Custom UINavigationBar does not honour given height

Question

I have a custom UINavigationBar, called MapNavBar. This class is declared as follows:

class MapNavBar: UINavigationBar {

override func sizeThatFits(_ size: CGSize) -> CGSize {
    let screenSize = UIScreen.main.bounds.size
    let landscape = screenSize.width > screenSize.height
    if landscape {
        let navBarHeight: CGFloat = 44.0
        return CGSize(width: screenSize.width, height: navBarHeight)
    }
    return super.sizeThatFits(size)
}

}

The custom navigation bar is assigned to the navigation controller like so:

navController.setValue(MapNavBar(), forKeyPath : "navigationBar")

Now when the orientation changes to landscape I would like to keep the navigation bar height to the standard (portrait orientation) height of 44. So in the MapController viewWillLayoutSubviews I do:

override func viewWillLayoutSubviews() {

    if let navController = ... {
        let screenSize = UIScreen.main.bounds.size
        let landscape = screenSize.width > screenSize.height
        if landscape {
            let navBarHeight = navController.navigationBar.sizeThatFits(screenSize).height

            // Resize navBar
            navController.navigationBar.frame = CGRect(x: 0, y: 0, width: Int(screenSize.width), height: Int(navBarHeight))
        }
    }
    super.viewWillLayoutSubviews()
}

Despite all efforts, the custom navigation bar height remains at 32 points when in landscape. I have checked and the navigationBar property of the navigation controller is indeed an instance of my custom MapNavBar.

Does anyone know why this happens and how to fix it?

Thanks

user_5519329 · Answer

Try this:

class MapNavBar: UINavigationBar {

    let navBarHeight: CGFloat = 64 //44 + 20 Where 20 is for status bar, it is hidden in landscape mode always

    override func sizeThatFits(_ size: CGSize) -> CGSize {

        let frame = self.frame
        let screenSize = UIScreen.main.bounds.size
        let landscape = screenSize.width > screenSize.height
        if landscape {
            return CGSize(width: frame.width, height: navBarHeight)
        }
        return super.sizeThatFits(size)
    }

    override func layoutSubviews() {
        super.layoutSubviews()

        let screenSize = UIScreen.main.bounds.size
        let landscape = screenSize.width > screenSize.height
        if landscape {
            let y = UIApplication.shared.statusBarFrame.height
            frame = CGRect(x: frame.origin.x, y:  y, width: frame.size.width, height: navBarHeight)

            for subview in self.subviews {
                var stringFromClass = NSStringFromClass(subview.classForCoder)
                if stringFromClass.contains("BarBackground") {
                    subview.frame = CGRect(x: 0, y: 0, width: self.frame.width, height: navBarHeight)
                    subview.backgroundColor = self.backgroundColor
                }

                stringFromClass = NSStringFromClass(subview.classForCoder)
                if stringFromClass.contains("BarContent") {
                    subview.frame = CGRect(x: subview.frame.origin.x, y: 0, width: subview.frame.width, height: navBarHeight)
                    subview.backgroundColor = self.backgroundColor
                }
            }
        }
    }
}

Custom UINavigationBar does not honour given height

1 Answers