I use this method to judge this device whether supports the captureTextFromCamera API : let tf = UITextField() tf.canPerformAction(#selector(UIResponder.captureTextFromCamera(_:)),withSender: nil) This will return false on iPhoneX and return true on iPhone13 Pro So I want to know: On iPhone13Pro tf.canPerformAction(#selector(UIResponder.captureTextFromCamera(_:)),withSender: nil) Can this method return the false ? Or this value won't change for every device? Can I assume that this method will always return true on iPhone13 Pro and will always false on iPhoneX?

I have set CADisableMinimumFrameDurationOnPhone to YES And My device is iPhone13 Pro. The refresh rate is be 120HZ max. But the touchesMoved callback call with a frequency of 60HZ (16.66ms) in UIViewController It should be 120HZ (0.008s) on IPhone 13 pro Here is test code: import SwiftUI class HomeViewController: UIViewController,UIScrollViewDelegate {       override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {     let time = CFAbsoluteTimeGetCurrent()     print(time - oldTime) // 0.016s. But it should be 0.008s on iPhone13Pro     oldTime = time   }       var oldTime:CFAbsoluteTime = 0       override func viewDidLoad() {     super.viewDidLoad()     self.view.backgroundColor = .red   } } So How can I increase this frequency to 120HZ ?.

I add two view on screen. One is the blue view, other is orange view. And I use CADisplayLink to change orange view 's frame according to the blueView.layer.presentation.frame As expected, the orange view should cover the blue view completely, but we can see a gap and we can see a little part of blue view during keyboard animation. Here is demo code: class SecondViewController: UIViewController {       let textField = UITextField()       override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {     self.textField.resignFirstResponder()   }       lazy var displayLink = CADisplayLink(target: self, selector: #selector(self.onDisplayLink))       @objc private func onDisplayLink () {     self.realBox.frame = CGRect(x: self.realBox.frame.origin.x, y: self.blueBox.layer.presentation()!.frame.origin.y, width: self.view.bounds.width, height: 100)   }       let blueBox = UIView()   let realBox = UIView()       override func viewDidLoad() {     super.viewDidLoad()     self.view.backgroundColor = .white           textField.frame = .init(x: 100, y: 100, width: 100, height: 100)     textField.backgroundColor = .red     self.view.addSubview(textField)           realBox.backgroundColor = .orange           blueBox.backgroundColor = .blue     blueBox.frame = .init(x: 0, y: self.view.bounds.height - 100, width: self.view.bounds.width, height: 100)     self.view.addSubview(blueBox)     self.view.addSubview(realBox)     realBox.frame = .init(x: 0, y:self.view.bounds.height - 100 , width: self.view.bounds.width, height: 100)           NotificationCenter.default.addObserver(forName: UIResponder.keyboardWillChangeFrameNotification, object: nil, queue: .main) { noti in       let userInfo = noti.userInfo!       let endFrame = userInfo[UIResponder.keyboardFrameEndUserInfoKey] as! CGRect       let isOpen = endFrame.intersects(self.view.bounds)       self.blueBox.frame = .init(x: 0, y: isOpen ? self.view.bounds.height - 100 - endFrame.height : self.view.bounds.height - 100, width: self.view.bounds.width, height: 100)     }           if #available(iOS 15.0, *) {       self.displayLink.preferredFrameRateRange = .init(minimum: 60, maximum: 120, preferred: 120)     } else {       self.displayLink.preferredFramesPerSecond = 120     }     self.displayLink.add(to: .main, forMode: .common)   } } So how to get an accurate value of the layer currently displayed on screen? Here is the video: https://github.com/luckysmg/daily_images/blob/main/RPReplay_Final1661168764.mov?raw=true

I think CAMetalLayer.nextDrawable() shouldn't be very time-consuming, it should be less than 1ms. But occasionally, it will take more than 5ms, just 7ms~13ms, which is a very long time. How can we optimize this? Since this will cause rendering junk.....

The new captureTextFromCamera API allow device to use OCR in UIResponder,but how can I know this device support OCR or not ? eg: iPhoneX:NO, iPhone13:YES