iOS 10 WKWebView 新機能 リンクを3D TouchでSafari以外の独自ViewControllerを表示する

import UIKit
import WebKit

class ViewController: UIViewController, WKUIDelegate {

    let webView = WKWebView()

    override func viewDidLoad() {
        super.viewDidLoad()

        self.view.backgroundColor = UIColor.white

        let web = self.webView
        web.uiDelegate = self
        web.allowsLinkPreview = true // Allow Peek & Pop 1/2
        self.view.addSubview(web)
        web.frame = self.view.bounds

        // httpsではないhttpのページを表示したい時はXcodeでATSの設定をします
        // ATSの設定方法は別途調べてください
        // be careful with ATS (App Transport Security) if you want to open a non-https page
        let url = URL(string: "https://www.amazon.co.jp/")!
        let request = URLRequest(url: url)
        web.load(request)
    }

    // Allow Peek & Pop 2/2
    func webView(_ webView: WKWebView, shouldPreviewElement elementInfo: WKPreviewElementInfo) -> Bool {
        return true
    }

    // Peek
    func webView(_ webView: WKWebView, previewingViewControllerForElement elementInfo: WKPreviewElementInfo, defaultActions previewActions: [WKPreviewActionItem]) -> UIViewController? {

        guard let url = elementInfo.linkURL else { return nil }
        print("\(type(of: self)) \(#function)  url:\(url)")

        var actions = [WKPreviewActionItem]()
        // Peekで表示しているページに対するアクションをview controllerへ渡します。
        // 表示するアクションを選択することもできます。
        // Just set all actions like
        // actions = previewActions
        // or filter any actions
        for action in previewActions {
            switch action.identifier {
            case WKPreviewActionItemIdentifierOpen:
                actions.append(action)
            case WKPreviewActionItemIdentifierAddToReadingList:
                actions.append(action)
            case WKPreviewActionItemIdentifierCopy:
                actions.append(action)
            case WKPreviewActionItemIdentifierShare:
                actions.append(action)
            default: break
            }
        }

        // アクションリストを表示したいのでUIViewControllerのサブクラスを使っています
        let vc = WebPreviewViewController(url: url, actions: actions)

        vc.preferredContentSize = vc.view.bounds.size

        return vc
    }

    // Pop
    func webView(_ webView: WKWebView, commitPreviewingViewController previewingViewController: UIViewController) {
        if previewingViewController is WebPreviewViewController {
            self.present(previewingViewController, animated: true) { }
        }
    }
}

class WebPreviewViewController: UIViewController {

    var webViewPreviewActionItems: [WKPreviewActionItem] = []
    var linkURL: URL?

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    private override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
        super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
    }

    convenience init(url: URL, actions: [WKPreviewActionItem]) {
        self.init(nibName: nil, bundle: nil)
        self.linkURL = url
        self.webViewPreviewActionItems = actions
    }

    // 受け取ったアクションのリストを表示するため
    override var previewActionItems: [UIPreviewActionItem] {
        get {
            return self.webViewPreviewActionItems
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        // Peek & Pop用のWKWebViewを表示
        if let url = self.linkURL {
            let web = WKWebView()
            web.frame = self.view.bounds
            self.view.addSubview(web)
            web.load(URLRequest(url: url))
        }
    }

}