public virtual IHistoryAction <TAction, TSender, TState> Redo()
{
if (_undoneActions.Count > 0)
{
_liveActions.Push(_undoneActions.Pop());
var top = _undoneActions.Peek();
top.RedoAction?.Invoke(top, _currentAction);
RedoOccured?.Invoke(this, top);
ActionOccured?.Invoke(this, EventArgs.Empty);
_redoCommand.OnCanExecuteChanged();
_currentAction = top;
return(top);
}
return(null);
}
public virtual IHistoryAction <TAction, TSender, TState> Undo()
{
var count = _liveActions.Count;
if (count > 1)
{
var pop = _liveActions.Pop();
if (!BackToActionOnUndo)
{
_undoneActions.Push(pop);
}
var top = _liveActions.Peek();
top.UndoAction?.Invoke(top, _currentAction);
UndoOccured?.Invoke(this, top);
ActionOccured?.Invoke(this, EventArgs.Empty);
_undoCommand.OnCanExecuteChanged();
_currentAction = top;
return(top);
}
return(null);
}
static Task Apply(Metadata meta, ActionOccured actionOccured, State s)
{
s.Value += 1;
return(Task.CompletedTask);
}
