touch.js

//  Based on Zeptos touch.js
//  https://raw.github.com/madrobby/zepto/master/src/touch.js
//  Zepto.js may be freely distributed under the MIT license.

(function(root) {
  'use strict';

  var $ = root.jQuery;

  if (!$ || $.fn.swipeLeft) {
    return;
  }

  var touch = {};
  var touchTimeout;
  var tapTimeout;
  var swipeTimeout;
  var longTapTimeout;
  var longTapDelay = 750;
  var gesture;

  function swipeDirection(x1, x2, y1, y2) {
    return Math.abs(x1 - x2) >= Math.abs(y1 - y2) ? (x1 - x2 > 0 ?
      'Left' : 'Right') : (y1 - y2 > 0 ? 'Up' : 'Down');
  }

  function longTap() {
    longTapTimeout = null;
    if (touch.last) {
      touch.el.trigger('longTap');
      touch = {};
    }
  }

  function cancelLongTap() {
    if (longTapTimeout) {
      clearTimeout(longTapTimeout);
    }
    longTapTimeout = null;
  }

  function cancelAll() {
    if (touchTimeout) {
      clearTimeout(touchTimeout);
    }
    if (tapTimeout) {
      clearTimeout(tapTimeout);
    }
    if (swipeTimeout) {
      clearTimeout(swipeTimeout);
    }
    if (longTapTimeout) {
      clearTimeout(longTapTimeout);
    }
    touchTimeout = tapTimeout = swipeTimeout = longTapTimeout = null;
    touch = {};
  }

  function isPrimaryTouch(event) {
    return event.pointerType == event.MSPOINTER_TYPE_TOUCH && event.isPrimary;
  }

  $(function() {
    var now;
    var delta;
    var deltaX = 0;
    var deltaY = 0;
    var firstTouch;

    if ('MSGesture' in window) {
      gesture = new MSGesture();
      gesture.target = document.body;
    }

    $(document)
      .on('MSGestureEnd gestureend', function(e) {

        var swipeDirectionFromVelocity = e.originalEvent.velocityX > 1 ?
          'Right' : e.originalEvent.velocityX < -1 ?
          'Left' : e.originalEvent.velocityY > 1 ?
          'Down' : e.originalEvent.velocityY < -1 ? 'Up' : null;

        if (swipeDirectionFromVelocity) {
          touch.el.trigger('swipe');
          touch.el.trigger('swipe' + swipeDirectionFromVelocity);
        }
      })
      // MSPointerDown: for IE10
      // pointerdown: for IE11
      .on('touchstart MSPointerDown pointerdown', function(e) {

        if (e.type == 'MSPointerDown' && !isPrimaryTouch(e.originalEvent)) {
          return;
        }

        firstTouch = (e.type == 'MSPointerDown' || e.type == 'pointerdown') ?
          e : e.originalEvent.touches[0];

        now = Date.now();
        delta = now - (touch.last || now);
        touch.el = $('tagName' in firstTouch.target ?
          firstTouch.target : firstTouch.target.parentNode);

        if (touchTimeout) {
          clearTimeout(touchTimeout);
        }

        touch.x1 = firstTouch.pageX;
        touch.y1 = firstTouch.pageY;

        if (delta > 0 && delta <= 250) {
          touch.isDoubleTap = true;
        }

        touch.last = now;
        longTapTimeout = setTimeout(longTap, longTapDelay);

        // adds the current touch contact for IE gesture recognition
        if (gesture && (e.type == 'MSPointerDown' || e.type == 'pointerdown' ||
          e.type == 'touchstart')) {
          gesture.addPointer(e.originalEvent.pointerId);
        }

      })
      // MSPointerMove: for IE10
      // pointermove: for IE11
      .on('touchmove MSPointerMove pointermove', function(e) {

        if (e.type == 'MSPointerMove' && !isPrimaryTouch(e.originalEvent)) {
          return;
        }

        firstTouch = (e.type == 'MSPointerMove' || e.type == 'pointermove') ?
          e : e.originalEvent.touches[0];

        cancelLongTap();
        touch.x2 = firstTouch.pageX;
        touch.y2 = firstTouch.pageY;

        deltaX += Math.abs(touch.x1 - touch.x2);
        deltaY += Math.abs(touch.y1 - touch.y2);
      })
      // MSPointerUp: for IE10
      // pointerup: for IE11
      .on('touchend MSPointerUp pointerup', function(e) {

        if (e.type == 'MSPointerUp' && !isPrimaryTouch(e.originalEvent)) {
          return;
        }

        cancelLongTap();

        // swipe
        if ((touch.x2 && Math.abs(touch.x1 - touch.x2) > 30) ||
          (touch.y2 && Math.abs(touch.y1 - touch.y2) > 30)) {

          swipeTimeout = setTimeout(function() {
            touch.el.trigger('swipe');
            touch.el.trigger('swipe' +
            (swipeDirection(touch.x1, touch.x2, touch.y1, touch.y2)));
            touch = {};
          }, 0);

          // normal tap
        } else if ('last' in touch) {

          // don't fire tap when delta position changed by more than 30 pixels,
          // for instance when moving to a point and back to origin
          if (isNaN(deltaX) || (deltaX < 30 && deltaY < 30)) {
            // delay by one tick so we can cancel the 'tap' event if 'scroll' fires
            // ('tap' fires before 'scroll')
            tapTimeout = setTimeout(function() {

              // trigger universal 'tap' with the option to cancelTouch()
              // (cancelTouch cancels processing of single vs double taps for faster 'tap' response)
              var event = $.Event('tap');
              event.cancelTouch = cancelAll;
              touch.el.trigger(event);

              // trigger double tap immediately
              if (touch.isDoubleTap) {
                touch.el.trigger('doubleTap');
                touch = {};
              }

              // trigger single tap after 250ms of inactivity
              else {
                touchTimeout = setTimeout(function() {
                  touchTimeout = null;
                  touch.el.trigger('singleTap');
                  touch = {};
                }, 250);
              }
            }, 0);
          } else {
            touch = {};
          }
          deltaX = deltaY = 0;
        }
      })
      // when the browser window loses focus,
      // for example when a modal dialog is shown,
      // cancel all ongoing events
      .on('touchcancel MSPointerCancel', cancelAll);

    // scrolling the window indicates intention of the user
    // to scroll, not tap or swipe, so cancel all ongoing events
    $(window).on('scroll', cancelAll);
  });

  ['swipe', 'swipeLeft', 'swipeRight', 'swipeUp', 'swipeDown',
    'doubleTap', 'tap', 'singleTap', 'longTap'].forEach(function(eventName) {
    $.fn[eventName] = function(callback) {
      return $(this).on(eventName, callback);
    };
  });
})(this);