Class used to open push notification channel on Wordfeud WP7

Pusher.cs

    // Maintains push notification channel
    public class Pusher : IManagePushNotification
    {
        public event EventHandler<PusherUriEventArgs> ChannelUriUpdated;

        private const string ChannelName = "WordfeudChannel";
        private HttpNotificationChannel _pushChannel;
        private bool _enabled;

        public void Enable()
        {
            if (_enabled)
                return;

            // Try to find the push channel.
            _pushChannel = HttpNotificationChannel.Find(ChannelName);

            // If the channel was not found, then create a new connection to the push service.
            if (_pushChannel == null)
            {
                _pushChannel = new HttpNotificationChannel(ChannelName);

                // Register for all the events before attempting to open the channel.
                _pushChannel.ChannelUriUpdated += PushChannel_ChannelUriUpdated;
                _pushChannel.ErrorOccurred += PushChannel_ErrorOccurred;

                OpenChannel();
            }
            else
            {
                // The channel was already open, so just register for all the events.
                _pushChannel.ChannelUriUpdated += PushChannel_ChannelUriUpdated;
                _pushChannel.ErrorOccurred += PushChannel_ErrorOccurred;

                // Display the URI for testing purposes. Normally, the URI would be passed back to your web service at this point.
                NotifyChannelUpdated(_pushChannel.ChannelUri);
            }

            _enabled = true;
        }

        public void Disable()
        {
            if (!_enabled)
                return;

            _pushChannel.UnbindToShellTile();
            _pushChannel.UnbindToShellToast();
            _pushChannel.Close();
            _pushChannel = null;

            _enabled = false;
        }

        private void OpenChannel()
        {
            try
            {
                _pushChannel.Open();

                // Bind this new channel for Toast events
                _pushChannel.BindToShellToast();

                // Bind this new channel for Tile events.
                var uris = new Collection<Uri> { new Uri("http://avatars.wordfeud.com") };
                _pushChannel.BindToShellTile(uris);
            }
            catch (InvalidOperationException e)
            {
                Debug.WriteLine(String.Format("Failed to open push channel: {0}", e));
                // Schedule retry
                ScheduleOpen();
            }
        }

        private void ScheduleOpen()
        {
            Scheduler.ThreadPool.Schedule(TimeSpan.FromSeconds(5.0), OpenChannel);
        }

        private void NotifyChannelUpdated(Uri channelUri)
        {
            if (ChannelUriUpdated != null && channelUri != null)
            {
                Debug.WriteLine(channelUri.ToString());
                ChannelUriUpdated(this, new PusherUriEventArgs(channelUri));
            }
        }

        /// <summary>
        /// Event handler for when the Push Channel Uri changes.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void PushChannel_ChannelUriUpdated(object sender, NotificationChannelUriEventArgs e)
        {
            NotifyChannelUpdated(e.ChannelUri);
        }

        /// <summary>
        /// Event handler for when a Push Notification error occurs.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void PushChannel_ErrorOccurred(object sender, NotificationChannelErrorEventArgs e)
        {
            Debug.WriteLine(String.Format("Push channel error occurred: {0}", e.ErrorType.ToString()));

            // Check if we need to retry opening the channel
            if (e.ErrorType == ChannelErrorType.ChannelOpenFailed || e.ErrorType == ChannelErrorType.PayloadFormatError)
            {
                // Schedule retry
                ScheduleOpen();
            }
        }
    }