private void TurtlesimSubscribe_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
if (_subscriber != null)
{
_subscriber.UnsubscribeAsync();
_subscriber = null;
}
}
public static void WaitForAnyPublisher(this IRosSubscriber subscriber, CancellationToken token = default)
{
if (subscriber == null)
{
throw new ArgumentNullException(nameof(subscriber));
}
Task.Run(() => subscriber.WaitForAnyPublisherAsync(token), token).WaitAndRethrow();
}
public TurtlesimSubscribe(string topic, IMessageDispatcher messageDispatcher)
{
InitializeComponent();
_viewModel = new TurtlesimSubscribeViewModel(topic);
_subscriber = new Subscriber <Twist>(topic, messageDispatcher, new RosMessageTypeAttributeHelper());
_subscriber.RosMessageReceived += _subscriber_RosMessageReceived;
_viewModel.Type = _subscriber.Type;
Loaded += TurtlesimSubscribe_Loaded;
Closing += TurtlesimSubscribe_Closing;
}
public static void WaitForAnyPublisher(this IRosSubscriber subscriber, int timeoutInMs)
{
using CancellationTokenSource tokenSource = new(timeoutInMs);
try
{
subscriber.WaitForAnyPublisher(tokenSource.Token);
}
catch (OperationCanceledException)
{
throw new TimeoutException("Wait for publisher timed out");
}
}
public static async Task WaitForAnyPublisherAsync(this IRosSubscriber subscriber,
CancellationToken token = default)
{
if (subscriber == null)
{
throw new ArgumentNullException(nameof(subscriber));
}
if (subscriber.NumActivePublishers != 0)
{
return;
}
using var linkedSource = CancellationTokenSource.CreateLinkedTokenSource(token, subscriber.CancellationToken);
while (subscriber.NumActivePublishers == 0)
{
await Task.Delay(200, linkedSource.Token);
}
}
public async Task UnsubscribeAsync(CancellationToken token)
{
token.ThrowIfCancellationRequested();
if (Subscriber == null)
{
return;
}
BagListener = null;
if (subscriberId != null)
{
await Subscriber.UnsubscribeAsync(subscriberId, token);
subscriberId = null;
}
Subscriber = null;
}
public async Task SubscribeAsync(RosClient client, IListener listener, CancellationToken token)
{
if (listener != null)
{
listeners.Add((Listener <T>)listener);
}
token.ThrowIfCancellationRequested();
if (client != null)
{
for (int t = 0; t < NumRetries; t++)
{
try
{
IRosSubscriber subscriber;
(subscriberId, subscriber) = await client.SubscribeAsync <T>(topic, Callback, token : token,
transportHint : TransportHint);
if (bagListener != null)
{
bagId = subscriber.Subscribe(bagListener.EnqueueMessage);
}
Subscriber = subscriber;
break;
}
catch (RoslibException e)
{
Core.Logger.Error($"Failed to subscribe to service (try {t.ToString()}): ", e);
await Task.Delay(WaitBetweenRetriesInMs, token);
}
}
}
else
{
Subscriber = null;
}
}
