Redmine

I recently had a situation where my Redmine site was very busy generating a Gantt chart from about 500 open issues. It finally opened the chart but while it was processing I was kinda left out in the cold. Is there a way to throw up a busy page telling the users to wait a bit? I'm primarily thinking of something like the one Bugzilla uses ("Please wait while your bugs are munched retrieved...") when you issue a long running request.

I have no idea how you would implement this but I would think that you would have to detect when a query was long running. Can you do that with RoR? Would this be a good candidate for a plug-in?

Thanx!
Richard