self.btnImage = wx.Bitmap("ellipse_blue.png")
        self.tool = tb.AddTool(101, "Checkable", self.btnImage,
                               shortHelp="Toggle this", kind=wx.ITEM_CHECK)


        self.Bind(wx.EVT_TOOL, self.OnToggleToolClick, self.tool)


    def OnToggleToolClick(self, event):
        print("toggled")
        # print(self.tbutton.GetValue()) works for tbutton but not the       bitmap button
        if event.IsChecked:
            print("checked")
        else:
            print("not checked")