animated zooming

Comments from John Cole to users@ list

Also, is there a way to expand or shrink a layer, so that when you zoom, the
map can be expanded/shrunk in real time until the layers can be refreshed?
Doing this really helps visualize where your zooming to and it is really
important when mouse wheel zooming to know what level your zooming to.

I'm interested in the development of this feature:
http://openlayers.org/pipermail/dev/2006-December/000176.html

Here is a current demo:
http://dev.openlayers.org/sandbox/emanuel/animatedZooming/demo.html

Current and next features you can read here:
http://openlayers.org/pipermail/dev/2007-February/000263.html

version 1.1:
Now, the demo scales the red rectangle in the overviewmap.

version 1.2:
zooming out with an extra tile

version 1.3:
- scale baselayer only
- support wms, wms untiled and image baselayers
- "smooth tile update" - it doesn't show a blank map after zooming (with slider)
- recenter overviewmap after drag, doubleclick and panning

version 1.4:
- animated panning integrated (also for overviewmap)
- animated zooming for +/- buttons, zoomBox, doubleclick, mousewheel, +/- keys (together with animated panning!)
- by using mousewheel: target below mousecursor stays at the same position after zooming; target not recenter
- new keys (pos1, end, page up/down) set for better panning

basics of animated zooming (unit tests included)

PanZoomBar supports animated zooming (included unit tests)

mouseWheel, zoomBox, DblClick supports animated zooming (included unit tests)

CverviewMap supports animated zooming and panning (included unit tests)

WMS untiled baselayer supports animated zooming (included unit tests)

Image baselayer supports animated zooming (included unit tests)

My final animated zooming patches are attached.
Please note: If you run animated zooming (core) patch _and_ animated panning patch you have to merge some hunks manually!
The overviewMap patch is also running without animtated zooming core.

You can test all animated zooming and panning patches in this Demo.

This code, although a wonderful demo, has had some significant problems blocking its integration into trunk. In some browsers, performance quickly degrades, and in general, the code is somewhat more complex than it could be.

Additionally, this code is now out of date -- this not being the fault of the patch creator, but simply the fact that previous attempts to integrate it into trunk have failed.

#933 has taken much of the core ideas in this code, and collected them into a patch that works better with the current way of working within OpenLayers. It was based in part upon this patch, and other general observations made in the interim.

It is unlikely that it will replicate all the behavior desired by this ticket. The active zooming as you move the panzoombar up and down, for example, is unlikely to remain in its current state -- but once #933 is implemented, it should be easier to integrate this type of behavior into your map.

I think this ticket, although interesting for historical reasons, is essentially a duplicate of #933 at this point. I appreciate all the work that emmanuel did, and I'm sorry that we didn't succeed in integrating it. I'm hoping that #933 implements the functionality that users are most interested in, and we can move forward with a cleaner implementation that works for everyone.

Emmanuel, thank you for your hard work. If anyone is interested in helping pursue testing and further work on #933, please feel free to do so -- and if you can't figure out how to help, please email the dev mailing list.