code: def ConfigureViewTypeChoices( self, event=None ):
          
          self.viewTypeTool.SetItems( getattr( self.loader, 'ROOTS', [] ))
          if self.loader and self.viewType in self.loader.ROOTS:
              self.viewTypeTool.SetSelection( self.loader.ROOTS.index( self.viewType ))
              
          # configure the menu with the available choices...
          def chooser( typ ):
              def Callback( event ):
                  if typ != self.viewType:
                      self.viewType = typ 
                      self.OnRootView( event )
              return Callback
          # Clear all previous items
          for item in self.viewTypeMenu.GetMenuItems():
              self.viewTypeMenu.DeleteItem( item )
          if self.loader and self.loader.ROOTS:
              for root in self.loader.ROOTS:
                  item = wx.MenuItem( 
                      self.viewTypeMenu, -1, root.title(), 
                      _("View hierarchy by %(name)s")%{
                          'name': root.title(),
                      },
                      kind=wx.ITEM_RADIO,
                  )
                  item.SetCheckable( True )
                  self.viewTypeMenu.AppendItem( item )
                  item.Check( root == self.viewType )
                  wx.EVT_MENU( self, item.GetId(), chooser( root ))
docs: Configure the set of View types in the toolbar (and menus)