[OpenLayers-Dev] preserving scale on base layer switching
tschaub at opengeo.org
Tue Feb 2 20:22:08 EST 2010
Currently, when a new base layer is set, we determine the new resolution
based on the previous map extent. An alternative would be to determine
the new resolution based on the previous scale. Preserving center and
scale makes better sense to me. I'm curious what others think.
The resolution based on extent method breaks down when extents are not
well defined. E.g. with an extent that wraps the date line. To see
this break-down in action, follow these steps:
1) open http://openlayers.org/dev/examples/google.html
2) click to zoom all the way out (you'll see multiple worlds)
3) open the switcher and change base layers
You should see the scale change.
Apply the patch for http://trac.openlayers.org/ticket/2457 and you
should see better behavior.
Thanks for any feedback.
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