/****************************************************************************
**
** Copyright (C) 2018 The Qt Company Ltd.
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**
** This file is part of the QtWidgets module of the Qt Toolkit.
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****************************************************************************/

//! [0]
    GLenum error = GL_NO_ERROR;
    do {
        error = glGetError();
        if (error != GL_NO_ERROR)
            // handle the error
    } while (error != GL_NO_ERROR);
//! [0]

//! [1]
    QSurfaceFormat format;
    // asks for a OpenGL 3.2 debug context using the Core profile
    format.setMajorVersion(3);
    format.setMinorVersion(2);
    format.setProfile(QSurfaceFormat::CoreProfile);
    format.setOption(QSurfaceFormat::DebugContext);

    QOpenGLContext *context = new QOpenGLContext;
    context->setFormat(format);
    context->create();
//! [1]

//! [2]
    QOpenGLContext *ctx = QOpenGLContext::currentContext();
    QOpenGLDebugLogger *logger = new QOpenGLDebugLogger(this);

    logger->initialize(); // initializes in the current context, i.e. ctx
//! [2]

//! [3]
    ctx->hasExtension(QByteArrayLiteral("GL_KHR_debug"))
//! [3]

//! [4]
    const QList<QOpenGLDebugMessage> messages = logger->loggedMessages();
    for (const QOpenGLDebugMessage &message : messages)
        qDebug() << message;
//! [4]

//! [5]
    connect(logger, &QOpenGLDebugLogger::messageLogged, receiver, &LogHandler::handleLoggedMessage);
    logger->startLogging();
//! [5]

//! [6]
    QOpenGLDebugMessage message =
        QOpenGLDebugMessage::createApplicationMessage(QStringLiteral("Custom message"));

    logger->logMessage(message);
//! [6]