Unfortunately, I have very little time this afternoon/evening (perhaps not
enough time to write a proper response)... but I'll try:
If the time between timeout calls is NOT important (ex: to update the
position of an element) then use setInterval. It basically acts like a
self-calling timeout, except that if the cpu is taxed the intervals can be
forced together. So a 13ms interval should fire at 13ms, 26ms, 39ms, etc...
but if the cpu/browser has other things to think about it may fire at 13ms,
38ms, 39ms... or something like that. If you're just updating the position
of something on screen it won't really matter because this will give you the
fastest response/update time. You should be able to find setInterval
examples anywhere on the internet.
A self-calling timeout acts like setInterval, except you're guaranteed some
separation between calls (because even if one is slightly delayed, the next
will always be #ms later). You would want to use this if the separation of
time is important (if you're doing some comparison between the previous
location and the current location, for instance). You can find a complex
example of this in the hoverIntent plug-in (look for the "compare"
function). The basic idea is that in the function your timeout calls, it
calls itself again if a certain condition is met. A simple example: (I
haven't written JavaScript in a while so someone may want to check if this
works)
var f = function(){
/* do stuff */
if ( something ) {
t = setTimeout( f, 13 );
}
};
var t = setTimeout( f, 13 );
Good luck,
Brian.
On 10/17/07, Alexandre Plennevaux <[EMAIL PROTECTED]> wrote:
>
> Brian,
>
> could you fastly elaborate (with a basic code sample if possible) on how
> to do this:
>
> use a self-calling timer to do any additional math/logic with those
> coordinates
>
>
> Thanks a lot for your time and help!
>
> alex
>
> ------------------------------
> *From:* jquery-en@googlegroups.com [mailto:[EMAIL PROTECTED] *On
> Behalf Of *Brian Cherne
> *Sent:* mercredi 17 octobre 2007 17:35
> *To:* jquery-en@googlegroups.com
> *Subject:* [jQuery] Re: continuous action while mouseover
>
> OnMouseOver
> - capture initial position
> - start onMouseMove listening
>
> OnMouseMove
> - capture mouse postion
>
> OnMouseOut
> - stop onMouseMove listening
>
> Note 1) OnMouseMove is a very cpu-expensive event. It literally fires with
> every tiny little move of the mouse. You'll want to you have onMouseMove
> handler very very simple to keep from maxing out the user's cpu. If
> possible, you may consider having onMouseMove store just mouse coordinates
> and use a self-calling timer to do any additional math/logic with those
> coordinates. The fastest timer (~13ms) is still much better (more
> cpu-friendly) than onMouseMove.
>
> Note 2) You may consider using hover instead of onMouseOver/onMouseOut ...
> unless you only have the one object and won't have to worry about executing
> onMouseOver with every crease in the DOM structure.
>
> I hope this helps.
>
> Brian.
>
> On 10/17/07, Alexandre Plennevaux <[EMAIL PROTECTED]> wrote:
> >
> >
> > Hi friends,
> >
> > i was wondering: how can i trigger an action while the mouse stays on a
> > specific area of the screen?
> >
> > i tried the following code: it works ONCE (when the mouseover event is
> > triggered) but not continuously, while the mouse i over my "active" zone.
> >
> > var centerX = $('#datascape').width()/2;
> > stepX = 240;
> > var $datascapeViewport = $('#ds-viewport');
> > $datascapeViewport.css({position: 'relative',left: 0+'px'})
> > .bind('mouseover',function(e){
> > var minX = $(this).width();
> > minX=-minX;
> > var maxX = 0;
> > var newLeft = 0;
> > var Position = $(this).offset();
> > if (e.pageX >= centerX) {
> > newLeft = Position.left-stepX;
> > } else
> > {
> > newLeft = parseInt(Position.left) + stepX;
> > }
> > //alert("\nposition.left="+Position.left
> > +"\nnewLeft="+newLeft+"\nstepX="+stepX);
> > newLeft = -newLeft;
> > if ((newLeft<maxX) && (newLeft>minX)) {
> > $(this).animate({left: newLeft+'px'},1000);
> > }
> > });
> >
> > just for background, i'm trying to have a very wide image scroll
> > horizontally according to the mouse position on the X axis, center being no
> > scroll, left position meaning scroll image right, and invertedly.
> >
> >
> > Thanks for your insight!
> >
> > Alexandre
> >
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> > 16/10/2007 14:14
> >
> >
> >
>
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> 16/10/2007 14:14
>
