clutter/backend: Remove 'finish_init()' vfunc

The original purpose of being able to report errors is no longer
relevant, since the Clutter backend is now practically a thin wrapper
around the actual backend, which has already dealt with error reporting.
Thus move this to the regular constructor path.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2016>

clutter/clutter/clutter-backend-private.h

@@ -62,8 +62,6 @@ struct _ClutterBackendClass
   GObjectClass parent_class;
 
   /* vfuncs */
-  gboolean              (* finish_init)        (ClutterBackend  *backend,
-                                                GError         **error);
   ClutterStageWindow *  (* create_stage)       (ClutterBackend  *backend,
                                                 ClutterStage    *wrapper,
                                                 GError         **error);
@@ -92,9 +90,6 @@ ClutterStageWindow *    _clutter_backend_create_stage                   (Clutter
 gboolean                _clutter_backend_create_context                 (ClutterBackend         *backend,
                                                                          GError                **error);
 
-gboolean                _clutter_backend_finish_init                    (ClutterBackend         *backend,
-                                                                         GError                **error);
-
 CLUTTER_EXPORT
 ClutterStageWindow *    clutter_backend_get_stage_window                (ClutterBackend         *backend);
 

clutter/clutter/clutter-backend.c

@@ -337,21 +337,6 @@ clutter_backend_init (ClutterBackend *self)
   self->fallback_resource_scale = 1.f;
 }
 
-gboolean
-_clutter_backend_finish_init (ClutterBackend  *backend,
-                              GError         **error)
-{
-  ClutterBackendClass *klass;
-
-  g_assert (CLUTTER_IS_BACKEND (backend));
-
-  klass = CLUTTER_BACKEND_GET_CLASS (backend);
-  if (klass->finish_init)
-    return klass->finish_init (backend, error);
-
-  return TRUE;
-}
-
 ClutterStageWindow *
 _clutter_backend_create_stage (ClutterBackend  *backend,
                                ClutterStage    *wrapper,

clutter/clutter/clutter-main.c

@@ -499,16 +499,6 @@ static gboolean
 clutter_init_real (ClutterContext  *clutter_context,
                    GError         **error)
 {
-  ClutterBackend *backend;
-
-  /* Note, creates backend if not already existing, though parse args will
-   * have likely created it
-   */
-  backend = clutter_context->backend;
-
-  if (!_clutter_backend_finish_init (backend, error))
-    return FALSE;
-
   /* If we are displaying the regions that would get redrawn with clipped
    * redraws enabled we actually have to disable the clipped redrawing
    * because otherwise we end up with nasty trails of rectangles everywhere.

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

@@ -68,37 +68,6 @@ static const gchar *atom_names[] = {
 /* various flags corresponding to pre init setup calls */
 static gboolean clutter_enable_stereo = FALSE;
 
-static gboolean
-meta_clutter_backend_x11_finish_init (ClutterBackend  *clutter_backend,
-                                      GError         **error)
-{
-  MetaClutterBackendX11 *clutter_backend_x11 =
-    META_CLUTTER_BACKEND_X11 (clutter_backend);
-  MetaClutterBackendX11Private *priv =
-    meta_clutter_backend_x11_get_instance_private (clutter_backend_x11);
-  MetaBackendX11 *backend_x11 = META_BACKEND_X11 (priv->backend);
-  Atom atoms[N_ATOM_NAMES];
-
-  clutter_backend_x11->xdisplay = meta_backend_x11_get_xdisplay (backend_x11);
-
-  XInternAtoms (clutter_backend_x11->xdisplay,
-                (char **) atom_names, N_ATOM_NAMES,
-                False, atoms);
-
-  clutter_backend_x11->atom_NET_WM_PID = atoms[0];
-  clutter_backend_x11->atom_NET_WM_PING = atoms[1];
-  clutter_backend_x11->atom_NET_WM_STATE = atoms[2];
-  clutter_backend_x11->atom_NET_WM_USER_TIME = atoms[3];
-  clutter_backend_x11->atom_WM_PROTOCOLS = atoms[4];
-  clutter_backend_x11->atom_WM_DELETE_WINDOW = atoms[5];
-  clutter_backend_x11->atom_XEMBED = atoms[6];
-  clutter_backend_x11->atom_XEMBED_INFO = atoms[7];
-  clutter_backend_x11->atom_NET_WM_NAME = atoms[8];
-  clutter_backend_x11->atom_UTF8_STRING = atoms[9];
-
-  return TRUE;
-}
-
 static gboolean
 check_onscreen_template (CoglRenderer         *renderer,
                          CoglOnscreenTemplate *onscreen_template,
@@ -233,8 +202,6 @@ meta_clutter_backend_x11_class_init (MetaClutterBackendX11Class *klass)
 {
   ClutterBackendClass *clutter_backend_class = CLUTTER_BACKEND_CLASS (klass);
 
-  clutter_backend_class->finish_init = meta_clutter_backend_x11_finish_init;
-
   clutter_backend_class->get_display = meta_clutter_backend_x11_get_display;
   clutter_backend_class->get_renderer = meta_clutter_backend_x11_get_renderer;
   clutter_backend_class->create_stage = meta_clutter_backend_x11_create_stage;
@@ -245,6 +212,8 @@ meta_clutter_backend_x11_class_init (MetaClutterBackendX11Class *klass)
 MetaClutterBackendX11 *
 meta_clutter_backend_x11_new (MetaBackend *backend)
 {
+  MetaBackendX11 *backend_x11 = META_BACKEND_X11 (backend);
+  Atom atoms[N_ATOM_NAMES];
   MetaClutterBackendX11 *clutter_backend_x11;
   MetaClutterBackendX11Private *priv;
 
@@ -252,6 +221,23 @@ meta_clutter_backend_x11_new (MetaBackend *backend)
   priv = meta_clutter_backend_x11_get_instance_private (clutter_backend_x11);
   priv->backend = backend;
 
+  clutter_backend_x11->xdisplay = meta_backend_x11_get_xdisplay (backend_x11);
+
+  XInternAtoms (clutter_backend_x11->xdisplay,
+                (char **) atom_names, N_ATOM_NAMES,
+                False, atoms);
+
+  clutter_backend_x11->atom_NET_WM_PID = atoms[0];
+  clutter_backend_x11->atom_NET_WM_PING = atoms[1];
+  clutter_backend_x11->atom_NET_WM_STATE = atoms[2];
+  clutter_backend_x11->atom_NET_WM_USER_TIME = atoms[3];
+  clutter_backend_x11->atom_WM_PROTOCOLS = atoms[4];
+  clutter_backend_x11->atom_WM_DELETE_WINDOW = atoms[5];
+  clutter_backend_x11->atom_XEMBED = atoms[6];
+  clutter_backend_x11->atom_XEMBED_INFO = atoms[7];
+  clutter_backend_x11->atom_NET_WM_NAME = atoms[8];
+  clutter_backend_x11->atom_UTF8_STRING = atoms[9];
+
   return clutter_backend_x11;
 }