import UIKit
import WebKit

class ViewController: UIViewController,WKUIDelegate {

    @IBOutlet weak var webView: WKWebView!
    @IBOutlet weak var activityIndicator: UIActivityIndicatorView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        webView.uiDelegate = self
        
        // Do any additional setup after loading the view,typically from a nib.
        let url = "https://example.com"
        let request = URLRequest(url: URL(string: url)!)
        self.webView.load(request)
        self.webView.addObserver(self,forKeyPath: #keyPath(WKWebView.isLoading),options: .new,context: nil)
        
        // Page Scrolling - false or true
        webView.scrollView.isScrollEnabled = false
        
    }
    
    // Open new tab links
    func webView(_ webView: WKWebView,createWebViewWith configuration: WKWebViewConfiguration,for navigationAction: WKNavigationAction,windowFeatures: WKWindowFeatures) -> WKWebView? {
      if navigationAction.targetFrame == nil,let url = navigationAction.request.url,let scheme = url.scheme {
        if ["http","https","mailto"].contains(where: { $0.caseInsensitiveCompare(scheme) == .orderedSame }) {
          UIApplication.shared.open(url,options: [:],completionHandler: nil)
        }
      }
      return nil
    }
    
    override func observeValue(forKeyPath keyPath: String?,of object: Any?,change: [NSKeyValueChangeKey : Any]?,context: UnsafeMutableRawPointer?) {
        if keyPath == "loading" {
            if webView.isLoading {
                activityIndicator.startAnimating()
                activityIndicator.isHidden = false
            } else {
                activityIndicator.stopAnimating()
                activityIndicator.isHidden = true
            }
        }
    }
}