refs #373: Progress on migration script to update the SimpleClick GUI.

The script is executed only if the project is using the SimpleClick
template, and it removes the InventoryBar, SettingsBar,
TextSettingsPopup and SoundSettingsPopup components.

addons/popochiu/migration/migration/popochiu_migration.gd

@@ -32,6 +32,10 @@ func _init() -> void:
 #endregion
 
 #region Virtual ####################################################################################
+func _is_migration_needed() -> bool:
+	return true
+
+
 func _do_migration() -> bool:
 	return false
 
@@ -60,7 +64,9 @@ func get_migration_name() -> String:
 ## Returns [true] if the current Popochiu migration version is newer than the user's migration
 ## version, which means a migration is needed.
 func is_migration_needed() -> bool:
-	return _version > PopochiuMigrationHelper.get_user_migration_version()
+	return (
+		_version > PopochiuMigrationHelper.get_user_migration_version() and _is_migration_needed()
+	)
 
 
 ## A helper function to display an error message in the [b]Output[/b] if there is an error doing 

addons/popochiu/migration/migration/popochiu_migration_template.gd

@@ -11,7 +11,6 @@ const STEPS = [
 ]
 
 
-
 #region Virtual ####################################################################################
 ## This is code specific for this migration. This should return [code]true[/code] if the migration
 ## is successful. This is called from [method do_migration] which checks to make sure the migration
@@ -36,4 +35,5 @@ func _is_reload_required() -> bool:
 #func _step1() -> Completion:
 	#return Completion.DONE
 
+
 #endregion

addons/popochiu/migration/migrations/popochiu_migration_4.gd

@@ -0,0 +1,71 @@
+@tool
+class_name PopochiuMigration4
+extends PopochiuMigration
+
+# Update constant values to be correct for your migration
+const VERSION = 4
+const DESCRIPTION = "short description of migration goes here"
+const STEPS = [
+	"Remove InventoryBar, SettingsBar, TextSettingsPopup and SoundSettingsPopup.",
+	"Add SimpleClickBar and SimpleClickSettingsPopup.",
+	"Update SaveAndLoadPopup.",
+]
+
+
+
+#region Virtual ####################################################################################
+func _is_migration_needed() -> bool:
+	return PopochiuResources.get_data_value("ui", "template", "") == "SimpleClick"
+
+
+func _do_migration() -> bool:
+	return await PopochiuMigrationHelper.execute_migration_steps(
+		self,
+		[
+			# Include the function names for each step here
+			_remove_non_used_components,
+			_step2,
+			_step3,
+		]
+	)
+
+
+func _is_reload_required() -> bool:
+	return false
+
+
+#endregion
+
+#region Private ####################################################################################
+func _remove_non_used_components() -> Completion:
+	var gui_scene := (ResourceLoader.load(
+		PopochiuResources.GUI_GAME_SCENE, "", ResourceLoader.CACHE_MODE_IGNORE
+	) as PackedScene).instantiate()
+	var nodes_to_remove: Array[Control] = []
+	for node_name: String in [
+		"InventoryBar", "SettingsBar", "TextSettingsPopup", "SoundSettingsPopup"
+	]:
+		var node: Node = gui_scene.find_child(node_name)
+		if is_instance_valid(node) and node is Control:
+			nodes_to_remove.append(node)
+	for node: Control in nodes_to_remove:
+		node.owner = null
+		node.queue_free()
+	await PopochiuEditorHelper.frame_processed()
+
+	var gui_packed_scene := PackedScene.new()
+	gui_packed_scene.pack(gui_scene)
+	ResourceSaver.save(gui_packed_scene, PopochiuResources.GUI_GAME_SCENE)
+
+	return Completion.DONE
+
+
+func _step2() -> Completion:
+	return Completion.DONE
+
+
+func _step3() -> Completion:
+	return Completion.DONE
+
+
+#endregion