title: RichEdit paint background
body: <p>I know how to change the background on a single row in a <code>TRichEdit</code> control. But because this is applied to the selected text only, I can't set the background color of the whole line (client left to client right), only to the text part.</p>
  
  <p>I tried to use the <code>WM_ERASEBKGND</code> message, but it doesn't work because a RichEdit control is painting the background in its <code>WM_PAINT</code> handler.</p>
  
  <p>I also tried to set the brush to <code>bsClear</code> before calling the <code>WM_PAINT</code> handler, but it didn't work either.</p>
  
  <p>Is it possible at all to have a custom drawn background?</p>