A ListView with Checkboxes (Using FragmentActivity)
Contents
Introduction
This example shows how to create a ListView with a CheckBox in each row, without having our Activity extend ListActivity. Instead we extend FragmentActivity.
Activity Source Listing
Most of the functionality is contained in the Activity class.
package org.windrealm.planetslistview;
import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.CheckBox;
import android.widget.ListView;
import android.widget.TextView;
import org.windrealm.planetslistview.R;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class MainActivity extends FragmentActivity {
private Planet[] planets ;
private ArrayAdapter<Planet> listAdapter ;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Find the ListView resource.
ListView mainListView = (ListView) findViewById( R.id.mainListView );
// When item is tapped, toggle checked properties of CheckBox and Planet.
mainListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick( AdapterView<?> parent, View item,
int position, long id) {
Planet planet = listAdapter.getItem( position );
planet.toggleChecked();
PlanetViewHolder viewHolder = (PlanetViewHolder) item.getTag();
viewHolder.getCheckBox().setChecked( planet.isChecked() );
}
});
// Create and populate planets.
planets = (Planet[]) getLastCustomNonConfigurationInstance() ;
if ( planets == null ) {
planets = new Planet[] {
new Planet("Mercury"), new Planet("Venus"), new Planet("Earth"),
new Planet("Mars"), new Planet("Jupiter"), new Planet("Saturn"),
new Planet("Uranus"), new Planet("Neptune"), new Planet("Ceres"),
new Planet("Pluto"), new Planet("Haumea"), new Planet("Makemake"),
new Planet("Eris"), new Planet("Epsilon Eridani"), new Planet("Gliese 876 b"),
new Planet("HD 209458 b")
};
}
ArrayList<Planet> planetList = new ArrayList<Planet>();
planetList.addAll( Arrays.asList(planets) );
// Set our custom array adapter as the ListView's adapter.
listAdapter = new PlanetArrayAdapter(this, planetList);
mainListView.setAdapter( listAdapter );
}
/** Holds planet data. */
private static class Planet {
private String name = "" ;
private boolean checked = false ;
public Planet() {}
public Planet( String name ) {
this.name = name ;
}
public Planet( String name, boolean checked ) {
this.name = name ;
this.checked = checked ;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public boolean isChecked() {
return checked;
}
public void setChecked(boolean checked) {
this.checked = checked;
}
public String toString() {
return name ;
}
public void toggleChecked() {
checked = !checked ;
}
}
/** Holds child views for one row. */
private static class PlanetViewHolder {
private CheckBox checkBox ;
private TextView textView ;
public PlanetViewHolder() {}
public PlanetViewHolder( TextView textView, CheckBox checkBox ) {
this.checkBox = checkBox ;
this.textView = textView ;
}
public CheckBox getCheckBox() {
return checkBox;
}
public void setCheckBox(CheckBox checkBox) {
this.checkBox = checkBox;
}
public TextView getTextView() {
return textView;
}
public void setTextView(TextView textView) {
this.textView = textView;
}
}
/** Custom adapter for displaying an array of Planet objects. */
private static class PlanetArrayAdapter extends ArrayAdapter<Planet> {
private LayoutInflater inflater;
public PlanetArrayAdapter( Context context, List<Planet> planetList ) {
super( context, R.layout.simplerow, R.id.rowTextView, planetList );
// Cache the LayoutInflate to avoid asking for a new one each time.
inflater = LayoutInflater.from(context) ;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// Planet to display
Planet planet = this.getItem( position );
// The child views in each row.
CheckBox checkBox ;
TextView textView ;
// Create a new row view
if ( convertView == null ) {
convertView = inflater.inflate(R.layout.simplerow, null);
// Find the child views.
textView = (TextView) convertView.findViewById( R.id.rowTextView );
checkBox = (CheckBox) convertView.findViewById( R.id.CheckBox01 );
// Optimization: Tag the row with it's child views, so we don't have to
// call findViewById() later when we reuse the row.
convertView.setTag( new PlanetViewHolder(textView,checkBox) );
// If CheckBox is toggled, update the planet it is tagged with.
checkBox.setOnClickListener( new View.OnClickListener() {
public void onClick(View v) {
CheckBox cb = (CheckBox) v ;
Planet planet = (Planet) cb.getTag();
planet.setChecked( cb.isChecked() );
}
});
}
// Reuse existing row view
else {
// Because we use a ViewHolder, we avoid having to call findViewById().
PlanetViewHolder viewHolder = (PlanetViewHolder) convertView.getTag();
checkBox = viewHolder.getCheckBox() ;
textView = viewHolder.getTextView() ;
}
// Tag the CheckBox with the Planet it is displaying, so that we can
// access the planet in onClick() when the CheckBox is toggled.
checkBox.setTag( planet );
// Display planet data
checkBox.setChecked( planet.isChecked() );
textView.setText( planet.getName() );
return convertView;
}
}
public Object onRetainCustomNonConfigurationInstance () {
return planets ;
}
}
Layouts Source Listing
activity_main.xml
<RelativeLayout 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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">
<ListView android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/mainListView">
</ListView>
</RelativeLayout>
simplerow.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView android:id="@+id/rowTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="10dp"
android:textSize="16sp" >
</TextView>
<CheckBox android:id="@+id/CheckBox01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="10dp"
android:layout_alignParentRight="true" android:layout_marginRight="6sp"
android:focusable="false">
</CheckBox>
</RelativeLayout>
Download Source Code
Project source for Android Studio can be downloaded here.