(function($) {

Drupal.behaviors.moduleFilterDynamicPosition = {
  attach: function(context) {
    var $window = $(window);

    $('#module-filter-wrapper', context).once('dynamic-position', function() {
      // Move the submit button just below the tabs.
      $('#module-filter-tabs').append($('#module-filter-submit'));

      var positionSubmit = function() {
        var $tabs = $('#module-filter-tabs');
        var $submit = $('#module-filter-submit', $tabs);

        // Vertical movement.
        var bottom = $tabs.offset().top + $tabs.outerHeight();
        if ($submit.hasClass('fixed-bottom')) {
          bottom += $submit.height();
        }
        if (bottom >= $window.height() + $window.scrollTop()) {
          $submit.addClass('fixed fixed-bottom');
          $tabs.css('padding-bottom', $submit.height());
        }
        else {
          $submit.removeClass('fixed fixed-bottom');
          $tabs.css('padding-bottom', 0);
        }

        // Horizontal movement.
        if ($submit.hasClass('fixed-bottom') || $submit.hasClass('fixed-top')) {
          var left = $tabs.offset().left - $window.scrollLeft();
          if (left != $submit.offset().left - $window.scrollLeft()) {
            $submit.css('left', left);
          }
        }
      };

      // Control the positioning.
      $window.scroll(positionSubmit);
      $window.resize(positionSubmit);
      var moduleFilter = $('input[name="module_filter[name]"]').data('moduleFilter');
      moduleFilter.element.bind('moduleFilter:adjustHeight', positionSubmit);
      moduleFilter.adjustHeight();
    });
  }
};

})(jQuery);