class TaskProgress(private val scene: GenericScene) : Container() {

    var timeMsParent = 0L
    var currentTime = 0L

    fun startProgress(size: Double, timeMs: Long, callback: ((taskProgress: TaskProgress) -> Unit)? = null) {

        timeMsParent = timeMs

        graphics {

            val paint = ColorPaint(Colors["#00D532"])
            val strokeInfo = Context2d.StrokeInfo(thickness = 4.0, pixelHinting = true)

            scene.launchImmediately {

                val drawArc = {
                    val angleDegrees = currentTime * (360.0 / timeMsParent) * PI / 180
                    stroke(paint, strokeInfo) {
                        arc(Screen.HALF_WIDTH, Screen.HALF_HEIGHT,  size * 0.53, 0, angleDegrees)
                    }
                }

                while (currentTime < timeMsParent) {
                    drawArc()
                    // sleep
                    val sleepTime = 30L
                    delay(sleepTime)
                    currentTime += sleepTime
                    println("---> $currentTime")
                    clear()
                }

                currentTime = timeMsParent
                drawArc()

                callback?.invoke(this@TaskProgress)
            }
        }
    }

    fun stop() {
        timeMsParent = 0
        currentTime = 0
    }
}