Write a PHP DBus client

<?php
/*
There are two php-dbus bindings.
1. GREE Labs's
http://labs.gree.jp/Top/OpenSource/DBus-en.html

GREE's php-dbus binding could not handle D-Bus signal.
Also you could not write a D-Bus service by GREE's binding.

2. Derick's
http://pecl.php.net/package/DBus

required: dbus library and header files, phpize (PECL tools).
Ubuntu packages: libdbus-1-dev, php5-dev

Derick's is most useful, but lacks of documents.
You need to see it's examples.
http://svn.php.net/viewvc/pecl/dbus/trunk/examples/
*/

$rhythmboxService = 'org.gnome.Rhythmbox';
$rhythmboxPlayer = '/org/gnome/Rhythmbox/Player';
$rhythmboxPlayerInterface = 'org.gnome.Rhythmbox.Player';
/*
dbus-send --session --print-reply \
    --dest=org.gnome.Rhythmbox \
    /org/gnome/Rhythmbox/Player \
    org.freedesktop.DBus.Introspectable.Introspect
*/

$d = new Dbus(Dbus::BUS_SESSION);

$playerProxy = $d->createProxy(
    $rhythmboxService, $rhythmboxPlayer, $rhythmboxPlayerInterface);

$uri = $playerProxy->getPlayingUri();
//透過 proxy 實體，呼叫 RhythmboxPlayer->getPlayingUri()。

//取得它目前正在播放的音樂檔名。


echo "Rhythmbox is playing: ", urldecode($uri), "\n";

$d->addWatch($rhythmboxPlayerInterface);
//傾聽 RhythmboxPlayer 介面的訊號。


while (true) {
    if ( !($s = $d->waitLoop(1000)) )
        continue;
    if ($s->matches($rhythmboxPlayerInterface, 'playingUriChanged')) {
        //過濾傾聽 Rhythmbox 改變曲目的訊號。

        $uri = $s->getData();
        echo "Rhythmbox changes to play: ", urldecode($uri), "\n";
    }
}

?>

<?php
/**
 * DBus2 class
 *
 * @license: LGPL
 * @author: rock
 */
class Dbus2 extends Dbus {
    function __construct($type) {
        parent::__construct($type);
        $this->signalReceivers = array();
    }

    //self.bus.add_signal_receiver(self.handler, dbus_interface=Hello.interface, signal_name = "SignalSay")

    function addSignalReceiver($callback, $interface, $signal) {
        if (!isset($this->signalReceivers[$interface]))
            $this->signalReceivers[$interface] = array();
        $this->signalReceivers[$interface][$signal] = $callback;

        $this->addWatch($interface);
        //var_dump($this->signalReceivers);

    }

    function mainLoop($time) {
        while (true) {
            $s = parent::waitLoop($time);
            $called = false;
            if ($s) {
                foreach ($this->signalReceivers as $interface => $members) {
                    foreach ($members as $signal => $callback) {
                        if ($s->matches($interface, $signal)) {
                            //echo "matches\n";

                            $reply = $s->getData();
                            if (is_array($reply))
                                call_user_func_array($callback, $reply);
                            else
                                call_user_func($callback, $reply);
                            $called = true;
                            break; //foreach members

                        }
                    }
                    if ($called)
                        break; //foreach receivers

                }
            }
        }
        return $s;
    }
}


$rhythmboxService = 'org.gnome.Rhythmbox';
$rhythmboxPlayer = '/org/gnome/Rhythmbox/Player';
$rhythmboxPlayerInterface = 'org.gnome.Rhythmbox.Player';

$d = new Dbus2(Dbus::BUS_SESSION); // use DBus2, not DBus


$playerProxy = $d->createProxy(
    $rhythmboxService, $rhythmboxPlayer, $rhythmboxPlayerInterface);

$uri = $playerProxy->getPlayingUri();

echo "Rhythmbox is playing: ", urldecode($uri), "\n";


function my_callback($uri) {
    echo "Rhythmbox changes to play: ", urldecode($uri), "\n";
}

$d->addSignalReceiver('my_callback', $rhythmboxPlayerInterface, 'playingUriChanged');

$d->mainLoop(1000);

?>