public SpecificResizeObserver() { Window.AddEventListener( "resize", () => { Logger.Debug(GetType(), "[SpecificResizeObserver] updating listeners?"); var updated = Document.Body.TraverseAll(x => { if (!x.IsResizeRecipient() || !_listeners.ContainsKey(x)) { return(false); } _listeners[x](); return(true); }); Logger.Debug(GetType(), "updated {0} listeners", updated); } ); }