protected override void OnPreviewMouseUp(MouseButtonEventArgs e)
{
base.OnPreviewMouseUp(e);
MainWindow mainWindow = GetMainWindow();
mainWindow.FillValues((Shape)DraggedElement, true, false);
// Reset the field whether the left or right mouse button was
// released, in case a context menu was opened on the drag element.
m_IsDragInProgress = false;
DraggedElement = null;
}
