Anchor Layout Example | Qt Widgets 6.4.1

- Qt 6.4
- Qt Widgets
- Anchor Layout Example
- Qt 6.4.1 Reference Documentation

# Anchor Layout Example

Demonstrates anchor layout in a graphics view scene.

The Anchor Layout example demonstrates the use of the QGraphicsAnchorLayout class.

The basic steps of this example are:

- Create a QGraphicsScene
- Create widgets
- Create a QGraphicsAnchorLayout
- Create a QGraphicsWidget
- Add vertical and horizontal anchors between the widgets
- View the scene with a QGraphicsView object

#### Creating a QGraphicsScene

         QGraphicsScene scene;
         scene.setSceneRect(0, 0, 800, 480);

#### Creating Widgets

         QGraphicsProxyWidget *a = createItem(minSize, prefSize, maxSize, "A");
         QGraphicsProxyWidget *b = createItem(minSize, prefSize, maxSize, "B");
         QGraphicsProxyWidget *c = createItem(minSize, prefSize, maxSize, "C");
         QGraphicsProxyWidget *d = createItem(minSize, prefSize, maxSize, "D");
         QGraphicsProxyWidget *e = createItem(minSize, prefSize, maxSize, "E");
         QGraphicsProxyWidget *f = createItem(QSizeF(30, 50), QSizeF(150, 50), maxSize, "F (overflow)");
         QGraphicsProxyWidget *g = createItem(QSizeF(30, 50), QSizeF(30, 100), maxSize, "G (overflow)");

#### Creating a Layout

         QGraphicsAnchorLayout *l = new QGraphicsAnchorLayout;
         l->setSpacing(0);

#### Creating a QGraphicsWidget

         QGraphicsWidget *w = new QGraphicsWidget(nullptr, Qt::Window);
         w->setPos(20, 20);
         w->setLayout(l);

#### Adding Anchors

         // vertical
         l->addAnchor(a, Qt::AnchorTop, l, Qt::AnchorTop);
         l->addAnchor(b, Qt::AnchorTop, l, Qt::AnchorTop);

         l->addAnchor(c, Qt::AnchorTop, a, Qt::AnchorBottom);
         l->addAnchor(c, Qt::AnchorTop, b, Qt::AnchorBottom);
         l->addAnchor(c, Qt::AnchorBottom, d, Qt::AnchorTop);
         l->addAnchor(c, Qt::AnchorBottom, e, Qt::AnchorTop);

         l->addAnchor(d, Qt::AnchorBottom, l, Qt::AnchorBottom);
         l->addAnchor(e, Qt::AnchorBottom, l, Qt::AnchorBottom);

         l->addAnchor(c, Qt::AnchorTop, f, Qt::AnchorTop);
         l->addAnchor(c, Qt::AnchorVerticalCenter, f, Qt::AnchorBottom);
         l->addAnchor(f, Qt::AnchorBottom, g, Qt::AnchorTop);
         l->addAnchor(c, Qt::AnchorBottom, g, Qt::AnchorBottom);

         // horizontal
         l->addAnchor(l, Qt::AnchorLeft, a, Qt::AnchorLeft);
         l->addAnchor(l, Qt::AnchorLeft, d, Qt::AnchorLeft);
         l->addAnchor(a, Qt::AnchorRight, b, Qt::AnchorLeft);

         l->addAnchor(a, Qt::AnchorRight, c, Qt::AnchorLeft);
         l->addAnchor(c, Qt::AnchorRight, e, Qt::AnchorLeft);

         l->addAnchor(b, Qt::AnchorRight, l, Qt::AnchorRight);
         l->addAnchor(e, Qt::AnchorRight, l, Qt::AnchorRight);
         l->addAnchor(d, Qt::AnchorRight, e, Qt::AnchorLeft);

         l->addAnchor(l, Qt::AnchorLeft, f, Qt::AnchorLeft);
         l->addAnchor(l, Qt::AnchorLeft, g, Qt::AnchorLeft);
         l->addAnchor(f, Qt::AnchorRight, g, Qt::AnchorRight);

#### Viewing the Scene with QGraphicsView

         scene.addItem(w);
         scene.setBackgroundBrush(Qt::darkGreen);
         QGraphicsView view(&scene);

         view.show();

Example project @ code.qt.io

See also Simple Anchor Layout Example.