I am trying to solve a larger problem and I am tipping on the fact that ARC apparently is releasing the view to my NSViewController too early. I think :) So I created a simple a
Add a property to hold the view controller. Your controller currently has nothing to keep it alive past the end of the method that allocates it.
Add:
@property (strong) TestViewController *tvc;
Modify:
self.tvc = [[TestViewController alloc] initWithNibName:@"TestViewController" bundle:nil];
(I'm curious...what do you see as the point of creating a view controller if all you want is the view it contains?)
Concerning the general approach, it seems that this is more properly behavior that should be implemented using a container view controller. That mechanism allows multiple view controllers to share the screen in an organized way.