i added
description is the XML
added description in my XML
Original works byFu-Kwun Hwang

Derived work Remix (finer customisation) legally by lookang under
This work is licensed under a Creative Commons Attribution 2.5 Taiwan License

to trace its development.

By the way, Your tip is fantastic!

i managed to make it work well even in full screen due to a modifcation.

added codes

Added variables
getwidth = double
Fixed relationship
getwidth = _view.centre.getWidth(); // centre is name of view