Function initScrollObserver

packages/rrweb/src/record/observer.ts:311–352

({
  scrollCb,
  doc,
  mirror,
  blockClass,
  blockSelector,
  sampling,
}: Pick<
  observerParam,
  'scrollCb' | 'doc' | 'mirror' | 'blockClass' | 'blockSelector' | 'sampling'
>)

}

export function initScrollObserver({
  scrollCb,
  doc,
  mirror,
  blockClass,
  blockSelector,
  sampling,
}: Pick<
  observerParam,
  'scrollCb' | 'doc' | 'mirror' | 'blockClass' | 'blockSelector' | 'sampling'
>): listenerHandler {
  const updatePosition = callbackWrapper(
    throttle<UIEvent>(
      callbackWrapper((evt) => {
        const target = getEventTarget(evt);
        if (
          !target ||
          isBlocked(target as Node, blockClass, blockSelector, true)
        ) {
          return;
        }
        const id = mirror.getId(target as Node);
        if (target === doc && doc.defaultView) {
          const scrollLeftTop = getWindowScroll(doc.defaultView);
          scrollCb({
            id,
            x: scrollLeftTop.left,
            y: scrollLeftTop.top,
          });
        } else {
          scrollCb({
            id,
            x: (target as HTMLElement).scrollLeft,
            y: (target as HTMLElement).scrollTop,
          });
        }
      }),
      sampling.scroll || 100,
    ),
  );
  return on('scroll', updatePosition, doc);
}

function initViewportResizeObserver(
  { viewportResizeCb }: observerParam,