Simple Anchor Layout Example

The Simple Anchor Layout example shows the basic use of the QGraphicsAnchorLayout class.

The example starts by creating a QGraphicsScene (scene), 3 widgets (a, b, and c), and a QGraphicsAnchorlayout (layout).

    QGraphicsScene scene;

    Widget *a = new Widget(Qt::blue, Qt::white, "a");
    a->setPreferredSize(100, 100);
    Widget *b = new Widget(Qt::green, Qt::black, "b");
    b->setPreferredSize(100, 100);
    Widget *c = new Widget(Qt::red, Qt::black, "c");
    c->setPreferredSize(100, 100);

    QGraphicsAnchorLayout *layout = new QGraphicsAnchorLayout;

First it anchors the top left corner of item a to the top left corner of layout. This can be done in two steps:

    layout->addAnchor(a, Qt::AnchorTop, layout, Qt::AnchorTop);
    layout->addAnchor(a, Qt::AnchorLeft, layout, Qt::AnchorLeft);

Or in one step:

    layout->addCornerAnchors(a, Qt::TopLeftCorner, layout, Qt::TopLeftCorner);

Then the right anchor of a is anchored to the left anchor of b, and the top of item b is anchored to the bottom of a.

    layout->addAnchor(b, Qt::AnchorLeft, a, Qt::AnchorRight);
    layout->addAnchor(b, Qt::AnchorTop, a, Qt::AnchorBottom);

Place a third widget c under widget b:

    layout->addAnchor(b, Qt::AnchorBottom, c, Qt::AnchorTop);

Items b and c are anchored to each other horizontally:

    layout->addAnchors(b, c, Qt::Horizontal);

Item c is anchored to the bottom right point of layout

    layout->addCornerAnchors(c, Qt::BottomRightCorner, layout, Qt::BottomRightCorner);

Finally, QGraphicsWidget w is displayed in QGraphicsView view.

    auto w = new QGraphicsWidget(nullptr, Qt::Window | Qt::CustomizeWindowHint | Qt::WindowTitleHint);
    w->setPos(20, 20);
    w->setMinimumSize(100, 100);
    w->setPreferredSize(320, 240);
    w->setLayout(layout);
    w->setWindowTitle(QApplication::translate("simpleanchorlayout", "QGraphicsAnchorLayout in use"));
    scene.addItem(w);

    QGraphicsView view;
    view.setScene(&scene);
    view.setWindowTitle(QApplication::translate("simpleanchorlayout", "Simple Anchor Layout"));

    view.resize(360, 320);
    view.show();

    return app.exec();

Example project @ code.qt.io