TIP: Create In-Place ToolTips on Your Own Controls

It is very easy to create in-place toolTips on your own control. For example, you can place one on a treeview control.

Step 1

In the window's header file, you must add a CToolTipCtrl instance and a TOOLINFO member. Also, you need to add a message map to handle the mouse messages.

protected:
   afx_msg void OnMouseMove(UINT nFlags, CPoint point);
   afx_msg void OnMouseLeave(WPARAM wPawam, LPARAM lParam);
      //}}AFX_MSG
      DECLARE_MESSAGE_MAP()
private:
   CToolTipCtrl m_toolTip;
   TOOLINFO   m_ti;

Step 2

In the window's implementation file, add the following to the end of Create to set the ToolTips.

m_toolTip.Create(this);
m_ti.cbSize = sizeof(m_ti);
m_ti.uFlags = TTF_IDISHWND|TTF_TRACK|TTF_ABSOLUTE |TTF_TRANSPARENT ;
m_ti.hwnd = m_hWnd;
m_ti.hinst = NULL;
m_ti.uId = (UINT)m_hWnd;
m_ti.lpszText = LPSTR_TEXTCALLBACK;
m_ti.rect.left = 0;
m_ti.rect.top = 0;
m_ti.rect.right = 0;
m_ti.rect.bottom = 0;

m_toolTip.SendMessage(TTM_ADDTOOL, 0, (LPARAM)&m_ti);

At the bottom of the message map, add the following:

   ON_WM_MOUSEMOVE()
   ON_MESSAGE(WM_MOUSELEAVE, OnMouseLeave)
END_MESSAGE_MAP()

Finally, add the message handler method as entered in the message map:

void CChildView::OnMouseMove(UINT nFlags, CPoint point)
{
   CDemoItem* pItem = GetItemAtPt(point);
   if(pItem == NULL)
   {
      m_toolTip.SendMessage(TTM_TRACKACTIVATE, FALSE, (LPARAM)&m_ti);
      return;
   }
   RECT rect;
   GetItemRect(pItem, &rect);
   POINT pt;

   TRACKMOUSEEVENT tk;
   tk.cbSize = sizeof(tk);
   tk.dwFlags = TME_LEAVE;
   tk.dwHoverTime = 0;
   tk.hwndTrack = m_hWnd;
   _TrackMouseEvent(&tk);
   pt.x = rect.left - 3;
   pt.y = rect.top - 2;
   ClientToScreen(&pt);
   m_toolTip.SendMessage(TTM_TRACKPOSITION, 0,
                         (LPARAM)MAKELPARAM(pt.x, pt.y));
   m_toolTip.SendMessage(TTM_TRACKACTIVATE, TRUE, (LPARAM)&m_ti);
}

void CChildView::OnMouseLeave(WPARAM wPawam, LPARAM lParam)
{
   m_toolTip.SendMessage(TTM_TRACKACTIVATE, FALSE, (LPARAM)&m_ti);
}