A utility that throttles input to a timer

Throttler.js

/** 
  * requires twttr.klass
  */
  
twttr.klass('twttr.Throttler', function(interval, callback) {
  this.interval = interval;
  this.callback = callback;
  this._items = [];
})

  .methods({
    start: function() {
      this._showNext();
      this._timer = setInterval(this._showNext, this.interval);
    },

    stop: function() {
      clearInterval(this.timer);
      this._timer = null;
    },

    _showNext: function() {
      var next = this.next();
      if (next) {
        this.callback(next);
      }
    },

    add: function(item) {
      this._items.unshift(item);
    },

    next: function() {
      if (this._items.length) {
        return this._items.shift();
      }
      return null;
    }
  });