godot-docs/classes/class_undoredo.rst

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.. DO NOT EDIT THIS FILE!!!
.. Generated automatically from Godot engine sources.
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.. XML source: https://github.com/godotengine/godot/tree/4.0/doc/classes/UndoRedo.xml.

.. _class_UndoRedo:

UndoRedo
========

**Inherits:** :ref:`Object<class_Object>`

Provides a high-level interface for implementing undo and redo operations.

.. rst-class:: classref-introduction-group

Description
-----------

UndoRedo works by registering methods and property changes inside "actions". You can create an action, then provide ways to do and undo this action using function calls and property changes, then commit the action.

When an action is committed, all of the ``do_*`` methods will run. If the :ref:`undo<class_UndoRedo_method_undo>` method is used, the ``undo_*`` methods will run. If the :ref:`redo<class_UndoRedo_method_redo>` method is used, once again, all of the ``do_*`` methods will run.

Here's an example on how to add an action:


.. tabs::

 .. code-tab:: gdscript

    var undo_redo = UndoRedo.new()
    
    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_my_button_pressed():
        var node = get_node("MyNode2D")
        undo_redo.create_action("Move the node")
        undo_redo.add_do_method(do_something)
        undo_redo.add_undo_method(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()

 .. code-tab:: csharp

    private UndoRedo _undoRedo;
    
    public override void _Ready()
    {
        _undoRedo = new UndoRedo();
    }
    
    public void DoSomething()
    {
        // Put your code here.
    }
    
    public void UndoSomething()
    {
        // Put here the code that reverts what's done by "DoSomething()".
    }
    
    private void OnMyButtonPressed()
    {
        var node = GetNode<Node2D>("MyNode2D");
        _undoRedo.CreateAction("Move the node");
        _undoRedo.AddDoMethod(new Callable(this, MethodName.DoSomething));
        _undoRedo.AddUndoMethod(new Callable(this, MethodName.UndoSomething));
        _undoRedo.AddDoProperty(node, "position", new Vector2(100, 100));
        _undoRedo.AddUndoProperty(node, "position", node.Position);
        _undoRedo.CommitAction();
    }



\ :ref:`create_action<class_UndoRedo_method_create_action>`, :ref:`add_do_method<class_UndoRedo_method_add_do_method>`, :ref:`add_undo_method<class_UndoRedo_method_add_undo_method>`, :ref:`add_do_property<class_UndoRedo_method_add_do_property>`, :ref:`add_undo_property<class_UndoRedo_method_add_undo_property>`, and :ref:`commit_action<class_UndoRedo_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 :ref:`add_do_method<class_UndoRedo_method_add_do_method>` and :ref:`add_undo_method<class_UndoRedo_method_add_undo_method>` out; the same goes for properties. You can also register more than one method/property in the order they should run.

If you are making an :ref:`EditorPlugin<class_EditorPlugin>` and want to integrate into the editor's undo history, use :ref:`EditorUndoRedoManager<class_EditorUndoRedoManager>` instead.

.. rst-class:: classref-reftable-group

Methods
-------

.. table::
   :widths: auto

   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | void                        | :ref:`add_do_method<class_UndoRedo_method_add_do_method>` **(** :ref:`Callable<class_Callable>` callable **)**                                                                                      |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | void                        | :ref:`add_do_property<class_UndoRedo_method_add_do_property>` **(** :ref:`Object<class_Object>` object, :ref:`StringName<class_StringName>` property, :ref:`Variant<class_Variant>` value **)**     |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | void                        | :ref:`add_do_reference<class_UndoRedo_method_add_do_reference>` **(** :ref:`Object<class_Object>` object **)**                                                                                      |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | void                        | :ref:`add_undo_method<class_UndoRedo_method_add_undo_method>` **(** :ref:`Callable<class_Callable>` callable **)**                                                                                  |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | void                        | :ref:`add_undo_property<class_UndoRedo_method_add_undo_property>` **(** :ref:`Object<class_Object>` object, :ref:`StringName<class_StringName>` property, :ref:`Variant<class_Variant>` value **)** |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | void                        | :ref:`add_undo_reference<class_UndoRedo_method_add_undo_reference>` **(** :ref:`Object<class_Object>` object **)**                                                                                  |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | void                        | :ref:`clear_history<class_UndoRedo_method_clear_history>` **(** :ref:`bool<class_bool>` increase_version=true **)**                                                                                 |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | void                        | :ref:`commit_action<class_UndoRedo_method_commit_action>` **(** :ref:`bool<class_bool>` execute=true **)**                                                                                          |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | void                        | :ref:`create_action<class_UndoRedo_method_create_action>` **(** :ref:`String<class_String>` name, :ref:`MergeMode<enum_UndoRedo_MergeMode>` merge_mode=0 **)**                                      |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | void                        | :ref:`end_force_keep_in_merge_ends<class_UndoRedo_method_end_force_keep_in_merge_ends>` **(** **)**                                                                                                 |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`String<class_String>` | :ref:`get_action_name<class_UndoRedo_method_get_action_name>` **(** :ref:`int<class_int>` id **)**                                                                                                  |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`int<class_int>`       | :ref:`get_current_action<class_UndoRedo_method_get_current_action>` **(** **)**                                                                                                                     |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`String<class_String>` | :ref:`get_current_action_name<class_UndoRedo_method_get_current_action_name>` **(** **)** |const|                                                                                                   |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`int<class_int>`       | :ref:`get_history_count<class_UndoRedo_method_get_history_count>` **(** **)**                                                                                                                       |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`int<class_int>`       | :ref:`get_version<class_UndoRedo_method_get_version>` **(** **)** |const|                                                                                                                           |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`bool<class_bool>`     | :ref:`has_redo<class_UndoRedo_method_has_redo>` **(** **)** |const|                                                                                                                                 |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`bool<class_bool>`     | :ref:`has_undo<class_UndoRedo_method_has_undo>` **(** **)** |const|                                                                                                                                 |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`bool<class_bool>`     | :ref:`is_committing_action<class_UndoRedo_method_is_committing_action>` **(** **)** |const|                                                                                                         |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`bool<class_bool>`     | :ref:`redo<class_UndoRedo_method_redo>` **(** **)**                                                                                                                                                 |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | void                        | :ref:`start_force_keep_in_merge_ends<class_UndoRedo_method_start_force_keep_in_merge_ends>` **(** **)**                                                                                             |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`bool<class_bool>`     | :ref:`undo<class_UndoRedo_method_undo>` **(** **)**                                                                                                                                                 |
   +-----------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

.. rst-class:: classref-section-separator

----

.. rst-class:: classref-descriptions-group

Signals
-------

.. _class_UndoRedo_signal_version_changed:

.. rst-class:: classref-signal

**version_changed** **(** **)**

Called when :ref:`undo<class_UndoRedo_method_undo>` or :ref:`redo<class_UndoRedo_method_redo>` was called.

.. rst-class:: classref-section-separator

----

.. rst-class:: classref-descriptions-group

Enumerations
------------

.. _enum_UndoRedo_MergeMode:

.. rst-class:: classref-enumeration

enum **MergeMode**:

.. _class_UndoRedo_constant_MERGE_DISABLE:

.. rst-class:: classref-enumeration-constant

:ref:`MergeMode<enum_UndoRedo_MergeMode>` **MERGE_DISABLE** = ``0``

Makes "do"/"undo" operations stay in separate actions.

.. _class_UndoRedo_constant_MERGE_ENDS:

.. rst-class:: classref-enumeration-constant

:ref:`MergeMode<enum_UndoRedo_MergeMode>` **MERGE_ENDS** = ``1``

Makes so that the action's "undo" operations are from the first action created and the "do" operations are from the last subsequent action with the same name.

.. _class_UndoRedo_constant_MERGE_ALL:

.. rst-class:: classref-enumeration-constant

:ref:`MergeMode<enum_UndoRedo_MergeMode>` **MERGE_ALL** = ``2``

Makes subsequent actions with the same name be merged into one.

.. rst-class:: classref-section-separator

----

.. rst-class:: classref-descriptions-group

Method Descriptions
-------------------

.. _class_UndoRedo_method_add_do_method:

.. rst-class:: classref-method

void **add_do_method** **(** :ref:`Callable<class_Callable>` callable **)**

Register a :ref:`Callable<class_Callable>` that will be called when the action is committed.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_add_do_property:

.. rst-class:: classref-method

void **add_do_property** **(** :ref:`Object<class_Object>` object, :ref:`StringName<class_StringName>` property, :ref:`Variant<class_Variant>` value **)**

Register a ``property`` that would change its value to ``value`` when the action is committed.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_add_do_reference:

.. rst-class:: classref-method

void **add_do_reference** **(** :ref:`Object<class_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.

::

    var node = Node2D.new()
    undo_redo.create_action("Add node")
    undo_redo.add_do_method(add_child.bind(node))
    undo_redo.add_do_reference(node)
    undo_redo.add_undo_method(remove_child.bind(node))
    undo_redo.commit_action()

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_add_undo_method:

.. rst-class:: classref-method

void **add_undo_method** **(** :ref:`Callable<class_Callable>` callable **)**

Register a :ref:`Callable<class_Callable>` that will be called when the action is undone.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_add_undo_property:

.. rst-class:: classref-method

void **add_undo_property** **(** :ref:`Object<class_Object>` object, :ref:`StringName<class_StringName>` property, :ref:`Variant<class_Variant>` value **)**

Register a ``property`` that would change its value to ``value`` when the action is undone.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_add_undo_reference:

.. rst-class:: classref-method

void **add_undo_reference** **(** :ref:`Object<class_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!).

::

    var node = $Node2D
    undo_redo.create_action("Remove node")
    undo_redo.add_do_method(remove_child.bind(node))
    undo_redo.add_undo_method(add_child.bind(node))
    undo_redo.add_undo_reference(node)
    undo_redo.commit_action()

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_clear_history:

.. rst-class:: classref-method

void **clear_history** **(** :ref:`bool<class_bool>` increase_version=true **)**

Clear the undo/redo history and associated references.

Passing ``false`` to ``increase_version`` will prevent the version number from increasing when the history is cleared.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_commit_action:

.. rst-class:: classref-method

void **commit_action** **(** :ref:`bool<class_bool>` execute=true **)**

Commit the action. If ``execute`` is ``true`` (which it is by default), all "do" methods/properties are called/set when this function is called.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_create_action:

.. rst-class:: classref-method

void **create_action** **(** :ref:`String<class_String>` name, :ref:`MergeMode<enum_UndoRedo_MergeMode>` merge_mode=0 **)**

Create a new action. After this is called, do all your calls to :ref:`add_do_method<class_UndoRedo_method_add_do_method>`, :ref:`add_undo_method<class_UndoRedo_method_add_undo_method>`, :ref:`add_do_property<class_UndoRedo_method_add_do_property>`, and :ref:`add_undo_property<class_UndoRedo_method_add_undo_property>`, then commit the action with :ref:`commit_action<class_UndoRedo_method_commit_action>`.

The way actions are merged is dictated by ``merge_mode``. See :ref:`MergeMode<enum_UndoRedo_MergeMode>` for details.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_end_force_keep_in_merge_ends:

.. rst-class:: classref-method

void **end_force_keep_in_merge_ends** **(** **)**

Stops marking operations as to be processed even if the action gets merged with another in the :ref:`MERGE_ENDS<class_UndoRedo_constant_MERGE_ENDS>` mode. See :ref:`start_force_keep_in_merge_ends<class_UndoRedo_method_start_force_keep_in_merge_ends>`.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_get_action_name:

.. rst-class:: classref-method

:ref:`String<class_String>` **get_action_name** **(** :ref:`int<class_int>` id **)**

Gets the action name from its index.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_get_current_action:

.. rst-class:: classref-method

:ref:`int<class_int>` **get_current_action** **(** **)**

Gets the index of the current action.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_get_current_action_name:

.. rst-class:: classref-method

:ref:`String<class_String>` **get_current_action_name** **(** **)** |const|

Gets the name of the current action, equivalent to ``get_action_name(get_current_action())``.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_get_history_count:

.. rst-class:: classref-method

:ref:`int<class_int>` **get_history_count** **(** **)**

Returns how many elements are in the history.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_get_version:

.. rst-class:: classref-method

:ref:`int<class_int>` **get_version** **(** **)** |const|

Gets the version. Every time a new action is committed, the **UndoRedo**'s version number is increased automatically.

This is useful mostly to check if something changed from a saved version.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_has_redo:

.. rst-class:: classref-method

:ref:`bool<class_bool>` **has_redo** **(** **)** |const|

Returns ``true`` if a "redo" action is available.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_has_undo:

.. rst-class:: classref-method

:ref:`bool<class_bool>` **has_undo** **(** **)** |const|

Returns ``true`` if an "undo" action is available.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_is_committing_action:

.. rst-class:: classref-method

:ref:`bool<class_bool>` **is_committing_action** **(** **)** |const|

Returns ``true`` if the **UndoRedo** is currently committing the action, i.e. running its "do" method or property change (see :ref:`commit_action<class_UndoRedo_method_commit_action>`).

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_redo:

.. rst-class:: classref-method

:ref:`bool<class_bool>` **redo** **(** **)**

Redo the last action.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_start_force_keep_in_merge_ends:

.. rst-class:: classref-method

void **start_force_keep_in_merge_ends** **(** **)**

Marks the next "do" and "undo" operations to be processed even if the action gets merged with another in the :ref:`MERGE_ENDS<class_UndoRedo_constant_MERGE_ENDS>` mode. Return to normal operation using :ref:`end_force_keep_in_merge_ends<class_UndoRedo_method_end_force_keep_in_merge_ends>`.

.. rst-class:: classref-item-separator

----

.. _class_UndoRedo_method_undo:

.. rst-class:: classref-method

:ref:`bool<class_bool>` **undo** **(** **)**

Undo the last action.

.. |virtual| replace:: :abbr:`virtual (This method should typically be overridden by the user to have any effect.)`
.. |const| replace:: :abbr:`const (This method has no side effects. It doesn't modify any of the instance's member variables.)`
.. |vararg| replace:: :abbr:`vararg (This method accepts any number of arguments after the ones described here.)`
.. |constructor| replace:: :abbr:`constructor (This method is used to construct a type.)`
.. |static| replace:: :abbr:`static (This method doesn't need an instance to be called, so it can be called directly using the class name.)`
.. |operator| replace:: :abbr:`operator (This method describes a valid operator to use with this type as left-hand operand.)`