== Introduction ==
I had trouble finding out how to resize a frame when controls were shown or hidden.  This documents the results of my search of the mailing lists and experiments.

== What Objects are Involved ==
wxPanel, wxSizer

== Process Overview ==
The code displays a frame with a toggle button and a pane below it containing some controls. Toggling the button shows and hides the control pane, resizing the frame as appropriate.

== Code Sample ==
The skeleton of this code is derived from the sample code at XrcStartingPoints.

{{{
import wx
from wx import xrc
GUI_FILENAME       = "t.xrc"
GUI_MAINFRAME_NAME = "FRAME1"
class MyApp( wx.App ):
    def OnInit( self ):
        self.res   = xrc.XmlResource( GUI_FILENAME )
        self.frame = self.res.LoadFrame( None, GUI_MAINFRAME_NAME )
        self.frame.Show(1)
        self.showControls = xrc.XRCCTRL(self.frame, 'showControls')
        self.controlPanel = xrc.XRCCTRL(self.frame, 'controlPanel')
        self.Bind( wx.EVT_TOGGLEBUTTON, self.OnChange, self.showControls)
        return 1
    def OnChange(self, event):
        sizer = self.frame.GetSizer()
        sizer.Show( self.controlPanel, show=self.showControls.GetValue(), recursive=True)
        size=sizer.GetMinSize()
        self.frame.SetMinSize(size)
        self.frame.Fit()
if __name__ == '__main__':
    app = MyApp(0)
    app.MainLoop()
}}}
and t.xrc:

{{{
<?xml version="1.0" encoding="cp1252"?>
<resource>
  <object class="wxFrame" name="FRAME1">
    <title>Test</title>
    <centered>1</centered>
    <object class="wxBoxSizer">
      <orient>wxVERTICAL</orient>
      <object class="sizeritem">
        <object class="wxToggleButton" name="showControls">
          <label>Show Controls</label>
          <checked>1</checked>
        </object>
      </object>
      <object class="sizeritem">
        <object class="wxPanel" name="controlPanel">
          <object class="wxBoxSizer">
            <orient>wxHORIZONTAL</orient>
            <object class="sizeritem">
              <object class="wxStaticText" name="theLabel">
                <label>Label:</label>
              </object>
            </object>
            <object class="sizeritem">
              <object class="wxTextCtrl" name="theTextControl"/>
              <option>1</option>
            </object>
          </object>
        </object>
      </object>
    </object>
  </object>
</resource>
}}}
=== Comments ===
I don't know if this is the best way to do this, but the code is clean and it works.  Please add any comments.