RTF-Based Tooltips

This code demonstrates using rich text in tooltips, as seen in Query Analyser utility of MS SQL Server 7.

It is more like a proof-of-concept then a finished code, and is heavily based on two classes from CodeGuru : TFXDataTip by S. Wilson and CAutoRichEditCtrl by Jeremy Iverson

First class was modifyed to hold a hidden AutoRichEdit control as a static member and use it for rendering the RTF text to the window. Function of AutoRichEdit are used to load text into the control.

Most of the magic behind the code is in the OnPaint handler of the tooltip window. The idea is to utilise RichEdit printing functions to copy the picture to screen DC instead of printer.

void TFXDataTip::OnPaint() 
{
	CPaintDC dc(this); // device context for painting

    CRect rect;
    GetClientRect(&rect);

    dc.SetBkColor(::GetSysColor(COLOR_INFOBK));
    //dc.SetTextColor(::GetSysColor(COLOR_INFOTEXT));
	//dc.SetMapMode(MM_TEXT);

	if(_richCtrl)
	{
		_richCtrl->SetRTF(m_tip);

		FORMATRANGE fr;
		fr.hdc = dc;
		fr.hdcTarget = dc;
		fr.rc = CRect((rect.Width( ) / 2), (_border / 2) ,m_size.cx*15, m_size.cy*15);
		fr.rcPage = CRect(0,0,0,0);
		fr.chrg.cpMin = 0;
		fr.chrg.cpMax = -1;
		
		_richCtrl->FormatRange( &fr );
	}

}

void CRich1Dlg::OnMouseMove(UINT nFlags, CPoint point) 
{
	CWnd *pwnd = ChildWindowFromPoint(point);
	if(pwnd)
	{
		int nID = pwnd->GetDlgCtrlID();

		switch(nID)
		{
			case IDC_RICH_PLACEHOLDER:
				m_datatip.Set(point, m_tip1);
				break;
			case IDC_TEXT:
				m_datatip.Set(point, m_tip2);
				break;
			case IDC_IMAGE_PLACEHOLDER:
				m_datatip.Set(point, m_tip3);
				break;
			default:
				break;
		}
	}
	CDialog::OnMouseMove(nFlags, point);
}

Issues and possible enhancements :