[OpenLayers-Users] Opacity of GoogleLayer, get selected layer

[Eric Lemoine]

On Fri, Jan 15, 2010 at 12:05 PM, Dirk Tanneberger
<dirk.tanneberger at unibas.ch> wrote:
> Hi Eric,  thanks for the fast reply.
>
> With the baseLayer-object it works. I tried to apply the method directly to
> the layer, maybe that was the problem.
> But still I have the problem, when changing the baseLayer. In my case I got
> three baseLayers and no matter which one is selected it should have a
> opacity.
> If I do it like this:
>
> var map = new OpenLayers.Map(options);
>
>     var google = new OpenLayers.Layer.Google(
>             "Google",
>             {'sphericalMercator': true}
>     );
>
>     var OSM = new OpenLayers.Layer.OSM("OSM");
>
>     var google_t = new OpenLayers.Layer.Google(
>                 "Google_Terrain",
>                 {type: G_PHYSICAL_MAP, 'sphericalMercator': true}
>     );
>
>     map.addLayers([OSM, google, google_t]);
>
>     map.baseLayer.setOpacity(0.5);
>
> the opacity is applied just to the initial baseLayer. The other layers don't
> have a opacity after being selected.
> I think, thats why I have to trigger the event, wether a layer is selected
> or not and set the opacity afterwards.
> Maybe it is possible to do so in the treepanel-object of the mapFish-API.
> Couldn't find anything appropriate so far, but I have to dig more into it.
> If you or somebody else got a hint, I would appreciate it very much.

<http://www.openlayers.org/dev/examples/spherical-mercator.html>

open the firebug console, and do:

map.layers[0].setOpacity(0.2) // -> this changes the opacity of the
current base layer
map.layers[1].setOpacity(0.2) // -> this changes the opacity of the
Google Satellite layer, although it's not the current base layer

now select the Google Satellite layer in the LayerSwitcher, its
opacity is expectedly 0.2.

Maybe I don't understand the issue you're having.

-- 
Eric Lemoine

Camptocamp France SAS
Savoie Technolac, BP 352
73377 Le Bourget du Lac, Cedex

Tel : 00 33 4 79 44 44 96
Mail : eric.lemoine at camptocamp.com
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