Class History<T>

Array-like structure with undo/redo functionality. It uses limited stack based on RingBuffer.

Type Parameters

T

Index

Constructors

Accessors

Methods

[iterator] canRedo canUndo current push redo undo

Constructors

constructor

new History<T>(
    capacity: number,
    items?: T[],
    currentPosition?: number,
): History<T>
Creates a new History instance.
Type Parameters
- T
Parameters
- capacity: number
  Maximum number of items the history can hold.
- Optionalitems: T[]
  Initial items to populate the history. If the number of items exceeds capacity, the oldest items will be discarded.
- currentPosition: number = -1
  Initial position relative to the end of history. Defaults to -1 (newest item).
Returns History<T>
Throws
if capacity is not a positive safe integer.

Throws
if currentPosition is out of bounds of history.
- Defined in history.ts:47

Accessors

capacity

get capacity(): number
Maximum number of items the history can hold.

Returns number
- Defined in history.ts:34

size

get size(): number
Number of items in the history.

Returns number
- Defined in history.ts:27

Methods

[iterator]

"[iterator]"(): IterableIterator<T>
An iterator for the items in the history.

Returns IterableIterator<T>
- Defined in history.ts:138

canRedo

canRedo(): boolean
Checks if there is a next item to redo to.

Returns boolean
true if there is a next item to redo to, false otherwise.
- Defined in history.ts:109

canUndo

canUndo(): boolean
Checks if there is a previous item to undo to.

Returns boolean
true if there is a previous item to undo to, false otherwise.
- Defined in history.ts:91

current

current(): undefined | T
Gets the current item.

Returns undefined | T
The current item or undefined if history is empty.
- Defined in history.ts:79

push

push(...items: T[]): number
Adds items to the end of the history. If the current item is not the latest, future history will be deleted. If the history is full, it will overwrite the oldest items.
Parameters
- ...items: T[]
  The items to add to the history.
Returns number
The new size of the history.
- Defined in history.ts:130

redo

redo(): undefined | T
Restore next item.

Returns undefined | T
The next item or undefined if there is no next item.
- Defined in history.ts:117

undo

undo(): undefined | T
Restore previous item.

Returns undefined | T
The previous item or undefined if there is no previous item.
- Defined in history.ts:99