- Qt 5.5
- Qt Widgets
- Anchor Layout Example
- main.cpp Example File
- Qt 5.5.1 Reference Documentation

# main.cpp Example File

graphicsview/anchorlayout/main.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
    ** You may use this file under the terms of the BSD license as follows:
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    ** "Redistribution and use in source and binary forms, with or without
    ** modification, are permitted provided that the following conditions are
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    **   * Redistributions of source code must retain the above copyright
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    **     the documentation and/or other materials provided with the
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    **     contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
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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();
    }