NSWindow mouseEntered without subclassing?

Question

I've got a program that accepts the native window handle of an NSWindow (that's already been created but not yet visible). I do this to change some native window styles and behaviors. I can do everything I need to except I can't get mouseEnter/mouseExit to work because it seems to require subclassing before instantiation. Is there a way around this? I really don't want to continuously poll the mouse position just for detecting mouseEnter and mouseExit of a portion of my window.

Note: I have to do it this way because I want to detect hover while the window isn't focused.

I can attach the tracking area, but without subclassing it I'm not sure how to hook into the events:

NSTrackingArea *area = [[NSTrackingArea alloc] initWithRect:CGRectMake(0, 0, 120, 300) options:NSTrackingMouseEnteredAndExited | NSTrackingInVisibleRect | NSTrackingActiveAlways owner:window userInfo:nil];

[window.contentView addTrackingArea:area];

P.S. I'm open to using C or Swift if it'd help.

Answer 1

You don't need to create a view to do that, your can use any custom object, for instance your controller, as a kind of delegate for the tracking methods :

NSView * theView     = window.contentView;
NSTrackingArea *area = [[NSTrackingArea alloc] initWithRect: theView.bounds
                             options:(NSTrackingMouseEnteredAndExited | NSTrackingMouseMoved | NSTrackingActiveAlways)
                               owner:myController //<-- your controller
                            userInfo:nil];
 [theView addTrackingArea:area];

From there, the tracking methods will be sent to 'myController'