[OpenLayers-Users] change layer style on zooming
Bart van den Eijnden
bartvde at opengeo.org
Mon Nov 5 08:17:11 PST 2012
Check out: http://dev.openlayers.org/releases/OpenLayers-2.12/examples/styles-context.html
that should give you a clue on how to handle this.
Best regards,
Bart
--
Bart van den Eijnden
OpenGeo - http://opengeo.org
Expert service straight from the developers.
On Nov 5, 2012, at 5:12 PM, eriktronic <etimmers at gmail.com> wrote:
> As I could not find an clear answer anywhere on google, I subscribed here to
> hopefully get some help from you.
>
> I build a map containing a lot of feature points, shown as small dots. As I
> zoom out I would like the circles to shrink, otherwise the underlying
> OpenStreetMap is completely lost. I tried doing so by applying a default
> style and adding a function to the event 'zoomend'. See this small example:
>
>
> var geoJson = {...}; // some geojson object
> var style = { 'pointRadius': 3, 'color': '#000000', 'fillColor': '#ffffff'
> };
> var map = new OpenLayers.map('map');
> var layer = new OpenLayers.Vector.Layer('layer', {'style': style} );
> var format = new OpenLayers.Format.GeoJSON({
> 'internalProjection': new OpenLayers.Projection("EPSG:900913"),
> 'externalProjection': new OpenLayers.Projection("EPSG:4326")
> });
> layer.addFeatures(format.read(geoJson));
> map.addLayer(layer);
> map.events.register('zoomend', layer, function(event) {
> var zoom = event.object.getZoom();
>
> if (zoom > 13)
> style.fillColor = '#ff0000'; // red (R)
> else
> style.fillColor = '#ffffff'; // white (W)
>
> // adding the next line solves the problem,
> // but to me it makes no sense
> // as the layer will be redrawn twice
> // in this case
> this.redraw();
> });
>
>
> This example gives each zoom level either
> red (R) or white (W) features:
>
>
> Apparently, changing the style will only be applied in the next zoom level,
> as the features have already been processed.
> For me this is undesired, is there any way to change the style AFTER zooming
> and BEFORE applying the style / redrawing the features?
>
> Many thanks in advance!
>
> Regards,
> Erik
>
>
>
> --
> View this message in context: http://osgeo-org.1560.n6.nabble.com/change-layer-style-on-zooming-tp5014035.html
> Sent from the OpenLayers Users mailing list archive at Nabble.com.
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