[Swift] Do not work backgound color of UITableViewHeaderFooterView

UITableViewHeaderFooterView can not set backgound color

We can not set the backgound color on UITableViewHeaderFooterView.
If set, we see the following log.

"Setting the background color on UITableViewHeaderFooterView has been deprecated. Please use contentView.backgroundColor instead."


if change backgroundColor, use the "contentView" that is included in UITableViewHeaderFooterView.

    sectionHeader?.contentView.backgroundColor = backgroundColor

How to use UIScreenEdgePanGestureRecognizer, via Swift Code

implement in UIViewController

I had implemented the screen edge swipe with using UIScreenEdgePanGestureRecognizer, without Storyboard.

We need to add edgePan to ViewController.view. if you want to handle the acton, you have to use #selector.

class ViewController: UIViewController {

    private let closer = SwipeEdgeCloser()
    
    override func viewDidLoad() {
        super.viewDidLoad()

        let edgePan = UIScreenEdgePanGestureRecognizer(target: self, action: #selector(handleScreenEdgeSwiped))
        edgePan.edges = .left
        view.addGestureRecognizer(edgePan)
    }

    @objc func handleScreenEdgeSwiped(_ recognizer: UIScreenEdgePanGestureRecognizer) {
        if recognizer.state == .recognized {
            print("Screen edge swiped!")
        }
    }
}

new class implemented Edge Swipe Gesture

If you do not like "fat UIViewController", you should new class implemented Edge Swipe Gesture.

class ViewController: UIViewController {

    private let closer = SwipeLeftEdgePanGesture()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        view.addGestureRecognizer(closer.panGesture)
    }
}

final class SwipeLeftEdgePanGesture {
    let panGesture: UIScreenEdgePanGestureRecognizer
    
    init() {
        panGesture = UIScreenEdgePanGestureRecognizer()
        panGesture.edges = .left
        panGesture.addTarget(self, action: #selector(SwipeLeftEdgePanGesture.screenEdgeSwiped))
    }
    
    @objc private func screenEdgeSwiped(_ recognizer: UIScreenEdgePanGestureRecognizer) {
        if recognizer.state == .recognized {
            print("SwipeLeftEdgePanGesture: Screen edge swiped!")
        }
    }
}