This task is to create a Spin Control widget for haiku, those requirements should be met :

• The code shall conform to the Haiku Coding Guidelines
• You have to use an appropriate widgets naming (ask your mentor).
• Your widget shall use the haiku's layout kit.

You can optionally start from one of these :

https://github.com/HaikuArchives/LibWalter/blob/master/src/general/Spinner.cpp

https://github.com/HaikuArchives/BeAE/blob/master/trunk/Core-src/SpinControl.h

If the task will be more big than expected, you can ask your mentors to create a second part of the task, if needed.