buzz.swift

import UIKit

class ViewController: UIViewController {
    var btHelper: BTHelper = BTHelper()
    var timer: Timer? = nil
    var bgTask = BackgroundTask()
    
    @objc func stop() { btHelper.shutOff() }
    @objc func action() { btHelper.startUp() }
    
    // User selected a new time interval in minutes
    // The 1 minute time out is for testing.
    // App defaults to 5 minutes refocus time out.
    @IBAction func poke(_ sender: Any) {
        guard let sc = sender as? UISegmentedControl else { return }
        timer?.invalidate()
        timer = Timer.scheduledTimer(timeInterval: 60.0 * [1.0, 3.0, 5.0, 10.0, 15.0, 30.0][sc.selectedSegmentIndex], target: self, selector: #selector(action), userInfo: nil, repeats: true)
        action()
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        
        // Live forever
        bgTask.startBackgroundTask()

        // Listen for device. Buzz on connect.
        // Observer lives forever. I don't bother to
        // save it for deallocation.
        NotificationCenter.default.addObserver(forName: NSNotification.Name(rawValue: "2A06"), object: nil, queue: .main) { note in
            print("Triggered:")
            self.btHelper.vibrate(degree: .low)
            self.perform(#selector(self.stop), with: nil, afterDelay: 5.0)
        }
        
        // Repeat every n seconds
        action()
        timer = Timer.scheduledTimer(timeInterval: 60.0 * 10, target: self, selector: #selector(action), userInfo: nil, repeats: true)
    }
}