探究3D touch

文章目录

1. 简介
2. 主屏幕 Quick Actions
3. Peek and Pop
4. UIPreviewInteraction
5. Low-Level Force API

简介

iOS 9+ / iPhone 6s +

提供访问app特性的便捷方式;
沉浸式的交互方式
提供连续性的用户体验（Peek and Pop)

主屏幕 Quick Actions

2 types:

Static
在Info.plist中定义

Dynamic
在app加载后通过代码动态创建；可以包含一个系统图标/自定义图标/通讯录地址

// 1. create a ShortcutIcon
	let contactName = "Lexi Torres"
	var cocntactIcon: UIApplicationShortcutIcon? = nil
	
	if CNContactStore.authorizationStatus(for: .contacts) == .authorized {
		let predicate = CNContact.predicateForContacts(matchingName: contactName)
		let contacts = try? CNContactStore().unifiedContacts(matching: predicate, keysToFetch: [])
		if let contact = contacts?.first {
			contactIcon = UIApplicationShortcutIcon(contact: contact)
		}
	}
	
	let icon = contactIcon ?? UIApplicationShortcutIcon(type: .message)
	
	// 2. create action using the icon
	let type = "com.company.app.sendChatTo"
	let subtitle = "Send a chat"
	let shortcutItem1 = UIApplicationShortcutItem(type: type, 
	                                    localizedTitle: contactName ,
	                                 localizedSubtitle: subtitle,
	                                              icon: icon)
	 // 3. add more shortcutItem if necessary
	 ...
	 
	 let shortcutItems = [shortcutItem1, ...]
	 // 4. register to application
	 application.shortcutItems = shortcutItems

处理action

  // on app activation
  func application(application: UIApplication,
  			performActionFor shortcutItem: UIApplicationShortcutItem,
  			completionHandler: @escaping(Bool) -> Void ){
  			let didHandle: Bool = /* handle logic using shortcutItem */
  			
  			completionHandler(didHandle)
  	}
  	
  	// on app launch, 在App完全退出的情况下，上面方法Handler返回的是NO。
// 这就需要我们在下面方法中也加入相应的回调处理
  	func application(application: UIApplication,
  	didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
  		var performAdditionalHandling = true
  		if let shortcutItem = launchOptions?[UIApplicationLaunchOptionsKey.shortcutItem] as? UIApplicationShortcutItem {
  		
  		   /* handle logic using shortcutItem */
  		 
		performAdditionalHandling = false
  		}
  		return performAdditionalHandling
  	}

最佳实践：

每个app都需要提供quick actions
用于high-value的任务上
使quick actions 可预测
quick actions的处理逻辑要注意向前兼容（Be prepared to handle dynamic quick actions from a previous version of your app)
添加的功能不能只通过quick action才能使用

Peek and Pop

Registered View Controller
需要实现 UIViewControllerPreviewingDelegate

// 1. Comforming previewing delegate
class ChatTableViewControlelr: UITableViewController, UIViewControllerPreviewingDelegate {
	// 2. register
	override func viewDidLoad() {
		super.viewDidLoad()
		...
		registerForPreviewing(with: self, sourceView: tableView)
	}
	
	
	// 3. previewing delegate implement
	func previewingContext(_ previewingContext: UIViewControllerPreviewing,
	        viewControllerForLocation location: CGPoint) -> UIViewController? {
		guard let indexPath = tableView.indexPathForRow(at: location) else { return nil }
		
		let chatDetailViewController = ...
		chatDetailViewController.chatItem = chatItem(at: indexPath)
		let cellRect = tableView.rectForRow(at: indexPath)
		let sourceRect = previewingContext.sourceView.convert(cellRect, from: tableView)
		previewingContext.sourceRect = sourceRect
		
		return chatDetailViewController
	
	}
	
	func previewingContext(_ previewingContext: UIViewControllerPreviewing, 
	             commit viewControllerToCommit: UIViewController) {
		show(viewControllerToCommit, sender: self)
	}
	
	// optional actions
	
	override func previewActionItems() -> [UIPreviewActionItem] {
	let heart = UIPreviewAction(title: "heart", style: .default) { (action, viewController) in
			// Send a heart
			
		}
	} 
	// 也可以用UIPreviewActionGroup() 包装一组actions
	let replyActions = [action1, action2]
	let sendReply = UIPreviewActionGroup(title: "a group reply" style: .default, actions: replyActions)
	
	return [heart, sendReply]
}

其他的action styles: .selected, .destructive

最佳实践
- 能够被tapped的content应该支持 Peek and Pop
- Return a preview view controller consistently
- Don’t take too long in the previewing delegate
- Set the previewing context sourceRect

UIPreviewInteraction

同样的Peek and Pop处理过程 + 自动Haptic Feedback + 自定义界面

实现 UIPreviewInteractionDelegate

// 1. comfrom
extension ChatDetailViewController: UIPreviewInteractionDelegate {
var replyPreviewInteraction: UIPreviewInteraction!
}
// 2. create 
override func viewDidLoad() {
	super.viewDidLoad()
	...
	
	replyPreviewInteraction = UIPreviewInteraction(view: view)
	replyPreviewInteraction.delegate = self
}
previewInteractionShouldBegin()
// 3. preveiw transition
func previewInteraction(_ previewInteraction: UIPreviewInteraction,
didUPdatePreveiwTransition transitionProgress: CGFloat,
ended: Bool) {
   // progress value [0, 1]
	updateForPreview(progress: transitionProgress)
	
	if ended {
		completePreview()
	}
	
}
// 4. cancel handling
func previewInteractionDidCancel(_ previewInteraction: UIPreviewInteraction) {
	UIView.animate(withDuration: 0.4) {
		self.updateForPreview(progress: 0)
		self.resetToInitialAppearance()
	}
}
// 5. commit transition
func previewInteraction(_ previewInteraction: UIPreviewInteraction, 
didUpdateCommitTransition transitionProgress: CGFloat,
ended: Bool) {
	updateForCommit(progress: transitionProgress)
	
	if ended {
		completeCommit()
	}
}

Low-Level Force API

Properties on UITouch: force and maximumPossibleForce