cherrypick from ics-mr1 docs: source for nw app Change-Id: If50f407a0e56fa802fe9beedaa650e3a131872b2

Change-Id: I55d8668f4065129c844ada239f268a6621df4780
diff --git a/samples/training/network-usage/src/com/example/android/networkusage/SettingsActivity.java b/samples/training/network-usage/src/com/example/android/networkusage/SettingsActivity.java
new file mode 100644
index 0000000..73b72d2
--- /dev/null
+++ b/samples/training/network-usage/src/com/example/android/networkusage/SettingsActivity.java
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package com.example.android.networkusage;
+
+import android.content.SharedPreferences;
+import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
+import android.os.Bundle;
+import android.preference.PreferenceActivity;
+import com.example.android.networkusage.R;
+
+/**
+ * This preference activity has in its manifest declaration an intent filter for
+ * the ACTION_MANAGE_NETWORK_USAGE action. This activity provides a settings UI
+ * for users to specify network settings to control data usage.
+ */
+public class SettingsActivity extends PreferenceActivity
+        implements
+            OnSharedPreferenceChangeListener {
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        // Loads the XML preferences file.
+        addPreferencesFromResource(R.xml.preferences);
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+
+        // Registers a callback to be invoked whenever a user changes a preference.
+        getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+
+        // Unregisters the listener set in onResume().
+        // It's best practice to unregister listeners when your app isn't using them to cut down on
+        // unnecessary system overhead. You do this in onPause().
+        getPreferenceScreen()
+                .getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this);
+    }
+
+    // Fires when the user changes a preference.
+    @Override
+    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
+        // Sets refreshDisplay to true so that when the user returns to the main
+        // activity, the display refreshes to reflect the new settings.
+        NetworkActivity.refreshDisplay = true;
+    }
+}