_addTouchEventListeners()

in src/site/assets/js/bootstrap.esm.js [1284:1337]

• 39 lines of code
• 13 McCabe index (conditional complexity)

  _addTouchEventListeners() {
    const start = event => {
      if (this._pointerEvent && (event.pointerType === POINTER_TYPE_PEN || event.pointerType === POINTER_TYPE_TOUCH)) {
        this.touchStartX = event.clientX;
      } else if (!this._pointerEvent) {
        this.touchStartX = event.touches[0].clientX;
      }
    };

    const move = event => {
      // ensure swiping with one touch and not pinching
      this.touchDeltaX = event.touches && event.touches.length > 1 ? 0 : event.touches[0].clientX - this.touchStartX;
    };

    const end = event => {
      if (this._pointerEvent && (event.pointerType === POINTER_TYPE_PEN || event.pointerType === POINTER_TYPE_TOUCH)) {
        this.touchDeltaX = event.clientX - this.touchStartX;
      }

      this._handleSwipe();

      if (this._config.pause === 'hover') {
        // If it's a touch-enabled device, mouseenter/leave are fired as
        // part of the mouse compatibility events on first tap - the carousel
        // would stop cycling until user tapped out of it;
        // here, we listen for touchend, explicitly pause the carousel
        // (as if it's the second time we tap on it, mouseenter compat event
        // is NOT fired) and after a timeout (to allow for mouse compatibility
        // events to fire) we explicitly restart cycling
        this.pause();

        if (this.touchTimeout) {
          clearTimeout(this.touchTimeout);
        }

        this.touchTimeout = setTimeout(event => this.cycle(event), TOUCHEVENT_COMPAT_WAIT + this._config.interval);
      }
    };

    SelectorEngine.find(SELECTOR_ITEM_IMG, this._element).forEach(itemImg => {
      EventHandler.on(itemImg, EVENT_DRAG_START, e => e.preventDefault());
    });

    if (this._pointerEvent) {
      EventHandler.on(this._element, EVENT_POINTERDOWN, event => start(event));
      EventHandler.on(this._element, EVENT_POINTERUP, event => end(event));

      this._element.classList.add(CLASS_NAME_POINTER_EVENT);
    } else {
      EventHandler.on(this._element, EVENT_TOUCHSTART, event => start(event));
      EventHandler.on(this._element, EVENT_TOUCHMOVE, event => move(event));
      EventHandler.on(this._element, EVENT_TOUCHEND, event => end(event));
    }
  }