Use Safe Area Layout programmatically

Question

Since I don't use storyboards to create my views, I was wondering if there's the "Use Safe Area Guides" option programmatically or something like that.

I've tried to anchor my views to

view.safeAreaLayoutGuide

but they keep overlapping the top notch in the iPhone X simulator.

Answer 1

For those of you who use SnapKit, just like me, the solution is anchoring your constraints to view.safeAreaLayoutGuide like so:

yourView.snp.makeConstraints { (make) in
    if #available(iOS 11.0, *) {
        //Bottom guide
        make.bottom.equalTo(view.safeAreaLayoutGuide.snp.bottomMargin)
        //Top guide
        make.top.equalTo(view.safeAreaLayoutGuide.snp.topMargin)
        //Leading guide
        make.leading.equalTo(view.safeAreaLayoutGuide.snp.leadingMargin)
        //Trailing guide
        make.trailing.equalTo(view.safeAreaLayoutGuide.snp.trailingMargin)

     } else {
        make.edges.equalToSuperview()
     }
}

Answer 2

I'm using this instead of add leading and trailing margin constraints to the layoutMarginsGuide:

UILayoutGuide *safe = self.view.safeAreaLayoutGuide;
yourView.translatesAutoresizingMaskIntoConstraints = NO;
[NSLayoutConstraint activateConstraints:@[
                                           [safe.trailingAnchor constraintEqualToAnchor:yourView.trailingAnchor],
                                           [yourView.leadingAnchor constraintEqualToAnchor:safe.leadingAnchor],
                                           [yourView.topAnchor constraintEqualToAnchor:safe.topAnchor],
                                           [safe.bottomAnchor constraintEqualToAnchor:yourView.bottomAnchor]
                                          ]];

Please also check the option for lower version of ios 11 from Krunal's answer.

Answer 3

Use UIWindow or UIView's safeAreaInsets .bottom .top .left .right

// #available(iOS 11.0, *)
// height - UIApplication.shared.keyWindow!.safeAreaInsets.bottom

// On iPhoneX
// UIApplication.shared.keyWindow!.safeAreaInsets.top =  44
// UIApplication.shared.keyWindow!.safeAreaInsets.bottom = 34

// Other devices
// UIApplication.shared.keyWindow!.safeAreaInsets.top =  0
// UIApplication.shared.keyWindow!.safeAreaInsets.bottom = 0

// example
let window = UIApplication.shared.keyWindow!
let viewWidth = window.frame.size.width
let viewHeight = window.frame.size.height - window.safeAreaInsets.bottom
let viewFrame = CGRect(x: 0, y: 0, width: viewWidth, height: viewHeight)
let aView = UIView(frame: viewFrame)
aView.backgroundColor = .red
view.addSubview(aView)
aView.autoresizingMask = [.flexibleWidth, .flexibleHeight]

Answer 4

Here is sample code (Ref from: Safe Area Layout Guide):
If you create your constraints in code use the safeAreaLayoutGuide property of UIView to get the relevant layout anchors. Let’s recreate the above Interface Builder example in code to see how it looks:

Assuming we have the green view as a property in our view controller:

private let greenView = UIView()

We might have a function to set up the views and constraints called from viewDidLoad:

private func setupView() {
  greenView.translatesAutoresizingMaskIntoConstraints = false
  greenView.backgroundColor = .green
  view.addSubview(greenView)
}

Create the leading and trailing margin constraints as always using the layoutMarginsGuide of the root view:

 let margins = view.layoutMarginsGuide
    NSLayoutConstraint.activate([
      greenView.leadingAnchor.constraint(equalTo: margins.leadingAnchor),
      greenView.trailingAnchor.constraint(equalTo: margins.trailingAnchor)
 ])

Now, unless you are targeting iOS 11 and later, you will need to wrap the safe area layout guide constraints with #available and fall back to top and bottom layout guides for earlier iOS versions:

if #available(iOS 11, *) {
  let guide = view.safeAreaLayoutGuide
  NSLayoutConstraint.activate([
   greenView.topAnchor.constraintEqualToSystemSpacingBelow(guide.topAnchor, multiplier: 1.0),
   guide.bottomAnchor.constraintEqualToSystemSpacingBelow(greenView.bottomAnchor, multiplier: 1.0)
   ])

} else {
   let standardSpacing: CGFloat = 8.0
   NSLayoutConstraint.activate([
   greenView.topAnchor.constraint(equalTo: topLayoutGuide.bottomAnchor, constant: standardSpacing),
   bottomLayoutGuide.topAnchor.constraint(equalTo: greenView.bottomAnchor, constant: standardSpacing)
   ])
}

Result:

Here is Apple Developer Official Documentation for Safe Area Layout Guide

Safe Area is required to handle user interface design for iPhone-X. Here is basic guideline for How to design user interface for iPhone-X using Safe Area Layout

Answer 5

Use constraints with visual format and you get respect for the safe area for free.

class ViewController: UIViewController {

    var greenView = UIView()

    override func viewDidLoad() {
        super.viewDidLoad()
        greenView.backgroundColor = .green
        view.addSubview(greenView)
    }
    override func viewWillLayoutSubviews() {
        super.viewWillLayoutSubviews()

        greenView.translatesAutoresizingMaskIntoConstraints = false
        let views : [String:Any] = ["greenView":greenView]
        view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|-[greenView]-|", options: [], metrics: nil, views: views))
        view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|-[greenView]-|", options: [], metrics: nil, views: views))
    }
}

Answer 6

SafeAreaLayoutGuide is UIView property,

The top of the safeAreaLayoutGuide indicates the unobscured top edge of the view (e.g, not behind the status bar or navigation bar, if present). Similarly for the other edges.

Use safeAreaLayoutGuide for avoid our objects clipping/overlapping from rounded corners, navigation bars, tab bars, toolbars, and other ancestor views.

We can create safeAreaLayoutGuide object & set object constraints respectively.

Constraints for Portrait + Landscape is -

        self.edgesForExtendedLayout = []//Optional our as per your view ladder

        let newView = UIView()
        newView.backgroundColor = .red
        self.view.addSubview(newView)
        newView.translatesAutoresizingMaskIntoConstraints = false
        if #available(iOS 11.0, *) {
            let guide = self.view.safeAreaLayoutGuide
            newView.trailingAnchor.constraint(equalTo: guide.trailingAnchor).isActive = true
            newView.leadingAnchor.constraint(equalTo: guide.leadingAnchor).isActive = true
            newView.topAnchor.constraint(equalTo: guide.topAnchor).isActive = true
            newView.heightAnchor.constraint(equalToConstant: 100).isActive = true

        }
        else {
            NSLayoutConstraint(item: newView, attribute: .top, relatedBy: .equal, toItem: view, attribute: .top, multiplier: 1.0, constant: 0).isActive = true
            NSLayoutConstraint(item: newView, attribute: .leading, relatedBy: .equal, toItem: view, attribute: .leading, multiplier: 1.0, constant: 0).isActive = true
            NSLayoutConstraint(item: newView, attribute: .trailing, relatedBy: .equal, toItem: view, attribute: .trailing, multiplier: 1.0, constant: 0).isActive = true

            newView.heightAnchor.constraint(equalToConstant: 100).isActive = true
        }

UILayoutGuide

safeAreaLayoutGuide