Helper to manage UndoRedo in the editor or custom tools.
Helper to manage UndoRedo in the editor or custom tools. It works by registering methods and property changes inside 'actions'. Common behavior is to create an action, then add do/undo calls to functions or property changes, then committing the action. Here's an example on how to add an action to Godot editor's own 'undoredo': [codeblock] var undo_redo = get_undo_redo() # Method of EditorPlugin.

func do_something(): pass # Put your code here.

func undo_something(): pass # Put here the code that reverts what's done by "do_something()".

func _on_MyButton_pressed(): var node = get_node("MyNode2D") undo_redo.create_action("Move the node") undo_redo.add_do_method(self, "do_something") undo_redo.add_undo_method(self, "undo_something") undo_redo.add_do_property(node, "position", Vector2(100,100)) undo_redo.add_undo_property(node, "position", node.position) undo_redo.commit_action() [/codeblock] [method create_action], [method add_do_method], [method add_undo_method], [method add_do_property], [method add_undo_property], and [method commit_action] should be called one after the other, like in the example. Not doing so could lead to crashes. If you don't need to register a method you can leave [method add_do_method] and [method add_undo_method] out, and so it goes for properties. You can register more than one method/property.
Register a method that will be called when the action is committed.
Register a property value change for 'do'.
Register a reference for 'do' that will be erased if the 'do' history is lost. This is useful mostly for new nodes created for the 'do' call. Do not use for resources.
Register a method that will be called when the action is undone.
Register a property value change for 'undo'.
Register a reference for 'undo' that will be erased if the 'undo' history is lost. This is useful mostly for nodes removed with the 'do' call (not the 'undo' call!).
Clear the undo/redo history and associated references. Passing [code]false[/code] to [code]increase_version[/code] will prevent the version number to be increased from this.
Commit the action. All 'do' methods/properties are called/set when this function is called.
Create a new action. After this is called, do all your calls to [method add_do_method], [method add_undo_method], [method add_do_property], and [method add_undo_property], then commit the action with [method commit_action]. The way actions are merged is dictated by the [code]merge_mode[/code] argument. See [enum MergeMode] for details.
Get the name of the current action.
Get the version, each time a new action is committed, the version number of the UndoRedo is increased automatically. This is useful mostly to check if something changed from a saved version.
Redo last action.
Undo last action.
Makes [code]do[/code]/[code]undo[/code] operations stay in separate actions.
Makes so that the action's [code]do[/code] operation is from the first action created and the [code]undo[/code] operation is from the last subsequent action with the same name.
Makes subsequent actions with the same name be merged into one.