Adds background loading feature. Error handling.

App/Scripts/SceneLoader.gd

@@ -1,19 +1,28 @@
 extends Node
 
+signal scene_loaded
 
 var loading_screen = preload("res://App/Scenes/LoadingScreen/LoadingScreen.tscn")
 var scene_to_load : String
+var loaded_resource : Resource
 
 func reload_current_scene() -> void:
 	get_tree().reload_current_scene()
 
-func load_scene(path : String) -> void:
-	if path == "":
+func load_scene(path : String, in_background : bool = false) -> void:
+	if path == null or path.is_empty():
+		print("no path given to load")
 		return
 	if scene_to_load != path:
 		scene_to_load = path
 		ResourceLoader.load_threaded_request(scene_to_load)
+	else:
+		call_deferred("emit_signal", "scene_loaded")
+		return
 	get_tree().paused = false
+	if in_background:
+		set_process(true)
+		return
 	var err = get_tree().change_scene_to_packed(loading_screen)
 	if err:
 		print("failed to load loading screen: %d" % err)
@@ -34,4 +43,16 @@ func get_progress():
 func get_resource():
 	if scene_to_load == null or scene_to_load == "":
 		return ResourceLoader.THREAD_LOAD_INVALID_RESOURCE
-	return ResourceLoader.load_threaded_get(scene_to_load)
+	var current_loaded_resource = ResourceLoader.load_threaded_get(scene_to_load)
+	if current_loaded_resource != null:
+		loaded_resource = current_loaded_resource
+	return loaded_resource
+
+func _process(delta):
+	var status = get_status()
+	match(status):
+		ResourceLoader.THREAD_LOAD_INVALID_RESOURCE, ResourceLoader.THREAD_LOAD_FAILED:
+			set_process(false)
+		ResourceLoader.THREAD_LOAD_LOADED:
+			emit_signal("scene_loaded")
+			set_process(false)