//! [0]
QPainter painter(this);

painter.setPen(Qt::darkGreen);
painter.drawRect(1, 2, 6, 4);
//! [0]


//! [1]
QPainter painter(this);

painter.setPen(Qt::darkGreen);
painter.drawLine(2, 7, 6, 1);
//! [1]


//! [2]
QPainter painter(this);
painter.setRenderHint(
    QPainter::Antialiasing);
painter.setPen(Qt::darkGreen);
painter.drawRect(1, 2, 6, 4);
//! [2]


//! [3]
QPainter painter(this);
painter.setRenderHint(
    QPainter::Antialiasing);
painter.setPen(Qt::darkGreen);
painter.drawLine(2, 7, 6, 1);
//! [3]


//! [4]
QPainter painter(this);
painter.setWindow(QRect(-50, -50, 100, 100));
//! [4]


//! [5]
int side = qMin(width(), height())
int x = (width() - side / 2);
int y = (height() - side / 2);

painter.setViewport(x, y, side, side);
//! [5]