UndoRedo

    Category: Core

    Helper to manage undo/redo operations in the editor or custom tools.

    enum MergeMode:

    • MERGE_DISABLE = 0 — Makes ‘do’/’undo’ operations stay in separate actions.
    • MERGE_ALL = 2 — Makes subsequent actions with the same name be merged into one.

    Helper to manage undo/redo operations 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 the Godot editor’s own , from a plugin:

    create_action, , add_undo_method, , add_undo_property, and should be called one after the other, like in the example. Not doing so could lead to crashes.

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

    • void add_do_property ( object, String property, value )

    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.

    • add_undo_method ( Object object, method, … ) vararg

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

    • void add_undo_property ( Object object, property, Variant value )

    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!).

    • void clear_history ( increase_version=true )

    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.

    • void create_action ( String name, merge_mode=0 )

    Create a new action. After this is called, do all your calls to add_do_method, , add_do_property, and , then commit the action with commit_action.

    The way actions are merged is dictated by the argument. See for details.

    • String get_current_action_name ( ) const

    Get the name of the current action.

    • 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.

    • is_commiting_action ( ) const

    Returns if the UndoRedo is currently committing the action, i.e. running its ‘do’ method or property change (see ).

    Undo the last action.