Default Navigation Drawer View to ExpandableListView

Question

In Android Studio 2.1.2, if i create a default navigation activity I get this view:

Which uses the following activity_main.xml file:

Answer 1

This is the code for expandable list adapter:

public class ExpandListAdapter extends BaseExpandableListAdapter {
private Context _context;
private List _listDataHeader; // header titles
// child data in format of header title, child title
private HashMap> _listDataChild;

public ExpandListAdapter(Context context, List listDataHeader,
                         HashMap> listChildData) {
    this._context = context;
    this._listDataHeader = listDataHeader;
    this._listDataChild = listChildData;
}

@Override
public Object getChild(int groupPosition, int childPosititon) {
    return this._listDataChild.get(this._listDataHeader.get(groupPosition))
            .get(childPosititon);
}

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

@Override
public View getChildView(int groupPosition, final int childPosition,
                         boolean isLastChild, View convertView, ViewGroup parent) {

    final String childText = (String) getChild(groupPosition, childPosition);

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

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

    txtListChild.setText(childText);
    return convertView;
}

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

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

@Override
public int getGroupCount() {
    return this._listDataHeader.size();
}

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

@Override
public View getGroupView(int groupPosition, boolean isExpanded,
                         View convertView, ViewGroup parent) {
    String headerTitle = (String) getGroup(groupPosition);
    if (convertView == null) {
        LayoutInflater infalInflater = (LayoutInflater) this._context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = infalInflater.inflate(R.layout.list_group, null);
    }

    TextView lblListHeader = (TextView) convertView
            .findViewById(R.id.lblListHeader);
    lblListHeader.setTypeface(null, Typeface.BOLD);
    lblListHeader.setText(headerTitle);

    return convertView;
}

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

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

In your activity:

     private void enableExpandableList() {
      listDataHeader = new ArrayList();
      listDataChild = new HashMap>();
    expListView = (ExpandableListView) findViewById(R.id.left_drawer);

    prepareListData(listDataHeader, listDataChild);
    listAdapter = new ExpandListAdapter(this, listDataHeader, listDataChild);
    // setting list adapter
    expListView.setAdapter(listAdapter);

    expListView.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {

        @Override
        public boolean onGroupClick(ExpandableListView parent, View v,
                                    int groupPosition, long id) {
            // Toast.makeText(getApplicationContext(),
            // "Group Clicked " + listDataHeader.get(groupPosition),
            // Toast.LENGTH_SHORT).show();
            return false;
        }
    });
    // Listview Group expanded listener
    expListView.setOnGroupExpandListener(new ExpandableListView.OnGroupExpandListener() {

        @Override
        public void onGroupExpand(int groupPosition) {
            Toast.makeText(getApplicationContext(),
                    listDataHeader.get(groupPosition) + " Expanded",
                    Toast.LENGTH_SHORT).show();
        }
    });

    // Listview Group collasped listener
    expListView.setOnGroupCollapseListener(new ExpandableListView.OnGroupCollapseListener() {

        @Override
        public void onGroupCollapse(int groupPosition) {
            Toast.makeText(getApplicationContext(),
                    listDataHeader.get(groupPosition) + " Collapsed",
                    Toast.LENGTH_SHORT).show();

        }
    });

    // Listview on child click listener
    expListView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {

        @Override
        public boolean onChildClick(ExpandableListView parent, View v,
                                    int groupPosition, int childPosition, long id) {
            // TODO Auto-generated method stub
            // Temporary code:

            // till here
            Toast.makeText(
                    getApplicationContext(),
                    listDataHeader.get(groupPosition)
                            + " : "
                            + listDataChild.get(
                            listDataHeader.get(groupPosition)).get(
                            childPosition), Toast.LENGTH_SHORT)
                    .show();
            return false;
        }
    });}

Method to create List with data:

   private void prepareListData(List listDataHeader, Map> listDataChild) {


    // Adding child data
    listDataHeader.add("Product1");
    listDataHeader.add("product2");
    listDataHeader.add("Product3");

    // Adding child data
    List top = new ArrayList();
    top.add("x1");
    top.add("x2");
    top.add("x3");
    top.add("x4");
    top.add("x5");


    List mid = new ArrayList();
    mid.add("y1");
    mid.add("y2");
    mid.add("y3");

    List bottom = new ArrayList();
    bottom.add("z1");
    bottom.add("z2");
    bottom.add("z3");



    listDataChild.put(listDataHeader.get(0), top); // Header, Child data
    listDataChild.put(listDataHeader.get(1), mid);
    listDataChild.put(listDataHeader.get(2), bottom);
}

this code in layout xml

xml for ExplistHeader list_group.xml

xml for Explistchild list_item.xml