ShortcutItem

iPhone 11 之前，有一种主屏交互方式称之为 3D Touch，现在已经改为 Haptic Touch。 它是一种立体触控技术，可感应不同的触控压力。通过该技术可以给 App 设置最多 4 个不同的 ShortcutItem（快捷操作菜单），实现方式分为静态和动态两种。

• 静态配置通过 Info.plist 文件。

<key>UIApplicationShortcutItems</key>
<array>
    <dict>
        <key>UIApplicationShortcutItemIconType</key>
        <string>UIApplicationShortcutIconTypeSearch</string>
        <key>UIApplicationShortcutItemSubtitle</key>
        <string>副标题</string>
        <key>UIApplicationShortcutItemTitle</key>
        <string>标题</string>
        <key>UIApplicationShortcutItemType</key>
        <string>搜索</string>
    </dict>
    ...
</array>

• 动态配置通过代码设置。

extension AppDelegate {
    func shortcutItems() {
        // 图标
        let icon1 = UIApplicationShortcutIcon(systemImageName: "qrcode.viewfinder") // 系统图片
        let icon2 = UIApplicationShortcutIcon(templateImageName: "settings") // 自定义图片
        let icon3 = UIApplicationShortcutIcon(type: .search) // 系统类型

        // 菜单
        let item1 = UIApplicationShortcutItem(type: "1", localizedTitle: "扫描", localizedSubtitle: nil, icon: icon1, userInfo: nil)
        let item2 = UIApplicationShortcutItem(type: "2", localizedTitle: "设置", localizedSubtitle: nil, icon: icon2, userInfo: nil)
        let item3 = UIApplicationShortcutItem(type: "3", localizedTitle: "搜索", localizedSubtitle: nil, icon: icon3, userInfo: nil)

        // 设置
        UIApplication.shared.shortcutItems = [item1, item2, item3]
    }
}

• 点击事件响应。

// iOS13之前，使用AppDelegate的代理方法
func application(_ application: UIApplication, performActionFor shortcutItem: UIApplicationShortcutItem, completionHandler: @escaping (Bool) -> Void) {
    if shortcutItem.type == "1" {
        window?.rootViewController?.view.backgroundColor = .red
    } else if shortcutItem.type == "2" {
        window?.rootViewController?.view.backgroundColor = .green
    } else if shortcutItem.type == "3" {
        window?.rootViewController?.view.backgroundColor = .blue
    }
}

// iOS13之后，AppDelegate的代理方法不会被调用，需要使用SceneDelegate的代理方法
func windowScene(_ windowScene: UIWindowScene, performActionFor shortcutItem: UIApplicationShortcutItem, completionHandler: @escaping (Bool) -> Void) {
    if shortcutItem.type == "1" {
        window?.rootViewController?.view.backgroundColor = .red
    } else if shortcutItem.type == "2" {
        window?.rootViewController?.view.backgroundColor = .green
    } else if shortcutItem.type == "3" {
        window?.rootViewController?.view.backgroundColor = .blue
    }
}

UIMenu

• UIMenu 在 iOS 13 中引入，可以很方便的创建程序菜单和上下文菜单。

import UIKit

class ViewController: UIViewController {
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        // 显示工具条
        navigationController?.isToolbarHidden = false
        // 菜单绑定到UIBarButtonItem（iOS 14的构造函数）
        let addNewItem = UIBarButtonItem(systemItem: .add, primaryAction: nil, menu: createMenu())
        // 放到工具条
        toolbarItems = [addNewItem]
    }

    func createMenu() -> UIMenu {
        // 第一个菜单
        let favorite = UIAction(title: "Favorite", image: UIImage(systemName: "heart.fill")) { _ in
            print("favorite")
        }
        // 第二个菜单
        let share = UIAction(title: "Share", image: UIImage(systemName: "square.and.arrow.up.fill")) { _ in
            print("share")
        }
        // 第三个菜单
        let delete = UIAction(title: "Delete", image: UIImage(systemName: "trash.fill"), attributes: [.destructive]) { _ in
            print("delete")
        }
        // 创建菜单组
        let menuActions = [favorite, share, delete]
        // 创建UIMenu
        let addNewMenu = UIMenu(children: menuActions)

        return addNewMenu
    }
}

• iOS 14 中引入UIDeferredMenuElement，允许异步地创建 UIMenu，可以动态配置菜单的内容。

import UIKit

class ViewController: UIViewController {
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        // 放到导航条
        navigationItem.rightBarButtonItem = UIBarButtonItem(systemItem: .add, primaryAction: nil, menu: createMenu())
    }

    func createMenu() -> UIMenu {
        // 应该是是通过网络获取，这里直接从Bundle加载
        let menuItemsForUser = Bundle.main.decode([RemoteItem].self, from: "menu.json")
        // 创建UIDeferredMenuElement
        let dynamicElements = UIDeferredMenuElement { completion in
            // 创建UIAction
            let actions = menuItemsForUser.map { item in
                UIAction(title: item.title, image: UIImage(systemName: item.icon)) { _ in
                    print("\(item.title) tapped")
                }
            }
            // 一定要调用completion处理
            completion(actions)
        }

        return UIMenu(children: [dynamicElements])
    }
}

// 菜单Model
struct RemoteItem: Codable {
    let title: String
    let icon: String
}

// 加载文件并转Model
extension Bundle {
    func decode<T: Decodable>(_ type: T.Type, from file: String) -> T {
        guard let url = self.url(forResource: file, withExtension: nil) else {
            fatalError("Failed to find \(file) in bundle.")
        }
        guard let data = try? Data(contentsOf: url) else {
            fatalError("Failed to load \(file) from bundle.")
        }
        guard let model = try? JSONDecoder().decode(T.self, from: data) else {
            fatalError("Failed to decode \(file) from bundle.")
        }
        return model
    }
}

JSON内容如下：

[
    {
        "title": "Favorite",
        "icon": "heart.fill"
    },
    {
        "title": "Share",
        "icon": "square.and.arrow.up.fill"
    },
    {
        "title": "Delete",
        "icon": "trash.fill"
    }
]

Context Menus

• WWDC 2019 推出了上下文菜单（Context Menus），也是通过按压的方式触发，不同于 3D Touch（Haptic Touch），Context Menus 一般用于 App 内菜单的设置。
• 如果要启用上下文菜单，需要创建一个UIContextMenuInteraction并将其添加给某个触发的 UIView，然后指定 delegate，在代理方法创建 UIMenu 并返回UIContextMenuConfiguration即可。

import UIKit

class ViewController: UIViewController {    
    // 需要打开User Interaction
    @IBOutlet weak var imageView: UIImageView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建UIContextMenuInteraction
        let interaction = UIContextMenuInteraction(delegate: self)
        // 添加UIContextMenuInteraction
        // 换成其他UIView皆可
        imageView.addInteraction(interaction)
    }
}

// 代理方法
extension ViewController: UIContextMenuInteractionDelegate {
    func contextMenuInteraction(_ interaction: UIContextMenuInteraction, configurationForMenuAtLocation location: CGPoint) -> UIContextMenuConfiguration? {        
        // 第一个菜单
        let favorite = UIAction(title: "Favorite", image: UIImage(systemName: "heart.fill")) { action in
            print("favorite")
        }        
        // 第二个菜单
        let share = UIAction(title: "Share", image: UIImage(systemName: "square.and.arrow.up.fill")) { action in
            print("share")
        }
        // 第三个菜单
        let delete = UIAction(title: "Delete", image: UIImage(systemName: "trash.fill"), attributes: [.destructive]) { action in
            print("delete")
        }        
        // 返回UIContextMenuConfiguration
        return UIContextMenuConfiguration(identifier: nil, previewProvider: nil) { _ in
            UIMenu(children: [favorite, share, delete])
        }
    }
}