def show_help(self, *args):
'''Event handler for 'on_help' event of self.start_page
'''
self.help_dlg = HelpDialog()
self._popup = Popup(title='Kivy Designer Help',
content=self.help_dlg,
size_hint=(0.95, 0.95),
auto_dismiss=False)
self._popup.open()
self.help_dlg.bind(on_cancel=self._cancel_popup)
self.help_dlg.rst.source = 'help.rst'
