This app for the BlackBerry PlayBook utilizes the Native Development Kit (NDK)
and Qt 4.8 to create a custom widget for display on the screen.

The user is presented with a stylized slider that causes an indicator to be
repainted along the bottom, depending on the value of the slider.

Shamelessly lifted from Jan Bodnar at
http://zetcode.com/tutorials/qt4tutorial/customwidget/. Use as you see fit.