Peek and Pop

iOS9で追加された3D Touchの機能のひとつ
3D TouchやPeek and Popの詳細は以下の記事を参照
3D Touch 概要

Peek and PopのときのUIViewControllerのライフサイクル

Peek and Popを使用しているときの遷移前と遷移先のUIViewControllerのライフサイクルがどうなっているのか気になったので調査してみました。

コード

ViewController：最初の画面

ViewController

import UIKit

// 最初の画面
class ViewController: UIViewController , UIViewControllerPreviewingDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()
        print("ViewController viewDidLoad")        

        // self.viewに対してPeek and Popを登録
        registerForPreviewingWithDelegate(self, sourceView: self.view)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

    // 少し力を加えた段階で呼ばれる
    func previewingContext(previewingContext: UIViewControllerPreviewing, viewControllerForLocation location: CGPoint) -> UIViewController? {
        print("ViewController previewingContext location")

        // 遷移後の画面
        return SecondViewController()
    }

    // Popの段階で呼ばれる
    func previewingContext(previewingContext: UIViewControllerPreviewing, commitViewController viewControllerToCommit: UIViewController) {
        print("ViewController previewingContext viewControllerToCommit")
        showViewController(viewControllerToCommit, sender: self)
    }

    override func loadView() {
        super.loadView()
        print("ViewController loadView")
    }

    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        print("ViewController viewWillAppear")
    }

    override func viewWillDisappear(animated: Bool) {
        super.viewWillDisappear(animated)
        print("ViewController viewWillDisappear")
    }

    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        print("ViewController viewDidAppear")
    }
    override func viewDidDisappear(animated: Bool) {
        super.viewDidAppear(animated)
        print("ViewController viewDidDisappear")
    }

    override func viewWillLayoutSubviews() {
        super.viewWillLayoutSubviews()
        print("ViewController viewWillLayoutSubviews")
    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        print("ViewController viewDidLayoutSubviews")
    }    
}

SecondViewController：遷移後の画面

SecondViewController

import UIKit

// 遷移後の画面
class SecondViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        print("SecondViewController viewDidLoad")
    }

    override func loadView() {
        super.loadView()
        print("SecondViewController loadView")
    }

    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        print("SecondViewController viewWillAppear")
    }

    override func viewWillDisappear(animated: Bool) {
        super.viewWillDisappear(animated)
        print("SecondViewController viewWillDisappear")
    }

    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        print("SecondViewController viewDidAppear")
    }
    override func viewDidDisappear(animated: Bool) {
        super.viewDidAppear(animated)
        print("SecondViewController viewDidDisppear")
    }

    override func viewWillLayoutSubviews() {
        super.viewWillLayoutSubviews()
        print("SecondViewController viewWillLayoutSubviews")
    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        print("SecondViewController viewDidLayoutSubviews")
    }    
}

ライフサイクル

UIViewControllerのライフサイクル

1.起動時

起動時は通常のライフサイクルと同じなので特に問題なし

ViewController loadView
ViewController viewDidLoad
ViewController viewWillAppear
ViewController viewWillLayoutSubviews
ViewController viewDidLayoutSubviews
ViewController viewDidAppear

2.通常の画面遷移（presentViewControllerでの遷移）

SecondViewController loadView
SecondViewController viewDidLoad
ViewController viewWillDisappear
SecondViewController viewWillAppear
SecondViewController viewWillLayoutSubviews
SecondViewController viewDidLayoutSubviews
ViewController viewWillLayoutSubviews
ViewController viewDidLayoutSubviews
SecondViewController viewWillLayoutSubviews
SecondViewController viewDidLayoutSubviews
SecondViewController viewDidAppear
ViewController viewDidDisappear

3.少しだけ押した時

（func previewingContext(previewingContext: UIViewControllerPreviewing, viewControllerForLocation location: CGPoint) -> UIViewController?
が呼ばれるとき）

ViewController previewingContext location
SecondViewController loadView
SecondViewController viewDidLoad
SecondViewController viewWillAppear
SecondViewController viewWillLayoutSubviews
SecondViewController viewDidLayoutSubviews
SecondViewController viewWillLayoutSubviews
SecondViewController viewDidLayoutSubviews

この状態で指を離した場合

SecondViewController viewWillDisappear
SecondViewController viewDidDisppear

という感じで圧力を検知した時点でViewControllerの表示の準備されてすぐに表示できるような状態になっています。

4.Peek時（プレビューが表示される時）

SecondViewController viewDidAppear

この状態で指を話した場合

SecondViewController viewWillDisappear
SecondViewController viewDidDisppear

という感じで

PeekになったらviewDidAppearが呼ばれます。
この時点での通常の画面遷移との違いは遷移後のSecondViewControllerのviewDidAppearが呼ばれていても遷移前のViewControllerのviewWillDisappearやviewDidDisappearは呼ばれていません。(遷移前、遷移後両方のUIViewControllerがviewDidAppearの状態）

5.Pop時（ViewControllerが遷移する時）

SecondViewController viewWillDisappear
SecondViewController viewDidDisppear
ViewController previewingContext viewControllerToCommit
ViewController viewWillDisappear
SecondViewController viewWillAppear
SecondViewController viewDidAppear
ViewController viewDidDisappear
SecondViewController viewWillLayoutSubviews
SecondViewController viewDidLayoutSubviews