TextView TypeWriter

gistfile1.txt

extension UITextView {
    func setTextWithTypeAnimation(typedText: String, characterDelay: TimeInterval = 5.0) {
        text = ""
        var writingTask: DispatchWorkItem?
        writingTask = DispatchWorkItem { [weak weakSelf = self] in
            for character in typedText {
                DispatchQueue.main.async {
                    weakSelf?.text!.append(character)
                }
                Thread.sleep(forTimeInterval: characterDelay/100)
            }
        }
        
        if let task = writingTask {
            let queue = DispatchQueue(label: "typespeed", qos: DispatchQoS.userInteractive)
            queue.asyncAfter(deadline: .now() + 0.05, execute: task)
        }
    }
}

// 使い方
TEXTVIEW.setTextWithTypeAnimation(typedText: "STRING", characterDelay: 10.0)