title: How to make manual docking seamless / invisible?
body: <p>I am trying to use docking as an alternative to embedding (<a href="https://stackoverflow.com/questions/4385948/how-to-avoid-issues-when-embedding-a-tform-in-another-tform">related question</a>) a <code>TForm</code> into a <code>TWinControl</code> (in this case a <code>TTabSheet</code>).</p>
  
  <p>The user shouldn't notice that there are two different forms at all.</p>
  
  <p>How do I avoid the close button and "drag bar" at the top of the docked form?</p>
  
  <p>A simplified version of my code:</p>
  
  <pre><code>var
    TabSheet: TTabSheet;
    Form: TSubForm;
  begin
    TabSheet             := TTabSheet.Create(Self);
    TabSheet.DockSite    := True;
    TabSheet.PageControl := MainPageControl;
  
    Form := TSubForm.Create(TabSheet);
    Form.ManualDock(TabSheet);
    Form.Show;
  end;
  </code></pre>
  
  <p>PS: I don't want to use a <code>TFrame</code> which would of course be another alternative.</p>
  
  <p><strong>Update:</strong></p>
  
  <p>In this specific situation I am now considering to use <code>TTabControl</code> instead of <code>TPageControl</code>, so I can put all the controls into the master form.</p>
  
  <p>I am using MVC/MVA anyway so the logic is separated from the UI.</p>