Whether there is now content changed after last snapshot was taken
Add a new undo snapshot
The snapshot to add
Check whether can move current undo snapshot with the given step
The step to check, can be positive, negative or 0
True if can move current snapshot with the given step, otherwise false
Whether there is a snapshot added before auto complete and it can be undone now
Clear all undo snapshots after the current one
Move current snapshot with the given step if can move this step. Otherwise no action and return null
The step to move
If can move with the given step, returns the snapshot after move, otherwise null
Generated using TypeDoc
Represent an interface to provide functionalities to manager undo snapshots