NavMenuItemSelectedListener.kt

import android.annotation.SuppressLint
import android.support.design.widget.NavigationView
import android.support.v4.widget.DrawerLayout
import android.view.MenuItem
import androidx.navigation.NavController
import androidx.navigation.NavOptions

/**
 * @author https://github.com/viperwarp
 *
 * An OnNavigationItemSelectedListener made to work with Android Navigation Components when
 * you need to navigate between top level destinations using a Drawer style navigation menu.
 *
 * This listener must be set after calling {@code setupWithNavController(navController)} to replace
 * the listener that the Navigation Components add.
 *
 * Known Issues:
 * - When rotating or deep linking, the NavGraph is reloaded and reverts to the default startingDestination.
 * - I don't know if there's any issue with retaining the NavigationView or the NavController here, YMMV.
 * - This doesn't support navigating between peer views that are not top level Destinations
 *
 * Example Usage:
 * <pre>
 * {@code
 * nav_view.setupWithNavController(navController)
 * nav_view.setNavigationItemSelectedListener(NavMenuItemSelectedListener(nav_view, navController) {
 *     if (it.itemId == R.id.nav_logout) {
 *         onLogout()
 *     }
 *     drawer_layout.closeDrawer(GravityCompat.START)
 *     true
 * })
 * }
 * </pre>
 *
 * @param navigationView the menu view
 * @param navController navigation controller for the current NavGraph
 * @param onNoDestination fallback for handling menu items that don't link to a destination
 *
 */
class NavMenuItemSelectedListener(private val navigationView: NavigationView,
                                  private val navController: NavController,
                                  private val onNoDestination: (item: MenuItem) -> Boolean): NavigationView.OnNavigationItemSelectedListener {

    @SuppressLint("ResourceType")
    override fun onNavigationItemSelected(item: MenuItem): Boolean {
        if (navController.graph.findNode(item.itemId) != null) {
            navController.graph.startDestination = item.itemId // <- The Magic Sauce

            val options = with(NavOptions.Builder()) {
                setPopUpTo(R.navigation.my_nav_graph, true)
                build()
            }

            navController.navigate(item.itemId, null, options)
            val parent = navigationView.parent
            if (parent is DrawerLayout) {
                parent.closeDrawer(navigationView)
            }
            return true
        }

        return onNoDestination.invoke(item)
    }
}