/**
 * Limits the invocations of a function in a given time frame.
 *
 * The debounce function wrapper should be used sparingly. One clear use case
 * is limiting the invocation of a callback attached to the window resize event.
 *
 * Before using the debounce function wrapper, consider first whether the
 * callback could be attache to an event that fires less frequently or if the
 * function can be written in such a way that it is only invoked under specific
 * conditions.
 *
 * @param {Function} callback
 *   The function to be invoked.
 *
 * @param {Number} wait
 *   The time period within which the callback function should only be
 *   invoked once. For example if the wait period is 250ms, then the callback
 *   will only be called at most 4 times per second.
 */
Drupal.debounce = function (callback, wait) {

  "use strict";

  var timeout, result;
  return function () {
    var context = this;
    var args = arguments;
    var later = function () {
      timeout = null;
      result = callback.apply(context, args);
    };
    window.clearTimeout(timeout);
    timeout = window.setTimeout(later, wait);
    return result;
  };
};