Initial Android support

plugin.xml

@@ -14,10 +14,12 @@
 
     <author>Sebastián Katzer</author>
 
+    <!-- cordova -->
     <engines>
         <engine name="cordova" version=">=3.0.0" />
     </engines>
 
+    <!-- js -->
     <js-module src="www/background-mode.js" name="BackgroundMode">
         <clobbers target="plugin.backgroundMode" />
     </js-module>
@@ -49,9 +51,37 @@
 
     <!-- android -->
     <platform name="android">
-        <config-file target="config.xml" parent="/*">
+        <config-file target="res/xml/config.xml" parent="/*">
+            <feature name="BackgroundMode" >
+                <param name="android-package"
+                      value="de.appplant.cordova.plugin.background.BackgroundMode"/>
+            </feature>
+        </config-file>
+
+        <config-file target="res/xml/config.xml" parent="/*">
             <preference name="KeepRunning" value="true" />
         </config-file>
+
+        <config-file target="AndroidManifest.xml" parent="/manifest/application">
+            <!--
+             * Puts the service in a foreground state, where the system considers
+             * it to be something the user is actively aware of and thus not a
+             * candidate for killing when low on memory.
+            -->
+            <service
+                android:name="de.appplant.cordova.plugin.background.ForegroundService"
+                android:enabled="true" />
+
+        </config-file>
+
+        <source-file
+            src="src/android/BackgroundMode.java"
+            target-dir="src/de/appplant/cordova/plugin/background" />
+
+        <source-file
+            src="src/android/ForegroundService.java"
+            target-dir="src/de/appplant/cordova/plugin/background" />
+
     </platform>
 
     <!-- wp8 -->

src/android/BackgroundMode.java

@@ -0,0 +1,180 @@
+/*
+    Copyright 2013-2014 appPlant UG
+
+    Licensed to the Apache Software Foundation (ASF) under one
+    or more contributor license agreements.  See the NOTICE file
+    distributed with this work for additional information
+    regarding copyright ownership.  The ASF licenses this file
+    to you 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 de.appplant.cordova.plugin.background;
+
+import android.app.Activity;
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.Intent;
+import android.content.ServiceConnection;
+import android.os.IBinder;
+import android.util.Log;
+
+import org.apache.cordova.CallbackContext;
+import org.apache.cordova.CordovaPlugin;
+import org.json.JSONArray;
+import org.json.JSONException;
+
+public class BackgroundMode extends CordovaPlugin {
+
+    // Flag indicates if the app is in background or foreground
+    private boolean inBackground = false;
+
+    // Flag indicates if the plugin is enabled or disabled
+    private boolean isDisabled = false;
+
+    // Used to (un)bind the service to with the activity
+    private ServiceConnection connection = new ServiceConnection() {
+
+        @Override
+        public void onServiceConnected(ComponentName name, IBinder binder) {
+            // Nothing to do here
+            Log.d("BackgroundMode", "Service connected");
+        }
+
+        @Override
+        public void onServiceDisconnected(ComponentName name) {
+            Log.w("BackgroundMode", "Service disrupted");
+            //stopService();
+        }
+    };
+
+    /**
+     * Executes the request.
+     *
+     * @param action   The action to execute.
+     * @param args     The exec() arguments.
+     * @param callback The callback context used when
+     *                 calling back into JavaScript.
+     *
+     * @return
+     *      Returning false results in a "MethodNotFound" error.
+     *
+     * @throws JSONException
+     */
+    @Override
+    public boolean execute (String action, JSONArray args,
+                            CallbackContext callback) throws JSONException {
+
+        if (action.equalsIgnoreCase("observeLifeCycle")) {
+            // Nothing to do here
+            return true;
+        }
+
+        if (action.equalsIgnoreCase("enable")) {
+            enableMode();
+            return true;
+        }
+
+        if (action.equalsIgnoreCase("disable")) {
+            disableMode();
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Called when the system is about to start resuming a previous activity.
+     *
+     * @param multitasking
+     *      Flag indicating if multitasking is turned on for app
+     */
+    @Override
+    public void onPause(boolean multitasking) {
+        super.onPause(multitasking);
+        inBackground = true;
+        startService();
+    }
+
+
+    /**
+     * Called when the activity will start interacting with the user.
+     *
+     * @param multitasking
+     *      Flag indicating if multitasking is turned on for app
+     */
+    @Override
+    public void onResume(boolean multitasking) {
+        super.onResume(multitasking);
+        inBackground = false;
+        stopService();
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        stopService();
+    }
+
+    /**
+     * Enable the background mode.
+     */
+    private void enableMode() {
+        isDisabled = false;
+
+        if (inBackground) {
+            startService();
+        }
+    }
+
+    /**
+     * Disable the background mode.
+     */
+    private void disableMode() {
+        stopService();
+        isDisabled = true;
+    }
+
+    /**
+     * Bind the activity to a background service and put them into foreground
+     * state.
+     */
+    private void startService() {
+        Activity context = cordova.getActivity();
+
+        Intent intent = new Intent(
+                context, ForegroundService.class);
+
+        if (isDisabled)
+            return;
+
+        context.bindService(
+                intent, connection, Context.BIND_AUTO_CREATE);
+
+        context.startService(intent);
+    }
+
+    /**
+     * Bind the activity to a background service and put them into foreground
+     * state.
+     */
+    private void stopService() {
+        Activity context = cordova.getActivity();
+
+        Intent intent = new Intent(
+                context, ForegroundService.class);
+
+        context.unbindService(connection);
+        context.stopService(intent);
+    }
+}

src/android/ForegroundService.java

@@ -0,0 +1,164 @@
+/*
+    Copyright 2013-2014 appPlant UG
+
+    Licensed to the Apache Software Foundation (ASF) under one
+    or more contributor license agreements.  See the NOTICE file
+    distributed with this work for additional information
+    regarding copyright ownership.  The ASF licenses this file
+    to you 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 de.appplant.cordova.plugin.background;
+
+import android.app.Notification;
+import android.app.PendingIntent;
+import android.app.Service;
+import android.content.Context;
+import android.content.Intent;
+import android.content.res.Resources;
+import android.os.Build;
+import android.os.Handler;
+import android.os.IBinder;
+import android.util.Log;
+
+import java.util.Date;
+import java.util.Timer;
+import java.util.TimerTask;
+
+/**
+ * Puts the service in a foreground state, where the system considers it to be
+ * something the user is actively aware of and thus not a candidate for killing
+ * when low on memory.
+ */
+public class ForegroundService extends Service {
+
+    // Fixed ID for the 'foreground' notification
+    private static final int NOTIFICATION_ID = -574543954;
+
+    // Scheduler to exec periodic tasks
+    final Timer scheduler = new Timer();
+
+    // Used to keep the app alive
+    TimerTask keepAliveTask;
+
+    /**
+     * Allow clients to call on to the service.
+     */
+    @Override
+    public IBinder onBind (Intent intent) {
+        return null;
+    }
+
+    /**
+     * Put the service in a foreground state to prevent app from being killed
+     * by the OS.
+     */
+    @Override
+    public void onCreate () {
+        super.onCreate();
+        keepAwake();
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        sleepWell();
+    }
+
+    /**
+     * Put the service in a foreground state to prevent app from being killed
+     * by the OS.
+     */
+    public void keepAwake() {
+        final Handler handler = new Handler();
+
+        startForeground(NOTIFICATION_ID, makeNotification());
+
+        keepAliveTask = new TimerTask() {
+            @Override
+            public void run() {
+                handler.post(new Runnable() {
+                    public void run() {
+                        // Nothing to do here
+                        // Log.d("BackgroundMode", "" + new Date().getTime());
+                    }
+                });
+            }
+        };
+
+        scheduler.schedule(keepAliveTask, 0, 1000);
+    }
+
+    /**
+     * Stop background mode.
+     */
+    private void sleepWell() {
+        stopForeground(true);
+        keepAliveTask.cancel();
+    }
+
+    /**
+     * Create a notification as the visible part to be able to put the service
+     * in a foreground state.
+     *
+     * @return
+     *      A local ongoing notification which pending intent is bound to the
+     *      main activity.
+     */
+    @SuppressWarnings("deprecation")
+    private Notification makeNotification() {
+        Context context = getApplicationContext();
+        String pkgName  = context.getPackageName();
+        Intent intent   = context.getPackageManager()
+                .getLaunchIntentForPackage(pkgName);
+
+        PendingIntent contentIntent = PendingIntent.getActivity(
+                context, NOTIFICATION_ID, intent, PendingIntent.FLAG_CANCEL_CURRENT);
+
+        String title = "App is running in background";
+
+        Notification.Builder notification = new Notification.Builder(context)
+                .setContentTitle(title)
+                .setContentText(title)
+                .setTicker(title)
+                .setOngoing(true)
+                .setSmallIcon(getIconResId())
+                .setContentIntent(contentIntent);
+
+        if (Build.VERSION.SDK_INT < 16) {
+            // Build notification for HoneyComb to ICS
+            return notification.getNotification();
+        } else {
+            // Notification for Jellybean and above
+            return notification.build();
+        }
+    }
+
+    /**
+     * Retrieves the resource ID of the app icon.
+     *
+     * @return
+     *      The resource ID of the app icon
+     */
+    private int getIconResId () {
+        Context context = getApplicationContext();
+        Resources res   = context.getResources();
+        String pkgName  = context.getPackageName();
+
+        int resId;
+        resId = res.getIdentifier("icon", "drawable", pkgName);
+
+        return resId;
+    }
+}

www/background-mode.js

@@ -46,4 +46,6 @@ BackgroundMode.prototype = {
 
 var plugin = new BackgroundMode();
 
+document.addEventListener("backbutton", function () {}, false);
+
 module.exports = plugin;