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

# main.cpp Example File

graphicsview/simpleanchorlayout/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:
    **
    ** "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>

    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) Q_DECL_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();
    }