openlayers/openlayers — pull request #586 by lydonchandra (2012-07-11 03:32:20+00:00)
Title: Don't applyBackBuffer when moving to extent outside of current bounds

https://github.com/openlayers/openlayers/issues/582

With fix ( Layer/Grid-new.js )
http://demo.mapsolutions.com.au/IntraMaps80/Frontend/tests/integration/melton/default-dev-new.htm

Without fix ( Layer/Grid.js )
http://demo.mapsolutions.com.au/IntraMaps80/Frontend/tests/integration/melton/default-dev.htm

To compare them,
TYPE these address into “Enter your address” search box,
Select first match under dropdown
and press ENTER after each:

11 Abbington CR
3 Abelia CRT
60-78 Abey RD

Focus on the transition between images.

Default behaviour is to apply a backbuffer, which seems like blanking the map.

Proposed behaviour (default-dev-new.htm) is to apply backbuffer only when:
1.	new bounds intersect with old bounds.
2.	New bounds contains old bounds or vice versa (zoom-in/out)

The ideal behaviour is
to update map when image arrives on programmatic zoomToExtent,
http://gis.stackexchange.com/questions/28724/can-we-request-new-openlayer-wms-image-for-an-extent-without-moving-the-map

However, the proposed behaviour mentioned above is closest we can get (without much refactoring).
http://demo.mapsolutions.com.au/mapcontrol/melton/ is our map without openlayers.

Browser I’m using:
Chrome 20.0.1132.47 m /Win7

Let us know if you need more info.