Android Example of using PreferenceFragment

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In my old post "Preferences and SharedPreferences" describe how to implement PreferenceActivity calling deprecated addPreferencesFromResource() method. PreferenceActivity is the base class for an activity to show a hierarchy of preferences to the user. Prior to HONEYCOMB this class only allowed the display of a single set of preference; this functionality should now be found in the new PreferenceFragment class.

It's a example of using PreferenceFragment.

New a Android Application Project, AndroidPreferenceFragment, with Build SDK target Android 4.1 (API 16) and Minimum Required Android 3.0 (API 11), BlankActivity with Navigation Type of None.

Create /res/xml/preferences.xml to define our preferences.

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

    <PreferenceCategory
            android:title="PreferenceCategory A">

        <CheckBoxPreference
                android:key="checkbox_preference"
                android:title="title_checkbox_preference"
                android:summary="summary_checkbox_preference" />

    </PreferenceCategory>

    <PreferenceCategory
            android:title="PreferenceCategory B">

        <EditTextPreference
                android:key="edittext_preference"
                android:title="title_edittext_preference"
                android:summary="summary_edittext_preference"
                android:dialogTitle="dialog_title_edittext_preference" />

    </PreferenceCategory>

</PreferenceScreen>

Create PrefsFragment.java extends PreferenceFragment to addPreferencesFromResource.

package com.example.androidpreferencefragment;

import android.os.Bundle;
import android.preference.PreferenceFragment;

public class PrefsFragment extends PreferenceFragment {

 @Override
 public void onCreate(Bundle savedInstanceState) {
  // TODO Auto-generated method stub
  super.onCreate(savedInstanceState);
  
  // Load the preferences from an XML resource
        addPreferencesFromResource(R.xml.preferences);
 }

}

Create SetPreferenceActivity.java to load PrefsFragment.

package com.example.androidpreferencefragment;

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

public class SetPreferenceActivity extends Activity {

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  // TODO Auto-generated method stub
  super.onCreate(savedInstanceState);
  
  getFragmentManager().beginTransaction().replace(android.R.id.content,
                new PrefsFragment()).commit();
 }

}

Modify the main layout, /res/layout/activity_main.xml, to show the preference.

<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" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="@dimen/padding_medium"
        android:text="@string/hello_world"
        tools:context=".MainActivity" />
    
    <CheckBox
        android:id="@+id/prefCheckBox"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="CheckBoxPreference" />
    
    <TextView
        android:id="@+id/prefEditText"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
        
</LinearLayout>

The main activity, MainActivity.java.

package com.example.androidpreferencefragment;

import android.os.Bundle;
import android.preference.PreferenceManager;
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.CheckBox;
import android.widget.TextView;

public class MainActivity extends Activity {
 
 CheckBox prefCheckBox;
 TextView prefEditText;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        prefCheckBox = (CheckBox)findViewById(R.id.prefCheckBox);
     prefEditText = (TextView)findViewById(R.id.prefEditText);
     
     loadPref();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

 @Override
 public boolean onOptionsItemSelected(MenuItem item) {

  /*
   * Because it's onlt ONE option in the menu.
   * In order to make it simple, We always start SetPreferenceActivity
   * without checking.
   */
  
  Intent intent = new Intent();
        intent.setClass(MainActivity.this, SetPreferenceActivity.class);
        startActivityForResult(intent, 0); 
  
        return true;
 }

 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  // TODO Auto-generated method stub
  //super.onActivityResult(requestCode, resultCode, data);
  
  /*
   * To make it simple, always re-load Preference setting.
   */
  
  loadPref();
 }
    
 private void loadPref(){
  SharedPreferences mySharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
  
  boolean my_checkbox_preference = mySharedPreferences.getBoolean("checkbox_preference", false);
  prefCheckBox.setChecked(my_checkbox_preference);

  String my_edittext_preference = mySharedPreferences.getString("edittext_preference", "");
     prefEditText.setText(my_edittext_preference);

 }
        
}

Finally, modify AndroidManifest.xml to add SetPreferenceActivity.

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.androidpreferencefragment"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="11"
        android:targetSdkVersion="15" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".SetPreferenceActivity"
            android:label="@string/title_activity_main" >
        </activity>
    </application>

</manifest>