It's not unreasonable to want to show an NSPopover from an NSToolbar - probably originating from an item on the toolbar - like this:
Unfortunately, showing a popover in Cocoa relies on the method
-(void)showRelativeToRect:(NSRect)positioningRect ofView:(NSView *)positioningView preferredEdge:(NSRectEdge)preferredEdge
but as NSToolbarItem inherits from NSObject rather than NSControl (which was possibly a sensible design decision 20 years ago) there's no easy way to get the NSToolbarItem's view - and hence to show the popover from the right place.
The trick is to put an NSButton inside the toolbar item, then use a property to keep track of it, and get its bounds when clicked. The code looks something like :
@property (nonatomic, strong) IBOutlet NSToolbarItem *showPopoverToolbarButton;
and
NSView *viewToShowFrom = [self.showPopoverToolbarButton view];
PopverDetailViewController *pdvc = [[PopoverDetailViewController alloc] initWithNibName:@"PopoverDetailViewController" bundle:nil];
self.popover = [[NSPopover alloc] init];
self.popover.contentViewController = pdvc;
self.popover.delegate = self;
[self.popover showRelativeToRect:[viewToShowFrom bounds] ofView:viewToShowFrom preferredEdge:0];
And there's one more thing. As presented, when clicked the toolbar item will show a nasty light square around itself, like this:
You can get rid of this by changing the button cell type to Momentary Change using Interface Builder.
