title: Allow child panel to handle mouse motion events
body: <p>I had a GUI application with the following layout:</p>
  
  <pre><code>wxFrame --&gt; wxBoxSizer --&gt; wxImagePanel
  </code></pre>
  
  <p>The wxImagePanel is a custom control (available <a href="http://wiki.wxwidgets.org/An_image_panel" rel="nofollow">here</a>).  I've modified it slightly to handle mouse events (using EVT_MOTION) like dragging that allows me to pan the image.</p>
  
  <p>Now, unfortunately, this looks ugly on Windows -- there's a dark gray background.  The recommended approach is to <a href="http://wiki.wxwidgets.org/WxFAQ#Why_are_backgrounds_of_windows_ugly.2C_dark_grey_on_Windows.3F_I_want_them_like_my_dialog_boxes." rel="nofollow">add a wxPanel</a> to the wxFrame -- this makes the ugly background go away.  The app is now layed out like this:</p>
  
  <pre><code>wxFrame --&gt; wxBoxSizer --&gt; wxPanel --&gt; wxBoxSizer --&gt; wxImagePanel (a custom control)
  </code></pre>
  
  <p>It looks a lot better, but now the wxPanel I've added is grabbing all the mouse motion events.  They don't get through to the child wxImagePanel, so I can't pan my image anymore.</p>
  
  <p>How can I make sure the mouse motion events make it through to the child wxImagePanel?</p>