For Medium article "Android Dynamic Custom View is Easy"

onDraw.kt

override fun onDraw(canvas: Canvas ?) {
  // draw switcher (green rect)
  canvas?.drawRoundRect(switcherRect, switcherCornerRadius, switcherCornerRadius, switcherPaint)

  // draw icon (white rect)
  canvas?.withTranslation(x = iconTranslateX) {
      drawRoundRect(iconRect, switcherCornerRadius, switcherCornerRadius, iconPaint)
  }
}