1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 5 * in compliance with the License. You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software distributed under the License 10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 11 * or implied. See the License for the specific language governing permissions and limitations under 12 * the License. 13 */ 14 15 package com.example.android.networkusage; 16 17 import android.content.SharedPreferences; 18 import android.content.SharedPreferences.OnSharedPreferenceChangeListener; 19 import android.os.Bundle; 20 import android.preference.PreferenceActivity; 21 import com.example.android.networkusage.R; 22 23 /** 24 * This preference activity has in its manifest declaration an intent filter for 25 * the ACTION_MANAGE_NETWORK_USAGE action. This activity provides a settings UI 26 * for users to specify network settings to control data usage. 27 */ 28 public class SettingsActivity extends PreferenceActivity 29 implements 30 OnSharedPreferenceChangeListener { 31 32 @Override 33 protected void onCreate(Bundle savedInstanceState) { 34 super.onCreate(savedInstanceState); 35 36 // Loads the XML preferences file. 37 addPreferencesFromResource(R.xml.preferences); 38 } 39 40 @Override 41 protected void onResume() { 42 super.onResume(); 43 44 // Registers a callback to be invoked whenever a user changes a preference. 45 getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this); 46 } 47 48 @Override 49 protected void onPause() { 50 super.onPause(); 51 52 // Unregisters the listener set in onResume(). 53 // It's best practice to unregister listeners when your app isn't using them to cut down on 54 // unnecessary system overhead. You do this in onPause(). 55 getPreferenceScreen() 56 .getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this); 57 } 58 59 // Fires when the user changes a preference. 60 @Override 61 public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) { 62 // Sets refreshDisplay to true so that when the user returns to the main 63 // activity, the display refreshes to reflect the new settings. 64 NetworkActivity.refreshDisplay = true; 65 } 66 } 67
