title: cannot set position of wx.frame on openbox
body: <p>i am playing with wxPython and try to set position of frame:</p>
  
  <pre><code>import wx
  
  app = wx.App()
  p = wx.Point(200,  200)
  frame = wx.Frame(None, title = 'test position', pos = p)
  frame.Show(True)
  print('frame position: ', frame.GetPosition())
  
  app.MainLoop()
  </code></pre>
  
  <p>even though <code>print('frame position: ', frame.GetPosition())</code> shows the correct postion, the frame is shown in top left corner of screen.
  Alternatively i tried</p>
  
  <pre><code>frame.SetPosition(p)
  frame.Move(p)
  </code></pre>
  
  <p>without success.</p>
  
  <p>my environment: ArchLinux 5.3.13, python 3.8.0, wxpython 4.0.7, openbox 3.6.1</p>
  
  <p>On cinnamom the code works as expected. How to solve this on openbox?</p>
  
  <p>edit 07,12,2019:
  i could set postion of a dialog in openbox config <code>~/.config/openbox/rc.xml</code>:</p>
  
  <pre><code>&lt;application name="fahrplan.py"
              class="Fahrplan.py"
          groupname="fahrplan.py"
         groupclass="Fahrplan.py"
              title="Fahrplan *" 
               type="dialog"&gt; 
    &lt;position force="no"&gt; 
      &lt;x&gt;760&lt;/x&gt; 
      &lt;y&gt;415&lt;/y&gt;
    &lt;/position&gt;               
  &lt;/application&gt;
  </code></pre>
  
  <p>i got name, class etc. from obxprop. x and y are calculated to center a dialog of 400 x 250 px on screen of 1920 x 1080 px.</p>
  
  <p>This static solution is not suitable for me. I want to place dynamically generated popups.  </p>