Expandable List adapter Android App Source Code

activity_main.xml

===================

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout 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:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical"

android:background="#f4f4f4"

tools:context="com.sam.web.expandablelistview.MainActivity">

<ExpandableListView

android:id="@+id/expandableListViewId"

android:layout_width="match_parent"

android:layout_height="match_parent"></ExpandableListView>

</LinearLayout>

======================================================================

group_layout.xml

====================

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout

xmlns:android="http://schemas.android.com/apk/res/android"

android:padding="8dp"

android:background="#ffbb00"

android:layout_width="match_parent"

android:layout_height="wrap_content">

<TextView

android:paddingLeft="?android:expandableListPreferredItemPaddingLeft"

android:textSize="17sp"

android:id="@+id/headerTextViewId"

android:layout_width="match_parent"

android:layout_height="wrap_content" />

</LinearLayout>

==========================================================================

child_layout.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="55dp">

<TextView

android:paddingLeft="?android:expandableListPreferredChildPaddingLeft"

android:textSize="17sp"

android:paddingBottom="5dp"

android:textColor="#000000"

android:id="@+id/childTextViewId"

android:layout_width="match_parent"

android:layout_height="wrap_content" />

</LinearLayout>

==============================================================================

MainActivity.java

==================

package com.sam.web.expandablelistview;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.widget.ExpandableListView;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

public class MainActivity extends AppCompatActivity {

private ExpandableListView expandableListView;

private CustomAdapter customAdapter;

List<String> listDataHeader;

HashMap<String,List<String>>listDataChild;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

prepareListData();

expandableListView=(ExpandableListView) findViewById(R.id.expandableListViewId);

customAdapter=new CustomAdapter(this,listDataHeader,listDataChild);

expandableListView.setAdapter(customAdapter);

}

private void prepareListData() {

String[] headerString=getResources().getStringArray(R.array.abbreviations_list_header);

String[] childString=getResources().getStringArray(R.array.abbreviations_list_child);

listDataHeader=new ArrayList<>();

listDataChild=new HashMap<>();

for (int i=0; i<headerString.length; i++){

// adding header data

listDataHeader.add(headerString[i]);

List<String> child=new ArrayList<>();

child.add(childString[i]);

listDataChild.put(listDataHeader.get(i),child);

}

============================================================================

CustomAdapter.java

=====================

package com.sam.web.expandablelistview;

import android.content.Context;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.BaseExpandableListAdapter;

import android.widget.TextView;

import java.util.HashMap;

import java.util.List;

/**

* Created by maudud on 1/22/18.

public class CustomAdapter extends BaseExpandableListAdapter {

private Context context;

List<String> listDataHeader;

HashMap<String,List<String>> listDataChild;

public CustomAdapter(Context context, List<String> listDataHeader, HashMap<String, List<String>> listDataChild) {

this.context = context;

this.listDataHeader = listDataHeader;

this.listDataChild = listDataChild;

}

@Override

public int getGroupCount() {

return listDataHeader.size();

}

@Override

public int getChildrenCount(int i) {

return listDataChild.get(listDataHeader.get(i)).size();

}

@Override

public Object getGroup(int i) {

return listDataHeader.get(i);

}

@Override

public Object getChild(int i, int i1) {

return listDataChild.get(listDataHeader.get(i)).get(i1);

}

@Override

public long getGroupId(int i) {

return i;

}

@Override

public long getChildId(int i, int i1) {

return i1;

}

@Override

public boolean hasStableIds() {

return false;

}

@Override

public View getGroupView(int i, boolean b, View view, ViewGroup viewGroup) {

String headerText=(String) getGroup(i);

if(view==null){

LayoutInflater inflater= (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

view=inflater.inflate(R.layout.group_layout,null);

}

TextView textView=view.findViewById(R.id.headerTextViewId);

textView.setText(headerText);

return view;

}

@Override

public View getChildView(int i, int i1, boolean b, View view, ViewGroup viewGroup) {

String childText=(String) getChild(i,i1);

if(view==null){

LayoutInflater inflater= (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

view=inflater.inflate(R.layout.child_layout,null);

}

TextView textView=view.findViewById(R.id.childTextViewId);

textView.setText(childText);

return view;

}

@Override

public boolean isChildSelectable(int groupPosition, int childPosition) {

return false;

}

===============================================================================

strings.xml

=================

<string name="app_name">ExpandableListView</string>

<string-array name="abbreviations_list_header">

</string-array>

<string-array name="abbreviations_list_child">

<item>Advanced audio coding