function computeAutoPlacement()

in js/popper.js [697:746]


function computeAutoPlacement(placement, refRect, popper, reference, boundariesElement) {
  var padding = arguments.length > 5 && arguments[5] !== undefined ? arguments[5] : 0;

  if (placement.indexOf('auto') === -1) {
    return placement;
  }

  var boundaries = getBoundaries(popper, reference, padding, boundariesElement);

  var rects = {
    top: {
      width: boundaries.width,
      height: refRect.top - boundaries.top
    },
    right: {
      width: boundaries.right - refRect.right,
      height: boundaries.height
    },
    bottom: {
      width: boundaries.width,
      height: boundaries.bottom - refRect.bottom
    },
    left: {
      width: refRect.left - boundaries.left,
      height: boundaries.height
    }
  };

  var sortedAreas = Object.keys(rects).map(function (key) {
    return _extends({
      key: key
    }, rects[key], {
      area: getArea(rects[key])
    });
  }).sort(function (a, b) {
    return b.area - a.area;
  });

  var filteredAreas = sortedAreas.filter(function (_ref2) {
    var width = _ref2.width,
        height = _ref2.height;
    return width >= popper.clientWidth && height >= popper.clientHeight;
  });

  var computedPlacement = filteredAreas.length > 0 ? filteredAreas[0].key : sortedAreas[0].key;

  var variation = placement.split('-')[1];

  return computedPlacement + (variation ? '-' + variation : '');
}