swift - Popover is not displayed correctly in landscape mode

Question

Popover takes the complete screen when displayed in landscape mode, it works correctly in portrait mode though. Also, it is does not disappear when i click outside the popover in landscape mode.

I connected the popover through the storyboard. Inside the popoverviewcontroller I placed a view which contains the buttons. The code for the viewdidload() of the popoverviewcontroller is:

override func viewDidLoad() {
    super.viewDidLoad()

    self.preferredContentSize = popoverView.frame.size
        }

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

Portrait:

landscape:

Answer 1

The answer from @Jake2Finn works for Swift 4.0.

The trait parameter specifically is required to fix the landscape problem:

traitCollection: UITraitCollection

Without it the function adaptive... only works for portrait.