The issue you will have here is that when the event executes, it will be in the context of the event (window for resize, the DOM element for click, mouse overs etc), not your class - so this
will not be a handle on your class.
You can solve it by using...
window.onresize = this.onWindowResized.bind(this);
This is one instance where bind
is more graceful than fat-arrow syntax.