main.cpp Example File

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  #include <QtWidgets>

  static QGraphicsProxyWidget *createItem(const QSizeF &minimum = QSizeF(100.0, 100.0),
                                          const QSizeF &preferred = QSize(150.0, 100.0),
                                          const QSizeF &maximum = QSizeF(200.0, 100.0),
                                          const QString &name = "0")
  {
      QGraphicsProxyWidget *w = new QGraphicsProxyWidget;
      w->setWidget(new QPushButton(name));
      w->setData(0, name);
      w->setMinimumSize(minimum);
      w->setPreferredSize(preferred);
      w->setMaximumSize(maximum);

      w->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);
      return w;
  }

  int main(int argc, char **argv)
  {
      QApplication app(argc, argv);

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

      QSizeF minSize(30, 100);
      QSizeF prefSize(210, 100);
      QSizeF maxSize(300, 100);

      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)");

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

      QGraphicsWidget *w = new QGraphicsWidget(0, Qt::Window);
      w->setPos(20, 20);
      w->setLayout(l);

      // 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);

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

      view.show();

      return app.exec();
  }