracker = meta_cursor_tracker_get_for_screen (NULL);
+  MetaCursorTracker *cursor_tracker = meta_backend_get_cursor_tracker (backend);
 
   /* XXX */
   guint32 time_ = 0;
@@ -327,7 +327,7 @@ meta_backend_native_warp_pointer (MetaBackend *backend,
   clutter_evdev_warp_pointer (device, time_, x, y);
 
   /* Warp displayed pointer cursor. */
-  meta_cursor_tracker_update_position (tracker, x, y);
+  meta_cursor_tracker_update_position (cursor_tracker, x, y);
 }
 
 static void

src/core/events.c

@@ -253,7 +253,8 @@ meta_display_handle_event (MetaDisplay        *display,
         }
       else
         {
-          MetaCursorTracker *cursor_tracker = meta_cursor_tracker_get_for_screen (NULL);
+          MetaCursorTracker *cursor_tracker =
+            meta_backend_get_cursor_tracker (backend);
 
           meta_cursor_tracker_update_position (cursor_tracker,
                                                event->motion.x,

src/core/screen.c

@@ -1263,14 +1263,15 @@ meta_screen_update_cursor (MetaScreen *screen)
   MetaCursor cursor = screen->current_cursor;
   Cursor xcursor;
   MetaCursorSprite *cursor_sprite;
-  MetaCursorTracker *tracker = meta_cursor_tracker_get_for_screen (screen);
+  MetaBackend *backend = meta_get_backend ();
+  MetaCursorTracker *cursor_tracker = meta_backend_get_cursor_tracker (backend);
 
   cursor_sprite = meta_cursor_sprite_from_theme (cursor);
 
   if (meta_is_wayland_compositor ())
     manage_root_cursor_sprite_scale (screen, cursor_sprite);
 
-  meta_cursor_tracker_set_root_cursor (tracker, cursor_sprite);
+  meta_cursor_tracker_set_root_cursor (cursor_tracker, cursor_sprite);
   g_object_unref (cursor_sprite);
 
   /* Set a cursor for X11 applications that don't specify their own */
@@ -1378,7 +1379,8 @@ MetaWindow*
 meta_screen_get_mouse_window (MetaScreen  *screen,
                               MetaWindow  *not_this_one)
 {
-  MetaCursorTracker *tracker = meta_cursor_tracker_get_for_screen (screen);
+  MetaBackend *backend = meta_get_backend ();
+  MetaCursorTracker *cursor_tracker = meta_backend_get_cursor_tracker (backend);
   MetaWindow *window;
   int x, y;
 
@@ -1386,7 +1388,7 @@ meta_screen_get_mouse_window (MetaScreen  *screen,
     meta_topic (META_DEBUG_FOCUS,
                 "Focusing mouse window excluding %s\n", not_this_one->desc);
 
-  meta_cursor_tracker_get_pointer (tracker, &x, &y, NULL);
+  meta_cursor_tracker_get_pointer (cursor_tracker, &x, &y, NULL);
 
   window = meta_stack_get_default_focus_window_at_point (screen->stack,
                                                          screen->active_workspace,
@@ -1665,7 +1667,7 @@ meta_screen_get_current_monitor (MetaScreen *screen)
   MetaBackend *backend = meta_get_backend ();
   MetaMonitorManager *monitor_manager =
     meta_backend_get_monitor_manager (backend);
-  MetaCursorTracker *tracker = meta_cursor_tracker_get_for_screen (screen);
+  MetaCursorTracker *cursor_tracker = meta_backend_get_cursor_tracker (backend);
   int n_logical_monitors =
     meta_monitor_manager_get_num_logical_monitors (monitor_manager);
 
@@ -1679,7 +1681,7 @@ meta_screen_get_current_monitor (MetaScreen *screen)
     {
       int x, y;
 
-      meta_cursor_tracker_get_pointer (tracker, &x, &y, NULL);
+      meta_cursor_tracker_get_pointer (cursor_tracker, &x, &y, NULL);
       meta_screen_get_current_monitor_for_pos (screen, x, y);
     }
 
@@ -2968,9 +2970,10 @@ gboolean
 meta_screen_handle_xevent (MetaScreen *screen,
                            XEvent     *xevent)
 {
-  MetaCursorTracker *tracker = meta_cursor_tracker_get_for_screen (screen);
+  MetaBackend *backend = meta_get_backend ();
+  MetaCursorTracker *cursor_tracker = meta_backend_get_cursor_tracker (backend);
 
-  if (meta_cursor_tracker_handle_xevent (tracker, xevent))
+  if (meta_cursor_tracker_handle_xevent (cursor_tracker, xevent))
     return TRUE;
 
   return FALSE;

src/core/window.c

@@ -7691,15 +7691,15 @@ window_focus_on_pointer_rest_callback (gpointer data)
   MetaFocusData *focus_data = data;
   MetaWindow *window = focus_data->window;
   MetaDisplay *display = window->display;
-  MetaScreen *screen = window->screen;
+  MetaBackend *backend = meta_get_backend ();
-  MetaCursorTracker *tracker = meta_cursor_tracker_get_for_screen (screen);
+  MetaCursorTracker *cursor_tracker = meta_backend_get_cursor_tracker (backend);
   int root_x, root_y;
   guint32 timestamp;
 
   if (meta_prefs_get_focus_mode () == G_DESKTOP_FOCUS_MODE_CLICK)
     goto out;
 
-  meta_cursor_tracker_get_pointer (tracker, &root_x, &root_y, NULL);
+  meta_cursor_tracker_get_pointer (cursor_tracker, &root_x, &root_y, NULL);
 
   if (root_x != focus_data->pointer_x ||
       root_y != focus_data->pointer_y)

src/wayland/meta-wayland-pointer.c

@@ -480,7 +480,8 @@ meta_wayland_pointer_on_cursor_changed (MetaCursorTracker *cursor_tracker,
 void
 meta_wayland_pointer_enable (MetaWaylandPointer *pointer)
 {
-  MetaCursorTracker *cursor_tracker = meta_cursor_tracker_get_for_screen (NULL);
+  MetaBackend *backend = meta_get_backend ();
+  MetaCursorTracker *cursor_tracker = meta_backend_get_cursor_tracker (backend);
   ClutterDeviceManager *manager;
 
   pointer->pointer_clients =
@@ -503,7 +504,8 @@ meta_wayland_pointer_enable (MetaWaylandPointer *pointer)
 void
 meta_wayland_pointer_disable (MetaWaylandPointer *pointer)
 {
-  MetaCursorTracker *cursor_tracker = meta_cursor_tracker_get_for_screen (NULL);
+  MetaBackend *backend = meta_get_backend ();
+  MetaCursorTracker *cursor_tracker = meta_backend_get_cursor_tracker (backend);
 
   g_signal_handlers_disconnect_by_func (cursor_tracker,
                                         (gpointer) meta_wayland_pointer_on_cursor_changed,
@@ -965,7 +967,8 @@ meta_wayland_pointer_get_relative_coordinates (MetaWaylandPointer *pointer,
 void
 meta_wayland_pointer_update_cursor_surface (MetaWaylandPointer *pointer)
 {
-  MetaCursorTracker *cursor_tracker = meta_cursor_tracker_get_for_screen (NULL);
+  MetaBackend *backend = meta_get_backend ();
+  MetaCursorTracker *cursor_tracker = meta_backend_get_cursor_tracker (backend);
 
   if (pointer->current)
     {