router.js

import React from "react";
import { Platform, StatusBar } from "react-native";
import {
  DrawerNavigator,
  StackNavigator,
  TabNavigator,
  SwitchNavigator
} from "react-navigation";

import Icon from 'react-native-vector-icons/Ionicons';

import Home from './tabs/Home';
import Settings from './tabs/Settings';
import Profile from './screens/Profile';
import Modal from './screens/Modal';
import Drawer from './components/Drawer';
import Login from './screens/user/Login';

const headerStyle = {
  marginTop: Platform.OS === "android" ? StatusBar.currentHeight : 0
};

// Stack navigation for Settings and Profile screens
const SettingsTab = StackNavigator({
  Settings: {
    screen: Settings,
    navigationOptions: {
      header: null,              
      headerBackTitle: 'Back',    
    },
  },
  Profile: {
    screen: Profile,
    navigationOptions: ({ navigation }) => ({
      title: `${navigation.state.params.user} Profili`,
    }),
  },
}, {
  headerMode: 'screen',
});

// Tab navigation for Home and Settings screens
const TabNavigation = TabNavigator({
  Home: {
    screen: Home,
    navigationOptions: {
      tabBarLabel: 'Home',
      tabBarIcon: ({ tintColor, focused }) => <Icon
        name={focused ? 'ios-home' : 'ios-home-outline'}
        size={26}
        style={{ color: tintColor }}
      />
    },
  },
  Settings: {
    screen: SettingsTab,
    navigationOptions: {
      tabBarLabel: 'Settings',
      tabBarIcon: ({ tintColor, focused }) => <Icon
        name={focused ? 'ios-settings' : 'ios-settings-outline'}
        size={26}
        style={{ color: tintColor }}
      />
    },
  },
});

const TabsWithDrawerNavigation = DrawerNavigator({
  Tabs: {
    screen: TabNavigation,
  }
}, {
  contentComponent: props => <Drawer {...props} />
});

export const createRootNavigator = (signedIn = false) => {
  return StackNavigator(
    {
      // bunlarda normal alttan açılmayacak modelsiz sayfalar olcak
      SignedIn: {
        screen: TabsWithDrawerNavigation,
      },
      SignedOut: {
        screen: Login
      },
      // alttan açılcak sayfa bu
      Modal: {
        screen: Modal
      },
    },
    {
      // alttan açılmayı saglayan func.
      mode: 'modal', 
      headerMode: 'none',
      initialRouteName: signedIn ? "SignedIn" : "SignedOut"
    }
  );
};