[OpenLayers-Dev] Fwd: [Patch] Smoother dragging of the map on older computers

[Håkon]

> * Some events which get resent, like mouse moves when panning are ok to drop
> * Other one-off events, like click to query should not be dropped.
>
> Are you able to distinguish between the two?
Yes I am, only the drag-event is dropped. Actually, the event is not
completely dropped. I need to update an integer containing the number
of pixels that the mouse has moved, but the actual map is not updated.
It could probably be possible to avoid this too, but I don't think it
creates a great overhead.

I just got an idea, maybe it could have been done "higher up",
somewhere in the actual event handling instead of down in the
panMap-method. This way, it will affect other drag-events too. I'll
have to have a look at that.

I forgot to add a link to the ticket, so here it is:
http://trac.openlayers.org/ticket/1125

On Nov 7, 2007 4:58 AM, Cameron Shorter <cameron.shorter at gmail.com> wrote:
> Hakon,
> Great idea. I haven't looked at the code, but am interested to know:
> * Some events which get resent, like mouse moves when panning are ok to drop
> * Other one-off events, like click to query should not be dropped.
>
> Are you able to distinguish between the two?
>
>
> Håkon wrote:
> > Hi,
> >
> > The wiki said that I should mail the list after posting a patch to
> > trac, so here I am. Description from trac:
> > "When the openlayers map is dragged around, a lot of events are sent,
> > and the map is updated on every one of them, which takes quite some
> > time. Because of this, the map feels slow, especially on old
> > computers. This can be solved by creating a short timeout when the
> > event is received, which will update the map a little later. Any
> > events inbetween are ignored.
> >
> > I created a patch with a possible way to implement this. It passes the
> > unit tests and it appears to work well in most browsers (tested in
> > Firefox 2, Opera 9.5 Beta and IE 6 (IEs for Linux)). If you run the
> > two versions side by side, you can really feel a difference.
> >
> > The updateMap-method in my patch would probably be more logical as an
> > anonymous function in the timeout-call, but then a the function would
> > have been created every time the timeout is created instead of only
> > once when OSM is loaded.
> >
> > I don't know the code structure in OpenLayers very well, so there
> > might be better ways to implement it."
> >
> > It was pointed out that maybe the ticket was created under the wrong
> > component. I have no idea, so I'll have to ask some of you whether it
> > is in the right position, and if not, where it should be.
> >
> > The wiki also said that I should state clearly that I wanted the patch
> > reviewed, so, ehm... I want the patch reviewed.
> > _______________________________________________
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> > Dev at openlayers.org
> > http://openlayers.org/mailman/listinfo/dev
> >
> >
>
>
> --
> Cameron Shorter
> Geospatial Systems Architect
> Tel: +61 (0)2 8570 5050
> Mob: +61 (0)419 142 254
>
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