title: Delphi VirtualTreeview.OnAfterItemPaint issue when scrolling?
body: <p>I'm getting issues drawing using <strong>OnAfterItemPaint</strong> event when horizontal scrolling is performed.</p>
  
  <p>Basically what I want to achieve is the merging of selected cells effect, say for example 1 text for column 1 &amp; 2, another text for column 3 &amp; 4, etc... So far VT doesn't have any support for column merging, so I have to manually draw it.</p>
  
  <p>Is there a workaround or another event that I should use instead?</p>
  
  <p>Using: Delphi 7 + VirtualTreeview 4.8.5</p>
  
  <p>Event source:</p>
  
  <pre><code>begin
    TargetCanvas.TextOut(ItemRect.Left+ VT1.OffsetX, ItemRect.Top,
      '1234567890ABCDEF1234567890ABCDEF1234567890ABCDEF');
  end;
  </code></pre>
  
  <p>Before scroll:</p>
  
  <p><a href="http://a.imagehost.org/0869/screen1.gif" rel="nofollow noreferrer">alt text http://a.imagehost.org/0869/screen1.gif</a></p>
  
  <p>After scroll (Scroll Right, then Scroll Left):</p>
  
  <p><a href="http://a.imagehost.org/0645/screen2.gif" rel="nofollow noreferrer">alt text http://a.imagehost.org/0645/screen2.gif</a></p>