Autolayout of View Controller View in a Container - objective-c

Question

I have an NSWindow that has 2 container views within it, all in one xib, like so:
In another xib, I have a the view for the sidebar, managed by a different view controller, like so:
When I add the subview to the container view, I do it like this:
self.sidebarViewController.view.frame = self.sidebarContainer.bounds;
[self.sidebarContainer addSubview:self.sidebarViewController.view];
When I build and run, and resize this window, this is what happens:
The container tracks the height of it's superview properly, but the sidebar view itself does not track the height of the container.
How can I set things up so that the height of the sidebarVCs' view tracks the height of the container as the window is resized?
I think I've solved it like so:
[self.sidebarViewController.view setTranslatesAutoresizingMaskIntoConstraints:NO];
NSLayoutConstraint *w = [NSLayoutConstraint constraintWithItem:self.sidebarViewController.view attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:0.0 constant:150.0];
NSArray *c1 = [NSLayoutConstraint constraintsWithVisualFormat:#"V:|[view]|"
options:0
metrics:nil
views:#{ #"view":self.sidebarViewController.view }];
[self.sidebarContainer addConstraints:c1];
[self.sidebarContainer addConstraint:w];
I still don't yet understand why the autoresizemask layout constraint doesn't do this automatically, but I think I'm closer to understanding the relationships between the views here.

Answer 1

Use NSBoxes as containers. In your sidebar, add an NSBox inside the NSView and constrain all sides to the view. Then when you want to swap in a view for the side bar you can call container (the NSBox object) setContentView:.