PopupWindow objects can be clicked multiple times, opening multiple popup windows for the same object. How can I prevent this?
A bit more detail: I have an application which displays a graphic. The user can click on elements of the graphic to call up an information panel about that element using PopupWindow. The user might have several of these popups open at once. To prevent confusion, I would like to make sure that the user cannot open more than one popup per object. I can't see a straightforward approach to doing this, so I'm hoping for some ideas from this fine community.
Example code:
DynamicModule[{col = ConstantArray[Blue, 5]},
Graphics[{Table[With[{i = i},
PopupWindow[
Dynamic[
col[[i]] = If[CurrentValue["MouseOver"], Red, Blue];
{Dynamic@col[[i]], Disk[{i, 0}, 0.5]}],
Dynamic[
col[[i]] = If[CurrentValue["MouseOver"], Red, Blue];
Framed[Style["Disk " <> ToString[i], White, 20],
FrameMargins -> 80, Background -> Dynamic@col[[i]]]],
WindowSize -> 280]
], {i, 5}]}]]
Here I have clicked on disk 4 twice, opening a duplicate of the information window. I want to prevent that:

PopupWindowtitle and then check everyNotebooks[]every second or so to close duplicates? – Ajasja Oct 30 '12 at 11:57PopoupWindow[], because once issued it will ever bring up a window with the specified contents. You can, however, create a notebook if it hasn't been created yet. You may useFE`Evaluate[FEPrivate`GetPopupList["MenuListWindows"]]to check the currently active notebooks. – belisarius Oct 30 '12 at 13:20Notebooks[]doesn't? – Simon Woods Oct 30 '12 at 21:01WindowFloating->False. – Simon Woods Oct 31 '12 at 8:58