<?xml version="1.0" encoding="UTF-8" ?> <class name="UndoRedo" inherits="Object" version="4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd"> <brief_description> Helper to manage undo/redo operations in the editor or custom tools. </brief_description> <description> 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 [UndoRedo], from a plugin: [codeblocks] [gdscript] 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() [/gdscript] [csharp] public UndoRedo UndoRedo; public override void _Ready() { UndoRedo = GetUndoRedo(); // Method of EditorPlugin. } 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(this, nameof(DoSomething)); UndoRedo.AddUndoMethod(this, nameof(UndoSomething)); UndoRedo.AddDoProperty(node, "position", new Vector2(100, 100)); UndoRedo.AddUndoProperty(node, "position", node.Position); UndoRedo.CommitAction(); } [/csharp] [/codeblocks] [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; the same goes for properties. You can also register more than one method/property. </description> <tutorials> </tutorials> <methods> <method name="add_do_method"> <return type="void" /> <param index="0" name="callable" type="Callable" /> <description> Register a [Callable] that will be called when the action is committed. </description> </method> <method name="add_do_property"> <return type="void" /> <param index="0" name="object" type="Object" /> <param index="1" name="property" type="StringName" /> <param index="2" name="value" type="Variant" /> <description> Register a [param property] that would change its value to [param value] when the action is committed. </description> </method> <method name="add_do_reference"> <return type="void" /> <param index="0" name="object" type="Object" /> <description> 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. </description> </method> <method name="add_undo_method"> <return type="void" /> <param index="0" name="callable" type="Callable" /> <description> Register a [Callable] that will be called when the action is undone. </description> </method> <method name="add_undo_property"> <return type="void" /> <param index="0" name="object" type="Object" /> <param index="1" name="property" type="StringName" /> <param index="2" name="value" type="Variant" /> <description> Register a [param property] that would change its value to [param value] when the action is undone. </description> </method> <method name="add_undo_reference"> <return type="void" /> <param index="0" name="object" type="Object" /> <description> 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!). </description> </method> <method name="clear_history"> <return type="void" /> <param index="0" name="increase_version" type="bool" default="true" /> <description> Clear the undo/redo history and associated references. Passing [code]false[/code] to [param increase_version] will prevent the version number from increasing when the history is cleared. </description> </method> <method name="commit_action"> <return type="void" /> <param index="0" name="execute" type="bool" default="true" /> <description> Commit the action. If [param execute] is [code]true[/code] (which it is by default), all "do" methods/properties are called/set when this function is called. </description> </method> <method name="create_action"> <return type="void" /> <param index="0" name="name" type="String" /> <param index="1" name="merge_mode" type="int" enum="UndoRedo.MergeMode" default="0" /> <description> 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 [param merge_mode]. See [enum MergeMode] for details. </description> </method> <method name="end_force_keep_in_merge_ends"> <return type="void" /> <description> Stops marking operations as to be processed even if the action gets merged with another in the [constant MERGE_ENDS] mode. See [method start_force_keep_in_merge_ends]. </description> </method> <method name="get_action_name"> <return type="String" /> <param index="0" name="id" type="int" /> <description> Gets the action name from its index. </description> </method> <method name="get_current_action"> <return type="int" /> <description> Gets the index of the current action. </description> </method> <method name="get_current_action_name" qualifiers="const"> <return type="String" /> <description> Gets the name of the current action, equivalent to [code]get_action_name(get_current_action())[/code]. </description> </method> <method name="get_history_count"> <return type="int" /> <description> Returns how many elements are in the history. </description> </method> <method name="get_version" qualifiers="const"> <return type="int" /> <description> 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. </description> </method> <method name="has_redo" qualifiers="const"> <return type="bool" /> <description> Returns [code]true[/code] if a "redo" action is available. </description> </method> <method name="has_undo" qualifiers="const"> <return type="bool" /> <description> Returns [code]true[/code] if an "undo" action is available. </description> </method> <method name="is_committing_action" qualifiers="const"> <return type="bool" /> <description> Returns [code]true[/code] if the [UndoRedo] is currently committing the action, i.e. running its "do" method or property change (see [method commit_action]). </description> </method> <method name="redo"> <return type="bool" /> <description> Redo the last action. </description> </method> <method name="start_force_keep_in_merge_ends"> <return type="void" /> <description> Marks the next "do" and "undo" operations to be processed even if the action gets merged with another in the [constant MERGE_ENDS] mode. Return to normal operation using [method end_force_keep_in_merge_ends]. </description> </method> <method name="undo"> <return type="bool" /> <description> Undo the last action. </description> </method> </methods> <signals> <signal name="version_changed"> <description> Called when [method undo] or [method redo] was called. </description> </signal> </signals> <constants> <constant name="MERGE_DISABLE" value="0" enum="MergeMode"> Makes "do"/"undo" operations stay in separate actions. </constant> <constant name="MERGE_ENDS" value="1" enum="MergeMode"> 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. </constant> <constant name="MERGE_ALL" value="2" enum="MergeMode"> Makes subsequent actions with the same name be merged into one. </constant> </constants> </class>