跨平台 HTML touchend 事件处理

Question

In reading about the touchend event, it seem that the behavior is somewhat inconsistent across different devices. I simply want to know the best and simplest way to determine whether all touching has ceased. Do I understand correctly that I can't rely on event.touches being null or empty when this is the case because some devices will include the ended touch in that list? Do I understand correctly that I can't rely on changedTouches being the same length as touches when this is the case because some devices will exclude the ended touch from touches?

Answer 1

For now only OSX (ipad, iphone) support ongesturechange event on their browser. All the other events are supported in all devices, here are some of them and that is the way how to use them. To detect touch end you can use touchend even, it is the same over all devices and it will fires when all fingers are not in touch:

$(someel).bind('touchend',callback');

To detect touch support just use this

var touchy=("ontouchstart" in document.documentElement)?true:false;

Safari developers ipad guide has a good documentation on this.

UPDATE: In fact I was wrong, touchend fires every time a finger lifts up: here is an excellent pdf for you: http://www.albanx.com/programing/ajaxupload/uploaded/SafariJSRef.pdf look at page 21.