Window animates width but not height

Question

I have a preferences window with a NSTabViewController hooked up to the toolbar for selecting tabs. I want the window to be resizable, and to resize if necessary when switching tabs to fit the new tab's size.

I'm subclassing NSTabViewController with the following overload:

override var selectedTabViewItemIndex: Int
{
  didSet
  {
    guard let view = tabViewItems[selectedTabViewItemIndex].view,
          let window = view.window
    else { return }

    let minSize = view.fittingSize
    let contentRect = NSWindow.contentRect(forFrameRect: window.frame,
                                           styleMask: window.styleMask)
    let minRect = NSRect(origin: contentRect.origin, size: minSize)
    let newRect = minRect.union(contentRect)
    let newFrame = NSWindow.frameRect(forContentRect: newRect,
                                      styleMask: window.styleMask)

    window.animator().setFrame(newFrame, display: true, animate: true)
  }
}

The result is that it animates resizing horizontally, and at the end it suddenly resizes vertically as well. How do I get it to just animate both directions at once?

Answer 1

Do you have height constraints on any of the tabs? Those might prevent the window from getting larger (even while offscreen).