Interface IObservable

tests/FlyoutsAndMenus/cascadingFlyouts.ts:23–26

    var DEFAULT_CHAIN_SIZE = 6;

    interface IObservable {
        addEventListener(eventName: string, eventHandler: Function, useCapture?: boolean): void;
        removeEventListener(eventName: string, eventHandler: Function, useCapture?: boolean): void;
    }
    var listenOnce = (observable: IObservable, eventName: string, callback: () => any): void => {
        observable.addEventListener(eventName, function handler() {
            observable.removeEventListener(eventName, handler, false);