//click undo
public void HandleUndoButtonClick(object sender, System.EventArgs e)
{
_model.ClickUndo();
_buttonUndo.Enabled = _model.GetUndoEnable();
_buttonRedo.Enabled = _model.GetRedoEnable();
}
//click clear
private void HandleClearButtonClick(object sender, RoutedEventArgs e)
{
_model.Clear();
_undo.IsEnabled = _model.GetUndoEnable();
_redo.IsEnabled = _model.GetRedoEnable();
}
