[Qt-interest] show the needle of the compass

[Stefanos Antaris]

Hello.I try to make a compass.I didn't manage to install the qwt 
libraries on my Mac so i just took all the header files and the cpp 
files and i put them into my qt application.So i have made a QwtCompass 
and i can't show the needle of the compass.Can anyone help me?I have 
made an QwtCompass object but i don't know what do i have to do 
next.Moreover can i change the needle size?