myrickchow32

class AVFoundataionDemoViewController: BaseViewController {
  let avSpeechSynthesizer = AVSpeechSynthesizer()
  override func viewDidLoad() {
      super.viewDidLoad()  
      avSpeechSynthesizer.delegate = self
  }
}

extension AVFoundataionDemoViewController: AVSpeechSynthesizerDelegate {
  func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer, didStart utterance: AVSpeechUtterance) {

myrickchow32

var avSpeechSynthesizer: AVSpeechSynthesizer!

override func viewWillDisappear(_ animated: Bool) {
  super.viewWillDisappear(animated)
  avSpeechSynthesizer.stopSpeaking(at: .immediate)
}

myrickchow32

class AppDelegate: UIResponder, UIApplicationDelegate {
  func applicationDidEnterBackground(_ application: UIApplication) {
    // AVSpeechSynthesizer will be automatically stopped with a smooth volume reduction
    // The parameter of stopping the speech is AVSpeechBoundary.immediate
    print("applicationDidEnterBackground")
  }
  
  func applicationDidBecomeActive(_ application: UIApplication) {
    // AVSpeechSynthesizer will be automatically resumed
    print("applicationDidBecomeActive")

myrickchow32

// Utterance contains with both English and Traditional Chinese words
let utterance = AVSpeechUtterance(string: "Hong Kong（香港）is in Asia.")
utterance.voice = AVSpeechSynthesisVoice(language: "zh-HK")

let avSpeechSynthesizer = AVSpeechSynthesizer()
avSpeechSynthesizer.speak(utterance)

myrickchow32

/*
  Three possible outcomes:
  1. The user selected accent in "en-AU" category
  2. iOS default accent in "en-AU" category
     2.1 Compact
     2.2 Enhanced (if user has downloaded)
*/
let voice = AVSpeechSynthesisVoice(language: "en-AU")

myrickchow32

func getUtteranceWithDelay(preUtteranceDelayInSecond: Int, postUtteranceDelayInSecond: Int) -> AVSpeechUtterance {
  let utterance = AVSpeechUtterance(string: "Hello world")
  utterance.preUtteranceDelay = TimeInterval.init(exactly: preUtteranceDelayInSecond)!
  utterance.postUtteranceDelay = TimeInterval.init(exactly: postUtteranceDelayInSecond)!
  return utterance
}

let avSpeechSynthesizer = AVSpeechSynthesizer()
avSpeechSynthesizer.speak(getUtteranceWithDelay(preUtteranceDelayInSecond: 1, postUtteranceDelayInSecond: 2))
avSpeechSynthesizer.speak(getUtteranceWithDelay(preUtteranceDelayInSecond: 1, postUtteranceDelayInSecond: 2))

myrickchow32

/*
  **********************************
  Voice identifier: com.apple.ttsbundle.Maged-compact
  Voice language: ar-SA
  Voice name: Maged
  Voice quality: 1
  **********************************
  Voice identifier: com.apple.ttsbundle.Zuzana-compact
  Voice language: cs-CZ
  Voice name: Zuzana

myrickchow32

import UIKit
// Step 1: Import AVFoundation library
import AVFoundation

class AVFoundataionDemoViewController: BaseViewController {
  var avSpeechSynthesizer: AVSpeechSynthesizer!
  
  @IBAction func startSpeechAction(_ sender: Any) {
    // Step 4: Stop any existing speech, else it will not start !!!
    avSpeechSynthesizer.stopSpeaking(at: .immediate)

myrickchow32

func getUtterance(_ speechString: String) -> AVSpeechutterance {
  let utterance = AVSpeechUtterance(string: speechString)
  utterance.voice = ... 
  utterance.rate = ...
  utterance.pitchMultiplier = ...
  utterance.volume = ...
  utterance.preUtteranceDelay = ...
  utterance.postUtteranceDelay = ...
  return utterance
}

myrickchow32

/*
  No compile and runtime error
  Outcome: only "First AVSpeechSynthesizer" is outputed
*/
let firstAvSpeechSynthesizer = AVSpeechSynthesizer()
firstAvSpeechSynthesizer.speak(getUtterance("First AVSpeechSynthesizer"))

let secondAvSpeechSynthesizer = AVSpeechSynthesizer()
secondAvSpeechSynthesizer.speak(getUtterance("Second AVSpeechSynthesizer"))