main.cpp Example File

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  #include <QtWidgets>

  class Widget : public QGraphicsWidget
  {
  public:
      Widget(const QColor &color, const QColor &textColor, const QString &caption,
             QGraphicsItem *parent = 0)
          : QGraphicsWidget(parent)
          , caption(caption)
          , color(color)
          , textColor(textColor)
      {
      }

      void paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget * = 0) override
      {
          QFont font;
          font.setPixelSize(0.75 * qMin(boundingRect().width(), boundingRect().height()));

          painter->fillRect(boundingRect(), color);
          painter->save();
          painter->setFont(font);
          painter->setPen(textColor);
          painter->drawText(boundingRect(), Qt::AlignCenter, caption);
          painter->restore();
      }

  private:
      QString caption;
      QColor color;
      QColor textColor;
  };

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

      QGraphicsScene *scene = new QGraphicsScene();

      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();
  /*
      layout->addAnchor(a, Qt::AnchorTop, layout, Qt::AnchorTop);
      layout->addAnchor(a, Qt::AnchorLeft, layout, Qt::AnchorLeft);
  */
      layout->addCornerAnchors(a, Qt::TopLeftCorner, layout, Qt::TopLeftCorner);

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

      // Place a third widget below the second.
      layout->addAnchor(b, Qt::AnchorBottom, c, Qt::AnchorTop);

  /*
      layout->addAnchor(b, Qt::AnchorLeft, c, Qt::AnchorLeft);
      layout->addAnchor(b, Qt::AnchorRight, c, Qt::AnchorRight);
  */

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

      // Anchor the bottom-right corner of the third widget to the bottom-right
      // corner of the layout.
      layout->addCornerAnchors(c, Qt::BottomRightCorner, layout, Qt::BottomRightCorner);

      QGraphicsWidget *w = new QGraphicsWidget(0, 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 = new QGraphicsView();
      view->setScene(scene);
      view->setWindowTitle(QApplication::translate("simpleanchorlayout", "Simple Anchor Layout"));

      view->resize(360, 320);
      view->show();

      return app.exec();
  }