A method to control navigation graphs in bottomNavigationBar

BottomNavigation.kt

/**
     * Called on first creation and when restoring state.
     */
    private fun setupBottomNavigationBar(recreated: Boolean) {
        val bottomNavigationView = findViewById<BottomNavigationView>(R.id.bottomNavigation)

        val navGraphIds = listOf(TABS.BROWSE.navId, TABS.SEARCH.navId, TABS.FEED.navId, TABS.PROFILE.navId, TABS.PLUS.navId)

        // Setup the bottom navigation view with a list of navigation graphs
        val controller = bottomNavigationView.setupWithNavController(
                navGraphIds = navGraphIds,
                fragmentManager = supportFragmentManager,
                containerId = R.id.nav_host_container,
                intent = intent,
                navigationInterface = object : NavigationInterface {
                    override fun onTabSelected(selectedTab: TABS) {
                        changePlayButtonColor(selectedTab == TABS.FEED)
                        currentTab = selectedTab
                    }
                }
        )

        // click on floating action button actually clicks on hidden bottom navigation button
        navigationVideo.setOnClickListener {
            bottomNavigationView.findViewById<View>(R.id.home).performClick()
        }

        // Whenever the selected controller changes, setup the action bar.
        controller.observe(this, Observer { navController ->
            setupActionBarWithNavController(navController)
        })
        currentNavController = controller

        //set feed as default if first launched
        if (!recreated) bottomNavigationView.selectedItemId = TABS.FEED.buttonId
    }