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