block1.js

export type ViewabilityConfig = {
  /**
   * Minimum amount of time (in milliseconds) that an item must be physically viewable before the
   * viewability callback will be fired. A high number means that scrolling through content without
   * stopping will not mark the content as viewable.
   */
  minimumViewTime?: number,

  /**
   * Percent of viewport that must be covered for a partially occluded item to count as
   * "viewable", 0-100. Fully visible items are always considered viewable. A value of 0 means
   * that a single pixel in the viewport makes the item viewable, and a value of 100 means that
   * an item must be either entirely visible or cover the entire viewport to count as viewable.
   */
  viewAreaCoveragePercentThreshold?: number,

  /**
   * Similar to `viewAreaPercentThreshold`, but considers the percent of the item that is visible,
   * rather than the fraction of the viewable area it covers.
   */
  itemVisiblePercentThreshold?: number,

  /**
   * Nothing is considered viewable until the user scrolls or `recordInteraction` is called after
   * render.
   */
  waitForInteraction?: boolean,
|};