Resolved. I'm creating a fullscreen app with C++ and Qt. In the screen l have a graphicsScene (and a View for it) that takes out a section of the screen. l can't figure out how to get the coordinates right.
l want the view size to match the size of the container. l can either create a view that is larger than the container so there are scrollbars (don't want initially) but the point (0,0) is at the top-left corner (l want this) OR a view that is smaller but the point (0,0) is no longer in the top-left corner, there are 'margins'. l want the (0,0) point to be top-left so l can programmatically draw a grid.
scene = new NoteMatrix(LayoutB2);
view = new QGraphicsView(scene);
scene->setSceneRect(0,0,view->frameSize().width(), view->frameSize().height());
view->fitInView(view->sceneRect());
view->setAlignment(Qt::AlignLeft);
scene->addRect(0, 0, scene->width(), scene->height()); //visualize boundaries
QWidget *widget = new QWidget(parent);
widget->setLayout(LayoutB2);
mainLayout->setStretchFactor(widget, 1);
setCentralWidget(widget);
I resolved my initial problem. There was nothing wrong with the coordinates. I need to set the alignment to whichever side l wish, in this scenario left.