AttachBody.prototype._positionDropdown = function()

in adminlte/html/plugins/select2/js/select2.full.js [4472:4557]
63 lines of code
16 McCabe index (conditional complexity)

  AttachBody.prototype._positionDropdown = function () {
    var $window = $(window);

    var isCurrentlyAbove = this.$dropdown.hasClass('select2-dropdown--above');
    var isCurrentlyBelow = this.$dropdown.hasClass('select2-dropdown--below');

    var newDirection = null;

    var offset = this.$container.offset();

    offset.bottom = offset.top + this.$container.outerHeight(false);

    var container = {
      height: this.$container.outerHeight(false)
    };

    container.top = offset.top;
    container.bottom = offset.top + container.height;

    var dropdown = {
      height: this.$dropdown.outerHeight(false)
    };

    var viewport = {
      top: $window.scrollTop(),
      bottom: $window.scrollTop() + $window.height()
    };

    var enoughRoomAbove = viewport.top < (offset.top - dropdown.height);
    var enoughRoomBelow = viewport.bottom > (offset.bottom + dropdown.height);

    var css = {
      left: offset.left,
      top: container.bottom
    };

    // Determine what the parent element is to use for calculating the offset
    var $offsetParent = this.$dropdownParent;

    // For statically positioned elements, we need to get the element
    // that is determining the offset
    if ($offsetParent.css('position') === 'static') {
      $offsetParent = $offsetParent.offsetParent();
    }

    var parentOffset = {
      top: 0,
      left: 0
    };

    if (
      $.contains(document.body, $offsetParent[0]) ||
      $offsetParent[0].isConnected
      ) {
      parentOffset = $offsetParent.offset();
    }

    css.top -= parentOffset.top;
    css.left -= parentOffset.left;

    if (!isCurrentlyAbove && !isCurrentlyBelow) {
      newDirection = 'below';
    }

    if (!enoughRoomBelow && enoughRoomAbove && !isCurrentlyAbove) {
      newDirection = 'above';
    } else if (!enoughRoomAbove && enoughRoomBelow && isCurrentlyAbove) {
      newDirection = 'below';
    }

    if (newDirection == 'above' ||
      (isCurrentlyAbove && newDirection !== 'below')) {
      css.top = container.top - parentOffset.top - dropdown.height;
    }

    if (newDirection != null) {
      this.$dropdown
        .removeClass('select2-dropdown--below select2-dropdown--above')
        .addClass('select2-dropdown--' + newDirection);
      this.$container
        .removeClass('select2-container--below select2-container--above')
        .addClass('select2-container--' + newDirection);
    }

    this.$dropdownContainer.css(css);
  };