pausable.js

  var PausableObservable = (function (__super__) {
    inherits(PausableObservable, __super__);
    function PausableObservable(source, pauser) {
      this.source = source;
      this.controller = new Subject();
      this.paused = true;

      if (pauser && pauser.subscribe) {
        this.pauser = this.controller.merge(pauser);
      } else {
        this.pauser = this.controller;
      }

      __super__.call(this);
    }

    PausableObservable.prototype._subscribe = function (o) {
      var conn = this.source.publish(),
        subscription = conn.subscribe(o),
        connection = disposableEmpty;

      var pausable = this.pauser.startWith(!this.paused).distinctUntilChanged().subscribe(function (b) {
        if (b) {
          connection = conn.connect();
        } else {
          connection.dispose();
          connection = disposableEmpty;
        }
      });

      return new NAryDisposable([subscription, connection, pausable]);
    };

    PausableObservable.prototype.pause = function () {
      this.paused = true;
      this.controller.onNext(false);
    };

    PausableObservable.prototype.resume = function () {
      this.paused = false;
      this.controller.onNext(true);
    };

    return PausableObservable;

  }(Observable));

  /**
   * Pauses the underlying observable sequence based upon the observable sequence which yields true/false.
   * @example
   * var pauser = new Rx.Subject();
   * var source = Rx.Observable.interval(100).pausable(pauser);
   * @param {Observable} pauser The observable sequence used to pause the underlying sequence.
   * @returns {Observable} The observable sequence which is paused based upon the pauser.
   */
  observableProto.pausable = function (pauser) {
    return new PausableObservable(this, pauser);
  };