Show NSWindow on right click in NSTableView - objective-c

Question

I'd like to display an NSWindow when right clicking an item in an NSTableView, similarly to how the available outlets are shown in Interface Builder when you right click an object:
Unfortunately you can only use an NSMenu subclass as the menu property.
I also didn't find a delegate method of NSTableView that notifies about right clicks.
I was able to subclass NSTableView and implement rightMouseDown: and rightMouseUp: to be notified about those events, but if I set the menu property of the row cells to nil, they are not highlighted when right clicked, even though I call the super implementation):
- (void)rightMouseDown:(NSEvent *)theEvent {
[super rightMouseDown:theEvent];
NSPoint eventLocation = [theEvent locationInWindow];
eventLocation = [self convertPoint:eventLocation fromView:nil];
NSInteger rowIndex = [self rowAtPoint:eventLocation];
NSLog(#"Right clicked at row index %d", rowIndex);
}
I would like to have the highlight effect in the image below but display a window instead of the context menu:

Answer 1

First for the right click: explicitly select the row on right click (e.g. via this message). Then create your own NSWindow descendant, set an own NSView class as contentView and in the view you can draw the black background, rounded borders and what not. Show this window in your right click handler.

Answer 2

You can use an NSPopover, which works quite nicely. A popover creates a window for you, even if it is somewhat hidden. You'll get it from your controls if you send them the window message, and can register to listen for events, for instance.
The whole popover can be created in IB, and just have to implement the showRelativeToRect:ofView:preferredEdge: method in code.
To catch the right click event, you can use rightMouseDown:, which is originally defined in NSResponder, but is overridden in NSView to simply catch the event and show menu and it doesn't pass the event upwards in the responder chain (or the inheritance chain, for that matter). Hence, you simply implement that method to call showRelativeToRect:ofView:preferredEdge:.
You will typically need to have the contents in an NSViewController and its own accompanying nib file.
The NSPopover's contentViewController property can be set in IB, too.
All in all, not much code needed.
This tutorial is useful.