swiper/src/components/core/events/onScroll.js

Most modern mobile touch slider and framework with hardware accelerated transitions

export default function () {
  const swiper = this;
  const { wrapperEl } = swiper;
  swiper.previousTranslate = swiper.translate;
  swiper.translate = swiper.isHorizontal() ? -wrapperEl.scrollLeft : -wrapperEl.scrollTop;
  // eslint-disable-next-line
  if (swiper.translate === -0) swiper.translate = 0;

  swiper.updateActiveIndex();
  swiper.updateSlidesClasses();

  let newProgress;
  const translatesDiff = swiper.maxTranslate() - swiper.minTranslate();
  if (translatesDiff === 0) {
    newProgress = 0;
  } else {
    newProgress = (swiper.translate - swiper.minTranslate()) / (translatesDiff);
  }
  if (newProgress !== swiper.progress) {
    swiper.updateProgress(swiper.translate);
  }

  swiper.emit('setTranslate', swiper.translate, false);
}