private void ToggleDecoration(object sender, MouseButtonEventArgs e) { if (e.ChangedButton != MouseButton.Left) { return; } var newLeft = _showingDecoration ? Left - LeftBorderWidth : Left + LeftBorderWidth; var newTop = _showingDecoration ? Top + TitleBarHeight : Top - TitleBarHeight; var newWindow = new PreviewWindow(_toPreview, newLeft, newTop, !_showingDecoration) { WindowClosed = WindowClosed }; newWindow.Show(); Close(); }