android - Adding expandableListView to NavigationView

Question

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:

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

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

Answer 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.

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