Introduction to touch events and virtual mouse events in jQuery mobile page development

Introduction to touch events and virtual mouse events in jQuery mobile page development_jquery

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Release： 2016-05-16 15:27:48

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Touch event (touch)
There are some touch events that are customizable in jQuery Mobile. However, these events are only available when a user interacting with a touch-enabled device visits your jQuery Mobile site. When these events are available, you can trigger any custom JavaScript in response to five different events: tap, taphold, swipe, swipeleft, and swiperight.

tap: Triggered after a quick and complete tap

taphold (tap and hold): Triggered after tapping and holding (about one second)

swipe: An event triggered when the horizontal drag is greater than 30px or the vertical drag is less than 20px within one second. How long and how many pixels to drag can be set. This event has its associated attributes, which are

scrollSupressionThreshold (default: 10px) – Horizontal dragging greater than this value will not trigger.
durationThreshold (default: 1000ms) – If the sliding time exceeds this value, no sliding event will be generated.
horizontalDistanceThreshold (default: 30px) – A sliding event will occur only when the horizontal swipe distance exceeds this value.
verticalDistanceThreshold (default: 75px) – A sliding event will occur only if the vertical swipe distance is smaller than this value.
swipeleft (left swipe): triggered when the swipe event is in the left direction

swiperight (right swipe): triggered when the swipe event is in the right direction

To bind these events, you only need to program in document.ready(), as shown in the following code example:

<!DOCTYPE HTML>
<html>
<head>
 <title>Understanding the jQuery Mobile API</title>
 <link rel="stylesheet" href="jquery.mobile.css" />
 <script src="jquery.js"></script>
 <script type="text/java script">
  $(document).ready(function(){
   $(".tap-hold-test").bind("taphold", function(event) {
    $(this).html("Tapped and held");
   }); 
  });
 </script>
 <script src="jquery.mobile.js"></script>
</head>

<body>
 <div data-role="page" id="my-page">
  <div data-role="header">
      <h1>Header</h1>
    </div>
    <div data-role="content">
      <ul data-role="listview" id="my-list">
        <li class="tap-hold-test">Tap and hold test</li>
      </ul>
  </div>
 </div>
</body>
</html>

Copy after login

As you can see from the above code, a list is bound to the taphold event. When the DOM is loaded and the taphold event is triggered, the Tapped and held prompt message will be displayed.

Virtual mouse events
We provide a series of "virtual" mouse events in an attempt to abstract mouse and touch events. This allows developers to register listeners for basic mouse events such as mousedown, mousemove, mouseup, and click. Plug-ins will be in a touch environment, and the plug-ins will maintain the order in which they are triggered in a traditional mouse environment. For example: vmouseup is always triggered before vmousedown, vmousedown is always triggered before vmouseup, etc. Virtual mouse events will also normalize the coordinate information released from the book sword. Therefore, the coordinates of the pageX, pageY, screenX, screenY, clientX, and clientY properties of the event object can be used in touch-based devices.

vmouseover: handle normalized events of touch or mouseover

vmousedown: handle normalized events of touchstart or mousedown

vmousemove: handles normalized events of touchmove or mousemove

vmouseup: handle normalized events of touchend or mouseup

vclick: handles normalized events of touchend or mouse click. On touch-based devices, this event is fired after the vmouseup event.

vmousecancel: handles the normalized event of touch or mouse mousecancel

Warning: Use vclick with caution
Be careful using vclick on touch devices. The Webkit-based browser will generate mousedown, mouseup, and click events 300ms after the touchend event is triggered. The targets of these generated mouse events are calculated when they fire, based on the location of the touch event, and in some cases can result in different calculations on different devices or even different OS's on the same device. This means that the target element of the original click event may not be the same as the target element of the mouse event generated by the browser itself.
We recommend using the click method instead of the vclick method in events where the touch may change the content below the point you clicked. Such events include page transitions and other behaviors such as shrinking/stretching, which may cause the screen to change or the content to be completely replaced.

Cancel the default click behavior of an element
The application calls a vclick event to cancel the default click event for an element. On mouse-based devices, calling the preventDefault() method on a vclick event is equivalent to calling the preventDefault() method on the temporal bubbling phase of a real click. On touch-based devices it's a little more complicated, because the actual click event will be triggered 300 milliseconds after the vclick event is triggered. For touch devices, calling the preventDefault() method on the vclick event will cause some code in the vmouse plug-in to try to capture the next click event. So according to the caveat above, it is difficult to match a touch event with its corresponding mouse event because their goals are different. So attempts by the vmouse plugin to identify a matching click event via coordinates will usually fail.
In some cases, the recognition of the target and coordinates of the two events will fail, which will cause the click event to be triggered or the default action of the element to be executed, or when the content is changed or replaced, the click event of other elements is triggered. . If such a bug occurs regularly on a given element, we recommend using click-driven triggering for the action.