Zepto tap 穿透bug、解決移動端點擊穿透問題

標籤：inter   int   stc   0ms   冒泡   ade   cli   pos   option   

　　當兩個層重疊在一起時，或是有個彈窗，使用Zepto的tap事件時，點擊上面的一層時會觸發下面一層的事件，特別是底層如果是input框時，必“穿 透”，“google”說原因是“tap事件實際上是在冒泡到body上時才觸發”，也就是Zepto的tap事件是綁定在document上的，所以會導致，這個還未求證。如， 當點擊關閉按鈕，如果下面有商品a連結，則會穿透（關閉的同時，觸發了連結）；  

現象原因：

　　zepto的tap通過兼聽綁定在document上的touch事件來完成tap事件的類比的,及tap事件是冒泡到document上觸發的，再點擊完成時的tap事件(touchstart\touchend)需要冒泡到document上才會觸發，而在冒泡到document之前，用 戶手的接觸螢幕(touchstart)和離開螢幕(touchend)是會觸發click事件的,因為click事件有延遲觸發(這就是為什麼移動端不 用click而用tap的原因)(大概是300ms,為了實現safari的雙擊事件的設計)，所以在執行完tap事件之後，彈出來的選擇組件馬 上就隱藏了，此時click事件還在延遲的300ms之中，當300ms到來的時候，click到的其實不是完成而是隱藏之後的下方的元素，如果正下方的 元素繫結的有click事件此時便會觸發，如果沒有綁定click事件的話就當沒click，但是正下方的是input輸入框(或者select選擇框或 者單選複選框)，點擊預設聚焦而彈出輸入鍵盤，也就出現了上面的點透現象。

 

解決方案如下：

1、使用github上有一個叫做fastclick的庫；

2、監聽touchend事件，並在事件中使用preventDefault()阻止冒泡；

$(".js-egg-close").on("touchend", function(e) { //這裡使用touchstart事件也是可以的，    e.preventDefault();    $(‘.sec_dlg_eggs‘).remove();    $(".eggs_bg").remove();});

3、使用css3的pointer-events=true,pointer-events=none切換來實現；

4.延遲一定的時間來處理事件。與jquery的動畫(fadeIn()，fadeOut())等配合感覺良好；

$(id).fadeIn(300);

5.如果還不奏效，終極解決方案是用click提代tap；

設定點擊事件為_tap：_tap = touchend in document ? "touchend":"click"；這樣在執行的過程中就可以直接調用div.on(_tap, function(){}) 

 

下面我們貼下zepto.1.1.6 tap事件的源碼：

;(function($){      var touch = {},          touchTimeout, tapTimeout, swipeTimeout, longTapTimeout,          longTapDelay = 750,          gesture    　 
　　 // 判斷左右上下滑動的方向    function swipeDirection(x1, x2, y1, y2) {
　　　　　// Math.abs()：返回數位絕對值        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 == ‘touch‘ ||  event.pointerType == event.MSPOINTER_TYPE_TOUCH) && event.isPrimary      }        function isPointerEventType(e, type){          return (e.type == ‘pointer‘+type || e.type.toLowerCase() == ‘mspointer‘+type)      }        $(document).ready(function(){          var now, delta, deltaX = 0, deltaY = 0, firstTouch, _isPointerType            if (‘MSGesture‘ in window) {              gesture = new MSGesture()              gesture.target = document.body          }            $(document)              .bind(‘MSGestureEnd‘, function(e){                  var swipeDirectionFromVelocity =                          e.velocityX > 1 ? ‘Right‘ : e.velocityX < -1 ? ‘Left‘ : e.velocityY > 1 ? ‘Down‘ : e.velocityY < -1 ? ‘Up‘ : null;                  if (swipeDirectionFromVelocity) {                      touch.el.trigger(‘swipe‘)                      touch.el.trigger(‘swipe‘+ swipeDirectionFromVelocity)                  }              })              .on(‘touchstart MSPointerDown pointerdown‘, function(e){                  if((_isPointerType = isPointerEventType(e, ‘down‘)) &&                      !isPrimaryTouch(e)) return                  firstTouch = _isPointerType ? e : e.touches[0]                  if (e.touches && e.touches.length === 1 && touch.x2) {                      // Clear out touch movement data if we have it sticking around                      // This can occur if touchcancel doesn‘t fire due to preventDefault, etc.                      touch.x2 = undefined                      touch.y2 = undefined                  }                  now = Date.now()                  delta = now - (touch.last || now)                  touch.el = $(‘tagName‘ in firstTouch.target ?                      firstTouch.target : firstTouch.target.parentNode)                  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 && _isPointerType) gesture.addPointer(e.pointerId);              })              .on(‘touchmove MSPointerMove pointermove‘, function(e){                  if((_isPointerType = isPointerEventType(e, ‘move‘)) &&                      !isPrimaryTouch(e)) return                  firstTouch = _isPointerType ? e : e.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)              })              .on(‘touchend MSPointerUp pointerup‘, function(e){                  if((_isPointerType = isPointerEventType(e, ‘up‘)) &&                      !isPrimaryTouch(e)) 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 (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) {                                  if (touch.el) touch.el.trigger(‘doubleTap‘)                                  touch = {}                              }                                // trigger single tap after 250ms of inactivity                              else {                                  touchTimeout = setTimeout(function(){                                      touchTimeout = null                                      if (touch.el) 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 pointercancel‘, 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);         }    })  })(Zepto) 

 

 。

Zepto tap 穿透bug、解決移動端點擊穿透問題