navigation control needs destroy

Taking this out of my queue. Still a good idea, I just don't want too many tickets without patches to consider. Since I reported this, I'm reserving the right to close it.

Ok, seems important enough to reopen this.

For example:

• go to http://openlayers.org
• open firebug
• run the following

  c = map.controls[0];
  map.destroy();
  

• then peruse things like

  c.dragPan.handler.map.layerContainerDiv
  

In general, I think the handlers are in good shape. They clean up after themseles without a problem.

In general, controls which use a handler with the variable name 'handler' are in good shape. Some problems, but nothing major.

The problem seems to be in the case where controls use *more* than one handler, and are therefore responsible for cleaning up after themselves. This applies to the Navigation control, which has no destroy() method at all.

About to attach a patch which takes care of at least some of this problem. I have no idea if you (tim) are looking for more serious work in a general sense. I still feel that the only way, right now, to address this problem systematically is to get a working copy of 'Drip' running, and go start messing with the things you care about. It's very easy to see quickly where memory leaks are happening, and they're typically easy to fix, but doing it by evaluating the controls manually seems likely to either be a pain in the butt, or miss something.

I think this should go in. There are still plenty of issues, but I'll just keep them in mind (you can still explore c.wheelHandler.evt.element and such things if you have a reference to the nav control). I'll make other tickets as things come up.

applied in r5891

This ticket is a duplication of #1289