clutter/backend: Keep a back pointer to the Context

Will be useful in the upcoming commits

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3977>

clutter/clutter/clutter-backend-private.h

@@ -38,6 +38,8 @@ struct _ClutterBackend
   /*< private >*/
   GObject parent_instance;
 
+  ClutterContext *context;
+
   CoglRenderer *cogl_renderer;
   CoglDisplay *cogl_display;
   CoglContext *cogl_context;

clutter/clutter/clutter-backend.c

@@ -61,6 +61,15 @@ enum
   LAST_SIGNAL
 };
 
+enum
+{
+  PROP_0,
+  PROP_CONTEXT,
+  N_PROPS
+};
+
+static GParamSpec *pspecs[N_PROPS] = { 0 };
+
 G_DEFINE_ABSTRACT_TYPE (ClutterBackend, clutter_backend, G_TYPE_OBJECT)
 
 static guint backend_signals[LAST_SIGNAL] = { 0, };
@@ -89,6 +98,44 @@ clutter_backend_dispose (GObject *gobject)
   G_OBJECT_CLASS (clutter_backend_parent_class)->dispose (gobject);
 }
 
+static void
+clutter_backend_get_property (GObject      *object,
+                              guint         prop_id,
+                              GValue       *value,
+                              GParamSpec   *pspec)
+{
+  ClutterBackend *backend = CLUTTER_BACKEND (object);
+
+  switch (prop_id)
+    {
+    case PROP_CONTEXT:
+      g_value_set_object (value, backend->context);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+clutter_backend_set_property (GObject      *object,
+                              guint         prop_id,
+                              const GValue *value,
+                              GParamSpec   *pspec)
+{
+  ClutterBackend *backend = CLUTTER_BACKEND (object);
+
+  switch (prop_id)
+    {
+    case PROP_CONTEXT:
+      backend->context = g_value_get_object (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
 static void
 clutter_backend_real_resolution_changed (ClutterBackend *backend)
 {
@@ -238,6 +285,8 @@ clutter_backend_class_init (ClutterBackendClass *klass)
   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 
   gobject_class->dispose = clutter_backend_dispose;
+  gobject_class->get_property = clutter_backend_get_property;
+  gobject_class->set_property = clutter_backend_set_property;
 
   /**
    * ClutterBackend::resolution-changed:
@@ -284,6 +333,15 @@ clutter_backend_class_init (ClutterBackendClass *klass)
                   NULL, NULL, NULL,
                   G_TYPE_NONE, 0);
 
+  pspecs[PROP_CONTEXT] =
+    g_param_spec_object ("context", NULL, NULL,
+                         CLUTTER_TYPE_CONTEXT,
+                         G_PARAM_READWRITE |
+                         G_PARAM_STATIC_STRINGS |
+                         G_PARAM_CONSTRUCT_ONLY);
+
+  g_object_class_install_properties (gobject_class, N_PROPS, pspecs);
+
   klass->resolution_changed = clutter_backend_real_resolution_changed;
 
   klass->create_context = clutter_backend_real_create_context;

clutter/clutter/clutter-context.c

@@ -267,7 +267,7 @@ clutter_context_new (ClutterBackendConstructor   backend_constructor,
   init_clutter_debug (context);
   context->show_fps = clutter_show_fps;
 
-  context->backend = backend_constructor (user_data);
+  context->backend = backend_constructor (context, user_data);
   context->settings = clutter_settings_get_default ();
   _clutter_settings_set_backend (context->settings,
                                  context->backend);

clutter/clutter/clutter-context.h

@@ -24,7 +24,8 @@
 #include "cogl-pango/cogl-pango.h"
 
 
-typedef ClutterBackend * (* ClutterBackendConstructor) (gpointer user_data);
+typedef ClutterBackend * (* ClutterBackendConstructor) (ClutterContext *context,
+                                                        gpointer        user_data);
 
 #define CLUTTER_TYPE_CONTEXT (clutter_context_get_type ())
 CLUTTER_EXPORT

src/backends/meta-backend-private.h

@@ -55,7 +55,8 @@ struct _MetaBackendClass
 {
   GObjectClass parent_class;
 
-  ClutterBackend * (* create_clutter_backend) (MetaBackend *backend);
+  ClutterBackend * (* create_clutter_backend) (MetaBackend    *backend,
+                                               ClutterContext *context);
 
   void (* post_init) (MetaBackend *backend);
 

src/backends/meta-backend.c

@@ -1201,11 +1201,13 @@ static GSourceFuncs clutter_source_funcs = {
 };
 
 static ClutterBackend *
-meta_clutter_backend_constructor (gpointer user_data)
+meta_clutter_backend_constructor (ClutterContext *context,
+                                  gpointer        user_data)
 {
   MetaBackend *backend = META_BACKEND (user_data);
 
-  return META_BACKEND_GET_CLASS (backend)->create_clutter_backend (backend);
+  return META_BACKEND_GET_CLASS (backend)->create_clutter_backend (backend,
+                                                                   context);
 }
 
 static ClutterSeat *

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

@@ -124,9 +124,10 @@ meta_backend_native_dispose (GObject *object)
 }
 
 static ClutterBackend *
-meta_backend_native_create_clutter_backend (MetaBackend *backend)
+meta_backend_native_create_clutter_backend (MetaBackend    *backend,
+                                            ClutterContext *context)
 {
-  return CLUTTER_BACKEND (meta_clutter_backend_native_new (backend));
+  return CLUTTER_BACKEND (meta_clutter_backend_native_new (backend, context));
 }
 
 static ClutterSeat *

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

@@ -118,11 +118,13 @@ meta_clutter_backend_native_class_init (MetaClutterBackendNativeClass *klass)
 }
 
 MetaClutterBackendNative *
-meta_clutter_backend_native_new (MetaBackend *backend)
+meta_clutter_backend_native_new (MetaBackend    *backend,
+                                 ClutterContext *context)
 {
   MetaClutterBackendNative *clutter_backend_native;
 
   clutter_backend_native = g_object_new (META_TYPE_CLUTTER_BACKEND_NATIVE,
+                                         "context", context,
                                          NULL);
   clutter_backend_native->backend = backend;
 

src/backends/native/meta-clutter-backend-native.h

@@ -33,4 +33,5 @@ G_DECLARE_FINAL_TYPE (MetaClutterBackendNative, meta_clutter_backend_native,
                       META, CLUTTER_BACKEND_NATIVE,
                       ClutterBackend)
 
-MetaClutterBackendNative * meta_clutter_backend_native_new (MetaBackend *backend);
+MetaClutterBackendNative * meta_clutter_backend_native_new (MetaBackend    *backend,
+                                                            ClutterContext *context);

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

@@ -609,9 +609,10 @@ meta_backend_x11_post_init (MetaBackend *backend)
 }
 
 static ClutterBackend *
-meta_backend_x11_create_clutter_backend (MetaBackend *backend)
+meta_backend_x11_create_clutter_backend (MetaBackend    *backend,
+                                         ClutterContext *context)
 {
-  return CLUTTER_BACKEND (meta_clutter_backend_x11_new (backend));
+  return CLUTTER_BACKEND (meta_clutter_backend_x11_new (backend, context));
 }
 
 static MetaColorManager *

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

@@ -137,14 +137,17 @@ meta_clutter_backend_x11_class_init (MetaClutterBackendX11Class *klass)
 }
 
 MetaClutterBackendX11 *
-meta_clutter_backend_x11_new (MetaBackend *backend)
+meta_clutter_backend_x11_new (MetaBackend    *backend,
+                              ClutterContext *context)
 {
   MetaBackendX11 *backend_x11 = META_BACKEND_X11 (backend);
   Atom atoms[N_ATOM_NAMES];
   MetaClutterBackendX11 *clutter_backend_x11;
   MetaClutterBackendX11Private *priv;
 
-  clutter_backend_x11 = g_object_new (META_TYPE_CLUTTER_BACKEND_X11, NULL);
+  clutter_backend_x11 = g_object_new (META_TYPE_CLUTTER_BACKEND_X11,
+                                      "context", context,
+                                      NULL);
   priv = meta_clutter_backend_x11_get_instance_private (clutter_backend_x11);
   priv->backend = backend;
 

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

@@ -56,4 +56,5 @@ G_DECLARE_FINAL_TYPE (MetaClutterBackendX11, meta_clutter_backend_x11,
                       META, CLUTTER_BACKEND_X11,
                       ClutterBackend)
 
-MetaClutterBackendX11 * meta_clutter_backend_x11_new (MetaBackend *backend);
+MetaClutterBackendX11 * meta_clutter_backend_x11_new (MetaBackend    *backend,
+                                                      ClutterContext *context);