Function flip

app/src/static/js/react-bootstrap.js:4526–4605

* @function * @memberof Modifiers * @argument {Object} data - The data object generated by update method * @argument {Object} options - Modifiers configuration and options * @returns {Object} The data object, properly modified

(data, options)

 */

function flip(data, options) {
  // if `inner` modifier is enabled, we can't use the `flip` modifier
  if (isModifierEnabled(data.instance.modifiers, 'inner')) {
    return data;
  }

  if (data.flipped && data.placement === data.originalPlacement) {
    // seems like flip is trying to loop, probably there's not enough space on any of the flippable sides
    return data;
  }

  var boundaries = getBoundaries(data.instance.popper, data.instance.reference, options.padding, options.boundariesElement, data.positionFixed);
  var placement = data.placement.split('-')[0];
  var placementOpposite = getOppositePlacement(placement);
  var variation = data.placement.split('-')[1] || '';
  var flipOrder = [];

  switch (options.behavior) {
    case BEHAVIORS.FLIP:
      flipOrder = [placement, placementOpposite];
      break;

    case BEHAVIORS.CLOCKWISE:
      flipOrder = clockwise(placement);
      break;

    case BEHAVIORS.COUNTERCLOCKWISE:
      flipOrder = clockwise(placement, true);
      break;

    default:
      flipOrder = options.behavior;
  }

  flipOrder.forEach(function (step, index) {
    if (placement !== step || flipOrder.length === index + 1) {
      return data;
    }

    placement = data.placement.split('-')[0];
    placementOpposite = getOppositePlacement(placement);
    var popperOffsets = data.offsets.popper;
    var refOffsets = data.offsets.reference; // using floor because the reference offsets may contain decimals we are not going to consider here

    var floor = Math.floor;
    var overlapsRef = placement === 'left' && floor(popperOffsets.right) > floor(refOffsets.left) || placement === 'right' && floor(popperOffsets.left) < floor(refOffsets.right) || placement === 'top' && floor(popperOffsets.bottom) > floor(refOffsets.top) || placement === 'bottom' && floor(popperOffsets.top) < floor(refOffsets.bottom);
    var overflowsLeft = floor(popperOffsets.left) < floor(boundaries.left);
    var overflowsRight = floor(popperOffsets.right) > floor(boundaries.right);
    var overflowsTop = floor(popperOffsets.top) < floor(boundaries.top);
    var overflowsBottom = floor(popperOffsets.bottom) > floor(boundaries.bottom);
    var overflowsBoundaries = placement === 'left' && overflowsLeft || placement === 'right' && overflowsRight || placement === 'top' && overflowsTop || placement === 'bottom' && overflowsBottom; // flip the variation if required

    var isVertical = ['top', 'bottom'].indexOf(placement) !== -1; // flips variation if reference element overflows boundaries

    var flippedVariationByRef = !!options.flipVariations && (isVertical && variation === 'start' && overflowsLeft || isVertical && variation === 'end' && overflowsRight || !isVertical && variation === 'start' && overflowsTop || !isVertical && variation === 'end' && overflowsBottom); // flips variation if popper content overflows boundaries

    var flippedVariationByContent = !!options.flipVariationsByContent && (isVertical && variation === 'start' && overflowsRight || isVertical && variation === 'end' && overflowsLeft || !isVertical && variation === 'start' && overflowsBottom || !isVertical && variation === 'end' && overflowsTop);
    var flippedVariation = flippedVariationByRef || flippedVariationByContent;