[mutter] Move cursor tracker ownership to the backend

[Jonas Ådahl <jadahl src gnome org>]

commit 317b734dcc626e285bbb68adcf5a82eac4a4dab6
Author: Jonas Ådahl <jadahl gmail com>
Date:   Tue Nov 29 20:30:22 2016 +0800

    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       |    1 +
 src/backends/meta-backend.c               |   18 +++++++++++++++---
 src/backends/meta-cursor-tracker.c        |   16 +++++-----------
 src/backends/native/meta-backend-native.c |    4 ++--
 src/core/events.c                         |    3 ++-
 src/core/screen.c                         |   19 +++++++++++--------
 src/core/window.c                         |    6 +++---
 src/wayland/meta-wayland-pointer.c        |    9 ++++++---
 8 files changed, 45 insertions(+), 31 deletions(-)
---
diff --git a/src/backends/meta-backend-private.h b/src/backends/meta-backend-private.h
index 07b7af1..b26aaec 100644
--- a/src/backends/meta-backend-private.h
+++ b/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);
diff --git a/src/backends/meta-backend.c b/src/backends/meta-backend.c
index ac6bd30..22b691e 100644
--- a/src/backends/meta-backend.c
+++ b/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;
diff --git a/src/backends/meta-cursor-tracker.c b/src/backends/meta-cursor-tracker.c
index e070425..3e1d76b 100644
--- a/src/backends/meta-cursor-tracker.c
+++ b/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)
-    _cursor_tracker = meta_cursor_tracker_new ();
+  MetaBackend *backend = meta_get_backend ();
+  MetaCursorTracker *tracker = meta_backend_get_cursor_tracker (backend);
+
+  g_assert (tracker);
 
-  return _cursor_tracker;
+  return tracker;
 }
 
 static void
diff --git a/src/backends/native/meta-backend-native.c b/src/backends/native/meta-backend-native.c
index b23aec1..7b53ccd 100644
--- a/src/backends/native/meta-backend-native.c
+++ b/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
diff --git a/src/core/events.c b/src/core/events.c
index 6b808c8..6bf75c3 100644
--- a/src/core/events.c
+++ b/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,
diff --git a/src/core/screen.c b/src/core/screen.c
index 0b360e8..172ad39 100644
--- a/src/core/screen.c
+++ b/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;
diff --git a/src/core/window.c b/src/core/window.c
index c3ac435..9db1b25 100644
--- a/src/core/window.c
+++ b/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;
-  MetaCursorTracker *tracker = meta_cursor_tracker_get_for_screen (screen);
+  MetaBackend *backend = meta_get_backend ();
+  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)
diff --git a/src/wayland/meta-wayland-pointer.c b/src/wayland/meta-wayland-pointer.c
index 986a61c..4578f3e 100644
--- a/src/wayland/meta-wayland-pointer.c
+++ b/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)
     {