/// <summary>
/// Gets the object where the subscription is registered for
/// </summary>
/// <returns>The <see cref="object"/></returns>
protected override object GetSubscriptionObject(IMessageBusEventHandlerSubscription messageBusEventHandlerSubscription)
{
if (messageBusEventHandlerSubscription is ObjectChangedMessageBusEventHandlerSubscription objectChangedMessageBusEventHandlerSubscription)
{
return(objectChangedMessageBusEventHandlerSubscription.Thing as object ?? objectChangedMessageBusEventHandlerSubscription.Type);
}
return(null);
}
/// <summary>
/// Register a message bus event handler
/// </summary>
/// <param name="listener">The <see cref="IObservable{T}"/> to listen to for message bus messages</param>
/// <param name="messageBusEventHandlerSubscription">The <see cref="IMessageBusEventHandlerSubscription"/> instance that holds information about the event handler</param>
/// <returns>A <see cref="MessageBusEventHandlerDisposer"/> as an <see cref="IDisposable"/></returns>
public IDisposable RegisterEventHandler(IObservable <T> listener, IMessageBusEventHandlerSubscription messageBusEventHandlerSubscription)
{
return(Task.Run
(() =>
{
if (!this.MessageBusHandlerDataList.TryGetValue(listener, out var messageBusEventHandlerSubscriptionDictionary))
{
messageBusEventHandlerSubscriptionDictionary = new Dictionary <object, HashSet <IMessageBusEventHandlerSubscription> >();
this.MessageBusHandlerDataList.Add(listener, messageBusEventHandlerSubscriptionDictionary);
// At least one subscription, otherwise the CDPMessageBus could remove the listener unexpectedly
this.disposables.Add(
listener
.ObserveOn(RxApp.MainThreadScheduler)
.Subscribe(
x =>
this.HandleEvents(listener, x)));
}
var subscriptionObject = this.GetSubscriptionObject(messageBusEventHandlerSubscription);
if (subscriptionObject == null)
{
return new MessageBusEventHandlerDisposer(new Action(() => { }));
}
if (!messageBusEventHandlerSubscriptionDictionary.TryGetValue(subscriptionObject, out var messageBusEventHandlerSubscriptionHashSet))
{
messageBusEventHandlerSubscriptionHashSet = new HashSet <IMessageBusEventHandlerSubscription>();
messageBusEventHandlerSubscriptionDictionary.Add(subscriptionObject, messageBusEventHandlerSubscriptionHashSet);
}
messageBusEventHandlerSubscriptionHashSet.Add(messageBusEventHandlerSubscription);
Action cleanUpAction = () =>
{
if (messageBusEventHandlerSubscriptionHashSet.Contains(messageBusEventHandlerSubscription))
{
messageBusEventHandlerSubscriptionHashSet.Remove(messageBusEventHandlerSubscription);
}
if (!messageBusEventHandlerSubscriptionHashSet.Any())
{
messageBusEventHandlerSubscriptionDictionary.Remove(subscriptionObject);
}
messageBusEventHandlerSubscription.Dispose();
};
return new MessageBusEventHandlerDisposer(cleanUpAction);
}
).Result);
}
/// <summary>
/// Gets the object where the subscription is registered for
/// </summary>
/// <returns>The <see cref="object"/></returns>
protected virtual object GetSubscriptionObject(IMessageBusEventHandlerSubscription messageBusEventHandlerSubscription)
{
return(this);
}