JWSAndroidClientService.java

//	---------------------------------------------------------------------------
//	jWebSocket - Copyright (c) 2010 jwebsocket.org
//	---------------------------------------------------------------------------
//	This program is free software; you can redistribute it and/or modify it
//	under the terms of the GNU Lesser General Public License as published by the
//	Free Software Foundation; either version 3 of the License, or (at your
//	option) any later version.
//	This program is distributed in the hope that it will be useful, but WITHOUT
//	ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
//	FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
//	more details.
//	You should have received a copy of the GNU Lesser General Public License along
//	with this program; if not, see <http://www.gnu.org/licenses/lgpl.html>.
//	---------------------------------------------------------------------------
package org.jwebsocket.android.library;

import java.util.ArrayList;
import java.util.List;

import android.app.NotificationManager;
import android.app.Service;
import android.content.Intent;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;

/**
 * @author puran
 */
public class JWSAndroidClientService extends Service {

	/** For showing and hiding our notification. */
	NotificationManager mNM;
	/** Keeps track of all current registered clients. */
	List<Messenger> mClients = new ArrayList<Messenger>();
	/** Holds last value set by a client. */
	int mValue = 0;

	/**
	 * Command to the service to register a client, receiving callbacks from the
	 * service. The Message's replyTo field must be a Messenger of the client
	 * where callbacks should be sent.
	 */
	static final int MSG_REGISTER_CLIENT = 1;

	/**
	 * Command to the service to unregister a client, ot stop receiving
	 * callbacks from the service. The Message's replyTo field must be a
	 * Messenger of the client as previously given with MSG_REGISTER_CLIENT.
	 */
	static final int MSG_UNREGISTER_CLIENT = 2;

	/**
	 * Command to service to set a new value. This can be sent to the service to
	 * supply a new value, and will be sent by the service to any registered
	 * clients with the new value.
	 */
	static final int MSG_SET_VALUE = 3;

	/**
	 * Handler of incoming messages from clients.
	 */
	class IncomingHandler extends Handler {
		@Override
		public void handleMessage(Message msg) {
			switch (msg.what) {
			case MSG_REGISTER_CLIENT:
				mClients.add(msg.replyTo);
				break;
			case MSG_UNREGISTER_CLIENT:
				mClients.remove(msg.replyTo);
				break;
			case MSG_SET_VALUE:
				mValue = msg.arg1;
				for (int i = mClients.size() - 1; i >= 0; i--) {
					try {
						mClients.get(i).send(
								Message.obtain(null, MSG_SET_VALUE, mValue, 0));
					} catch (RemoteException e) {
						// The client is dead. Remove it from the list;
						// we are going through the list from back to front
						// so this is safe to do inside the loop.
						mClients.remove(i);
					}
				}
				break;
			default:
				super.handleMessage(msg);
			}
		}
	}

	/**
	 * Target we publish for clients to send messages to IncomingHandler.
	 */
	final Messenger mMessenger = new Messenger(new IncomingHandler());

	@Override
	public void onCreate() {
		mNM = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);

		// Display a notification about us starting.
		showNotification();
	}

	@Override
	public void onDestroy() {
		// Cancel the persistent notification.
		// Tell the user we stopped.
	}

	/**
	 * When binding to the service, we return an interface to our messenger for
	 * sending messages to the service.
	 */
	@Override
	public IBinder onBind(Intent intent) {
		return mMessenger.getBinder();
	}

	/**
	 * Show a notification while this service is running.
	 */
	private void showNotification() {
	}
}