NSPopover transiency when popover is in status bar

Question

I'm making an app which lives in status bar. When status item is clicked, NSPopover pops up.

It looks like this:

Here's the problem: I want it to be "transient", that is if I click anywhere outside of the popover, it will close. And while NSPopoverBehaviorTransient works fine when popover is in a window, it doesn't work when it's in status bar.

How can I implement such behavior myself?

Answer 1

It turned out to be easy:

- (IBAction)openPopover:(id)sender
{
    // (open popover)

    if(popoverTransiencyMonitor == nil)
    {
        popoverTransiencyMonitor = [NSEvent addGlobalMonitorForEventsMatchingMask:NSLeftMouseDownMask|NSRightMouseDownMask handler:^(NSEvent* event)
                                    {
                                        [self closePopover:sender];
                                    }];
    }
}

- (IBAction)closePopover:(id)sender
{
    if(popoverTransiencyMonitor)
    {
        [NSEvent removeMonitor:popoverTransiencyMonitor];

        popoverTransiencyMonitor = nil;
    }

    // (close popover)
}

What wasn't easy, though, is that there are nasty issues with having a popover pop out of NSStatusItem (it didn't behave as desired when Mission Control was invoked or space switched to a full-screen window). I had to implement a custom window that always floats above the NSStatusItem and deals with switching to a full-screen window etc. It seemed easy, but clearly status items weren't designed for something like that ;)