void LayoutManager_ActivePaneChanged(object sender, ActivePaneChangedEventArgs e)
 {
     if (e.DockableViewModel is BaseDockingViewModel)
         (e.DockableViewModel as BaseDockingViewModel).IsActiveView = e.IsActive;
 }
 /// <summary>
 /// React on active window pane changes.
 /// </summary>
 /// <param name="sender"></param>
 /// <param name="e"></param>
 protected virtual void ReactOnActivePaneChanged(object sender, ActivePaneChangedEventArgs e)
 {
     (e.DockableViewModel as BaseDockingViewModel).IsActiveView = true;
 }