Communication between a working thread and UI thread

Some API like requesting user location, needs to be called in the main UI thread. How to send a message from a working thread to main UI thread? Here is an example:

	class T4StationService : Service() {
	var mLocSer: LocationService? = null
	var mHandler: MyHandler? = null
	inner class MyHandler(looper: Looper) : Handler(looper) {
	override fun handleMessage(msg: Message?) {
	super.handleMessage(msg)
	// call some function that needs to be called in UI thread
	}
	}
	override fun onCreate() {
	super.onCreate()
	// create handler in the main UI thread
	mHandler = MyHandler(Looper.getMainLooper())
	// start a new thread
	Thread(MyRunnable()).start()
	}
	// inner is required to access outter class method
	inner class MyRunnable : Runnable {
	override fun run() {
	// send message to handle running in UI thread
	val message = mHandler?.obtainMessage(1)
	message?.sendToTarget()
	(0..15).map {
	println("about to sleep")
	Thread.sleep(1000)
	}
	}
	}
	}

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