Add get_default method to obtain the singleton instance

include/river.h

@@ -79,9 +79,14 @@ G_DECLARE_FINAL_TYPE (AstalRiverRiver, astal_river_river, ASTAL_RIVER, RIVER, GO
  *
  * Returns: (nullable): a newly created connection to river
  */
-
 AstalRiverRiver *astal_river_river_new();
 
+/**
+ * astal_river_river_get_default
+ *
+ * Returns: (nullable) (transfer none): gets the default River object.
+ */
+AstalRiverRiver* astal_river_river_get_default();
 /**
  * astal_river_river_get_outputs
  * @self: the AstalRiverRiver object

src/river.c

@@ -1,5 +1,6 @@
 
 
+#include "river.h"
 #include "river-private.h"
 #include <gio/gio.h>
 #include <wayland-client-protocol.h>
@@ -295,7 +296,7 @@ static gboolean astal_river_river_initable_init (GInitable *initable, GCancellab
 }
 
 static void astal_river_river_initable_iface_init (GInitableIface *iface) {
-  iface->init = astal_river_river_initable_init;
+    iface->init = astal_river_river_initable_init;
 }
 
 static void astal_river_river_init(AstalRiverRiver *self) {
@@ -303,7 +304,7 @@ static void astal_river_river_init(AstalRiverRiver *self) {
 }
 
 AstalRiverRiver *astal_river_river_new() {
-  return g_initable_new(ASTAL_RIVER_TYPE_RIVER, NULL, NULL, NULL);
+    return g_initable_new(ASTAL_RIVER_TYPE_RIVER, NULL, NULL, NULL);
 }
 
 static void disconnect_signal (gpointer key, gpointer value, gpointer user_data) {
@@ -314,6 +315,15 @@ static void disconnect_signal (gpointer key, gpointer value, gpointer user_data)
     g_signal_handler_disconnect (output, GPOINTER_TO_UINT(value));
 }
 
+AstalRiverRiver* astal_river_river_get_default() {
+  static AstalRiverRiver *self = NULL;
+
+  if (self == NULL)
+    self = astal_river_river_new();
+
+  return self;
+}
+
 static void astal_river_river_finalize(GObject *object) {
 
     AstalRiverRiver *self = ASTAL_RIVER_RIVER(object);