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From: Ben Bacarisse <ben.usenet@bsb.me.uk>
Newsgroups: comp.lang.javascript
Subject: Re: Differentiate between touch start and click
Date: Fri, 16 Sep 2016 11:25:15 +0100
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Andrew Poulos <ap_prog@hotmail.com> writes:

> I have a touchstart event and a click event both triggering this function
>
> function checkTrigger(e){
>   if (e.type != "click") {
>     e = e.touches[0];
>   }
>
>   var elem = document.elementFromPoint(e.pageX - window.pageXOffset,
>                                        e.pageY - window.pageYOffset);
>   ...
> }
>
> To tell whether it was a touchstart or a click I'm using
>   (e.type != "click")
> is that the right way to differentiate between the two or should I
> have two smaller functions (one for each event) which then pass on the
> relevant values to checkTrigger?

I don't think it matters much but I would, in general, make the test
positive (logically you are doing something when it's a touch event, not
when it isn't a click event).  Indeed, you might even want to test for
the touches property itself.

I'd be more concerned about the pageX/pageY stuff which is not
standardised (though I may be behind the times on that).  You usually
get the target element using "e.target" and "this" will usually refer to
the element to which the listener was added.

-- 
Ben.