Navigation drawer is always inflated

Question

I was trying to add 3 fixed tabs and a navigation drawer... But when i run the app the navigation drawer is always open and when i click on items of navigation drawer it force closes the app with following error

java.lang.IllegalArgumentException: No drawer view found with gravity LEFT

Mainactivity.java

public class MainActivity extends AppCompatActivity implements
FragmentDrawer.FragmentDrawerListener {

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

private Toolbar mToolbar;
private TabLayout tabLayout;
private ViewPager viewPager;
private FragmentDrawer drawerFragment;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mToolbar = (Toolbar) findViewById(R.id.toolbar);

    setSupportActionBar(mToolbar);
    //getSupportActionBar().setDisplayShowHomeEnabled(true);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

    drawerFragment = (FragmentDrawer)
            getSupportFragmentManager().findFragmentById(R.id.fragment_navigation_drawer);
    drawerFragment.setUp(R.id.fragment_navigation_drawer, (DrawerLayout) findViewById(R.id.drawer_layout), mToolbar);
    drawerFragment.setDrawerListener(this);

    // display the first navigation drawer view on app launch
    displayView(0);

    viewPager = (ViewPager) findViewById(R.id.viewpager);
    setupViewPager(viewPager);

    tabLayout = (TabLayout) findViewById(R.id.tabs);
    tabLayout.setupWithViewPager(viewPager);
}

private void setupViewPager(ViewPager viewPager){
    ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
    adapter.addFragment(new HomeFragment(), "ONE");
    adapter.addFragment(new FriendsFragment(), "TWO");
    adapter.addFragment(new MessagesFragment(), "THREE");
    viewPager.setAdapter(adapter);
}


class ViewPagerAdapter extends FragmentPagerAdapter {
    private final List<Fragment> mFragmentList = new ArrayList<>();
    private final List<String> mFragmentTitleList = new ArrayList<>();

    public ViewPagerAdapter(FragmentManager manager) {
        super(manager);
    }

    @Override
    public Fragment getItem(int position) {
        return mFragmentList.get(position);
    }

    @Override
    public int getCount() {
        return mFragmentList.size();
    }

    public void addFragment(Fragment fragment, String title) {
        mFragmentList.add(fragment);
        mFragmentTitleList.add(title);
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return mFragmentTitleList.get(position);
    }
}



@Override
public void onDrawerItemSelected(View view, int position) {
    displayView(position);
}

private void displayView(int position) {
    Fragment fragment = null;
    String title = getString(R.string.app_name);
    switch (position) {
        case 0:
            fragment = new HomeFragment();
            title = getString(R.string.title_home);
            break;
        case 1:
            fragment = new FriendsFragment();
            title = getString(R.string.title_friends);
            break;
        case 2:
            fragment = new MessagesFragment();
            title = getString(R.string.title_messages);
            break;
        default:
            break;
    }

    if (fragment != null) {
        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction fragmentTransaction =  fragmentManager.beginTransaction();
        fragmentTransaction.replace(R.id.container_body, fragment);
        fragmentTransaction.commit();

        // set the toolbar title
        getSupportActionBar().setTitle(title);
    }
}
}

FragmentDrawer.java

public class FragmentDrawer extends android.support.v4.app.Fragment {

private static String TAG = FragmentDrawer.class.getSimpleName();
private RecyclerView recyclerView;
private ActionBarDrawerToggle mDrawerToggle;
private DrawerLayout mDrawerLayout;
private NavigationDrawerAdapter adapter;
private View containerView;
private static String[] titles = null;
private FragmentDrawerListener drawerListener;

public FragmentDrawer() {

}

public void setDrawerListener(FragmentDrawerListener listener) {
    this.drawerListener = listener;
}

public static List<NavDrawerItem> getData() {
    List<NavDrawerItem> data = new ArrayList<>();


    // preparing navigation drawer items
    for (int i = 0; i < titles.length; i++) {
        NavDrawerItem navItem = new NavDrawerItem();
        navItem.setTitle(titles[i]);
        data.add(navItem);
    }
    return data;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // drawer labels
    titles = getActivity().getResources().getStringArray(R.array.nav_drawer_labels);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflating view layout
    View layout = inflater.inflate(R.layout.fragment_navigation_drawer, container, false);
    recyclerView = (RecyclerView) layout.findViewById(R.id.drawerList);

    adapter = new NavigationDrawerAdapter(getActivity(), getData());
    recyclerView.setAdapter(adapter);
    recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
    recyclerView.addOnItemTouchListener(new RecyclerTouchListener(getActivity(), recyclerView, new ClickListener() {
        @Override
        public void onClick(View view, int position) {
            drawerListener.onDrawerItemSelected(view, position);
            mDrawerLayout.closeDrawer(containerView);
        }

        @Override
        public void onLongClick(View view, int position) {

        }
    }));

    return layout;
}


public void setUp(int fragmentId, DrawerLayout drawerLayout, final Toolbar toolbar) {
    containerView = getActivity().findViewById(fragmentId);
    mDrawerLayout = drawerLayout;
    mDrawerToggle = new ActionBarDrawerToggle(getActivity(), drawerLayout, toolbar, R.string.drawer_open, R.string.drawer_close) {
        @Override
        public void onDrawerOpened(View drawerView) {
            super.onDrawerOpened(drawerView);
            getActivity().invalidateOptionsMenu();
        }

        @Override
        public void onDrawerClosed(View drawerView) {
            super.onDrawerClosed(drawerView);
            getActivity().invalidateOptionsMenu();
        }

        @Override
        public void onDrawerSlide(View drawerView, float slideOffset) {
            super.onDrawerSlide(drawerView, slideOffset);
            toolbar.setAlpha(1 - slideOffset / 2);
        }
    };

    mDrawerLayout.setDrawerListener(mDrawerToggle);
    mDrawerLayout.post(new Runnable() {
        @Override
        public void run() {
            mDrawerToggle.syncState();
        }
    });

}

public static interface ClickListener {
    public void onClick(View view, int position);

    public void onLongClick(View view, int position);
}

static class RecyclerTouchListener implements RecyclerView.OnItemTouchListener {

    private GestureDetector gestureDetector;
    private ClickListener clickListener;

    public RecyclerTouchListener(Context context, final RecyclerView recyclerView, final ClickListener clickListener) {
        this.clickListener = clickListener;
        gestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
            @Override
            public boolean onSingleTapUp(MotionEvent e) {
                return true;
            }

            @Override
            public void onLongPress(MotionEvent e) {
                View child = recyclerView.findChildViewUnder(e.getX(), e.getY());
                if (child != null && clickListener != null) {
                    clickListener.onLongClick(child, recyclerView.getChildPosition(child));
                }
            }
        });
    }

    @Override
    public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {

        View child = rv.findChildViewUnder(e.getX(), e.getY());
        if (child != null && clickListener != null && gestureDetector.onTouchEvent(e)) {
            clickListener.onClick(child, rv.getChildPosition(child));
        }
        return false;
    }

    @Override
    public void onTouchEvent(RecyclerView rv, MotionEvent e) {
    }

    @Override
    public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {

    }


}

public interface FragmentDrawerListener {
    public void onDrawerItemSelected(View view, int position);
}
}

activity_main.xml

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">

<android.support.design.widget.CoordinatorLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:id="@+id/container_toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">


        <android.support.design.widget.AppBarLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
        <include
            android:id="@+id/toolbar"
            layout="@layout/toolbar" />
            <android.support.design.widget.TabLayout
                android:id="@+id/tabs"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                app:tabMode="fixed"
                app:tabGravity="fill"/>

        </android.support.design.widget.AppBarLayout>

    </LinearLayout>

    <FrameLayout
        android:id="@+id/container_body"
        android:layout_width="fill_parent"
        android:layout_height="0dp"
        android:layout_weight="1" />

        <android.support.v4.view.ViewPager
            android:id="@+id/viewpager"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"  />


</LinearLayout>


<fragment
    android:id="@+id/fragment_navigation_drawer"
    android:name="com.coastallabs.chat.devchat.activity.FragmentDrawer"
    android:layout_width="@dimen/nav_drawer_width"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    app:layout="@layout/fragment_navigation_drawer"
    tools:layout="@layout/fragment_navigation_drawer" />

Answer 1

You have the container_body FrameLayout configured to take up any remaining vertical space in the layout (layout_height="0dp", layout_weight="1"), but the ViewPager has its layout_height set to match_parent, so it's taking all the space, and squeezing the FrameLayout to 0 height.

As far as the problem with the Fragments changing, you've got two different methods of handling Fragments going on in your code. Since you're using the ViewPager, you don't need to deal with FragmentTransactions. Change the displayView() method in MainActivity as follows:

private void displayView(int position) {
    String title = getString(R.string.app_name);
    switch (position) {
        case 0:
            title = getString(R.string.title_home);
            break;
        case 1:
            title = getString(R.string.title_friends);
            break;
        case 2:
            title = getString(R.string.title_messages);
            break;
        default:
            break;
    }
    getSupportActionBar().setTitle(title);

    viewPager.setCurrentItem(position);
}

You can also remove the container_body FrameLayout from your layout XML.