Click on a tab of a pane event

Here are some hints:

1. Override CXTPDockingPaneManager and its OnCreatePane:

class CDockingPaneManager : public CXTPDockingPaneManager
{
public:
 CDockingPaneManager();
 virtual ~CDockingPaneManager();

protected:
 virtual CXTPDockingPaneBase* OnCreatePane(XTPDockingPaneType type, CXTPDockingPaneLayout* pLayout);

};

2. if type == xtpPaneTypeAutoHidePanel return custom derived CXTPDockingPaneAutoHidePanel class.

3. catch  in csutom CDockingPaneAutoHidePanel its OnLButtonDown

void CDockingPaneAutoHidePanel::OnLButtonDown(UINT /*nFlags*/, CPoint point)
{
 CXTPDockingPane* pPane = HitTest(point);
 if (pPane)
 {
  if (m_pActiveWnd && m_pActiveWnd->m_pPane->GetSelected() == pPane)
  {
   pPane->SetFocus();

  } else
  {
   CloseActiveWindow();
   GetDockingPaneManager()->ShowPane(pPane );
  }
 }
}

I think you have quite old ToolkitPro version. In last versions it was protected.

Change your sources to make it protected and rebuild library