text: var PREFIXED_TOUCH_ACTION = prefixed(TEST_ELEMENT.style, 'touchAction');
  var NATIVE_TOUCH_ACTION = PREFIXED_TOUCH_ACTION !== undefined;
  
  // magical touchAction value
  var TOUCH_ACTION_COMPUTE = 'compute';
  var TOUCH_ACTION_AUTO = 'auto';
  var TOUCH_ACTION_MANIPULATION = 'manipulation'; // not implemented
  var TOUCH_ACTION_NONE = 'none';
  var TOUCH_ACTION_PAN_X = 'pan-x';
  var TOUCH_ACTION_PAN_Y = 'pan-y';
  
  /**
   * Touch Action
   * sets the touchAction property or uses the js alternative
   * @param {Manager} manager
   * @param {String} value
   * @constructor
   */
  function TouchAction(manager, value) {
      this.manager = manager;
      this.set(value);
  }
  
  TouchAction.prototype = {
      /**
       * set the touchAction value on the element or enable the polyfill
       * @param {String} value
       */
      set: function(value) {
          // find out the touch-action by the event handlers
          if (value == TOUCH_ACTION_COMPUTE) {
              value = this.compute();
          }
  
          if (NATIVE_TOUCH_ACTION && this.manager.element.style) {
              this.manager.element.style[PREFIXED_TOUCH_ACTION] = value;
          }
          this.actions = value.toLowerCase().trim();
      },
  
      /**
       * just re-set the touchAction value
       */
      update: function() {
          this.set(this.manager.options.touchAction);
      },
  
      /**
       * compute the value for the touchAction property based on the recognizer's settings
       * @returns {String} value
       */
      compute: function() {
          var actions = [];
          each(this.manager.recognizers, function(recognizer) {
              if (boolOrFn(recognizer.options.enable, [recognizer])) {
                  actions = actions.concat(recognizer.getTouchAction());
              }
          });
          return cleanTouchActions(actions.join(' '));
      },
  
      /**
       * this method is called on each input cycle and provides the preventing of the browser behavior
       * @param {Object} input
       */
      preventDefaults: function(input) {
          // not needed with native support for the touchAction property
          if (NATIVE_TOUCH_ACTION) {
              return;
          }
  
          var srcEvent = input.srcEvent;
          var direction = input.offsetDirection;
  
          // if the touch action did prevented once this session
          if (this.manager.session.prevented) {
              srcEvent.preventDefault();
              return;
          }
  
          var actions = this.actions;
          var hasNone = inStr(actions, TOUCH_ACTION_NONE);
          var hasPanY = inStr(actions, TOUCH_ACTION_PAN_Y);
          var hasPanX = inStr(actions, TOUCH_ACTION_PAN_X);
  
          if (hasNone) {
              //do not prevent defaults if this is a tap gesture
  
              var isTapPointer = input.pointers.length === 1;
              var isTapMovement = input.distance < 2;
              var isTapTouchTime = input.deltaTime < 250;
  
              if (isTapPointer && isTapMovement && isTapTouchTime) {
                  return;
              }
          }
  
          if (hasPanX && hasPanY) {
              // `pan-x pan-y` means browser handles all scrolling/panning, do not prevent
              return;
          }
  
          if (hasNone ||
              (hasPanY && direction & DIRECTION_HORIZONTAL) ||
              (hasPanX && direction & DIRECTION_VERTICAL)) {
              return this.preventSrc(srcEvent);
          }
      },
  
      /**
       * call preventDefault to prevent the browser's default behavior (scrolling in most cases)
       * @param {Object} srcEvent
       */
      preventSrc: function(srcEvent) {
          this.manager.session.prevented = true;
          srcEvent.preventDefault();
      }
  };
  
  /**
   * when the touchActions are collected they are not a valid value, so we need to clean things up. *
   * @param {String} actions
   * @returns {*}
   */
  function cleanTouchActions(actions) {
      // none
      if (inStr(actions, TOUCH_ACTION_NONE)) {
          return TOUCH_ACTION_NONE;
      }
  
      var hasPanX = inStr(actions, TOUCH_ACTION_PAN_X);
      var hasPanY = inStr(actions, TOUCH_ACTION_PAN_Y);
  
      // if both pan-x and pan-y are set (different recognizers
      // for different directions, e.g. horizontal pan but vertical swipe?)
      // we need none (as otherwise with pan-x pan-y combined none of these
      // recognizers will work, since the browser would handle all panning
      if (hasPanX && hasPanY) {
          return TOUCH_ACTION_NONE;
      }
  
      // pan-x OR pan-y
      if (hasPanX || hasPanY) {
          return hasPanX ? TOUCH_ACTION_PAN_X : TOUCH_ACTION_PAN_Y;
      }
  
      // manipulation
      if (inStr(actions, TOUCH_ACTION_MANIPULATION)) {
          return TOUCH_ACTION_MANIPULATION;
      }
  
      return TOUCH_ACTION_AUTO;
  }
  