This is the code for expandable list adapter:
public class ExpandListAdapter extends BaseExpandableListAdapter {
private Context _context;
private List<String> _listDataHeader; // header titles
// child data in format of header title, child title
private HashMap<String, List<String>> _listDataChild;
public ExpandListAdapter(Context context, List<String> listDataHeader,
HashMap<String, List<String>> 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<String>();
listDataChild = new HashMap<String, List<String>>();
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<String> listDataHeader, Map<String,
List<String>> listDataChild) {
// Adding child data
listDataHeader.add("Product1");
listDataHeader.add("product2");
listDataHeader.add("Product3");
// Adding child data
List<String> top = new ArrayList<String>();
top.add("x1");
top.add("x2");
top.add("x3");
top.add("x4");
top.add("x5");
List<String> mid = new ArrayList<String>();
mid.add("y1");
mid.add("y2");
mid.add("y3");
List<String> bottom = new ArrayList<String>();
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 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
android:id="@+id/act_bar"
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">
<!--app:menu="@menu/activity_main_drawer"-->
<ExpandableListView
android:id="@+id/left_drawer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="@dimen/nav_header_height"
android:background="@color/Background"
android:dividerHeight="0dp" />
</android.support.design.widget.NavigationView>
</android.support.v4.widget.DrawerLayout>
xml for ExplistHeader list_group.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:paddingTop="10dp"
android:padding="30dp"
android:background="@color/Background">
<TextView
android:id="@+id/lblListHeader"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingLeft="?
android:attr/expandableListPreferredItemPaddingLeft"
android:textSize="17dp"
android:textColor="@color/colorTextPrimary" />
</LinearLayout>
xml for Explistchild list_item.xml
<?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="55dip"
android:background="@color/Background"
android:orientation="vertical" >
<TextView
android:id="@+id/lblListItem"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="17dip"
android:paddingTop="5dp"
android:paddingBottom="5dp"
android:paddingLeft="?
android:attr/expandableListPreferredChildPaddingLeft" />
</LinearLayout>