Thanks in advance

trying to learn programming and starting with Qt. This is my first program.

Using a pre-built program Qt 4.2.3 that builds a basic spreadsheet as its central widget
spreadsheet = new Spreadsheet;
setCentralWidget(spreadsheet);

I dont want a spreadsheet, text edit, or anything like that.

What I want is a blank mainwindow so I can draw lines on it. Just lines, big and small.

How do I set my central widget and what do I use QGraphicsScene or QGraphicsView? Whats the difference?

Looking to make my mainwindow an area I can draw lines on but dont know if I use QGraphicsScene or QGraphicsView.

Also, what would be the code to use?
QGraphicsView.= new QGraphicsView;
setCentralWidget(QGraphicsView.);

Thanks in advance and any help is appreciated.