Toggle button event handler

def OnToggle(self, event):
        """Toggle button event handler"""

        if self.selection_toggle_button.GetValue():
            self.entry_line.last_selection = self.entry_line.GetSelection()
            self.entry_line.last_selection_string = \
                self.entry_line.GetStringSelection()
            self.entry_line.last_table = self.main_window.grid.current_table
            self.entry_line.Disable()
            post_command_event(self, self.EnterSelectionModeMsg)

        else:
            self.entry_line.Enable()
            post_command_event(self, self.GridActionTableSwitchMsg,
                               newtable=self.entry_line.last_table)
            post_command_event(self, self.ExitSelectionModeMsg)