title: wxPython: wx.Panel of AuiManager has empty space of gray
body: <p>I am trying to make a window with 2 panels. One panel is just a notebook panel. The second panel contains a toolbar on top and a text control on the bottom. I want to arrange this panel in my frame using wx.aui.AuiManager. </p>
  
  <p>The problem is that I get a <strong>big empty space of grey in my custom panel</strong>. </p>
  
  <p>Here is my code:</p>
  
  <pre><code>import wx
  import wx.aui
  import images # contains toolbar icons
  
  class MyFrame(wx.Frame):
      def __init__(self):
          wx.Frame.__init__(self, None, wx.ID_ANY,
                              "AUI Tutorial",
                              size=(600,400))
  
          self._mgr = wx.aui.AuiManager()
          self._mgr.SetManagedWindow(self)
  
          notebook = wx.aui.AuiNotebook(self)
          nb_panel = TabPanel(notebook)
          my_panel = MyPanel(self)
          notebook.AddPage(nb_panel, "First Tab", False)
  
          self._mgr.AddPane(notebook,
                            wx.aui.AuiPaneInfo().Name("notebook-content").
                            CenterPane().PaneBorder(False))
          self._mgr.AddPane(my_panel,
                            wx.aui.AuiPaneInfo().Name("txtctrl-content").
                            CenterPane().PaneBorder(False))
          self._mgr.GetPane("notebook-content").Show().Top().Layer(0).Row(0).Position(0)
          self._mgr.GetPane("txtctrl-content").Show().Bottom().Layer(1).Row(0).Position(0)
  
          self._mgr.Update()
  
  
  class MyPanel(wx.Panel):
      """
      My panel with a toolbar and richtextctrl
      """
      def __init__(self,parent):
          wx.Panel.__init__(self,parent=parent,id=wx.ID_ANY)
  
          sizer = wx.BoxSizer(wx.VERTICAL)
  
          toolbar = wx.ToolBar(self,-1)
          toolbar.AddLabelTool(wx.ID_EXIT, '', images._rt_smiley.GetBitmap())
          self.Bind(wx.EVT_TOOL, self.OnExit, id=wx.ID_EXIT)
  
          toolbar.Realize()
          sizer.Add(toolbar,proportion=0,flag=wx.ALL | wx.ALIGN_TOP)
  
          text = ""
          txtctrl = wx.TextCtrl(self,-1, text, wx.Point(0, 0), wx.Size(150, 90),
                             wx.NO_BORDER | wx.TE_MULTILINE | wx.TE_READONLY|wx.HSCROLL)
  
          sizer.Add(txtctrl,proportion=0,flag=wx.EXPAND)        
          self.SetSizer(sizer)
  
      def OnExit(self,event):
          self.Close()
  
  
  class TabPanel(wx.Panel):
      def __init__(self,parent):
          wx.Panel.__init__(self,parent=parent,id=wx.ID_ANY)
  
          sizer = wx.BoxSizer(wx.VERTICAL)
          txtOne = wx.TextCtrl(self, wx.ID_ANY, "")
          txtTwo = wx.TextCtrl(self, wx.ID_ANY, "")
  
          sizer = wx.BoxSizer(wx.VERTICAL)
          sizer.Add(txtOne, 0, wx.ALL, 5)
          sizer.Add(txtTwo, 0, wx.ALL, 5)
          self.SetSizer(sizer)
  
  
  if __name__ == "__main__":
      app = wx.PySimpleApp()
      frame = MyFrame()
      frame.Show()
      app.MainLoop()
  </code></pre>
  
  <p><strong>So, how do I fix my code so that I don't have that grey block taking up MyPanel? Also, my toolbar button doesn't seem to run self.OnExit(). Why is that?</strong></p>
  
  <p>Thank you for your help.</p>