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Re: Setting focus

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Scott Sauyet wrote on 30 mrt 2013 in comp.lang.javascript:

> Eric Bednarz wrote:
>> Scott Sauyet writes:
>>> [...] In fact, certain style animations would never use
>>> `setTimeout` at all,
>>
>> Right. CSS transitions, animations, keyframes. Or, for scripting,
>> requestAnimationFrame.
>>
>>> choosing `setInterval` instead,
>>
>> Oh my.
> 
> Please remember the context: a discussion about whether it was
> necessary to clean up behind a `setTimeout`.  I was bringing a class
> of animations into this as an example of code that often made heavy
> uses of `setTimeout` often without doing the cleanup that Thomas
> insisted was necessary.  I was not trying to list all the forms of
> animation available.
> 
> Thomas claims to have evidence that he's unwilling to share that code
> of this sort is necessary:
> 
>     var field = …
> 
>     var t = window.setTimeout(function () {
>       field.focus();
>       window.clearTimeout(t);
>       field = null;
>       t = null;

This does not clean up the window.setTimeout,
but only gives another [i.c. null] value 
to the variable pointer t.

If the window.setTimeout would still exist,
which I doubt, it just would not be reachable anymore.

And that would make possible garbage collection later?
No I doubt that, in any reasonable javascript implementation.

However if the window.setTimeout is anonymous, as below,
the availability to garbage collection would be the same.

And anyway, a "spent" window.setTimeout,
either fired or reset, should either not need garbage collection,
or should get that independent of any useless still existing pointer.


>     }, 50);
> 
> and that my alternative is harmful:
> 
>     (function() {
>         var field = …;
>         window.setTimeout(function () {
>             field.focus();
>         }, 50);
>     }());
> 
> I've never seen any evidence of that.  That's the context of these
> discussion.  Animations are not really central to the point, just one
> example.
> 
>   -- Scott
> 



-- 
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

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Thread

Setting focus Tim Slattery <Slattery_T@bls.gov> - 2013-02-28 14:30 -0500
  Re: Setting focus Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-02-28 20:50 +0100
    Re: Setting focus Tim Slattery <Slattery_T@bls.gov> - 2013-02-28 16:05 -0500
      Re: Setting focus Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-02-28 22:17 +0100
        Re: Setting focus Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2013-02-28 23:16 +0100
          Re: Setting focus Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-02-28 23:36 +0100
            Re: Setting focus Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2013-03-01 08:21 +0100
              Re: Setting focus Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-01 13:10 +0100
          Re: Setting focus "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2013-02-28 23:37 +0100
            Re: Setting focus Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2013-03-01 08:18 +0100
              Re: Setting focus Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-01 13:12 +0100
                Re: Setting focus Bernd Nawothnig <Bernd.Nawothnig@t-online.de> - 2013-03-02 15:16 +0100
        Re: Setting focus Scott Sauyet <scott.sauyet@gmail.com> - 2013-03-21 20:06 -0700
          Re: Setting focus Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2013-03-22 10:03 +0100
            Re: Setting focus Tim Slattery <Slattery_T@bls.gov> - 2013-03-22 08:53 -0400
              Re: Setting focus Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-23 15:09 +0100
            Re: Setting focus Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-23 15:07 +0100
              Re: Setting focus Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2013-03-24 12:38 +0100
                Re: Setting focus Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-24 13:42 +0100
                Re: Setting focus Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2013-03-24 13:54 +0100
          Re: Setting focus Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-23 15:04 +0100
            Re: Setting focus Scott Sauyet <scott.sauyet@gmail.com> - 2013-03-23 17:35 -0700
              Re: Setting focus Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-24 10:41 +0100
                Re: Setting focus Scott Sauyet <scott.sauyet@gmail.com> - 2013-03-24 16:42 -0700
                Re: Setting focus Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-30 14:27 +0100
                Re: Setting focus Scott Sauyet <scott.sauyet@gmail.com> - 2013-03-30 09:25 -0700
                Re: Setting focus Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-30 19:50 +0100
                Re: Setting focus Scott Sauyet <scott.sauyet@gmail.com> - 2013-03-30 17:11 -0700
              Re: Setting focus Eric Bednarz <bednarz@fahr-zur-hoelle.org> - 2013-03-30 01:02 +0100
                Re: Setting focus Scott Sauyet <scott.sauyet@gmail.com> - 2013-03-30 09:17 -0700
                Re: Setting focus "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2013-03-30 17:55 +0100

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