swiper/esm/components/core/events/onTouchStart.js

Most modern mobile touch slider and framework with hardware accelerated transitions

import { getWindow, getDocument } from 'ssr-window';
import $ from '../../../utils/dom';
import { extend, now } from '../../../utils/utils';
export default function onTouchStart(event) {
  var swiper = this;
  var document = getDocument();
  var window = getWindow();
  var data = swiper.touchEventsData;
  var params = swiper.params,
      touches = swiper.touches;

  if (swiper.animating && params.preventInteractionOnTransition) {
    return;
  }

  var e = event;
  if (e.originalEvent) e = e.originalEvent;
  var $targetEl = $(e.target);

  if (params.touchEventsTarget === 'wrapper') {
    if (!$targetEl.closest(swiper.wrapperEl).length) return;
  }

  data.isTouchEvent = e.type === 'touchstart';
  if (!data.isTouchEvent && 'which' in e && e.which === 3) return;
  if (!data.isTouchEvent && 'button' in e && e.button > 0) return;
  if (data.isTouched && data.isMoved) return; // change target el for shadow root componenet

  var swipingClassHasValue = !!params.noSwipingClass && params.noSwipingClass !== '';

  if (swipingClassHasValue && e.target && e.target.shadowRoot && event.path && event.path[0]) {
    $targetEl = $(event.path[0]);
  }

  if (params.noSwiping && $targetEl.closest(params.noSwipingSelector ? params.noSwipingSelector : "." + params.noSwipingClass)[0]) {
    swiper.allowClick = true;
    return;
  }

  if (params.swipeHandler) {
    if (!$targetEl.closest(params.swipeHandler)[0]) return;
  }

  touches.currentX = e.type === 'touchstart' ? e.targetTouches[0].pageX : e.pageX;
  touches.currentY = e.type === 'touchstart' ? e.targetTouches[0].pageY : e.pageY;
  var startX = touches.currentX;
  var startY = touches.currentY; // Do NOT start if iOS edge swipe is detected. Otherwise iOS app cannot swipe-to-go-back anymore

  var edgeSwipeDetection = params.edgeSwipeDetection || params.iOSEdgeSwipeDetection;
  var edgeSwipeThreshold = params.edgeSwipeThreshold || params.iOSEdgeSwipeThreshold;

  if (edgeSwipeDetection && (startX <= edgeSwipeThreshold || startX >= window.innerWidth - edgeSwipeThreshold)) {
    return;
  }

  extend(data, {
    isTouched: true,
    isMoved: false,
    allowTouchCallbacks: true,
    isScrolling: undefined,
    startMoving: undefined
  });
  touches.startX = startX;
  touches.startY = startY;
  data.touchStartTime = now();
  swiper.allowClick = true;
  swiper.updateSize();
  swiper.swipeDirection = undefined;
  if (params.threshold > 0) data.allowThresholdMove = false;

  if (e.type !== 'touchstart') {
    var preventDefault = true;
    if ($targetEl.is(data.formElements)) preventDefault = false;

    if (document.activeElement && $(document.activeElement).is(data.formElements) && document.activeElement !== $targetEl[0]) {
      document.activeElement.blur();
    }

    var shouldPreventDefault = preventDefault && swiper.allowTouchMove && params.touchStartPreventDefault;

    if ((params.touchStartForcePreventDefault || shouldPreventDefault) && !$targetEl[0].isContentEditable) {
      e.preventDefault();
    }
  }

  swiper.emit('touchStart', e);
}