I guess you should differentiate the target (before and after Oreo)
int LAYOUT_FLAG;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
LAYOUT_FLAG = WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY;
} else {
LAYOUT_FLAG = WindowManager.LayoutParams.TYPE_PHONE;
}
params = new WindowManager.LayoutParams(
WindowManager.LayoutParams.WRAP_CONTENT,
WindowManager.LayoutParams.WRAP_CONTENT,
LAYOUT_FLAG,
WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE | WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
PixelFormat.TRANSLUCENT);