Odtnhj

I want to bind the esc key so i can switch screens on android back button press.
My understanding is that I have done screen management through the kv file and it has caused me trouble getting the online binding examples (that use management done in the py file) to work.
This is what I have:
weather.kv

ScreenManager:
 id: screen_manager

 SearchScreen:
 id: search_screen
 name: 'SearchScreen'
 manager: screen_manager
 ForecastScreen:
 id: forecast_screen
 name: 'ForecastScreen'
 manager: screen_manager
<SearchScreen>:

<ForecastScreen>:

Then in the main.py

class SearchScreen(Screen):
 location = StringProperty('No location') 
 def set_location(self, address):
 self.location = str(address)
 self.manager.current = "ForecastScreen"


class ForecastScreen(Screen):
 #code

sm=Builder.load_file('weather.kv')
class WeatherApp(App):
 def build(self):
 Window.bind(on_keyboard=self.on_key)
 return sm

 def on_key(self, window, key, *args):
 if key == 27: # the esc key
 if self.screen_manager.current_screen.name == "SearchScreen":
 return False # exit the app from this page
 elif self.screen_manager.current_screen.name == "ForecastScreen":
 self.screen_manager.current = "SearchScreen"
 return True

if __name__ == "__main__":
 WeatherApp().run()

Let me know if you need to see more of my code. Button based screen switching works but the self.screen_manager says that screen_manager is not part of the self object.