[OpenLayers-Users] Delaying Layer Initialization

[Christopher Schmidt]

On Fri, Jul 27, 2007 at 01:51:18AM -0700, GregM wrote:

Erik, can you take a look at this when you get a chance?

-- Chris

> 
> I have corrected it in Map.js setCenter function
> with some additional lines inside 'for' code below:
> 
> for (var i = 0; i < this.layers.length; i++) {
>                 var layer = this.layers[i];
>                 if (!layer.isBaseLayer) {
>                     
>                     var moveLayer;
>                     var inRange = layer.calculateInRange();
>                     if (layer.inRange != inRange) {
>                         // Layer property has changed. We are going 
>                         // to call moveLayer so that the layer can be turned
>                         // off or on.   
>                         layer.inRange = inRange;
>                         //do NOT download tiles if not in scale limit
>                         moveLayer = (layer.visibility && layer.inRange); //
> was ... = true;
>                         //switch off layer after going beyond scale limit
>                         if (layer.visibility && !layer.inRange)
>                             layer.setVisibility(false);
>                         this.events.triggerEvent("changelayer");
>                     } else {
>                         // If nothing has changed, then we only move the
> layer
>                         // if it is visible and inrange.
>                         moveLayer = (layer.visibility && layer.inRange);
>                         //switch off layer after going beyond scale limit
>                         if (layer.visibility && !layer.inRange)
>                             layer.setVisibility(false);
>                     }
>                     if (moveLayer) {
>                         layer.moveTo(bounds, zoomChanged, dragging);
>                     }
>                 }                
>             }
> 
> 
> 
> GregM wrote:
> > 
> > I would add that tiles for invisible layers are downloaded from server not
> > only on map/layer initialization, but also while layer goes beyond its
> > minScale. 
> > Value of minScale is making layer not downloaded while initialization but
> > after zooming to scale < minScale.
> > 
> > Is this already filled as bug in tickets ? Because I cannot find it. 
> > 
> > Is there any workaround for this for OE 2.4 ?
> > 
> > Greg
> > 
> > 
> > 
> > Christopher Schmidt-4 wrote:
> >> 
> >> On Sat, May 26, 2007 at 10:28:39AM +0200, Arnd Wippermann wrote:
> >>> Hello Christopher,
> >>> 
> >>> I have the same problem (therefor I'm still using Openlayers 1.0).
> >> 
> >> Okay, thanks. I'd heard reports, but they were always vague in the
> >> problems they were reporting.  
> >>> OpenLayers should only load tiles for the baselayer from gis.ibbeck.de
> >>> and
> >>> wms.jpl.nasa.gov for the world image. If you use firebug, you could see,
> >>> that the tiles for the other servers are also loaded.
> >> 
> >> Agreed. I'll file this as a bug against 2.5. Since it's been around since
> >> the start of the 2.0 branch, it's not enough to delay 2.4. 
> >> 
> >>> After the first load of the map, pan and zoom loads only the tiles for
> >>> the
> >>> visible servers.
> >>> 
> >>> http://gis.ibbeck.de/ginfo/ibbOLClient/OLC2.3%20RC1.html?MAPNR=10000&LAYERS=
> >>> 11200,12700,11500,11500,10600,10700,10900,11000,10000&ZOOM=3&CENTER=10.1745,
> >>> 50.819 
> >>> 
> >>> (If I load the newest version from
> >>> http://svn.openlayers.org/branches/openlayers/2.4/, Revision 3188 says
> >>> the
> >>> html-page and my svn-program, the OpenLayers.VERSION_NUMBER is still
> >>> "$Revision: 2942 $". Miss I something or is this a bug).
> >> 
> >> This is expected -- the VERSION_NUMBER is relevant to the last time that
> >> file was updated. Part of the release process is to edit the
> >> OpenLayers.js file (to change the license), so releases get a new
> >> VERSION_NUMBER -- it's only useful on releases. Unfortunately, I don't
> >> know of a better way to automate this. 
> >> 
> >>> Is it possible with the number of the revision also deliver a variable
> >>> with
> >>> the plain text for the OpenLayers Version(example: 2.4 RC4).
> >> 
> >> There is no automatic way of doing this, and it's a step that I fear
> >> would be missed if we made it a human intervention step, which is why
> >> it's not done. If you're actually using RC4 -- that is, from the /tags/
> >> instead of the branch -- the VERSION_NUMBER represents that.
> >> 
> >> Regards,
> >> -- 
> >> Christopher Schmidt
> >> MetaCarta
> >> _______________________________________________
> >> Users mailing list
> >> Users at openlayers.org
> >> http://openlayers.org/mailman/listinfo/users
> >> 
> >> 
> > 
> > 
> 
> -- 
> View this message in context: http://www.nabble.com/Delaying-Layer-Initialization-tf3816850.html#a11797327
> Sent from the OpenLayers Users mailing list archive at Nabble.com.
> 
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> 

-- 
Christopher Schmidt
MetaCarta