public IDisposable Subscribe(IGraphicsProviderObserver observer)
{
if (!_observers.Contains(observer))
{
_observers.Add(observer);
// Provide observer with existing data.
var graphics = _cache.GetGraphics(observer.LayerId);
foreach (var singleGraphic in graphics)
{
observer.OnPublish(singleGraphic);
}
}
return(new GraphicsProviderUnsubscriber(_observers, observer));
}
public GraphicsProviderUnsubscriber(List <IGraphicsProviderObserver> observers, IGraphicsProviderObserver observer)
{
_observers = observers;
_observer = observer;
}
