Thanks for reply, tbscope

I tried function you mentioned above which threw an error as:
error: no matching function for call to ‘BuildingPainter::BuildingPainter(QGLFormat, GLHandle* const)’
Can you point me to sample use of function you mentioned??
Also will it be able to take OpenGL context (openGL states) from calling function?

BTW, I am trying to model real world scenes(Park) in openGL and "BuildingPainter" creates "Building" model (Basic modelling only, by cubes etc.)