backends: Make meta_backend_update_last_device() take a clutter device

Instead of a pretty x11 specific device ID. This also updates the argument
of the ::last-device-changed signal to be a ClutterInputDevice.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/852

src/backends/meta-backend-private.h

@@ -168,7 +168,7 @@ void meta_backend_freeze_updates (MetaBackend *backend);
 void meta_backend_thaw_updates (MetaBackend *backend);
 
 void meta_backend_update_last_device (MetaBackend        *backend,
-                                      int          device_id);
+                                      ClutterInputDevice *device);
 
 gboolean meta_backend_get_relative_motion_deltas (MetaBackend *backend,
                                                   const        ClutterEvent *event,

src/backends/meta-backend.c

@@ -148,7 +148,7 @@ struct _MetaBackendPrivate
 
   GHashTable *device_monitors;
 
-  int current_device_id;
+  ClutterInputDevice *current_device;
 
   MetaPointerConstraint *client_pointer_constraint;
   MetaDnd *dnd;
@@ -425,13 +425,13 @@ on_device_removed (ClutterDeviceManager *device_manager,
   /* If the device the user last interacted goes away, check again pointer
    * visibility.
    */
-  if (priv->current_device_id == device_id)
+  if (priv->current_device == device)
     {
       MetaCursorTracker *cursor_tracker = priv->cursor_tracker;
       gboolean has_touchscreen, has_pointing_device;
       ClutterInputDeviceType device_type;
 
-      priv->current_device_id = 0;
+      priv->current_device = NULL;
 
       device_type = clutter_input_device_get_device_type (device);
       has_touchscreen = check_has_slave_touchscreen (device_manager);
@@ -770,7 +770,7 @@ meta_backend_class_init (MetaBackendClass *klass)
                   G_SIGNAL_RUN_LAST,
                   0,
                   NULL, NULL, NULL,
-                  G_TYPE_NONE, 1, G_TYPE_INT);
+                  G_TYPE_NONE, 1, CLUTTER_TYPE_INPUT_DEVICE);
   signals[LID_IS_CLOSED_CHANGED] =
     g_signal_new ("lid-is-closed-changed",
                   G_TYPE_FROM_CLASS (object_class),
@@ -1171,17 +1171,12 @@ update_last_device (MetaBackend *backend)
   MetaBackendPrivate *priv = meta_backend_get_instance_private (backend);
   MetaCursorTracker *cursor_tracker = priv->cursor_tracker;
   ClutterInputDeviceType device_type;
-  ClutterDeviceManager *manager;
-  ClutterInputDevice *device;
 
   priv->device_update_idle_id = 0;
-  manager = clutter_device_manager_get_default ();
+  device_type = clutter_input_device_get_device_type (priv->current_device);
-  device = clutter_device_manager_get_device (manager,
-                                              priv->current_device_id);
-  device_type = clutter_input_device_get_device_type (device);
 
   g_signal_emit (backend, signals[LAST_DEVICE_CHANGED], 0,
-                 priv->current_device_id);
+                 priv->current_device);
 
   switch (device_type)
     {
@@ -1200,23 +1195,18 @@ update_last_device (MetaBackend *backend)
 
 void
 meta_backend_update_last_device (MetaBackend        *backend,
-                                 int          device_id)
+                                 ClutterInputDevice *device)
 {
   MetaBackendPrivate *priv = meta_backend_get_instance_private (backend);
-  ClutterDeviceManager *manager;
-  ClutterInputDevice *device;
 
-  if (priv->current_device_id == device_id)
+  if (priv->current_device == device)
     return;
 
-  manager = clutter_device_manager_get_default ();
-  device = clutter_device_manager_get_device (manager, device_id);
-
   if (!device ||
       clutter_input_device_get_device_mode (device) == CLUTTER_INPUT_MODE_MASTER)
     return;
 
-  priv->current_device_id = device_id;
+  priv->current_device = device;
 
   if (priv->device_update_idle_id == 0)
     {

src/backends/x11/meta-backend-x11.c

@@ -46,6 +46,7 @@
 #include "backends/meta-stage-private.h"
 #include "backends/x11/meta-clutter-backend-x11.h"
 #include "backends/x11/meta-event-x11.h"
+#include "backends/x11/meta-seat-x11.h"
 #include "backends/x11/meta-stage-x11.h"
 #include "backends/x11/meta-renderer-x11.h"
 #include "clutter/clutter.h"
@@ -242,6 +243,9 @@ handle_device_change (MetaBackendX11 *x11,
                       XIEvent        *event)
 {
   XIDeviceChangedEvent *device_changed;
+  ClutterInputDevice *device;
+  ClutterBackend *backend;
+  ClutterSeat *seat;
 
   if (event->evtype != XI_DeviceChanged)
     return;
@@ -251,8 +255,11 @@ handle_device_change (MetaBackendX11 *x11,
   if (device_changed->reason != XISlaveSwitch)
     return;
 
-  meta_backend_update_last_device (META_BACKEND (x11),
+  backend = meta_backend_get_clutter_backend (META_BACKEND (x11));
+  seat = clutter_backend_get_default_seat (backend);
+  device = meta_seat_x11_lookup_device_id (META_SEAT_X11 (seat),
                                            device_changed->sourceid);
+  meta_backend_update_last_device (META_BACKEND (x11), device);
 }
 
 /* Clutter makes the assumption that there is only one X window

src/core/events.c

@@ -273,10 +273,7 @@ meta_display_handle_event (MetaDisplay        *display,
   source = clutter_event_get_source_device (event);
 
   if (source)
-    {
+    meta_backend_update_last_device (backend, source);
-      meta_backend_update_last_device (backend,
-                                       clutter_input_device_get_device_id (source));
-    }
 
 #ifdef HAVE_WAYLAND
   if (meta_is_wayland_compositor () && event->type == CLUTTER_MOTION)