1 files changed, 25 insertions, 9 deletions
diff --git a/examples/datavisualization/bars/main.cpp b/examples/datavisualization/bars/main.cpp
index f6d8752c..6eb718fa 100644
--- a/examples/datavisualization/bars/main.cpp
+++ b/examples/datavisualization/bars/main.cpp
@@ -1,23 +1,31 @@
-/******************************************************************************
+/****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
-** This file is part of the Qt Data Visualization module.
-**
-** $QT_BEGIN_LICENSE:COMM$
+** This file is part of the Qt Data Visualization module of the Qt Toolkit.
 **
+** $QT_BEGIN_LICENSE:GPL$
 ** Commercial License Usage
 ** Licensees holding valid commercial Qt licenses may use this file in
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 or (at your option) any later version
+** approved by the KDE Free Qt Foundation. The licenses are as published by
+** the Free Software Foundation and appearing in the file LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
 **
 ** $QT_END_LICENSE$
 **
-******************************************************************************/
+****************************************************************************/
 
 #include "graphmodifier.h"
 
@@ -30,6 +38,7 @@
 #include <QtWidgets/QSlider>
 #include <QtWidgets/QFontComboBox>
 #include <QtWidgets/QLabel>
+#include <QtWidgets/QMessageBox>
 #include <QtGui/QScreen>
 #include <QtGui/QFontDatabase>
 
@@ -41,6 +50,13 @@ int main(int argc, char **argv)
     QWidget *container = QWidget::createWindowContainer(widgetgraph);
     //! [0]
 
+    if (!widgetgraph->hasContext()) {
+        QMessageBox msgBox;
+        msgBox.setText("Couldn't initialize the OpenGL context.");
+        msgBox.exec();
+        return -1;
+    }
+
     QSize screenSize = widgetgraph->screen()->size();
     container->setMinimumSize(QSize(screenSize.width() / 2, screenSize.height() / 1.5));
     container->setMaximumSize(screenSize);