// For each undo action, push onto the redo stack and pop off the undo stack
public void Undo(Spreadsheet sheet)
{
UndoRedoCollection undo = Undos.Pop();
Redos.Push(undo.Exec(sheet));
}
// Pop off redo, push action to undo
public void Redo(Spreadsheet sheet)
{
UndoRedoCollection redo = Redos.Pop();
Undos.Push(redo.Exec(sheet));
}
public void PerformRedo(Spreadsheet sheet) // Perform Redo command
{
UndoRedoCollection redo = _redos.Pop();
_undos.Push(redo.Exec(sheet));
}