Hamburger icon not working for Navigation Architecture Components

Question

So I have used the navigation architecture components with java although I followed the codelabds that use kotlin. My code is working but I have detected a few issues: 1. The hamburger icon is visible but does not work. Sliding the screen from the left displays the navigation drawer. 2. The back button for fragments does not work either.

I thought it is an issue with the toolbar but I do not think so because I have an overflow menu that works just fine.

How do I solve these issues, please? I am so close to figuring this out but I am stuck.

Below is the code.

    package com.disruption.globalmail;

import android.os.Bundle;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;

import java.util.HashSet;
import java.util.Set;

import androidx.navigation.NavController;
import androidx.navigation.fragment.NavHostFragment;
import androidx.navigation.ui.AppBarConfiguration;
import androidx.navigation.ui.NavigationUI;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = MainActivity.class.getSimpleName();

    private AppBarConfiguration mAppBarConfiguration;

    public static String mRequestUrl = "url here";
    private DrawerLayout mDrawerLayout;
    private NavController mNavController;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        ActionBar actionBar = getSupportActionBar();
        assert actionBar != null;
        actionBar.setDisplayHomeAsUpEnabled(true);
        actionBar.setHomeAsUpIndicator(R.drawable.ic_launcher_background);

        NavHostFragment navHostFragment = (NavHostFragment) getSupportFragmentManager()
                .findFragmentById(R.id.my_nav_host_fragment);


        assert navHostFragment != null;
        mNavController = navHostFragment.getNavController();


        Set<Integer> topLevelDests = new HashSet<>();
        topLevelDests.add(R.id.top_news_dest);
        topLevelDests.add(R.id.duplicate_top_news_dest);

        mDrawerLayout = findViewById(R.id.drawer_layout);

        mAppBarConfiguration = new AppBarConfiguration.Builder(topLevelDests)
                .setDrawerLayout(mDrawerLayout)
                .build();

        setupActionBar(mNavController);

        setupNavigationMenu(mNavController);
    }

    private void setupNavigationMenu(NavController navController) {
        NavigationView navigationView = findViewById(R.id.nav_view);
        NavigationUI.setupWithNavController(navigationView, navController);
    }

    private void setupActionBar(NavController navController) {
        // This allows NavigationUI to decide what label to show in the action bar
        // By using appBarConfig, it will also determine whether to
        // show the up arrow or drawer menu icon
        NavigationUI.setupActionBarWithNavController(this, navController, mDrawerLayout);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        return NavigationUI.onNavDestinationSelected(item, mNavController)
                || super.onOptionsItemSelected(item);
    }

    @Override
    public void onBackPressed() {
        if (mDrawerLayout.isDrawerOpen(GravityCompat.START)) {
            mDrawerLayout.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }
}

and the layout below

    <?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:background="?attr/colorPrimary"
            android:layout_width="match_parent"
            android:theme="@style/AppTheme.AppBarOverlay"
            android:layout_height="wrap_content" />

        <fragment
            android:id="@+id/my_nav_host_fragment"
            android:name="androidx.navigation.fragment.NavHostFragment"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:defaultNavHost="true"
            app:navGraph="@navigation/news_nav_graph" />

    </LinearLayout>

    <android.support.design.widget.NavigationView
        android:id="@+id/nav_view"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        app:menu="@menu/menu_nav_drawer" />

</android.support.v4.widget.DrawerLayout>

Answer 1

Try this:

package com.disruption.globalmail;

import android.os.Bundle;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;

import java.util.HashSet;
import java.util.Set;

import androidx.navigation.NavController;
import androidx.navigation.fragment.NavHostFragment;
import androidx.navigation.ui.AppBarConfiguration;

// I'm not sure that you want to use only NavigationUI for 
// some of those methods. Try using these instead.
import androidx.navigation.ui.NavigationUI.navigateUp
import androidx.navigation.ui.onNavDestinationSelected
import androidx.navigation.ui.setupActionBarWithNavController
import androidx.navigation.ui.setupWithNavController

public class MainActivity extends AppCompatActivity {

    private static final String TAG = MainActivity.class.getSimpleName();

    private AppBarConfiguration mAppBarConfiguration;

    public static String mRequestUrl = "url here";
    private DrawerLayout mDrawerLayout;
    private NavController mNavController;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        ActionBar actionBar = getSupportActionBar();
        assert actionBar != null;
        actionBar.setDisplayHomeAsUpEnabled(true);
        actionBar.setHomeAsUpIndicator(R.drawable.ic_launcher_background);

        NavHostFragment navHostFragment = (NavHostFragment) getSupportFragmentManager().findFragmentById(R.id.my_nav_host_fragment);

        assert navHostFragment != null;
        mNavController = navHostFragment.getNavController();

        Set<Integer> topLevelDests = new HashSet<>();
        topLevelDests.add(R.id.top_news_dest);
        topLevelDests.add(R.id.duplicate_top_news_dest);

        mDrawerLayout = findViewById(R.id.drawer_layout);

        mAppBarConfiguration = new AppBarConfiguration.Builder(topLevelDests)
            .setDrawerLayout(mDrawerLayout)
            .build();

        setupActionBar(mNavController);

        setupNavigationMenu(mNavController);
    }

    private void setupNavigationMenu(NavController navController) {
        NavigationView navigationView = findViewById(R.id.nav_view);
        navigationView.setupWithNavController(navController);
    }

    private void setupActionBar(NavController navController) {
        // This allows NavigationUI to decide what label to show in the action bar
        // By using appBarConfig, it will also determine whether to
        // show the up arrow or drawer menu icon
        setupActionBarWithNavController(navController, mDrawerLayout);
    }

    // This might just fix your issue by itself.
    @Override
    public boolean onSupportNavigateUp() {
        return navigateUp(mNavController, mDrawerLayout)
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        return item.onNavDestinationSelected(mNavController)
            || super.onOptionsItemSelected(item);
    }

    @Override
    public void onBackPressed() {
        if (mDrawerLayout.isDrawerOpen(GravityCompat.START)) {
            mDrawerLayout.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }
}

Your problem could be using the wrong navigation methods for setup, but I think this addition might do it for you without having to change those:

@Override
public boolean onSupportNavigateUp() {
    return navigateUp(mNavController, mDrawerLayout)
}

I haven't tried overriding the onCreateOptionsMenu, so I'm not sure if you are doing that correctly. Otherwise, you're definitely on the right track.