Any possibility to get events through hardware buttons.

Question

Is it possible to get any events on our application through hardware button pressed.

Like:Volume button/Home button.

Answer 1

I hope it helps you!!

When user press home button you get to know by appDelegates methods.

func applicationWillResignActive(_ application: UIApplication) {
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
}

func applicationDidEnterBackground(_ application: UIApplication) {
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}

func applicationWillEnterForeground(_ application: UIApplication) {
    // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
}

func applicationDidBecomeActive(_ application: UIApplication) {
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}

func applicationWillTerminate(_ application: UIApplication) {
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}

When user press volume button, if you want to detect it.

func listenVolumeButton(){

    let audioSession = AVAudioSession.sharedInstance()
    audioSession.setActive(true, error: nil)
    audioSession.addObserver(self, forKeyPath: "outputVolume",
        options: NSKeyValueObservingOptions.New, context: nil)
}

override func observeValueForKeyPath(keyPath: String, ofObject object: AnyObject,
    change: [NSObject : AnyObject], context: UnsafeMutablePointer<Void>) {
    if keyPath == "outputVolume"{
        print("got in here")
    }
}

Answer 2

You can observe outputVolume property to detect volume button actions,

func volumeAction() {
    let audioSession = AVAudioSession.sharedInstance()
    do {
        try audioSession.setActive(true, options: [])
        audioSession.addObserver(self, forKeyPath: "outputVolume",
                                 options: .new, context: nil)
    } catch {
        print("Error")
    }
}

override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
    if keyPath == "outputVolume"{
        print("volume changed")
    }
}

As Home Button is no longer available in newer devices, you can make use of Biometric authentication(Face ID or Touch ID) for the same.