var VENDOR_PREFIXES = ['', 'webkit', 'Moz', 'MS', 'ms', 'o'];//前缀
var TEST_ELEMENT = document.createElement('div');//测试元素
var TYPE_FUNCTION = 'function';//函数

//----------------------------Input----------------------------------------
var MOBILE_REGEX = /mobile|tablet|ip(ad|hone|od)|android/i;//判断移动端的正则

var SUPPORT_TOUCH = ('ontouchstart' in window);//判断是否支持touch事件
var SUPPORT_POINTER_EVENTS = prefixed(window, 'PointerEvent') !== undefined;//判断是否支持指针事件
var SUPPORT_ONLY_TOUCH = SUPPORT_TOUCH && MOBILE_REGEX.test(navigator.userAgent);//判断是触屏

var INPUT_TYPE_TOUCH = 'touch';
var INPUT_TYPE_PEN = 'pen';
var INPUT_TYPE_MOUSE = 'mouse';
var INPUT_TYPE_KINECT = 'kinect';

var COMPUTE_INTERVAL = 25;

var INPUT_START = 1;//1 2 4 8 16方便使用"与"跟"或"判断
var INPUT_MOVE = 2;
var INPUT_END = 4;
var INPUT_CANCEL = 8;

var DIRECTION_NONE = 1;
var DIRECTION_LEFT = 2;
var DIRECTION_RIGHT = 4;
var DIRECTION_UP = 8;
var DIRECTION_DOWN = 16;

var DIRECTION_HORIZONTAL = DIRECTION_LEFT | DIRECTION_RIGHT;
var DIRECTION_VERTICAL = DIRECTION_UP | DIRECTION_DOWN;
var DIRECTION_ALL = DIRECTION_HORIZONTAL | DIRECTION_VERTICAL;

var PROPS_XY = ['x', 'y'];
var PROPS_CLIENT_XY = ['clientX', 'clientY'];

var MOUSE_ELEMENT_EVENTS = 'mousedown';
var MOUSE_WINDOW_EVENTS = 'mousemove mouseup';

var POINTER_ELEMENT_EVENTS = 'pointerdown';
var POINTER_WINDOW_EVENTS = 'pointermove pointerup pointercancel';

var SINGLE_TOUCH_TARGET_EVENTS = 'touchstart';
var SINGLE_TOUCH_WINDOW_EVENTS = 'touchstart touchmove touchend touchcancel';

var TOUCH_TARGET_EVENTS = 'touchstart touchmove touchend touchcancel';

//----------------------------TouchAction----------------------------------------
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';

//----------------------------Recognizer----------------------------------------
var STATE_POSSIBLE = 1;
var STATE_BEGAN = 2;
var STATE_CHANGED = 4;
var STATE_ENDED = 8;
var STATE_RECOGNIZED = STATE_ENDED;//已完成recognize
var STATE_CANCELLED = 16;
var STATE_FAILED = 32;


//----------------------------Manager----------------------------------------
var STOP = 1;
var FORCED_STOP = 2;

var layer = document.getElementById('layer');
var mc = new Hammer(layer);

function Hammer(element, options) {
    options = options || {};
    options.recognizers = ifUndefined(options.recognizers, Hammer.defaults.preset);
    return new Manager(element, options);
}

preset: [
        // RecognizerClass, options, [recognizeWith, ...], [requireFailure, ...]
        [RotateRecognizer, {enable: false}],
        [PinchRecognizer, {enable: false}, ['rotate']],
        [SwipeRecognizer, {direction: DIRECTION_HORIZONTAL}],
        [PanRecognizer, {direction: DIRECTION_HORIZONTAL}, ['swipe']],
        [TapRecognizer],
        [TapRecognizer, {event: 'doubletap', taps: 2}, ['tap']],
        [PressRecognizer]
]

var mc = new Hammer.Manager(layer);
mc.add(new Hammer.Tap());

assign(Hammer, {
  Tap: TapRecognizer,
  Pan: PanRecognizer,
  Swipe: SwipeRecognizer,
  //...省略其他值
});

update: function() {
    this.set(this.manager.options.touchAction);
}

var PREFIXED_TOUCH_ACTION = prefixed(TEST_ELEMENT.style, 'touchAction');
var NATIVE_TOUCH_ACTION = PREFIXED_TOUCH_ACTION !== undefined;
set: function(value) {
  // 自己做计算
  if (value == TOUCH_ACTION_COMPUTE) {
    value = this.compute();
  }
  //支持原生"touch-action"就直接赋值
  if (NATIVE_TOUCH_ACTION && this.manager.element.style) {
    this.manager.element.style[PREFIXED_TOUCH_ACTION] = value;
  }
  this.actions = value.toLowerCase().trim();//缓存属性值，用于后面的polyfill
}

var layer = document.getElementById('layer');
var mc = new Hammer.Manager(layer);
mc.add(new Hammer.Tap());

mc.on('tap', function(e) {
    layer.style.display = "none";
    e.preventDefault();
});