(function ($) {

"use strict";

//
// $.fn.offsetRelative dependency (https://gist.github.com/3191472)
//

$.fn.offsetRelative = $.fn.offsetRelative || function (selector) {
  selector || (selector = '*');

  var elOffset     = this.offset(),
      parentOffset = this.parent().closest(selector).offset();

  return {
    left: elOffset.left - parentOffset.left,
    top: elOffset.top - parentOffset.top
  };
};

//
// Inside plugin
//

$.fn.inside = $.fn.inside || function (container, includeMargin) {
  includeMargin || (includeMargin = false);

  var $el = this.eq(0),
      $container = $(container);

  if (!$.contains($container.get(0), $el.get(0))) {
    return;
  }

  var o = $el.offsetRelative($container),
      w = $container.outerWidth(includeMargin),
      h = $container.outerHeight(includeMargin),

      W = $el.outerWidth(includeMargin),
      H = $el.outerHeight(includeMargin);

  return {
    left: (o.left + W) / (w + W),
    top:  (o.top  + H) / (h + H)
  };
};

//
// 'inside' special event
//

$.event.special.inside = $.event.special.inside || (function () {
  var registry = {};

  // Main handler
  function handler(key) {
    $(this).trigger('inside', $(this).inside(registry[key].handleObj.data.ancestor));
  }

  return {
    add: function (handleObj) {
      var frequency = handleObj.data.frequency || 200,
          key = handleObj.guid;

      // Interval
      var interval = setInterval($.proxy(function () {
        return handler.apply(this, [key]);
      }, this), frequency);

      // Store to the registry
      registry[key] = {
        handleObj: handleObj,
        interval: interval
      };
    },
    remove: function (handleObj) {
      var key = handleObj.guid;

      // Clear from the registry
      clearInterval(registry[key].interval);
      delete registry[key];
    }
  };
}());

}(jQuery));