rotateMarker.kt

fun rotateMarker(marker: Marker, toRotation: Float) {
    val handler = Handler()
    val start = SystemClock.uptimeMillis()
    val startRotation = marker.rotation
    val duration: Long = 300

    handler.post(object : Runnable {
        override fun run() {
            val elapsed = SystemClock.uptimeMillis() - start
            val t = LinearInterpolator().getInterpolation(elapsed.toFloat() / duration)

            val rot = t * toRotation + (1 - t) * startRotation

            marker.rotation = if (-rot > 180) rot / 2 else rot
            if (t < 1.0) {
                handler.postDelayed(this, 16)
            }
        }
    })
}