public override IDisposable Subscribe(IEventHandlingSettings handlingSettings)
{
if (handlingSettings == null)
{
throw new ArgumentNullException("handlingSettings");
}
if (!typeof(IEvent).IsAssignableFrom(handlingSettings.Type))
{
throw new Exception(string.Format("'{0}' does not implement '{1}'.", handlingSettings.Type, typeof(IEvent)));
}
lock (sync)
{
IList<IEventHandlingSettings> internalEventHandlers;
if (!Handlers.TryGetValue(handlingSettings.Type, out internalEventHandlers))
{
var newHandlers = new Dictionary<Type, IList<IEventHandlingSettings>>(Handlers) { { handlingSettings.Type, new List<IEventHandlingSettings> { handlingSettings } } };
Handlers = newHandlers;
}
else
{
if (handlingSettings.Unique && internalEventHandlers.Count > 0 && internalEventHandlers.Contains(handlingSettings))
{
return new Action(() => { }).AsDisposable();
}
var newInternalEventHandlers = new List<IEventHandlingSettings>(internalEventHandlers) { handlingSettings };
Handlers[handlingSettings.Type] = newInternalEventHandlers;
}
}
return UnsubscriptionAction(handlingSettings);
}
protected override IDisposable UnsubscriptionAction(IEventHandlingSettings handlingSettings)
{
Action action = delegate
{
lock (sync)
{
IList<IEventHandlingSettings> internalEventHandlers;
if (!Handlers.TryGetValue(handlingSettings.Type, out internalEventHandlers))
{
return;
}
var newInternalEventHandlers = new List<IEventHandlingSettings>(internalEventHandlers);
if (newInternalEventHandlers.Remove(handlingSettings))
{
Handlers[handlingSettings.Type] = newInternalEventHandlers;
}
}
};
return action.AsDisposable();
}