Q:

Using autolayout, how can I center a subview in an NSSplitView without forcing the width NSSplitView to be static?

I have an NSSplitView with content in both NSViews. The left NSView has 2 constraints – Equal Widths and Equal Heights. The right NSView has something simple, say an NSTextField, which is centered via constraints Center X Alignment and Center Y Alighment. This is what I hoped it would look like as I resize the window and/or the NSSplitView divider:

This is what's happening:

I've tried a great deal of configuration changes, I've tried using an NSSplitViewController vs just dropping an NSSplitView into an NSViewController to adjust more parameters programmatically, but I'm not having any luck. Whenever resizing the window, the left view always takes over the excess space. The same happens with the divider (it can be resized, but letting go of the mouse button causes it to snap right back). It seems there's something fundamental that I'm missing here.

A:

The text field's content hugging priority is probably higher than the split view item's holding priority. Fix that and the view should probably work the way you expect.
Also, if, when you resize the view, the left view is resizing with the window while the right view stays the same size, then that suggests that the left view's holding priority may be higher than the right's. You should make the side that you want to stay the same size have the higher holding priority.
That said, I'm not sure what you mean about the constraints you've set on the subviews. "The left NSView has 2 constraints – Equal Widths and Equal Heights." What do you mean here? Its width is equal to what? Its height is equal to what? Do you mean it has an aspect ratio constraint? Frankly, I can't think of what constraints of those kinds would make sense for a view within a split view.

