UndoRedo

Inherits: Object

Category: Core

Brief Description

Helper to manage UndoRedo in the editor or custom tools.

Methods

Variant add_do_method ( Object object, String method ) vararg
void add_do_property ( Object object, String property, Variant value )
void add_do_reference ( Object object )
Variant add_undo_method ( Object object, String method ) vararg
void add_undo_property ( Object object, String property, Variant value )
void add_undo_reference ( Object object )
void clear_history ( )
void commit_action ( )
void create_action ( String name, MergeMode merge_mode=0 )
String get_current_action_name ( ) const
int get_version ( ) const
bool redo ( )
bool undo ( )

Enumerations

enum MergeMode:

  • MERGE_DISABLE = 0
  • MERGE_ENDS = 1
  • MERGE_ALL = 2

Description

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’:

var undoredo = 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")
    undoredo.create_action("Move the node")
    undoredo.add_do_method(self, "do_something")
    undoredo.add_undo_method(self, "undo_something")
    undoredo.add_do_property(node, "position", Vector2(100,100))
    undoredo.add_undo_property(node, "position", node.position)
    undoredo.commit_action()

create_action, add_do_method, add_undo_method, add_do_property, add_undo_property, and 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 add_do_method and add_undo_method out, and so it goes for properties. You can register more than one method/property.

Method Descriptions

Register a method that will be called when the action is committed.

Register a property value change for ‘do’.

  • void add_do_reference ( Object object )

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’.

  • void add_undo_reference ( Object object )

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!).

  • void clear_history ( )

Clear the undo/redo history and associated references.

  • void commit_action ( )

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 add_do_method, add_undo_method, add_do_property, and add_undo_property, then commit the action with commit_action.

  • String get_current_action_name ( ) const

Get the name of the current action.

  • int get_version ( ) const

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.