UIViewControllerでoverride可能なメソッドを列挙してみる

# はじめに
`UIViewController`のことがよくわからないのでとりあえずoverrideできそうなメソッドというメソッドを全て持ってきました。
何のメソッドがいつ呼ばれるのかを調べるのに使えると思います。

## 環境
MacBook Air (M1, 2020)
macOS Big Sur 11.5.2（20G95）
Xcode Version 12.5.1 (12E507)
Swift version 5.4.2
Simulator Version 12.5.1 (961.1), iOS 14.5
実機 iOS 14.7.1 (18G82)

# 検証コード
少し長いです。
メソッド名を出力するだけです。
値を返さないといけないものに関しては次のように返しました。

|型|値|
|:-:|:-:|
|Bool|`true`|
|配列|`[]`|
|CGSize|`.zero`|
|クラス|`.init()`|

`registerForPreviewing(with:sourceView:)`に関しては返し方がわからないのでコメントアウトしています。

また、すでに非推奨となっているメソッドもありますが、一応含めています。

``` swift
import SwiftUI

struct TestView: UIViewControllerRepresentable {
    func makeUIViewController(context: Context) -> UIViewController {
        TestViewController()
    }
    
    func updateUIViewController(_ uiViewController: UIViewController, context: Context) {}
}

struct TestView_Preview: PreviewProvider {
    static var previews: some View {
        TestView()
    }
}

class TestViewController: UIViewController {
    override func preferredContentSizeDidChange(forChildContentContainer container: UIContentContainer) {
        super.preferredContentSizeDidChange(forChildContentContainer: container)
        print("\(#function)")
    }
    
    override func systemLayoutFittingSizeDidChange(forChildContentContainer container: UIContentContainer) {
        super.systemLayoutFittingSizeDidChange(forChildContentContainer: container)
        print("\(#function)")
    }
    
    override func size(forChildContentContainer container: UIContentContainer, withParentContainerSize parentSize: CGSize) -> CGSize {
        print("\(#function)")
        return .zero
    }
    
    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
        super.viewWillTransition(to: size, with: coordinator)
        print("\(#function)")
    }
    
    override func willTransition(to newCollection: UITraitCollection, with coordinator: UIViewControllerTransitionCoordinator) {
        super.willTransition(to: newCollection, with: coordinator)
        print("\(#function)")
    }
    
    override func loadView() {
        super.loadView()
        print("\(#function)")
    }
    
    override func loadViewIfNeeded() {
        super.loadViewIfNeeded()
        print("\(#function)")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        print("\(#function)")
    }
    
    override func performSegue(withIdentifier identifier: String, sender: Any?) {
        super.performSegue(withIdentifier: identifier, sender: sender)
        print("\(#function)")
    }
    
    override func shouldPerformSegue(withIdentifier identifier: String, sender: Any?) -> Bool {
        print("\(#function)")
        return true
    }
    
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        super.prepare(for: segue, sender: sender)
        print("\(#function)")
    }
    
    override func canPerformUnwindSegueAction(_ action: Selector, from fromViewController: UIViewController, sender: Any?) -> Bool {
        print("\(#function)")
        return true
    }
    
    override func canPerformUnwindSegueAction(_ action: Selector, from fromViewController: UIViewController, withSender sender: Any) -> Bool {
        print("\(#function)")
        return true
    }
    
    override func allowedChildrenForUnwinding(from source: UIStoryboardUnwindSegueSource) -> [UIViewController] {
        print("\(#function)")
        return []
    }
    
    override func childContaining(_ source: UIStoryboardUnwindSegueSource) -> UIViewController? {
        print("\(#function)")
        return UIViewController()
    }
    
    override func forUnwindSegueAction(_ action: Selector, from fromViewController: UIViewController, withSender sender: Any?) -> UIViewController? {
        print("\(#function)")
        return UIViewController()
    }
    
    override func unwind(for unwindSegue: UIStoryboardSegue, towards subsequentVC: UIViewController) {
        super.unwind(for: unwindSegue, towards: subsequentVC)
        print("\(#function)")
    }
    
    override func segueForUnwinding(to toViewController: UIViewController, from fromViewController: UIViewController, identifier: String?) -> UIStoryboardSegue? {
        print("\(#function)")
        return nil
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        print("\(#function)")
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        print("\(#function)")
    }
    
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        print("\(#function)")
    }
    
    override func viewDidDisappear(_ animated: Bool) {
        super.viewDidDisappear(animated)
        print("\(#function)")
    }
    
    override func viewWillLayoutSubviews() {
        super.viewWillLayoutSubviews()
        print("\(#function)")
    }
    
    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        print("\(#function)")
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        print("\(#function)")
    }
    
    override func present(_ viewControllerToPresent: UIViewController, animated flag: Bool, completion: (() -> Void)? = nil) {
        super.present(viewControllerToPresent, animated: flag, completion: completion)
        print("\(#function)")
    }
    
    override func dismiss(animated flag: Bool, completion: (() -> Void)? = nil) {
        super.dismiss(animated: flag, completion: completion)
        print("\(#function)")
    }
    
    override func setNeedsStatusBarAppearanceUpdate() {
        super.setNeedsStatusBarAppearanceUpdate()
        print("\(#function)")
    }
    
    override func targetViewController(forAction action: Selector, sender: Any?) -> UIViewController? {
        print("\(#function)")
        return UIViewController()
    }
    
    override func show(_ vc: UIViewController, sender: Any?) {
        super.show(vc, sender: sender)
        print("\(#function)")
    }
    
    override func showDetailViewController(_ vc: UIViewController, sender: Any?) {
        super.showDetailViewController(vc, sender: sender)
        print("\(#function)")
    }
    
    override func rotatingHeaderView() -> UIView? {
        print("\(#function)")
        return UIView()
    }
    
    override func rotatingFooterView() -> UIView? {
        print("\(#function)")
        return UIView()
    }
    
    override func willRotate(to toInterfaceOrientation: UIInterfaceOrientation, duration: TimeInterval) {
        super.willRotate(to: toInterfaceOrientation, duration: duration)
        print("\(#function)")
    }
    
    override func didRotate(from fromInterfaceOrientation: UIInterfaceOrientation) {
        super.didRotate(from: fromInterfaceOrientation)
        print("\(#function)")
    }
    
    override func willAnimateRotation(to toInterfaceOrientation: UIInterfaceOrientation, duration: TimeInterval) {
        super.willAnimateRotation(to: toInterfaceOrientation, duration: duration)
        print("\(#function)")
    }
    
    override func setEditing(_ editing: Bool, animated: Bool) {
        super.setEditing(editing, animated: animated)
        print("\(#function)")
    }
    
    override func addChild(_ childController: UIViewController) {
        super.addChild(childController)
        print("\(#function)")
    }
    
    override func removeFromParent() {
        super.removeFromParent()
        print("\(#function)")
    }
    
    override func transition(from fromViewController: UIViewController, to toViewController: UIViewController, duration: TimeInterval, options: UIView.AnimationOptions = [], animations: (() -> Void)?, completion: ((Bool) -> Void)? = nil) {
        super.transition(from: fromViewController, to: toViewController, duration: duration, options: options, animations: animations, completion: completion)
        print("\(#function)")
    }
    
    override func beginAppearanceTransition(_ isAppearing: Bool, animated: Bool) {
        super.beginAppearanceTransition(isAppearing, animated: animated)
        print("\(#function)")
    }
    
    override func endAppearanceTransition() {
        super.endAppearanceTransition()
        print("\(#function)")
    }
    
    override func setOverrideTraitCollection(_ collection: UITraitCollection?, forChild childViewController: UIViewController) {
        super.setOverrideTraitCollection(collection, forChild: childViewController)
        print("\(#function)")
    }
    
    override func overrideTraitCollection(forChild childViewController: UIViewController) -> UITraitCollection? {
        print("\(#function)")
        return UITraitCollection()
    }
    
    override func shouldAutomaticallyForwardRotationMethods() -> Bool {
        print("\(#function)")
        return true
    }
    
    override func willMove(toParent parent: UIViewController?) {
        super.willMove(toParent: parent)
        print("\(#function)")
    }
    
    override func didMove(toParent parent: UIViewController?) {
        super.didMove(toParent: parent)
        print("\(#function)")
    }
    
    override func encodeRestorableState(with coder: NSCoder) {
        super.encodeRestorableState(with: coder)
        print("\(#function)")
    }
    
    override func decodeRestorableState(with coder: NSCoder) {
        super.decodeRestorableState(with: coder)
        print("\(#function)")
    }
    
    override func applicationFinishedRestoringState() {
        super.applicationFinishedRestoringState()
        print("\(#function)")
    }
    
    override func updateViewConstraints() {
        super.updateViewConstraints()
        print("\(#function)")
    }
    
    override func viewLayoutMarginsDidChange() {
        super.viewLayoutMarginsDidChange()
        print("\(#function)")
    }
    
    override func viewSafeAreaInsetsDidChange() {
        super.viewSafeAreaInsetsDidChange()
        print("\(#function)")
    }
    
    override func addKeyCommand(_ keyCommand: UIKeyCommand) {
        super.addKeyCommand(keyCommand)
        print("\(#function)")
    }
    
    override func removeKeyCommand(_ keyCommand: UIKeyCommand) {
        super.removeKeyCommand(keyCommand)
        print("\(#function)")
    }
    
    /*override func registerForPreviewing(with delegate: UIViewControllerPreviewingDelegate, sourceView: UIView) -> UIViewControllerPreviewing {
        print("\(#function)")
        return UIViewControllerPreviewing
    }*/
    
    override func unregisterForPreviewing(withContext previewing: UIViewControllerPreviewing) {
        super.unregisterForPreviewing(withContext: previewing)
        print("\(#function)")
    }
    
    override func setNeedsUpdateOfScreenEdgesDeferringSystemGestures() {
        super.setNeedsUpdateOfScreenEdgesDeferringSystemGestures()
        print("\(#function)")
    }
    
    override func setNeedsUpdateOfHomeIndicatorAutoHidden() {
        super.setNeedsUpdateOfHomeIndicatorAutoHidden()
        print("\(#function)")
    }
    
    override func setNeedsUpdateOfPrefersPointerLocked() {
        super.setNeedsUpdateOfPrefersPointerLocked()
        print("\(#function)")
    }
    
}
```

# 結果
## シュミレータ(iPhone 8)
### 読み込まれた直後

```
loadView()
viewDidLoad()
willMove(toParent:)
viewWillAppear(_:)
viewLayoutMarginsDidChange()
didMove(toParent:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewDidAppear(_:)
didMove(toParent:)
```

### コントロールセンターを開いた直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### コントロールセンターを閉じた直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### 通知センターを開いた直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### 通知センターを閉じた直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### ９０度回転した直後

```
viewWillTransition(to:with:)
setNeedsUpdateOfScreenEdgesDeferringSystemGestures()
setNeedsUpdateOfHomeIndicatorAutoHidden()
setNeedsUpdateOfPrefersPointerLocked()
willTransition(to:with:)
setNeedsStatusBarAppearanceUpdate()
viewLayoutMarginsDidChange()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### 270度回転した直後

```
viewWillTransition(to:with:)
```

### 360度回転した直後

```
viewWillTransition(to:with:)
setNeedsUpdateOfScreenEdgesDeferringSystemGestures()
setNeedsUpdateOfHomeIndicatorAutoHidden()
setNeedsUpdateOfPrefersPointerLocked()
willTransition(to:with:)
setNeedsStatusBarAppearanceUpdate()
viewLayoutMarginsDidChange()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### ホームボタンでホーム画面に戻った直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### ホーム画面からAppスイッチャで戻った直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### サイドボタンでスリープした直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### サイドボタンでスリープから復帰した直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### Appスイッチャを開いてタスキルした直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

## 実機(iPad 8th Gen)
### 読み込まれた直後

```
loadView()
viewDidLoad()
willMove(toParent:)
viewWillAppear(_:)
viewLayoutMarginsDidChange()
didMove(toParent:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewDidAppear(_:)
didMove(toParent:)
```

### コントロールセンターを開いた直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### コントロールセンターを閉じた直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### 通知センターを開いた直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### 通知センターを閉じた直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### ９０度回転した直後

```
viewWillTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### 270度回転した直後

```
viewWillTransition(to:with:)
```

### 360度回転した直後

```
viewWillTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### ホームボタンでホーム画面に戻った直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillTransition(to:with:)
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillTransition(to:with:)
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### ホーム画面からAppスイッチャで戻った直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### サイドボタンでスリープした直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillTransition(to:with:)
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillTransition(to:with:)
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### サイドボタンでスリープから復帰した直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

### Appスイッチャを開いてタスキルした直後

```
willTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
viewWillDisappear(_:)
viewDidDisappear(_:)
willMove(toParent:)
removeFromParent()
```

# 考察
コントロールセンターを開いたり、通知センターを開いたり、デバイスを回転させたりした直後に呼ばれるメソッドは同じなようです。

そして基本的に何か変化があり、画面の再描画が必要な時には以下の３つが呼ばれるようです。

```
viewWillTransition(to:with:)
viewWillLayoutSubviews()
viewDidLayoutSubviews()
```

しかし画面が見えるようになる時も、見えなくなる時も呼ばれるのでよくわからないですね。