ExpandableListView
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. The items come from the
ExpandableListAdapter associated with this view.
Source Code
main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<ExpandableListView
android:id="@+id/android:list"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
</ExpandableListView>
</LinearLayout>
group.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="40dip"
android:text="Items"
android:textAppearance="?android:attr/textAppearanceLarge" />
</LinearLayout>
child.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<TextView
android:id="@+id/textViewchild"
android:layout_width="220dp"
android:layout_height="40dip"
android:text="child values "
android:textAppearance="?android:attr/textAppearanceMedium" />
<CheckBox
android:id="@+id/checkBoxchild"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="" />
</LinearLayout>
above xml files are declared for Main page where you can get the component Representation
and the other two are used to get the parent and child values
Activities of which uses the above xml files are shown below
package com.pack.android;
import android.app.ExpandableListActivity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.widget.ExpandableListView;
import android.widget.ExpandableListView.OnGroupExpandListener;
public class CoutmLIstActivity extends ExpandableListActivity {
DisplayMetrics dismat;
ExpandableListView matrix;
int width;
static final String Groupvalues[] = { "Android", "Flex", "Voice Xml",
};
static final String childvalues[][] = {
{ "SaiNath", "Anudeep", "Deppeak"},
{ "Kranthi", "Ramakrishna", "Nagarjuna" }, { "Sushma", "Meghana", "Sathya" } };
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ExpandableListView ep = getExpandableListView();
dismat = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dismat);
width = dismat.widthPixels;
ep.setIndicatorBounds(width - GetDipsFromPixel(50), width
- GetDipsFromPixel(10));
ep.setAdapter(new ExpandbleAdpter(CoutmLIstActivity.this));
ep.setOnGroupExpandListener(new OnGroupExpandListener() {
@Override
public void onGroupExpand(int groupPosition) {
}
});
}
public int GetDipsFromPixel(float pixels) {
final float scale = getResources().getDisplayMetrics().density;
return (int) (pixels * scale + 0.5f);
}
}
Adapter class for List Component
package com.pack.android;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.CompoundButton.OnCheckedChangeListener;
public class ExpandbleAdpter extends BaseExpandableListAdapter {
Context myconContext;
public ExpandbleAdpter(Context context) {
myconContext = context;
}
@Override
public Object getChild(int groupPosition, int childPosition) {
return null;
}
@Override
public long getChildId(int groupPosition, int childPosition) {
return 0;
}
@Override
public View getChildView(int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
if (convertView == null) {
LayoutInflater lay = (LayoutInflater) myconContext
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = lay.inflate(R.layout.child, null);
}
final TextView name = (TextView) convertView
.findViewById(R.id.textViewchild);
name
.setText(CoutmLIstActivity.childvalues[groupPosition][childPosition]);
CheckBox child = (CheckBox) convertView
.findViewById(R.id.checkBoxchild);
child.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
Toast.makeText(myconContext,
"Name" + name.getText().toString(), Toast.LENGTH_LONG)
.show();
}
});
return convertView;
}
@Override
public int getChildrenCount(int groupPosition) {
return CoutmLIstActivity.childvalues.length;
}
@Override
public Object getGroup(int groupPosition) {
return null;
}
@Override
public int getGroupCount() {
return CoutmLIstActivity.Groupvalues.length;
}
@Override
public long getGroupId(int groupPosition) {
return 0;
}
@Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
if (convertView == null) {
LayoutInflater lay2 = (LayoutInflater) myconContext
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = lay2.inflate(R.layout.group, null);
}
TextView cidlvalue = (TextView) convertView
.findViewById(R.id.textView1);
cidlvalue.setText(CoutmLIstActivity.Groupvalues[groupPosition]);
return convertView;
}
@Override
public boolean hasStableIds() {
return false;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return false;
}
}
Finally the tree view looks like as fallows
