annotate core/misc/displace.js @ 0:4c8ae668cc8c

Initial import (non-working)

/**
* DO NOT EDIT THIS FILE.
* See the following change record for more information,
* https://www.drupal.org/node/2815083
* @preserve
**/

(function ($, Drupal, debounce) {
  var offsets = {
    top: 0,
    right: 0,
    bottom: 0,
    left: 0
  };

  Drupal.behaviors.drupalDisplace = {
    attach: function attach() {
      if (this.displaceProcessed) {
        return;
      }
      this.displaceProcessed = true;

      $(window).on('resize.drupalDisplace', debounce(displace, 200));
    }
  };

  function displace(broadcast) {
    offsets = Drupal.displace.offsets = calculateOffsets();
    if (typeof broadcast === 'undefined' || broadcast) {
      $(document).trigger('drupalViewportOffsetChange', offsets);
    }
    return offsets;
  }

  function calculateOffsets() {
    return {
      top: calculateOffset('top'),
      right: calculateOffset('right'),
      bottom: calculateOffset('bottom'),
      left: calculateOffset('left')
    };
  }

  function calculateOffset(edge) {
    var edgeOffset = 0;
    var displacingElements = document.querySelectorAll('[data-offset-' + edge + ']');
    var n = displacingElements.length;
    for (var i = 0; i < n; i++) {
      var el = displacingElements[i];

      if (el.style.display === 'none') {
        continue;
      }

      var displacement = parseInt(el.getAttribute('data-offset-' + edge), 10);

      if (isNaN(displacement)) {
        displacement = getRawOffset(el, edge);
      }

      edgeOffset = Math.max(edgeOffset, displacement);
    }

    return edgeOffset;
  }

  function getRawOffset(el, edge) {
    var $el = $(el);
    var documentElement = document.documentElement;
    var displacement = 0;
    var horizontal = edge === 'left' || edge === 'right';

    var placement = $el.offset()[horizontal ? 'left' : 'top'];

    placement -= window['scroll' + (horizontal ? 'X' : 'Y')] || document.documentElement['scroll' + (horizontal ? 'Left' : 'Top')] || 0;

    switch (edge) {
      case 'top':
        displacement = placement + $el.outerHeight();
        break;

      case 'left':
        displacement = placement + $el.outerWidth();
        break;

      case 'bottom':
        displacement = documentElement.clientHeight - placement;
        break;

      case 'right':
        displacement = documentElement.clientWidth - placement;
        break;

      default:
        displacement = 0;
    }
    return displacement;
  }

  Drupal.displace = displace;
  $.extend(Drupal.displace, {
    offsets: offsets,

    calculateOffset: calculateOffset
  });
})(jQuery, Drupal, Drupal.debounce);