How to: Codejock tooltips on a tree control

 

I did it this way:

Turn off the internal tooltip control (TVS_NOTOOLTIPS) and replace it by a CXTPTooltipContext. This is a member of my tree control and handles all tooltip messages in OnWndMsg() (see code below).

I hope this helps. BTW if you prefer to use other tooltip paintings, you have to modify the tooltip context by deriving your own class...

 

class CMyTree : public CXTTreeCtrl
{
public:
 CMyTree();

 virtual ~CMyTree();

protected:
 virtual BOOL OnCmdMsg(UINT nID, int nCode, void* pExtra, AFX_CMDHANDLERINFO* pHandlerInfo);

private:
 BOOL    OnWndMsg(UINT message, WPARAM wParam, LPARAM lParam, LRESULT* pResult);
 INT_PTR   OnToolHitTest(CPoint point, TOOLINFO* pTI) const;

 CXTPToolTipContext* pContext_;

};

////////////////////////////////////////////////////

BOOL CMyTree::OnWndMsg(UINT message, WPARAM wParam, LPARAM lParam, LRESULT* pResult) {

 if (pContext_!=0)
  pContext_->FilterToolTipMessage(this, message, wParam, lParam);
 
 return CXTTreeCtrl::OnWndMsg(message, wParam, lParam, pResult);
}

INT_PTR CMyTree::OnToolHitTest(CPoint point, TOOLINFO* pTI) const {
 // hits against child windows always center the tip
 INT_PTR nHit = CWnd::OnToolHitTest(point, pTI);
 if (nHit!=-1)
  return nHit;
 if (pTI != NULL && pTI->cbSize >= sizeof(XTP_TOOLTIP_TOOLINFO))
 {
  UINT nFlags;
  HTREEITEM hItem=HitTest(point, &nFlags);
  if ((hItem != NULL) && (TVHT_ONITEM & nFlags)) {
   CRect rc;
   VERIFY(GetItemRect(hItem, rc, FALSE));
   nHit=reinterpret_cast<INT_PTR>(hItem);
   const MyObject* const pVar=dynamic_cast<MyObject*>(reinterpret_cast<MyBaseObject*>(GetItemData(hItem)));
   ASSERT(pVar!=NULL);
   if (pVar!=NULL) {
    TCHAR szText[4096];
    pVar->GetTooltipInfoText(szText, _countof(szText));
    CXTPToolTipContext::FillInToolInfo(pTI, m_hWnd, rc, nHit, szText);
    return nHit;
   }
  }
 }

 pContext_->CancelToolTips();

 return -1;
}