- Qt 5.3
- Qt Quick
- Qt Quick Widgets Example
- main.cpp Example File
- Qt 5.3.2 Reference Documentation

# main.cpp Example File

quickwidgets/quickwidget/main.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
    ** Contact: http://www.qt-project.org/legal
    **
    ** 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
    ** met:
    **   * Redistributions of source code must retain the above copyright
    **     notice, this list of conditions and the following disclaimer.
    **   * Redistributions in binary form must reproduce the above copyright
    **     notice, this list of conditions and the following disclaimer in
    **     the documentation and/or other materials provided with the
    **     distribution.
    **   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
    **     of its contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
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    ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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    #include <QQuickWidget>
    #include <QQmlError>
    #include <QtWidgets>

    class MainWindow : public QMainWindow {
        Q_OBJECT
    public:
        MainWindow();

    private slots:
        void quickWidgetStatusChanged(QQuickWidget::Status);
        void sceneGraphError(QQuickWindow::SceneGraphError error, const QString &message);

    private:
        QQuickWidget *m_quickWidget;
    };

    MainWindow::MainWindow()
       : m_quickWidget(new QQuickWidget)
    {
        QSurfaceFormat format;
        if (QCoreApplication::arguments().contains(QStringLiteral("--coreprofile"))) {
            format.setVersion(4, 4);
            format.setProfile(QSurfaceFormat::CoreProfile);
        }
        if (QCoreApplication::arguments().contains(QStringLiteral("--multisample")))
            format.setSamples(4);
        m_quickWidget->setFormat(format);

        QMdiArea *centralWidget = new QMdiArea;

        QLCDNumber *lcd = new QLCDNumber;
        lcd->display(1337);
        lcd->setMinimumSize(250,100);
        centralWidget ->addSubWindow(lcd);

        QUrl source("qrc:quickwidget/rotatingsquare.qml");

        connect(m_quickWidget, SIGNAL(statusChanged(QQuickWidget::Status)),
                this, SLOT(quickWidgetStatusChanged(QQuickWidget::Status)));
        connect(m_quickWidget, SIGNAL(sceneGraphError(QQuickWindow::SceneGraphError,QString)),
                this, SLOT(sceneGraphError(QQuickWindow::SceneGraphError,QString)));
        m_quickWidget->resize(300,300);
        m_quickWidget->setResizeMode(QQuickWidget::SizeRootObjectToView );
        m_quickWidget->setSource(source);

        centralWidget ->addSubWindow(m_quickWidget);

        setCentralWidget(centralWidget);

        QMenu *fileMenu = menuBar()->addMenu(tr("File"));
        QAction *quitAction = fileMenu->addAction(tr("Quit"));
        connect(quitAction, SIGNAL(triggered()), qApp, SLOT(quit()));
    }

    void MainWindow::quickWidgetStatusChanged(QQuickWidget::Status status)
    {
        if (status == QQuickWidget::Error) {
            QStringList errors;
            foreach (const QQmlError &error, m_quickWidget->errors())
                errors.append(error.toString());
            statusBar()->showMessage(errors.join(QStringLiteral(", ")));
        }
    }

    void MainWindow::sceneGraphError(QQuickWindow::SceneGraphError, const QString &message)
    {
         statusBar()->showMessage(message);
    }

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

        MainWindow mainWindow;
        mainWindow.show();

        return app.exec();
    }

    #include "main.moc"