C / C++ / MFC

if(lpDrawItemStruct->itemState & ODS_SELECTED)
{
Create and select much lighter gray brush
Draw rectangle
Delete the brush
}

struct a
{
   double Val1;
   double Val2;
   double Val3;
}

a a::operator + (a paramA1,a paramA2)
{
    paramA1.Val1 += paramA2.Val1;
    paramA1.Val1 += paramA2.Val1;
    paramA1.Val1 += paramA2.Val1;
    return paramA1;
}

void CImageViewer::OnInitialUpdate() 
{
	CFormView::OnInitialUpdate();

	if (m_ToolTip.Create(&m_lead, TTS_ALWAYSTIP) && 
		m_ToolTip.AddTool(&m_lead))
	{
		m_ToolTip.SendMessage(TTM_SETMAXTIPWIDTH, 0, SHRT_MAX);
		m_ToolTip.SendMessage(TTM_SETDELAYTIME, TTDT_AUTOPOP, SHRT_MAX);
		m_ToolTip.SendMessage(TTM_SETDELAYTIME, TTDT_INITIAL, 200);
		m_ToolTip.SendMessage(TTM_SETDELAYTIME, TTDT_RESHOW, 200);
	}
	else
	{
		TRACE("Error in creating ToolTip");
	}
}
BOOL CImageViewer::PreTranslateMessage(MSG* pMsg) 
{
	if (::IsWindow(m_ToolTip.m_hWnd) && pMsg->hwnd == m_lead.m_hWnd)
	{
	     switch(pMsg->message)
	     {
	     case WM_LBUTTONDOWN:	
	     case WM_MOUSEMOVE:
	     case WM_LBUTTONUP:	
	     case WM_RBUTTONDOWN:
	     case WM_MBUTTONDOWN:	
	     case WM_RBUTTONUP:
	     case WM_MBUTTONUP:
		{
			if(vecRects.size() > 0)
			{
				CPoint pt(pMsg->pt);
				ScreenToClient(&pt);
			
				float zoom = m_lead.GetPaintZoomFactor();
			
				float ix, iy;
				int xscroll, yscroll;
				xscroll = m_lead.GetScrollPos(SB_VERT);
				yscroll = m_lead.GetScrollPos(SB_HORZ);
				float newzoom = zoom / 100;
				ix = (pt.x + xscroll) * newzoom;
				iy = (pt.y + yscroll) * newzoom;
			
				pMsg->pt.y = iy;
				pMsg->pt.x = ix;
				
				m_lead.SetAutoRepaint(TRUE);
			
				m_ToolTip.RelayEvent(pMsg);
			
			}
			m_ToolTip.RelayEvent(pMsg);
		        break;
		     }
	     default:
		break;
	    }
        }
	
	return CFormView::PreTranslateMessage(pMsg);
}

BOOL CImageViewer::OnToolTipNeedText(UINT id, NMHDR * pNMHDR, LRESULT * pResult)
{
	BOOL bHandledNotify = FALSE;

	CPoint CursorPos;
	VERIFY(::GetCursorPos(&CursorPos));
	ScreenToClient(&CursorPos);

	CRect ClientRect;
	GetClientRect(ClientRect);

	// Make certain that the cursor is in the client rect, because the
	// mainframe also wants these messages to provide tooltips for the
	// toolbar.
	if (ClientRect.PtInRect(CursorPos))
	{
		TOOLTIPTEXT *pTTT = (TOOLTIPTEXT *)pNMHDR;
		m_pRectHit = HitTest(CursorPos);

		if (m_pRectHit)
		{
			// Adjust the text by filling in TOOLTIPTEXT
			CString strTip;
			strTip.Format("%s %s", m_pRectHit->szPartNumber.c_str(), 
				m_pRectHit->szDescription.c_str());
			ASSERT(strTip.GetLength() < sizeof(pTTT->szText));
			::strcpy(pTTT->szText, strTip);

			bHandledNotify = TRUE;
		}
		else
		{
			pTTT->szText[0] = 0;
		}
	}
	return bHandledNotify;
}

void CImageViewer::OnMouseMoveLeadctrl(short Button, short Shift, long x, long y) 
{
	if (::IsWindow(m_ToolTip.m_hWnd))
	{
		CPoint point(x, y);
		const CRects* pRectHit = HitTest(point);

		if (!pRectHit || pRectHit != m_pRectHit)
		{
			// Use Activate() to hide the tooltip.
			m_ToolTip.Activate(FALSE);		
		}

		if (pRectHit)
		{
			m_ToolTip.Activate(TRUE);
			m_pRectHit = pRectHit;
		}
	}
}