Android ExpandableListView Example

The Android Development Tutorials blog contains Basic as well as Advanced android tutorials.Go to Android Development Tutorials to get list of all Android Tutorials.

ExpandableListView

is a view that shows items in a vertically scrolling two-level list. This differs from the ListView by allowing two levels: groups which can individually be expanded to show its children.
Level 1 contains Parent items and Level 2 contains Child items.  The items are filled/populated from the ExpandableListAdapter associated with the Parent and Child view.

In below snapshot Fruits, Flowers, Animals, Birds are Parent Items and Apple,Mango,Banana,Orange,Lion,Tiger etc are Child Items.

 ExpandableListView Example

     In this example we will learn how to use ExpandableListView  and how to populate it's item through        ExpandableListAdapter

Steps:
1:  Create xml for Parent Item
2: Create xml for Child Item
3: Create MainActivity and populate the data for Parent and Child Items
4: Create ExpandableListAdapter class and implement getGroupView and getChildView  methods according to your need.

Also add clickListener in getChildView method to handle click events on child items.

Step1:

parent_view.xml

<CheckedTextView
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/textViewGroupName"
        android:layout_width="wrap_content"
        android:layout_height="60dp"
        android:layout_marginLeft="5dp"
        android:gravity="center_vertical"
        android:text="@string/hello_world"
        android:textSize="18dp"
        android:textColor="#FFFFFF"
        android:padding="10dp"
        android:textSelectHandleLeft="@string/hello_world"
        android:background="#009999"
        android:textStyle="bold" />

Step 2:

child_view.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="40dp"
    android:background="#99D6D6"
    android:clickable="true"
    android:orientation="vertical"
    android:paddingLeft="40dp"
    tools:context=".MainActivity" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="39dp"
        android:gravity="center_vertical" >

        <ImageView
            android:id="@+id/childImage"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:layout_margin="5dp"
            android:background="@drawable/ic_launcher"
            android:contentDescription="@string/hello_world" />

        <TextView
            android:id="@+id/textViewChild"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dp"
            android:text="@string/hello_world"
            android:textSize="16sp"
            android:textColor="#1919A3"
            android:textStyle="bold" />
    </LinearLayout>

    <View
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:background="@android:color/white" />

</LinearLayout>

Step 3:

ExpandableListMainActivity.java

public class ExpandableListMainActivity extends ExpandableListActivity
{
    // Create ArrayList to hold parent Items and Child Items
    private ArrayList<String> parentItems = new ArrayList<String>();
    private ArrayList<Object> childItems = new ArrayList<Object>();

    @Override
    public void onCreate(Bundle savedInstanceState)
    {

        super.onCreate(savedInstanceState);

       
        // Create Expandable List and set it's properties
        ExpandableListView expandableList = getExpandableListView();
        expandableList.setDividerHeight(2);
        expandableList.setGroupIndicator(null);
        expandableList.setClickable(true);

        // Set the Items of Parent
        setGroupParents();
        // Set The Child Data
        setChildData();

        // Create the Adapter
        MyExpandableAdapter adapter = new MyExpandableAdapter(parentItems, childItems);

        adapter.setInflater((LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE), this);
       
        // Set the Adapter to expandableList
        expandableList.setAdapter(adapter);
        expandableList.setOnChildClickListener(this);
    }

    // method to add parent Items
    public void setGroupParents()
    {
        parentItems.add("Fruits");
        parentItems.add("Flowers");
        parentItems.add("Animals");
        parentItems.add("Birds");
    }

    // method to set child data of each parent
    public void setChildData()
    {

        // Add Child Items for Fruits
        ArrayList<String> child = new ArrayList<String>();
        child.add("Apple");
        child.add("Mango");
        child.add("Banana");
        child.add("Orange");
       
        childItems.add(child);

        // Add Child Items for Flowers
        child = new ArrayList<String>();
        child.add("Rose");
        child.add("Lotus");
        child.add("Jasmine");
        child.add("Lily");
       
        childItems.add(child);

        // Add Child Items for Animals
        child = new ArrayList<String>();
        child.add("Lion");
        child.add("Tiger");
        child.add("Horse");
        child.add("Elephant");
       
        childItems.add(child);

        // Add Child Items for Birds
        child = new ArrayList<String>();
        child.add("Parrot");
        child.add("Sparrow");
        child.add("Peacock");
        child.add("Pigeon");
       
        childItems.add(child);
    }

}

Step 4:

MyExpandableAdapter.java

public class MyExpandableAdapter extends BaseExpandableListAdapter
{

    private Activity activity;
    private ArrayList<Object> childtems;
    private LayoutInflater inflater;
    private ArrayList<String> parentItems, child;

    // constructor
    public MyExpandableAdapter(ArrayList<String> parents, ArrayList<Object> childern)
    {
        this.parentItems = parents;
        this.childtems = childern;
    }

    public void setInflater(LayoutInflater inflater, Activity activity)
    {
        this.inflater = inflater;
        this.activity = activity;
    }
   
    // method getChildView is called automatically for each child view.
    //  Implement this method as per your requirement
    @Override
    public View getChildView(int groupPosition, final int childPosition, boolean isLastChild, View convertView, ViewGroup parent)
    {

        child = (ArrayList<String>) childtems.get(groupPosition);

        TextView textView = null;

        if (convertView == null) {
            convertView = inflater.inflate(R.layout.child_view, null);
        }
   
         // get the textView reference and set the value
        textView = (TextView) convertView.findViewById(R.id.textViewChild);
        textView.setText(child.get(childPosition));

        // set the ClickListener to handle the click event on child item
        convertView.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View view) {
                Toast.makeText(activity, child.get(childPosition),
                        Toast.LENGTH_SHORT).show();
            }
        });
        return convertView;
    }

    // method getGroupView is called automatically for each parent item
    // Implement this method as per your requirement
    @Override
    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent)
    {

        if (convertView == null) {
            convertView = inflater.inflate(R.layout.parent_view, null);
        }

        ((CheckedTextView) convertView).setText(parentItems.get(groupPosition));
        ((CheckedTextView) convertView).setChecked(isExpanded);

        return convertView;
    }

    @Override
    public Object getChild(int groupPosition, int childPosition)
    {
        return null;
    }

    @Override
    public long getChildId(int groupPosition, int childPosition)
    {
        return 0;
    }

    @Override
    public int getChildrenCount(int groupPosition)
    {
        return ((ArrayList<String>) childtems.get(groupPosition)).size();
    }

    @Override
    public Object getGroup(int groupPosition)
    {
        return null;
    }

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

    @Override
    public void onGroupCollapsed(int groupPosition)
    {
        super.onGroupCollapsed(groupPosition);
    }

    @Override
    public void onGroupExpanded(int groupPosition)
    {
        super.onGroupExpanded(groupPosition);
    }

    @Override
    public long getGroupId(int groupPosition)
    {
        return 0;
    }

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

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

}

 

 

New Advance Topics:                   Android LiveWallpaer Tutorial
Android ImageSwitcher                    Android TextSwitcher                                Android ViewFlipper
Android Gesture Detector               Handling/Detecting Swipe Events                Gradient Drawable
Detecting Missed Calls                    Hide Title Bar                                           GridView Animation
Android AlarmManager                 Android BootReceiver                       Vibrate Phone In a Desirable Pattern    
Developing for Different Screen Sizes           Showing Toast for Longer Time       Publishing your App
How to publish Android App on Google Play
Android TextWatcher                               Android ExpandableListView

 Beginning With Android
      Android : Introduction(What is Android)                                                              Configuring Eclipse for Android Development
     Creating Your First Android Project                                           Understanding Android Manifest File of your android app

 Advance Android Topics                                                              Customizing Android Views

      Customizing Toast In Android                                                        Customizing Radio Buttons

      Showing Toast for Longer Time                                                      Customizing Checkboxes In Android

      Customizing the Display Time of Toast                                           Customizing ProgressBar

      Using TimePickerDialog and DatePickerDialog In android                 Customizing Toast In Android

      Animating A Button In Android

      Populating ListView With DataBase                                           Android Animation

      Increasin Size of Checkboxes                                                   Using Android ImageSwitcher  

      Android ProgressBar                                                                 Using Android TextSwitcher

      Designing For Different Screen Sizes                                            GridView Animation

      Handling Keyboard Events                                                        Animating A Button In Android

Alarm Manager     
Android AlarmManger
Scheduling Task Using AlarmManger

Working With Layouts                                                                Working With Views

Understanding Layouts in Android                                                   Using Buttons and EditText in Android
Working with Linear Layout (With Example)                                     Using CheckBoxes in Android
Nested Linear Layout (With Example)                                              Using AutoCompleteTextView in Android                                                                                          Grid View
Relative Layout In Android                                                               ListView
Table Layout                                                                                   Android ProgressBar
Frame Layout(With Example)                                                          Customizing ProgressBar
Absolute Layout                                                                             Customizing Radio Buttons
Grid Layout                                                                                    Customizing Checkboxes In Android

Android Advance Views
Android Spinner                                                                           Android GalleryView
Android TabWidget                                                                      Android ExpandableListView

Android Components                                                                 Dialogs In Android

Activity In Android                                                                    Working With Alert Dialog
Activity Life Cycle                                                                    Adding Radio Buttons In Dialog
Starting Activity For Result                                                       Adding Check Boxes In Dialog
Sending Data from One Activity to Other in Android                    Creating Customized Dialogs in Android
Returning Result from Activity                                                   Creating Dialog To Collect User Input
Android : Service                                                                     DatePicker and TimePickerDialog
BroadcastReceiver                                                                   Using TimePickerDialog and DatePickerDialog In android

Menus In Android                                                                ListView:
Creating Option Menu                                                               Populating ListView With DataBase
Creating Context Menu In Android                                              Populating ListView with ArrayList
                                                                                               ListView with Custom Adapter

Toast                                                                                      Working With SMS
Customizing Toast In Android                                                       How to Send SMS in Android
Customizing the Display Time of Toast                                        How To Receive SMS
Customizing Toast At Runtime                                                  Accessing Inbox In Android
Adding Image in Toast
Showing Toast for Longer Time


TelephonyManager                                                            Storage: Storing Data In Android
Using Telephony Manager In Android                                          SharedPreferences In Android
                                                                                              Reading and Writing files to Internal Stoarage

Working With Incoming Calls                                       DataBase :  Introduction of SQLiteDataBase
How To Handle Incoming Calls in Android                                Working With Database in Android
How to Forward an Incoming Call In Android                            Creating Table In Android
CALL States In Android                                                          Inserting, Deleting and Updating Records In Table in Android


Miscellaneous
Notifications In Android
How To Vibrate The Android Phone
Sending Email In Android
Opening a webpage In Browser
How to Access PhoneBook In Android
Prompt User Input with an AlertDialog
How to Hide Title Bar In Android
How to show an Activity in Landscape or Portrait Mode only.
How to Set an Image as Wallpaper.