Class: UndoManager

Manager class returned by undoMiddleware that allows you to perform undo/redo actions.

Constructors

Constructor

new UndoManager(
   disposer, 
   subtreeRoot, 
   store?, 
   options
): UndoManager;

Creates an instance of UndoManager. Do not use directly, use undoMiddleware instead.

Parameters

Parameter	Type	Description
disposer	ActionMiddlewareDisposer	-
subtreeRoot	object	-
store?	UndoStore	-
options?	| UndoMiddlewareOptions<unknown> | undefined	-

Returns

UndoManager

Properties

store

readonly store: UndoStore;

The store currently being used to store undo/redo action events.

Accessors

canRedo

Get Signature

get canRedo(): boolean;

If redo can be performed (if there is at least one redo action available)

Returns

boolean

---

canUndo

Get Signature

get canUndo(): boolean;

If undo can be performed (if there is at least one undo action available).

Returns

boolean

---

isUndoRecordingDisabled

Get Signature

get isUndoRecordingDisabled(): boolean;

Returns if undo recording is currently disabled or not for this particular UndoManager.

Returns

boolean

---

redoLevels

Get Signature

get redoLevels(): number;

The number of redo actions available.

Returns

number

---

redoQueue

Get Signature

get redoQueue(): readonly UndoEvent[];

The redo stack, where the first operation to redo will be the last of the array. Do not manipulate this array directly.

Returns

readonly UndoEvent[]

---

undoLevels

Get Signature

get undoLevels(): number;

The number of undo actions available.

Returns

number

---

undoQueue

Get Signature

get undoQueue(): readonly UndoEvent[];

The undo stack, where the first operation to undo will be the last of the array. Do not manipulate this array directly.

Returns

readonly UndoEvent[]

Methods

clearRedo()

clearRedo(): void;

Clears the redo queue.

Returns

void

---

clearUndo()

clearUndo(): void;

Clears the undo queue.

Returns

void

---

createGroup()

createGroup(groupName?): object;

Creates a custom group that can be continued multiple times and then ended.

Parameters

Parameter	Type	Description
groupName?	string	Optional group name.

Returns

object

An API to continue/end the group.

continue()

continue<T>(fn): T;

Type Parameters

Type Parameter
T

Parameters

Parameter	Type
fn	() => T

Returns

T

end()

end(): void;

Returns

void

---

dispose()

dispose(): void;

Disposes the undo middleware.

Returns

void

---

redo()

redo(): void;

Redoes the previous action. Will throw if there is no action to redo.

Returns

void

---

undo()

undo(): void;

Undoes the last action. Will throw if there is no action to undo.

Returns

void

---

withGroup()

Call Signature

withGroup<T>(groupName, fn): T;

Runs a synchronous code block as an undo group. Note that nested groups are allowed.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Description
groupName	string	Group name.
fn	() => T	Code block.

Returns

T

Code block return value.

Call Signature

withGroup<T>(fn): T;

Runs a synchronous code block as an undo group. Note that nested groups are allowed.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Description
fn	() => T	Code block.

Returns

T

Code block return value.

---

withGroupFlow()

Call Signature

withGroupFlow<R>(groupName, fn): Promise<R>;

Runs an asynchronous code block as an undo group. Note that nested groups are allowed.

Type Parameters

Type Parameter
R

Parameters

Parameter	Type	Description
groupName	string	Group name.
fn	() => Generator<any, R, any>	Flow function.

Returns

Promise<R>

Flow function return value.

Call Signature

withGroupFlow<R>(fn): Promise<R>;

Runs an asynchronous code block as an undo group. Note that nested groups are allowed.

Type Parameters

Type Parameter
R

Parameters

Parameter	Type	Description
fn	() => Generator<any, R, any>	Flow function.

Returns

Promise<R>

Flow function return value.

---

withoutUndo()

withoutUndo<T>(fn): T;

Skips the undo recording mechanism for the code block that gets run synchronously inside.

Type Parameters

Type Parameter	Description
T	Code block return type.

Parameters

Parameter	Type	Description
fn	() => T	Code block to run.

Returns

T

The value returned by the code block.