//! [0]
QPrinter pr;
if (pr.setup()) {
    QPainter p(&pr);
    canvas.drawArea(canvas.rect(), &p);
}
//! [0]


//! [1]
void MyCanvasView::contentsMousePressEvent(QMouseEvent* e)
{
    Q3CanvasItemList l = canvas()->collisions(e->pos());
    for (Q3CanvasItemList::Iterator it=l.begin(); it!=l.end(); ++it) {
        if ((*it)->rtti() == Q3CanvasRectangle::RTTI)
            qDebug("A Q3CanvasRectangle lies somewhere at this point");
    }
}
//! [1]


//! [2]
QMatrix wm;
wm.scale(2, 2);   // Zooms in by 2 times
wm.rotate(90);    // Rotates 90 degrees counter clockwise
                  // around the origin.
wm.translate(0, -canvas->height());
                  // moves the canvas down so what was visible
                  // before is still visible.
myCanvasView->setWorldMatrix(wm);
//! [2]


//! [3]
QRect rc = QRect(myCanvasView->contentsX(), myCanvasView->contentsY(),
                 myCanvasView->visibleWidth(), myCanvasView->visibleHeight());
QRect canvasRect = myCanvasView->inverseWorldMatrix().mapRect(rc);
//! [3]


//! [4]
Q3CanvasItem* item;
// Find an item, e.g. with Q3CanvasItem::collisions().
...
if (item->rtti() == MySprite::RTTI) {
    MySprite* s = (MySprite*)item;
    if (s->isDamagable()) s->loseHitPoints(1000);
    if (s->isHot()) myself->loseHitPoints(1000);
    ...
}
//! [4]