RecordButton_8.kt

private val arcRect = RectF()

override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec)
    if (measuredHeight > 0 && measuredWidth > 0) {
       ...
        arcRect.set(0f, 0f, measuredWidth.toFloat(), measuredHeight.toFloat())
    }
}