Adding expandableListView to NavigationView

I have a menu defined in xml:

<group android:checkableBehavior="single" android:id="@+id/group">
    <item
        android:id="@+id/grades"
        android:icon="@drawable/ic_font_download_black_48dp"
        android:checked="false"
        android:title="Grades" >
        <menu>
            <item
                android:id="@+id/mp1"
                android:icon="@drawable/ic_looks_one_black_24dp"
                android:checked="false"
                android:title="MP1" />
            <item
                android:id="@+id/mp2"
                android:icon="@drawable/ic_looks_two_black_24dp"
                android:checked="false"
                android:title="MP2" />
            <item
                android:id="@+id/mp3"
                android:icon="@drawable/ic_font_download_black_48dp"
                android:checked="false"
                android:title="MP3" />
            <item
                android:id="@+id/mp4"
                android:icon="@drawable/ic_font_download_black_48dp"
                android:checked="false"
                android:title="MP4" />
        </menu>
    </item>
    <item
        android:id="@+id/schedule"
        android:icon="@drawable/ic_event_black_48dp"
        android:checked="false"
        android:title="Schedule" />
    <item
        android:id="@+id/attendance"
        android:icon="@drawable/ic_assignment_ind_black_48dp"
        android:checked="false"
        android:title="Attendance" />
    <item
        android:id="@+id/assignments"
        android:icon="@drawable/ic_assignment_black_48dp"
        android:checked="false"
        android:title="Assignments" />
    <item
        android:id="@+id/studentInfo"
        android:icon="@drawable/ic_account_circle_black_48dp"
        android:checked="false"
        android:title="Student Details" />
</group>
<group android:id="@+id/group2" android:checkableBehavior="single">
    <item
        android:id="@+id/placeholder"
        android:icon="@drawable/ic_android_black_48dp"
        android:checked="false"
        android:title="Placeholder" />
    <item
        android:id="@+id/placeholder2"
        android:icon="@drawable/ic_android_black_48dp"
        android:checked="false"
        android:title="Placeholder" />
</group>

which adds a submenu which looks like this: enter image description here

However, I am unable to make this submenu look like this: (collapsable)

enter image description here

I now know that I need to implement an expandableListView, but I am not sure how this would fit in with the menu I have already created.

Any advice is appreciated


Solution 1:

You can create it using custom ListView.

See the code below activity_navigation_view.xml

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

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!" />

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

        <ExpandableListView
            android:id="@+id/navigationmenu"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_marginTop="192dp"
            android:background="@android:color/white">
        </ExpandableListView>
    </android.support.design.widget.NavigationView>
</android.support.v4.widget.DrawerLayout>

The adapter for expandable list view is as follows.

ExpandableListAdapter.java

import android.content.Context;
import android.graphics.Typeface;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.HashMap;
import java.util.List;

public class ExpandableListAdapter extends BaseExpandableListAdapter {
    private Context mContext;
    private List<ExpandedMenuModel> mListDataHeader; // header titles

    // child data in format of header title, child title
    private HashMap<ExpandedMenuModel, List<String>> mListDataChild;
    ExpandableListView expandList;

    public ExpandableListAdapter(Context context, List<ExpandedMenuModel> listDataHeader, HashMap<ExpandedMenuModel, List<String>> listChildData, ExpandableListView mView) {
        this.mContext = context;
        this.mListDataHeader = listDataHeader;
        this.mListDataChild = listChildData;
        this.expandList = mView;
    }

    @Override
    public int getGroupCount() {
        int i = mListDataHeader.size();
        Log.d("GROUPCOUNT", String.valueOf(i));
        return this.mListDataHeader.size();
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        int childCount = 0;
        if (groupPosition != 2) {
            childCount = this.mListDataChild.get(this.mListDataHeader.get(groupPosition))
                .size();
        }
        return childCount;
    }

    @Override
    public Object getGroup(int groupPosition) {
        return this.mListDataHeader.get(groupPosition);
    }

    @Override
    public Object getChild(int groupPosition, int childPosition) {
        Log.d("CHILD", mListDataChild.get(this.mListDataHeader.get(groupPosition))
            .get(childPosition).toString());
        return this.mListDataChild.get(this.mListDataHeader.get(groupPosition))
            .get(childPosition);
    }

    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    @Override
    public boolean hasStableIds() {
        return false;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        ExpandedMenuModel headerTitle = (ExpandedMenuModel) getGroup(groupPosition);
        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this.mContext
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.listheader, null);
        }
        TextView lblListHeader = (TextView) convertView
            .findViewById(R.id.submenu);
        ImageView headerIcon = (ImageView) convertView.findViewById(R.id.iconimage);
        lblListHeader.setTypeface(null, Typeface.BOLD);
        lblListHeader.setText(headerTitle.getIconName());
        headerIcon.setImageResource(headerTitle.getIconImg());
        return convertView;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
        final String childText = (String) getChild(groupPosition, childPosition);

        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this.mContext
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.list_submenu, null);
        }

        TextView txtListChild = (TextView) convertView
            .findViewById(R.id.submenu);

        txtListChild.setText(childText);

        return convertView;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }
}

list_submenu.xml is as follows.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:orientation="vertical">

    <TextView
        android:id="@+id/submenu"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="20dp"
        android:padding="10dp"
        android:textColor="#000000"
        android:textSize="18sp"/>
</LinearLayout>

listheader.xml is as follows.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="2dp"
              android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginLeft="20dp"
        android:orientation="horizontal">

        <ImageView
            android:id="@+id/iconimage"
            android:layout_width="50dp"
            android:layout_height="50dp"
            android:paddingBottom="10dp"
            android:paddingLeft="10dp"
            android:paddingTop="10dp"/>

        <TextView
            android:id="@+id/submenu"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:padding="10dp"
            android:textColor="#000000"
            android:textSize="20sp"/>

    </LinearLayout>

</LinearLayout>

In your navigation view activity, set the adapter for the expandable list view. NavigationViewActivity.java

public class NavigationViewActivity extends AppCompatActivity {

    private DrawerLayout mDrawerLayout;
    ExpandableListAdapter mMenuAdapter;
    ExpandableListView expandableList;
    List<ExpandedMenuModel> listDataHeader;
    HashMap<ExpandedMenuModel, List<String>> listDataChild;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_navigation_view);
        final ActionBar ab = getSupportActionBar();
        /* to set the menu icon image*/
        ab.setHomeAsUpIndicator(android.R.drawable.ic_menu_add);
        ab.setDisplayHomeAsUpEnabled(true);
        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        expandableList = (ExpandableListView) findViewById(R.id.navigationmenu);
        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);

        if (navigationView != null) {
            setupDrawerContent(navigationView);
        }

        prepareListData();
        mMenuAdapter = new ExpandableListAdapter(this, listDataHeader, listDataChild, expandableList);

        // setting list adapter
        expandableList.setAdapter(mMenuAdapter);

        expandableList.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
            @Override
            public boolean onChildClick(ExpandableListView expandableListView, View view, int i, int i1, long l) {
                //Log.d("DEBUG", "submenu item clicked");
                return false;
            }
        });
        expandableList.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {
            @Override
            public boolean onGroupClick(ExpandableListView expandableListView, View view, int i, long l) {
                //Log.d("DEBUG", "heading clicked");
                return false;
            }
        });
    }

    private void prepareListData() {
        listDataHeader = new ArrayList<ExpandedMenuModel>();
        listDataChild = new HashMap<ExpandedMenuModel, List<String>>();

        ExpandedMenuModel item1 = new ExpandedMenuModel();
        item1.setIconName("heading1");
        item1.setIconImg(android.R.drawable.ic_delete);
        // Adding data header
        listDataHeader.add(item1);

        ExpandedMenuModel item2 = new ExpandedMenuModel();
        item2.setIconName("heading2");
        item2.setIconImg(android.R.drawable.ic_delete);
        listDataHeader.add(item2);

        ExpandedMenuModel item3 = new ExpandedMenuModel();
        item3.setIconName("heading3");
        item3.setIconImg(android.R.drawable.ic_delete);
        listDataHeader.add(item3);

        // Adding child data
        List<String> heading1 = new ArrayList<String>();
        heading1.add("Submenu of item 1");

        List<String> heading2 = new ArrayList<String>();
        heading2.add("Submenu of item 2");
        heading2.add("Submenu of item 2");
        heading2.add("Submenu of item 2");

        listDataChild.put(listDataHeader.get(0), heading1);// Header, Child data
        listDataChild.put(listDataHeader.get(1), heading2);

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                mDrawerLayout.openDrawer(GravityCompat.START);
                return true;
        }
        return super.onOptionsItemSelected(item);
    }

    private void setupDrawerContent(NavigationView navigationView) {
        //revision: this don't works, use setOnChildClickListener() and setOnGroupClickListener() above instead
        navigationView.setNavigationItemSelectedListener(
            new NavigationView.OnNavigationItemSelectedListener() {
                @Override
                public boolean onNavigationItemSelected(MenuItem menuItem) {
                    menuItem.setChecked(true);
                    mDrawerLayout.closeDrawers();
                    return true;
                }
            });
    }

}

ExpandedMenuModel class contains menu item details as follow.

ExpandedMenuModel.java

public class ExpandedMenuModel {

    String iconName = "";
    int iconImg = -1; // menu icon resource id

    public String getIconName() {
        return iconName;
    }
    public void setIconName(String iconName) {
        this.iconName = iconName;
    }
    public int getIconImg() {
        return iconImg;
    }
    public void setIconImg(int iconImg) {
        this.iconImg = iconImg;
    } 
}

[Side note]:

  1. Don't put import android.widget.ExpandableListAdapter; in NavigationViewActivity.java. This mistake can happen if you resolve import by Alt+Enter before create the file ExpandableListAdapter.java.

  2. Put compile 'com.android.support:design:23.3.0' in app's build.gradle, it's for "NavigationView" and its "import android.support.design.widget.NavigationView;" After that (Might require rebuild first) you can do Alt-Enter to resolve import.

The file hierarchy should look like (3 .java and 3 .xml from above):

enter image description here

The output screenshot:

enter image description here

Solution 2:

MainActivity.java

import android.graphics.Color;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.NavigationView;
import android.support.design.widget.Snackbar;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.ExpandableListView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

public class MainActivity extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {

    View view_Group;
    private DrawerLayout mDrawerLayout;
    ExpandableListAdapter mMenuAdapter;
    ExpandableListView expandableList;
    List<String> listDataHeader;
    HashMap<String, List<String>> listDataChild;
    //Icons, use as you want
    static int[] icon = { R.drawable.ico1, R.drawable.ico1,
            R.drawable.ico1, R.drawable.ico1,
            R.drawable.ico1, R.drawable.ico1, R.drawable.ico1};
    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        super.onWindowFocusChanged(hasFocus);
        if(android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.JELLY_BEAN_MR2) {
            expandableList.setIndicatorBounds(expandableList.getRight()- 80, expandableList.getWidth());
        } else {
            expandableList.setIndicatorBoundsRelative(expandableList.getRight()- 80, expandableList.getWidth());
        }
    }

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

        supportRequestWindowFeature(Window.FEATURE_ACTION_BAR_OVERLAY);
        //requestWindowFeature(Window.FEATURE_NO_TITLE);
        this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

        setContentView(R.layout.activity_main);

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

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.setDrawerListener(toggle);
        toggle.syncState();

        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        expandableList = (ExpandableListView) findViewById(R.id.navigationmenu);

        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);
        navigationView.setItemIconTintList(null);

        if (navigationView != null) {
            setupDrawerContent(navigationView);
        }
        prepareListData();
        mMenuAdapter = new ExpandableListAdapter(this, listDataHeader, listDataChild);

        // setting list adapter
        expandableList.setAdapter(mMenuAdapter);

        expandableList.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
            @Override
            public boolean onChildClick(ExpandableListView expandableListView,
                                        View view,
                                        int groupPosition,
                                        int childPosition, long id) {
                //Log.d("DEBUG", "submenu item clicked");
                Toast.makeText(MainActivity.this,
                        "Header: "+String.valueOf(groupPosition) +
                        "\nItem: "+ String.valueOf(childPosition), Toast.LENGTH_SHORT)
                        .show();
                view.setSelected(true);
                if (view_Group != null) {
                    view_Group.setBackgroundColor(Color.parseColor("#ffffff"));
                }
                view_Group = view;
                view_Group.setBackgroundColor(Color.parseColor("#DDDDDD"));
                mDrawerLayout.closeDrawers();
                return false;
            }
        });
        expandableList.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {
            @Override
            public boolean onGroupClick(ExpandableListView expandableListView, View view, int i, long l) {
                //Log.d("DEBUG", "heading clicked");
                return false;
            }
        });

    }

    private void prepareListData() {
        listDataHeader = new ArrayList<String>();
        listDataChild = new HashMap<String, List<String>>();

        // Adding data header
        listDataHeader.add("menu1");
        listDataHeader.add("menu2");
        listDataHeader.add("menu3");
        listDataHeader.add("menu4");
        listDataHeader.add("menu5");
        listDataHeader.add("menu6");
        listDataHeader.add("menu7");

        // Adding child data
        List<String> heading1 = new ArrayList<String>();
        heading1.add("Submenu");
        heading1.add("Submenu");
        heading1.add("Submenu");

        List<String> heading2 = new ArrayList<String>();
        heading2.add("Submenu");
        heading2.add("Submenu");
        heading2.add("Submenu");
        heading2.add("Submenu");

        List<String> heading3 = new ArrayList<String>();
        heading3.add("Submenu");
        heading3.add("Submenu");

        List<String> heading4 = new ArrayList<String>();
        heading4.add("Submenu");
        heading4.add("Submenu");

        List<String> heading5 = new ArrayList<String>();
        heading5.add("Submenu");
        heading5.add("Submenu");
        heading5.add("Submenu");

        List<String> heading6 = new ArrayList<String>();
        heading6.add("Submenu");
        heading6.add("Submenu");

        List<String> heading7 = new ArrayList<String>();
        heading4.add("Submenu");
        heading4.add("Submenu");

        listDataChild.put(listDataHeader.get(0), heading1);// Header, Child data
        listDataChild.put(listDataHeader.get(1), heading2);
        listDataChild.put(listDataHeader.get(2), heading3);
        listDataChild.put(listDataHeader.get(3), heading4);
        listDataChild.put(listDataHeader.get(4), heading5);
        listDataChild.put(listDataHeader.get(5), heading6);
        listDataChild.put(listDataHeader.get(6), heading7);
    }

    private void setupDrawerContent(NavigationView navigationView) {
        navigationView.setNavigationItemSelectedListener(
            new NavigationView.OnNavigationItemSelectedListener() {
                @Override
                public boolean onNavigationItemSelected(MenuItem menuItem) {
                    menuItem.setChecked(true);
                    mDrawerLayout.closeDrawers();
                    return true;
                }
            });
    }

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.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.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();

        /*if (id == R.id.nav_camera) {
            // Handle the camera action
        } else if (id == R.id.nav_gallery) {

        } else if (id == R.id.nav_slideshow) {

        } else if (id == R.id.nav_manage) {

        } else if (id == R.id.nav_share) {

        } else if (id == R.id.nav_send) {

        }*/

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }
}

ExpandableListAdapter.java

import android.content.Context;
import android.graphics.Typeface;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.HashMap;
import java.util.List;

/**
 * Created by Administrator on 9/1/16.
 */
public class ExpandableListAdapter extends BaseExpandableListAdapter {
    private Context mContext;
    private List<String> mListDataHeader; // header titles

    // child data in format of header title, child title
    private HashMap<String, List<String>> mListDataChild;
    ExpandableListView expandList;

    public ExpandableListAdapter(Context context,
                 List<String> listDataHeader,
                 HashMap<String,
                 List<String>> listChildData
    //        ,ExpandableListView mView
    )
    {
        this.mContext = context;
        this.mListDataHeader = listDataHeader;
        this.mListDataChild = listChildData;
        //this.expandList = mView;
    }

    @Override
    public int getGroupCount() {
        int i = mListDataHeader.size();
        //Log.d("GROUPCOUNT", String.valueOf(i));
        return i;
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return this.mListDataChild.get(
                this.mListDataHeader.get(groupPosition))
                .size();
    }

    @Override
    public Object getGroup(int groupPosition) {
        return this.mListDataHeader.get(groupPosition);
    }

    @Override
    public Object getChild(int groupPosition, int childPosition) {
        //Log.d("CHILD", mListDataChild.get(this.mListDataHeader.get(groupPosition))
        //        .get(childPosition).toString());
        return this.mListDataChild.get(
                this.mListDataHeader.get(groupPosition))
                .get(childPosition);
    }

    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    @Override
    public boolean hasStableIds() {
        return false;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        String headerTitle = (String) getGroup(groupPosition);
        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this.mContext
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.listheader, null);
        }
        TextView lblListHeader = (TextView) convertView
                .findViewById(R.id.submenu);
        ImageView headerIcon = (ImageView) convertView.findViewById(R.id.iconimage);
        lblListHeader.setTypeface(null, Typeface.BOLD);
        lblListHeader.setText(headerTitle);
        //lblListHeader.setText(headerTitle.getIconName());
        headerIcon.setImageResource(MainActivity.icon[groupPosition]);
        return convertView;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
        final String childText = (String) getChild(groupPosition, childPosition);

        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this.mContext
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.list_submenu, null);
        }

        TextView txtListChild = (TextView) convertView
                .findViewById(R.id.submenu);

        txtListChild.setText(childText);

        return convertView;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }
}

list_submenu.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout   xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="10dp"
        android:textColor="#000000"
        android:layout_marginLeft="44dp"
        android:textSize="14sp"
        android:id="@+id/submenu"/>
</LinearLayout>

listheader.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="2dp"
    android:orientation="vertical"
    xmlns:android="http://schemas.android.com/apk/res/android" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <ImageView
            android:layout_width="45dp"
            android:layout_height="45dp"
            android:paddingBottom="10dp"
            android:paddingLeft="10dp"
            android:paddingTop="10dp"
            android:id="@+id/iconimage"/>
        <TextView
            android:layout_width="match_parent"
            android:layout_height="45dp"
            android:padding="10dp"
            android:textColor="#000000"
            android:textSize="16sp"
            android:id="@+id/submenu"
            android:gravity="center_vertical" />
    </LinearLayout>

</LinearLayout>

activity_main.xml

<?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"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:openDrawer="start">

    <include
        layout="@layout/app_bar_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <android.support.design.widget.NavigationView
        android:id="@+id/nav_view"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:fitsSystemWindows="true"
        app:headerLayout="@layout/nav_header_main">

        <ExpandableListView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@android:color/white"
            android:layout_marginTop="160dp"
            android:choiceMode="singleChoice"
            android:id="@+id/navigationmenu">
        </ExpandableListView>

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

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

Hope this will work and some other files are in this example... I think you can solve those matters... It will look like as you are wanted...