Struct HistoryManager 

pub struct HistoryManager { /* private fields */ }

History manager for state machine edits

Maintains undo and redo stacks for state machine modifications. Supports configurable maximum history size to limit memory usage.

Implementations

impl HistoryManager

pub fn new() -> HistoryManager

Create a new history manager with default max history (50)

pub fn with_max_history(max_history: usize) -> HistoryManager

Create a new history manager with specified max history

pub fn push_state(&mut self, state: StateMachine)

Push a new state to the history

If there’s a current state, it’s moved to the undo stack. The new state becomes the current state.

pub fn undo(&mut self) -> Option<StateMachine>

Undo the last change

Moves the current state to the redo stack and restores the previous state from the undo stack. Returns the restored state if available.

pub fn redo(&mut self) -> Option<StateMachine>

Redo the last undone change

Moves the current state to the undo stack and restores the next state from the redo stack. Returns the restored state if available.

pub fn can_undo(&self) -> bool

Check if undo is possible

pub fn can_redo(&self) -> bool

Check if redo is possible

pub fn current(&self) -> Option<&StateMachine>

Get the current state

pub fn current_mut(&mut self) -> Option<&mut StateMachine>

Get the current state mutably

pub fn set_current(&mut self, state: StateMachine)

Set the current state without adding to history

Useful for temporary edits that shouldn’t be tracked.

pub fn clear(&mut self)

Clear all history

pub fn undo_count(&self) -> usize

Get the number of undo steps available

pub fn redo_count(&self) -> usize

Get the number of redo steps available

pub fn max_history(&self) -> usize

Get the maximum history size

pub fn set_max_history(&mut self, max_history: usize)

Set the maximum history size

If the new max is smaller than current history, older entries are removed.

Trait Implementations

impl Clone for HistoryManager

fn clone(&self) -> HistoryManager

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HistoryManager

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

Formats the value using the given formatter.

impl Default for HistoryManager

fn default() -> HistoryManager

Returns the “default value” for a type.