ExpandableListView with icon

This example display icon in ExpandableListView.

ExpandableListView with icon

Modify /res/layout/group_layout.xml to add a TextView to display our icon.

<?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:background="#000000"
    android:orientation="horizontal"
    android:padding="8dp" >

    <ImageView
        android:id="@+id/groupimage"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
        
        
    <TextView
        android:id="@+id/group"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:textColor="@android:color/white"
        android:textStyle="bold" />

</LinearLayout>

Modify getGroupView() in MyBaseExpandableListAdapter.java to set ImageView.

package com.example.androidexpandablelistview;

import java.util.HashMap;
import java.util.List;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.drawable.Drawable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class MyBaseExpandableListAdapter extends BaseExpandableListAdapter {
 
 private Context context;
    private List<String> listGroup;
    private HashMap<String, List<String>> listChild;

 public MyBaseExpandableListAdapter(Context c, List<String> lg,
            HashMap<String, List<String>> lc) {
  context = c;
  listGroup = lg;
  listChild = lc;
 }

 @Override
 public Object getChild(int groupPosition, int childPosition) {
  return listChild.get(listGroup.get(groupPosition)).get(childPosition);
 }

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

 @Override
 public View getChildView(int groupPosition, int childPosition, 
   boolean isLastChild, View convertView, ViewGroup parent) {
  
        if (convertView == null) {
            LayoutInflater infalInflater = 
              (LayoutInflater)context
              .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.item_layout, null);
        }
 
        TextView textViewItem = 
          (TextView)convertView.findViewById(R.id.item);
        
        String text = (String)getChild(groupPosition, childPosition);
 
        textViewItem.setText(text);
        return convertView;
 }

 @Override
 public int getChildrenCount(int groupPosition) {
  return listChild.get(listGroup.get(groupPosition)).size();
 }

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

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

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

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

        //get application resource/drawable not in Activity class, using context
        Resources contextResources = context.getResources();
        Drawable groupDrawable = contextResources.getDrawable(R.drawable.ic_launcher);
        //Set ImageView
        ImageView groupImage = (ImageView)convertView.findViewById(R.id.groupimage);
        groupImage.setImageDrawable(groupDrawable);
 
        TextView textViewGroup = (TextView)convertView.findViewById(R.id.group);
        textViewGroup.setText(textGroup);
 
        return convertView;
 }

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

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

}

Remark: Alternatively, you can set android:src in XML directly.

- For MainActivity.java and activity_main.xml, refer to last post "Detect user action on ExpandableListView, with various Listeners".
- For item_layout.xml, refer to the post "ExpandableListView example".

Detect user action on ExpandableListView, with various Listeners

This example implement various Listeners (OnChildClickListener, OnGroupClickListener, OnGroupCollapseListener and OnGroupExpandListener) to monitor user click on ExpandableListView.

ExpandableListView with Listeners

MainActivity.java

package com.example.androidexpandablelistview;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.ExpandableListView;
import android.widget.ExpandableListView.OnChildClickListener;
import android.widget.ExpandableListView.OnGroupClickListener;
import android.widget.ExpandableListView.OnGroupCollapseListener;
import android.widget.ExpandableListView.OnGroupExpandListener;
import android.widget.TextView;

public class MainActivity extends Activity {
 
 MyBaseExpandableListAdapter myBaseExpandableListAdapter;
    ExpandableListView myExpandableListView;
    List<String> myListForGroup;
    HashMap<String, List<String>> myMapForChild;
 
    TextView info;
    
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  info = (TextView)findViewById(R.id.info);
  
  myExpandableListView = (ExpandableListView)
    findViewById(R.id.myexpandablelistview);
 
        initData();
 
        myBaseExpandableListAdapter = new 
          MyBaseExpandableListAdapter(this, myListForGroup, myMapForChild);
 
        myExpandableListView.setAdapter(myBaseExpandableListAdapter);
        
        myExpandableListView.setOnChildClickListener(myOnChildClickListener);
        myExpandableListView.setOnGroupClickListener(myOnGroupClickListener);
        myExpandableListView.setOnGroupCollapseListener(myOnGroupCollapseListener);
        myExpandableListView.setOnGroupExpandListener(myOnGroupExpandListener);
 }
 
 private void initData() {
  myListForGroup = new ArrayList<String>();
  myMapForChild = new HashMap<String, List<String>>();

        List<String> listGroupA = new ArrayList<String>();
        listGroupA.add("A - 1");
        listGroupA.add("A - 2");
        listGroupA.add("A - 3");

        List<String> listGroupB = new ArrayList<String>();
        listGroupB.add("B - 1");
 
        List<String> listGroupC = new ArrayList<String>();
        listGroupC.add("C - 1");
        listGroupC.add("C - 2");
        
        myListForGroup.add("Group A");
        myListForGroup.add("Group B");
        myListForGroup.add("Group C");
        
        myMapForChild.put(myListForGroup.get(0), listGroupA);
        myMapForChild.put(myListForGroup.get(1), listGroupB);
        myMapForChild.put(myListForGroup.get(2), listGroupC);
    }
 
 OnChildClickListener myOnChildClickListener =
  new OnChildClickListener(){

   @Override
   public boolean onChildClick(ExpandableListView parent, 
    View v, int groupPosition, int childPosition, long id) {
    String strChild = (String)myBaseExpandableListAdapter
      .getChild(groupPosition, childPosition);
    info.setText("child clicked: " + strChild);
    return true;
   }};
   
 OnGroupClickListener myOnGroupClickListener =
  new OnGroupClickListener(){

   @Override
   public boolean onGroupClick(ExpandableListView parent, 
     View v, int groupPosition, long id) {
    String strGroup = (String)myBaseExpandableListAdapter
      .getGroup(groupPosition);
    info.setText("group clicked: " + strGroup);
    
    return false;
    //return false
    //otherwise, group will not expand when user click on it
   }};
  
 OnGroupCollapseListener myOnGroupCollapseListener =
  new OnGroupCollapseListener(){

   @Override
   public void onGroupCollapse(int groupPosition) {
    info.setText("group collapse: " + groupPosition);
   }};
   
 OnGroupExpandListener myOnGroupExpandListener =
  new OnGroupExpandListener(){

   @Override
   public void onGroupExpand(int groupPosition) {
    info.setText("group expand: " + groupPosition);
   }};

}

/res/layout/activity_main.xml, modify to add a TextView to display info.

<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="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="android-coding.blogspot.com"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/info"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    
    <ExpandableListView
        android:id="@+id/myexpandablelistview"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

For other files, MyBaseExpandableListAdapter.java, group_layout.xml and item_layout.xml, refer to ExpandableListView example.

Next:
- ExpandableListView with icon

ExpandableListView example

android.widget.ExpandableListView display two-level ListView: groups which can individually be expanded to show its children. The items come from the ExpandableListAdapter associated with this view.

Example:

ExpandableListView example

Create our custom MyBaseExpandableListAdapter extends BaseExpandableListAdapter, MyBaseExpandableListAdapter.java

package com.example.androidexpandablelistview;

import java.util.HashMap;
import java.util.List;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.TextView;

public class MyBaseExpandableListAdapter extends BaseExpandableListAdapter {
 
 private Context context;
    private List<String> listGroup;
    private HashMap<String, List<String>> listChild;

 public MyBaseExpandableListAdapter(Context c, List<String> lg,
            HashMap<String, List<String>> lc) {
  context = c;
  listGroup = lg;
  listChild = lc;
 }

 @Override
 public Object getChild(int groupPosition, int childPosition) {
  return listChild.get(listGroup.get(groupPosition)).get(childPosition);
 }

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

 @Override
 public View getChildView(int groupPosition, int childPosition, 
   boolean isLastChild, View convertView, ViewGroup parent) {
  
        if (convertView == null) {
            LayoutInflater infalInflater = 
              (LayoutInflater)context
              .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.item_layout, null);
        }
 
        TextView textViewItem = 
          (TextView)convertView.findViewById(R.id.item);
        
        String text = (String)getChild(groupPosition, childPosition);
 
        textViewItem.setText(text);
        return convertView;
 }

 @Override
 public int getChildrenCount(int groupPosition) {
  return listChild.get(listGroup.get(groupPosition)).size();
 }

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

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

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

 @Override
 public View getGroupView(int groupPosition, 
   boolean isExpanded, View convertView, 
   ViewGroup parent) {
  
        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater)context
              .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.group_layout, null);
        }
        
        String textGroup = (String)getGroup(groupPosition);
 
        TextView textViewGroup = (TextView)convertView.findViewById(R.id.group);
        textViewGroup.setText(textGroup);
 
        return convertView;
 }

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

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

}

/res/layout/group_layout.xml, layout of view of groups.

<?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:background="#000000"
    android:orientation="vertical"
    android:padding="8dp" >

    <TextView
        android:id="@+id/group"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:textColor="@android:color/white"
        android:textStyle="bold" />

</LinearLayout>

/res/layout/item_layout.xml, the layout of the view of children.

<?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:orientation="vertical" >

    <TextView
        android:id="@+id/item"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:textStyle="italic" />

</LinearLayout>

/res/layout/activity_main.xml, main layout of our activity, with <ExpandableListView>.

<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="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="android-coding.blogspot.com"
        android:textStyle="bold" />

    <ExpandableListView
        android:id="@+id/myexpandablelistview"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

MainActivity.java

package com.example.androidexpandablelistview;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import android.os.Bundle;
import android.app.Activity;
import android.widget.ExpandableListView;

public class MainActivity extends Activity {
 
 MyBaseExpandableListAdapter myBaseExpandableListAdapter;
    ExpandableListView myExpandableListView;
    List<String> myListForGroup;
    HashMap<String, List<String>> myMapForChild;
 

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  myExpandableListView = (ExpandableListView)
    findViewById(R.id.myexpandablelistview);
 
        initData();
 
        myBaseExpandableListAdapter = new 
          MyBaseExpandableListAdapter(this, myListForGroup, myMapForChild);
 
        myExpandableListView.setAdapter(myBaseExpandableListAdapter);
 }
 
 private void initData() {
  myListForGroup = new ArrayList<String>();
  myMapForChild = new HashMap<String, List<String>>();

        List<String> listGroupA = new ArrayList<String>();
        listGroupA.add("A - 1");
        listGroupA.add("A - 2");
        listGroupA.add("A - 3");

        List<String> listGroupB = new ArrayList<String>();
        listGroupB.add("B - 1");
 
        List<String> listGroupC = new ArrayList<String>();
        listGroupC.add("C - 1");
        listGroupC.add("C - 2");
        
        myListForGroup.add("Group A");
        myListForGroup.add("Group B");
        myListForGroup.add("Group C");
        
        myMapForChild.put(myListForGroup.get(0), listGroupA);
        myMapForChild.put(myListForGroup.get(1), listGroupB);
        myMapForChild.put(myListForGroup.get(2), listGroupC);
    }

}

Next: Detect user action on ExpandableListView, with various Listeners

android.text.TextUtils and android.text.Html

This example demonstrate how HTML encode/decode using android.text.TextUtils and android.text.Html.

HTML encode/decode

package com.example.androidtextutils;

import android.os.Bundle;
import android.app.Activity;
import android.text.Html;
import android.text.Spanned;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {

 EditText textSrc;
 TextView textDest1, textDest2, textDest3, textDest4, textDest5;
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  textSrc = (EditText)findViewById(R.id.textsrc);
  textDest1 = (TextView)findViewById(R.id.textdest1);
  textDest2 = (TextView)findViewById(R.id.textdest2);
  textDest3 = (TextView)findViewById(R.id.textdest3);
  textDest4 = (TextView)findViewById(R.id.textdest4);
  textDest5 = (TextView)findViewById(R.id.textdest5);

  Button buttonConvert = (Button)findViewById(R.id.convert);
  buttonConvert.setOnClickListener(buttonConvertOnClickListener);
 }
 
 View.OnClickListener buttonConvertOnClickListener =
  new View.OnClickListener(){

   @Override
   public void onClick(View arg0) {
    String src = (String) textSrc.getText().toString();
    String t_htmlEncode = TextUtils.htmlEncode(src);
    textDest1.setText(t_htmlEncode);
    Spanned t_htmlEncode_fromHtml = Html.fromHtml(t_htmlEncode);
    textDest2.setText(t_htmlEncode_fromHtml);
    
    Spanned t_fromHtml = Html.fromHtml(src);
    textDest3.setText(t_fromHtml);
    String t_fromHtml_toHtml = Html.toHtml(t_fromHtml);
    textDest4.setText(t_fromHtml_toHtml);
    
    String t_escapeHtml = Html.escapeHtml(src); //API 16
    textDest5.setText(t_escapeHtml);
   }};
 

}

<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="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="android-coding.blogspot.com" />

    <EditText
        android:id="@+id/textsrc"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <Button 
        android:id="@+id/convert"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Html-encode the string" />
    <TextView
        android:text="--- TextUtils.htmlEncode(src) ---"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <TextView
        android:id="@+id/textdest1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <TextView
        android:text="--- Html.fromHtml(TextUtils.htmlEncode(src)) ---"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <TextView
        android:id="@+id/textdest2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <TextView
        android:text="--- Html.fromHtml(src) ---"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <TextView
        android:id="@+id/textdest3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <TextView
        android:text="--- Html.toHtml(Html.fromHtml(src)) ---"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <TextView
        android:id="@+id/textdest4"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <TextView
        android:text="--- Html.escapeHtml(src) ---"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <TextView
        android:id="@+id/textdest5"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

Html-encode string using TextUtils.htmlEncode()

TextUtils.htmlEncode(String s) Html-encode the string.

TextUtils.htmlEncode()

package com.example.androidtextutils;

import android.os.Bundle;
import android.app.Activity;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {

 EditText textSrc;
 TextView textDest;
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  textSrc = (EditText)findViewById(R.id.textsrc);
  textDest = (TextView)findViewById(R.id.textdest);
  Button buttonConvert = (Button)findViewById(R.id.convert);
  buttonConvert.setOnClickListener(buttonConvertOnClickListener);
 }
 
 View.OnClickListener buttonConvertOnClickListener =
  new View.OnClickListener(){

   @Override
   public void onClick(View arg0) {
    String src = (String) textSrc.getText().toString();
    String dest = TextUtils.htmlEncode(src);
    textDest.setText(dest);
   }};
 

}

<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="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="android-coding.blogspot.com" />

    <EditText
        android:id="@+id/textsrc"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <Button 
        android:id="@+id/convert"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Html-encode the string" />
    <TextView
        android:id="@+id/textdest"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

More example of using android.text.TextUtils and android.text.Html