Struct UndoStack 

pub struct UndoStack { /* private fields */ }

Bounded undo and redo history of editor snapshots, where any new step clears the redo side.

Implementations

impl UndoStack

pub fn new(limit: usize) -> Self

An empty history keeping at most limit undo steps, 0 keeps none.

pub fn limit(&self) -> usize

The most undo steps kept.

pub fn set_limit(&mut self, limit: usize)

Change the limit, dropping the oldest steps beyond it.

pub fn record(&mut self, before: Snapshot)

Record the state before an edit and clear the redo side.

pub fn undo(&mut self, current: Snapshot) -> Option<Snapshot>

Step back: returns the state to restore and keeps current for redo.

pub fn redo(&mut self, current: Snapshot) -> Option<Snapshot>

Step forward again: returns the state to restore and keeps current for undo.

pub fn can_undo(&self) -> bool

Whether there is a step to undo.

pub fn can_redo(&self) -> bool

Whether there is a step to redo.

pub fn clear(&mut self)

Drop every step.

pub fn snapshots(&self) -> impl Iterator<Item = &Snapshot>

Every kept snapshot, undo steps oldest first and then redo steps.

Trait Implementations

impl Clone for UndoStack

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for UndoStack

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for UndoStack

fn default() -> Self

Returns the “default value” for a type.