import React from 'react'; import { Button, Platform } from 'react-native'; import { StackNavigator } from 'react-navigation'; import LoginView from './views/login'; import NewServerView from './views/serverNew'; import ListServerView from './views/serverList'; import RoomsListView from './views/roomsList'; import RoomView from './views/room'; const position = Platform.OS === 'ios' ? 'headerLeft' : 'headerRight'; const MainCardNavigator = StackNavigator({ Rooms: { screen: RoomsListView, navigationOptions: ({ navigation }) => ({ [position]: