UndoRedo
Provides a high-level interface for implementing undo and redo operations.
Provides a high-level interface for implementing undo and redo operations.
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 UndoRedo.Undo method is used, the undo_* methods will run. If the UndoRedo.Redo method is used, once again, all of the do_* methods will run.
Here's an example on how to add an action:
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 = GetEntity<Entity2D>("MyEntity2D");
_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();
}Before calling any of the add_(un)do_* methods, you need to first call UndoRedo.CreateAction. Afterwards you need to call UndoRedo.CommitAction.
If you don't need to register a method, you can leave UndoRedo.AddDoMethod and UndoRedo.AddUndoMethod out; the same goes for properties. You can also register more than one method/property.
If you are making an EditorPlugin and want to integrate into the editor's undo history, use EditorUndoRedoManager instead.
If you are registering multiple properties/method which depend on one another, be aware that by default undo operation are called in the same order they have been added. Therefore instead of grouping do operation with their undo operations it is better to group do on one side and undo on the other as shown below.
_undo_redo.CreateAction("Add object");
// DO
_undo_redo.AddDoMethod(new Callable(this, MethodName.CreateObject));
_undo_redo.AddDoMethod(new Callable(this, MethodName.AddObjectToSingleton));
// UNDO
_undo_redo.AddUndoMethod(new Callable(this, MethodName.RemoveObjectFromSingleton));
_undo_redo.AddUndoMethod(new Callable(this, MethodName.DestroyThatObject));
_undo_redo.CommitAction();Declarations checked against C# SDK 1.0.0. Expand a name to see declarations and documentation.
Constructors1
UndoRedoConstructor
public UndoRedo();Properties1
MaxStepsProperty
public int MaxSteps { get; set; }The maximum number of steps that can be stored in the undo/redo history. If the number of stored steps exceeds this limit, older steps are removed from history and can no longer be reached by calling UndoRedo.Undo. A value of 0 or lower means no limit.
Methods24
AddDoMethodvoid
public void AddDoMethod(Callable callable);Register a Callable that will be called when the action is committed.
| Name | Type | Default |
|---|---|---|
callable | Callable | — |
AddDoPropertyvoid
public void AddDoProperty(ReckfellObject @object, StringName property, Variant value);Register a property that would change its value to value when the action is committed.
| Name | Type | Default |
|---|---|---|
object | ReckfellObject | — |
property | StringName | — |
value | Variant | — |
AddDoReferencevoid
public void AddDoReference(ReckfellObject @object);Register a reference to an object that will be erased if the "do" history is deleted. This is useful for objects added by the "do" action and removed by the "undo" action.
When the "do" history is deleted, if the object is a RefCounted, it will be unreferenced. Otherwise, it will be freed. Do not use for resources.
| Name | Type | Default |
|---|---|---|
object | ReckfellObject | — |
AddUndoMethodvoid
public void AddUndoMethod(Callable callable);Register a Callable that will be called when the action is undone.
| Name | Type | Default |
|---|---|---|
callable | Callable | — |
AddUndoPropertyvoid
public void AddUndoProperty(ReckfellObject @object, StringName property, Variant value);Register a property that would change its value to value when the action is undone.
| Name | Type | Default |
|---|---|---|
object | ReckfellObject | — |
property | StringName | — |
value | Variant | — |
AddUndoReferencevoid
public void AddUndoReference(ReckfellObject @object);Register a reference to an object that will be erased if the "undo" history is deleted. This is useful for objects added by the "undo" action and removed by the "do" action.
When the "undo" history is deleted, if the object is a RefCounted, it will be unreferenced. Otherwise, it will be freed. Do not use for resources.
| Name | Type | Default |
|---|---|---|
object | ReckfellObject | — |
ClearHistoryvoid
public void ClearHistory(bool increaseVersion = 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.
| Name | Type | Default |
|---|---|---|
increaseVersion | bool | true |
CommitActionvoid
public void CommitAction(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.
| Name | Type | Default |
|---|---|---|
execute | bool | true |
CreateAction2 overloads
public void CreateAction(string name, UndoRedo.MergeMode mergeMode);Create a new action. After this is called, do all your calls to UndoRedo.AddDoMethod, UndoRedo.AddUndoMethod, UndoRedo.AddDoProperty, and UndoRedo.AddUndoProperty, then commit the action with UndoRedo.CommitAction.
The way actions are merged is dictated by merge_mode.
The way undo operation are ordered in actions is dictated by backward_undo_ops. When backward_undo_ops is false undo option are ordered in the same order they were added. Which means the first operation to be added will be the first to be undone.
| Name | Type | Default |
|---|---|---|
name | string | — |
mergeMode | UndoRedo.MergeMode | — |
public void CreateAction(string name, UndoRedo.MergeMode mergeMode = UndoRedo.MergeMode.Disable, bool backwardUndoOps = false);Create a new action. After this is called, do all your calls to UndoRedo.AddDoMethod, UndoRedo.AddUndoMethod, UndoRedo.AddDoProperty, and UndoRedo.AddUndoProperty, then commit the action with UndoRedo.CommitAction.
The way actions are merged is dictated by merge_mode.
The way undo operation are ordered in actions is dictated by backward_undo_ops. When backward_undo_ops is false undo option are ordered in the same order they were added. Which means the first operation to be added will be the first to be undone.
| Name | Type | Default |
|---|---|---|
name | string | — |
mergeMode | UndoRedo.MergeMode | UndoRedo.MergeMode.Disable |
backwardUndoOps | bool | false |
EndForceKeepInMergeEndsvoid
public void EndForceKeepInMergeEnds();Stops marking operations as to be processed even if the action gets merged with another in the UndoRedo.MergeMode.Ends mode. See UndoRedo.StartForceKeepInMergeEnds.
GetActionNamestring
public string GetActionName(int id);Gets the action name from its index.
| Name | Type | Default |
|---|---|---|
id | int | — |
stringGetCurrentActionint
public int GetCurrentAction();Gets the index of the current action.
intGetCurrentActionNamestring
public string GetCurrentActionName();Gets the name of the current action, equivalent to get_action_name(get_current_action()).
stringGetHistoryCountint
public int GetHistoryCount();Returns how many elements are in the history.
intGetMaxStepsint
public int GetMaxSteps();intGetVersionulong
public ulong GetVersion();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.
ulongHasRedobool
public bool HasRedo();Returns true if a "redo" action is available.
boolHasUndobool
public bool HasUndo();Returns true if an "undo" action is available.
boolIsCommittingActionbool
public bool IsCommittingAction();Returns true if the UndoRedo is currently committing the action, i.e. running its "do" method or property change (see UndoRedo.CommitAction).
boolRedobool
public bool Redo();Redo the last action. Returns false if there was no action to redo.
boolSetMaxStepsvoid
public void SetMaxSteps(int maxSteps);| Name | Type | Default |
|---|---|---|
maxSteps | int | — |
StartForceKeepInMergeEndsvoid
public void StartForceKeepInMergeEnds();Marks the next "do" and "undo" operations to be processed even if the action gets merged with another in the UndoRedo.MergeMode.Ends mode. Return to normal operation using UndoRedo.EndForceKeepInMergeEnds.
Undobool
public bool Undo();Undo the last action. Returns false if there was no action to undo.
boolSignals and events1
VersionChangedEvent
public event Action VersionChanged;Called when UndoRedo.Undo or UndoRedo.Redo was called.
UndoRedo.MergeMode
| Value | Description |
|---|---|
All = 2 | Merges this action with the previous one if they have the same name. |
Disable = 0 | Makes "do"/"undo" operations stay in separate actions. |
Ends = 1 | Merges this action with the previous one if they have the same name. Keeps only the first action's "undo" operations and the last action's "do" operations. Useful for sequential changes to a single value. |