Make QOpenGLWidget public

QOpenGLWidget is now public.

In addition Qt::WA_AlwaysStackOnTop is introduced to support the
special case of semi-transparent QOpenGLWidget or QQuickWidget on
top of regular widgets.

hellogl_es2 becomes the qopenglwidget example. This example performs
painting both via QPainter and native GL commands and has the OpenGL
widget combined with other, normal widgets.

The widget stack receives some changes when it comes to renderToTexture
widgets like QQuickWidget and QOpenGLWidget. Calling update() will now
result in a paint event, which is essential for QOpenGLWidget since we
want it to behave like a regular widget. The dirty region handling is
extended specially for such widgets due to performance reasons.
(an OpenGL content update must not result in any backingstore painting,
and is thus handled as a different kind of dirtiness)

[ChangeLog] Added QOpenGLWidget. This widget serves as a replacement for QGLWidget.

Task-number: QTBUG-36899
Task-number: QTBUG-40086
Change-Id: Ibf7f82fea99b39edfffd2fc088e7e0eadbca25cf
Reviewed-by: Paul Olav Tvete <paul.tvete@digia.com>

19 files changed, 941 insertions, 184 deletions

diff --git a/examples/opengl/hellogl_es2/hellogl_es2.pro b/examples/opengl/hellogl_es2/hellogl_es2.pro
deleted file mode 100644
index b15e8d1909..0000000000
--- a/examples/opengl/hellogl_es2/hellogl_es2.pro
+++ /dev/null
@@ -1,23 +0,0 @@
-QT += opengl widgets
-
-SOURCES += main.cpp
-SOURCES += glwidget.cpp
-SOURCES += mainwindow.cpp
-SOURCES += bubble.cpp
-
-HEADERS += glwidget.h
-HEADERS += mainwindow.h
-HEADERS += bubble.h
-
-RESOURCES += texture.qrc
-
-# install
-target.path = $$[QT_INSTALL_EXAMPLES]/opengl/hellogl_es2
-INSTALLS += target
-
-maemo5 {
-    # Debian package name may not contain numbers or special characters
-    # such as '_', lets change this in Maemo.
-    TARGET = helloglestwo
-    CONFIG += qt_example
-}
diff --git a/examples/opengl/hellogl_es2/mainwindow.cpp b/examples/opengl/hellogl_es2/mainwindow.cpp
deleted file mode 100644
index eb4ce0ac3e..0000000000
--- a/examples/opengl/hellogl_es2/mainwindow.cpp
+++ /dev/null
@@ -1,107 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2013 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.
-**
-**
-** 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,
-** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "mainwindow.h"
-
-#include <QApplication>
-#include <QMenuBar>
-#include <QGroupBox>
-#include <QGridLayout>
-#include <QSlider>
-#include <QLabel>
-#include <QTimer>
-
-#include "glwidget.h"
-
-MainWindow::MainWindow()
-{
-    GLWidget *glwidget = new GLWidget();
-    QLabel *label = new QLabel(this);
-    QTimer *timer = new QTimer(this);
-    QSlider *slider = new QSlider(this);
-    slider->setOrientation(Qt::Horizontal);
-
-    slider->setRange(0, 100);
-    slider->setSliderPosition(50);
-    timer->setInterval(10);
-    label->setText("A QGlWidget with OpenGl ES");
-    label->setAlignment(Qt::AlignHCenter);
-
-    QGroupBox * groupBox = new QGroupBox(this);
-    setCentralWidget(groupBox);
-    groupBox->setTitle("OpenGL ES Example");
-
-    QGridLayout *layout = new QGridLayout(groupBox);
-
-    layout->addWidget(glwidget,1,0,8,1);
-    layout->addWidget(label,9,0,1,1);
-    layout->addWidget(slider, 11,0,1,1);
-
-    groupBox->setLayout(layout);
-
-    QMenu *fileMenu = new QMenu("File");
-    QMenu *helpMenu = new QMenu("Help");
-    QMenu *showMenu = new QMenu("Show");
-    menuBar()->addMenu(fileMenu);
-    menuBar()->addMenu(showMenu);
-    menuBar()->addMenu(helpMenu);
-    QAction *exit = new QAction("Exit", fileMenu);
-    QAction *aboutQt = new QAction("AboutQt", helpMenu);
-    QAction *showLogo = new QAction("Show 3D Logo", showMenu);
-    QAction *showTexture = new QAction("Show 2D Texture", showMenu);
-    QAction *showBubbles = new QAction("Show bubbles", showMenu);
-    showBubbles->setCheckable(true);
-    showBubbles->setChecked(true);
-    fileMenu->addAction(exit);
-    helpMenu->addAction(aboutQt);
-    showMenu->addAction(showLogo);
-    showMenu->addAction(showTexture);
-    showMenu->addAction(showBubbles);
-
-    QObject::connect(timer, SIGNAL(timeout()), glwidget, SLOT(updateGL()));
-    QObject::connect(exit, SIGNAL(triggered(bool)), this, SLOT(close()));
-    QObject::connect(aboutQt, SIGNAL(triggered(bool)), qApp, SLOT(aboutQt()));
-
-    QObject::connect(showLogo, SIGNAL(triggered(bool)), glwidget, SLOT(setLogo()));
-    QObject::connect(showTexture, SIGNAL(triggered(bool)), glwidget, SLOT(setTexture()));
-    QObject::connect(showBubbles, SIGNAL(triggered(bool)), glwidget, SLOT(showBubbles(bool)));
-    QObject::connect(slider, SIGNAL(valueChanged(int)), glwidget, SLOT(setScaling(int)));
-    timer->start();
-}
diff --git a/examples/opengl/opengl.pro b/examples/opengl/opengl.pro
index aea281ce5c..fb5f02c07c 100644
--- a/examples/opengl/opengl.pro
+++ b/examples/opengl/opengl.pro
@@ -5,10 +5,9 @@ TEMPLATE      = subdirs
 contains(QT_CONFIG, dynamicgl) {
     SUBDIRS = hellowindow \
               contextinfo \
-              hellogl_es2
-} else: contains(QT_CONFIG, opengles2){
-    SUBDIRS   = hellogl_es2
-} else {
+              qopenglwidget \
+              threadedqopenglwidget
+} else: !contains(QT_CONFIG, opengles2) {
     SUBDIRS   = 2dpainting \
                 grabber \
                 hellogl \
@@ -22,6 +21,8 @@ contains(QT_CONFIG, dynamicgl) {
            paintedwindow \
            contextinfo \
            cube \
-           textures
+           textures \
+           qopenglwidget \
+           threadedqopenglwidget
 
 EXAMPLE_FILES = shared
diff --git a/examples/opengl/hellogl_es2/bubble.cpp b/examples/opengl/qopenglwidget/bubble.cpp
index 3e0f053bc8..bf04c64966 100644
--- a/examples/opengl/hellogl_es2/bubble.cpp
+++ b/examples/opengl/qopenglwidget/bubble.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** 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.
diff --git a/examples/opengl/hellogl_es2/bubble.h b/examples/opengl/qopenglwidget/bubble.h
index 60195b4415..ea33466ef7 100644
--- a/examples/opengl/hellogl_es2/bubble.h
+++ b/examples/opengl/qopenglwidget/bubble.h
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** 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.
diff --git a/examples/opengl/hellogl_es2/glwidget.cpp b/examples/opengl/qopenglwidget/glwidget.cpp
index 733475d321..e95ca363fc 100644
--- a/examples/opengl/hellogl_es2/glwidget.cpp
+++ b/examples/opengl/qopenglwidget/glwidget.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** 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.
@@ -43,19 +43,25 @@
 #include <QPaintEngine>
 #include <math.h>
 
+#include "mainwindow.h"
 #include "bubble.h"
 
-
 const int bubbleNum = 8;
 
-GLWidget::GLWidget(QWidget *parent)
-    : QGLWidget(parent)
+GLWidget::GLWidget(MainWindow *mw, bool button, const QColor &background)
+    : m_mainWindow(mw),
+      m_transparent(false),
+      m_btn(0),
+      m_hasButton(button),
+      m_background(background)
 {
+    QSurfaceFormat format;
+    format.setDepthBufferSize(24);
+    format.setStencilBufferSize(8);
+    setFormat(format);
+
     qtLogo = true;
     frames = 0;
-    setAttribute(Qt::WA_PaintOnScreen);
-    setAttribute(Qt::WA_NoSystemBackground);
-    setAutoBufferSwap(false);
     m_showBubbles = true;
     setMinimumSize(300, 250);
 }
@@ -66,10 +72,10 @@ GLWidget::~GLWidget()
 
 void GLWidget::setScaling(int scale) {
 
-    if (scale > 50)
-        m_fScale = 1 + qreal(scale -50) / 50 * 0.5;
-    else if (scale < 50)
-        m_fScale =  1- (qreal(50 - scale) / 50 * 1/2);
+    if (scale > 30)
+        m_fScale = 1 + qreal(scale - 30) / 30 * 0.25;
+    else if (scale < 30)
+        m_fScale =  1 - (qreal(30 - scale) / 30 * 0.25);
     else
       m_fScale = 1;
 }
@@ -173,12 +179,14 @@ void GLWidget::initializeGL ()
 {
     initializeOpenGLFunctions();
 
-    glClearColor(0.1f, 0.1f, 0.2f, 1.0f);
-
     glGenTextures(1, &m_uiTexture);
-    m_uiTexture = bindTexture(QImage(":/qt.png"));
+    QImage img = QImage(":/qt.png").convertToFormat(QImage::Format_RGBA8888);
+    glBindTexture(GL_TEXTURE_2D, m_uiTexture);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, img.width(), img.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, img.constBits());
 
-    QGLShader *vshader1 = new QGLShader(QGLShader::Vertex, this);
+    QOpenGLShader *vshader1 = new QOpenGLShader(QOpenGLShader::Vertex, this);
     const char *vsrc1 =
         "attribute highp vec4 vertex;\n"
         "attribute mediump vec3 normal;\n"
@@ -195,7 +203,7 @@ void GLWidget::initializeGL ()
         "}\n";
     vshader1->compileSourceCode(vsrc1);
 
-    QGLShader *fshader1 = new QGLShader(QGLShader::Fragment, this);
+    QOpenGLShader *fshader1 = new QOpenGLShader(QOpenGLShader::Fragment, this);
     const char *fsrc1 =
         "varying mediump vec4 color;\n"
         "void main(void)\n"
@@ -212,7 +220,7 @@ void GLWidget::initializeGL ()
     normalAttr1 = program1.attributeLocation("normal");
     matrixUniform1 = program1.uniformLocation("matrix");
 
-    QGLShader *vshader2 = new QGLShader(QGLShader::Vertex);
+    QOpenGLShader *vshader2 = new QOpenGLShader(QOpenGLShader::Vertex);
     const char *vsrc2 =
         "attribute highp vec4 vertex;\n"
         "attribute highp vec4 texCoord;\n"
@@ -229,7 +237,7 @@ void GLWidget::initializeGL ()
         "}\n";
     vshader2->compileSourceCode(vsrc2);
 
-    QGLShader *fshader2 = new QGLShader(QGLShader::Fragment);
+    QOpenGLShader *fshader2 = new QOpenGLShader(QOpenGLShader::Fragment);
     const char *fsrc2 =
         "varying highp vec4 texc;\n"
         "uniform sampler2D tex;\n"
@@ -252,9 +260,6 @@ void GLWidget::initializeGL ()
     matrixUniform2 = program2.uniformLocation("matrix");
     textureUniform2 = program2.uniformLocation("tex");
 
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
-
     m_fAngle = 0;
     m_fScale = 1;
     createGeometry();
@@ -270,12 +275,10 @@ void GLWidget::paintGL()
 
     painter.beginNativePainting();
 
-    glClearColor(0.1f, 0.1f, 0.2f, 1.0f);
+    glClearColor(m_background.red() / 255.0f, m_background.green() / 255.0f,
+                 m_background.blue() / 255.0f, m_transparent ? 0.0f : 1.0f);
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
-
     glFrontFace(GL_CW);
     glCullFace(GL_FRONT);
     glEnable(GL_CULL_FACE);
@@ -313,14 +316,12 @@ void GLWidget::paintGL()
     if (const int elapsed = time.elapsed()) {
         QString framesPerSecond;
         framesPerSecond.setNum(frames /(elapsed / 1000.0), 'f', 2);
-        painter.setPen(Qt::white);
-        painter.drawText(20, 40, framesPerSecond + " fps");
+        painter.setPen(m_transparent ? Qt::black : Qt::white);
+        painter.drawText(20, 40, framesPerSecond + " paintGL calls / s");
     }
 
     painter.end();
 
-    swapBuffers();
-
     QMutableListIterator<Bubble*> iter(bubbles);
 
     while (iter.hasNext()) {
@@ -461,3 +462,28 @@ void GLWidget::extrude(qreal x1, qreal y1, qreal x2, qreal y2)
     normals << n;
     normals << n;
 }
+
+void GLWidget::setTransparent(bool transparent)
+{
+    setAttribute(Qt::WA_AlwaysStackOnTop, transparent);
+    m_transparent = transparent;
+    // Call update() on the top-level window after toggling AlwayStackOnTop to make sure
+    // the entire backingstore is updated accordingly.
+    window()->update();
+}
+
+void GLWidget::resizeGL(int w, int h)
+{
+    if (m_hasButton) {
+        if (!m_btn) {
+            m_btn = new QPushButton("A widget on top.\nPress me!", this);
+            connect(m_btn, &QPushButton::clicked, this, &GLWidget::handleButtonPress);
+        }
+        m_btn->move(w / 2, h / 2);
+    }
+}
+
+void GLWidget::handleButtonPress()
+{
+    m_mainWindow->addNew();
+}
diff --git a/examples/opengl/hellogl_es2/glwidget.h b/examples/opengl/qopenglwidget/glwidget.h
index 00073aa047..6c43ac1576 100644
--- a/examples/opengl/hellogl_es2/glwidget.h
+++ b/examples/opengl/qopenglwidget/glwidget.h
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** 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.
@@ -41,33 +41,45 @@
 #ifndef GLWIDGET_H
 #define GLWIDGET_H
 
-#include <QGLWidget>
+#include <QOpenGLWidget>
 #include <QOpenGLFunctions>
-#include <QGLShaderProgram>
+#include <QOpenGLShaderProgram>
 #include <QVector3D>
 #include <QMatrix4x4>
 #include <QTime>
 #include <QVector>
+#include <QPushButton>
 
 class Bubble;
-class GLWidget : public QGLWidget, protected QOpenGLFunctions
+class MainWindow;
+
+class GLWidget : public QOpenGLWidget, protected QOpenGLFunctions
 {
     Q_OBJECT
 public:
-    GLWidget(QWidget *parent = 0);
+    GLWidget(MainWindow *mw, bool button, const QColor &background);
     ~GLWidget();
+
 public slots:
     void setScaling(int scale);
     void setLogo();
     void setTexture();
     void showBubbles(bool);
+    void setTransparent(bool transparent);
+
+private slots:
+    void handleButtonPress();
+
 protected:
-    void paintGL ();
-    void initializeGL ();
+    void resizeGL(int w, int h) Q_DECL_OVERRIDE;
+    void paintGL() Q_DECL_OVERRIDE;
+    void initializeGL() Q_DECL_OVERRIDE;
+
 private:
-    GLuint  m_uiTexture;
-    qreal   m_fAngle;
-    qreal   m_fScale;
+    MainWindow *m_mainWindow;
+    GLuint m_uiTexture;
+    qreal m_fAngle;
+    qreal m_fScale;
     bool m_showBubbles;
     void paintTexturedCube();
     void paintQtLogo();
@@ -81,8 +93,8 @@ private:
     QList<Bubble*> bubbles;
     int frames;
     QTime time;
-    QGLShaderProgram program1;
-    QGLShaderProgram program2;
+    QOpenGLShaderProgram program1;
+    QOpenGLShaderProgram program2;
     int vertexAttr1;
     int normalAttr1;
     int matrixUniform1;
@@ -91,5 +103,10 @@ private:
     int texCoordAttr2;
     int matrixUniform2;
     int textureUniform2;
+    bool m_transparent;
+    QPushButton *m_btn;
+    bool m_hasButton;
+    QColor m_background;
 };
+
 #endif
diff --git a/examples/opengl/hellogl_es2/main.cpp b/examples/opengl/qopenglwidget/main.cpp
index 5fb3385989..2156e60155 100644
--- a/examples/opengl/hellogl_es2/main.cpp
+++ b/examples/opengl/qopenglwidget/main.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** 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.
diff --git a/examples/opengl/qopenglwidget/mainwindow.cpp b/examples/opengl/qopenglwidget/mainwindow.cpp
new file mode 100644
index 0000000000..f09acacaf0
--- /dev/null
+++ b/examples/opengl/qopenglwidget/mainwindow.cpp
@@ -0,0 +1,152 @@
+/****************************************************************************
+**
+** 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.
+**
+**
+** 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,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "mainwindow.h"
+
+#include <QApplication>
+#include <QMenuBar>
+#include <QGroupBox>
+#include <QSlider>
+#include <QLabel>
+#include <QCheckBox>
+#include <QSpinBox>
+
+#include "glwidget.h"
+
+MainWindow::MainWindow()
+    : m_nextX(1), m_nextY(1)
+{
+    GLWidget *glwidget = new GLWidget(this, true, qRgb(20, 20, 50));
+    QLabel *label = new QLabel(this);
+    m_timer = new QTimer(this);
+    QSlider *slider = new QSlider(this);
+    slider->setOrientation(Qt::Horizontal);
+
+    QLabel *updateLabel = new QLabel("Update interval");
+    QSpinBox *updateInterval = new QSpinBox(this);
+    updateInterval->setSuffix(" ms");
+    updateInterval->setValue(10);
+    updateInterval->setToolTip("Interval for the timer that calls update().\n"
+                               "Note that on most systems the swap will block to wait for vsync\n"
+                               "and therefore an interval < 16 ms will likely lead to a 60 FPS update rate.");
+    QGroupBox *updateGroupBox = new QGroupBox(this);
+    QCheckBox *transparent = new QCheckBox("Transparent background", this);
+    transparent->setToolTip("Toggles Qt::WA_AlwaysStackOnTop and transparent clear color for glClear().\n"
+                            "Note how the button on top stacks incorrectly when enabling this.");
+    QHBoxLayout *updateLayout = new QHBoxLayout;
+    updateLayout->addWidget(updateLabel);
+    updateLayout->addWidget(updateInterval);
+    updateLayout->addWidget(transparent);
+    updateGroupBox->setLayout(updateLayout);
+
+    slider->setRange(0, 50);
+    slider->setSliderPosition(30);
+    m_timer->setInterval(10);
+    label->setText("A QOpenGLWidget");
+    label->setAlignment(Qt::AlignHCenter);
+
+    QGroupBox * groupBox = new QGroupBox(this);
+    setCentralWidget(groupBox);
+    groupBox->setTitle("QOpenGLWidget Example");
+
+    m_layout = new QGridLayout(groupBox);
+
+    m_layout->addWidget(glwidget,1,0,8,1);
+    m_layout->addWidget(label,9,0,1,1);
+    m_layout->addWidget(updateGroupBox, 10, 0, 1, 1);
+    m_layout->addWidget(slider, 11,0,1,1);
+
+    groupBox->setLayout(m_layout);
+
+    QMenu *fileMenu = new QMenu("&File");
+    QMenu *helpMenu = new QMenu("&Help");
+    QMenu *showMenu = new QMenu("&Show");
+    menuBar()->addMenu(fileMenu);
+    menuBar()->addMenu(showMenu);
+    menuBar()->addMenu(helpMenu);
+    QAction *exit = new QAction("E&xit", fileMenu);
+    QAction *aboutQt = new QAction("About Qt", helpMenu);
+    QAction *showLogo = new QAction("Show 3D Logo", showMenu);
+    QAction *showTexture = new QAction("Show 2D Texture", showMenu);
+    QAction *showBubbles = new QAction("Show bubbles", showMenu);
+    showBubbles->setCheckable(true);
+    showBubbles->setChecked(true);
+    fileMenu->addAction(exit);
+    helpMenu->addAction(aboutQt);
+    showMenu->addAction(showLogo);
+    showMenu->addAction(showTexture);
+    showMenu->addAction(showBubbles);
+
+    connect(exit, SIGNAL(triggered(bool)), this, SLOT(close()));
+    connect(aboutQt, SIGNAL(triggered(bool)), qApp, SLOT(aboutQt()));
+
+    connect(m_timer, SIGNAL(timeout()), glwidget, SLOT(update()));
+
+    connect(showLogo, SIGNAL(triggered(bool)), glwidget, SLOT(setLogo()));
+    connect(showTexture, SIGNAL(triggered(bool)), glwidget, SLOT(setTexture()));
+    connect(showBubbles, SIGNAL(triggered(bool)), glwidget, SLOT(showBubbles(bool)));
+    connect(slider, SIGNAL(valueChanged(int)), glwidget, SLOT(setScaling(int)));
+    connect(transparent, &QCheckBox::toggled, glwidget, &GLWidget::setTransparent);
+
+    connect(updateInterval, SIGNAL(valueChanged(int)), this, SLOT(updateIntervalChanged(int)));
+
+    m_timer->start();
+}
+
+void MainWindow::updateIntervalChanged(int value)
+{
+    m_timer->setInterval(value);
+    m_timer->start();
+}
+
+void MainWindow::addNew()
+{
+    if (m_nextY == 4)
+        return;
+    GLWidget *w = new GLWidget(this, false, qRgb(qrand() % 256, qrand() % 256, qrand() % 256));
+    connect(m_timer, SIGNAL(timeout()), w, SLOT(update()));
+    m_layout->addWidget(w, m_nextY, m_nextX, 1, 1);
+    if (m_nextX == 3) {
+        m_nextX = 1;
+        ++m_nextY;
+    } else {
+        ++m_nextX;
+    }
+}
diff --git a/examples/opengl/qopenglwidget/mainwindow.h b/examples/opengl/qopenglwidget/mainwindow.h
new file mode 100644
index 0000000000..9db3e8cbec
--- /dev/null
+++ b/examples/opengl/qopenglwidget/mainwindow.h
@@ -0,0 +1,66 @@
+/****************************************************************************
+**
+** 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.
+**
+**
+** 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,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef MAINWINDOW_H
+#define MAINWINDOW_H
+
+#include <QMainWindow>
+#include <QTimer>
+#include <QGridLayout>
+
+class MainWindow : public QMainWindow
+{
+    Q_OBJECT
+
+public:
+    MainWindow();
+    void addNew();
+
+private slots:
+    void updateIntervalChanged(int value);
+
+private:
+    QTimer *m_timer;
+    QGridLayout *m_layout;
+    int m_nextX;
+    int m_nextY;
+};
+
+#endif
diff --git a/examples/opengl/qopenglwidget/qopenglwidget.pro b/examples/opengl/qopenglwidget/qopenglwidget.pro
new file mode 100644
index 0000000000..0165285c02
--- /dev/null
+++ b/examples/opengl/qopenglwidget/qopenglwidget.pro
@@ -0,0 +1,15 @@
+QT += widgets
+
+SOURCES += main.cpp \
+           glwidget.cpp \
+           mainwindow.cpp \
+           bubble.cpp
+
+HEADERS += glwidget.h \
+           mainwindow.h \
+           bubble.h
+
+RESOURCES += texture.qrc
+
+target.path = $$[QT_INSTALL_EXAMPLES]/opengl/qopenglwidget
+INSTALLS += target
diff --git a/examples/opengl/hellogl_es2/qt.png b/examples/opengl/qopenglwidget/qt.png
index 79e383cf50..79e383cf50 100644
--- a/examples/opengl/hellogl_es2/qt.png
+++ b/examples/opengl/qopenglwidget/qt.png
diff --git a/examples/opengl/hellogl_es2/texture.qrc b/examples/opengl/qopenglwidget/texture.qrc
index ff1d0e535f..ff1d0e535f 100644
--- a/examples/opengl/hellogl_es2/texture.qrc
+++ b/examples/opengl/qopenglwidget/texture.qrc
diff --git a/examples/opengl/threadedqopenglwidget/glwidget.cpp b/examples/opengl/threadedqopenglwidget/glwidget.cpp
new file mode 100644
index 0000000000..34d97bf1bf
--- /dev/null
+++ b/examples/opengl/threadedqopenglwidget/glwidget.cpp
@@ -0,0 +1,356 @@
+/****************************************************************************
+**
+** 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.
+**
+**
+** 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,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "glwidget.h"
+#include <math.h>
+#include <QGuiApplication>
+
+const int bubbleNum = 8;
+
+GLWidget::GLWidget(QWidget *parent)
+    : QOpenGLWidget(parent)
+{
+    QSurfaceFormat format;
+    format.setDepthBufferSize(16);
+    setFormat(format);
+
+    setMinimumSize(300, 250);
+
+    connect(this, &QOpenGLWidget::aboutToCompose, this, &GLWidget::onAboutToCompose);
+    connect(this, &QOpenGLWidget::frameSwapped, this, &GLWidget::onFrameSwapped);
+    connect(this, &QOpenGLWidget::aboutToResize, this, &GLWidget::onAboutToResize);
+    connect(this, &QOpenGLWidget::resized, this, &GLWidget::onResized);
+
+    m_thread = new QThread;
+    m_renderer = new Renderer(this);
+    m_renderer->moveToThread(m_thread);
+    connect(m_thread, &QThread::finished, m_renderer, &QObject::deleteLater);
+
+    connect(this, &GLWidget::renderRequested, m_renderer, &Renderer::render);
+    connect(m_renderer, &Renderer::contextWanted, this, &GLWidget::grabContext);
+
+    m_thread->start();
+}
+
+GLWidget::~GLWidget()
+{
+    m_renderer->prepareExit();
+    m_thread->quit();
+    m_thread->wait();
+    delete m_thread;
+}
+
+void GLWidget::onAboutToCompose()
+{
+    // We are on the gui thread here. Composition is about to
+    // begin. Wait until the render thread finishes.
+    m_renderer->lockRenderer();
+}
+
+void GLWidget::onFrameSwapped()
+{
+    m_renderer->unlockRenderer();
+    // Assuming a blocking swap, our animation is driven purely by the
+    // vsync in this example.
+    emit renderRequested();
+}
+
+void GLWidget::onAboutToResize()
+{
+    m_renderer->lockRenderer();
+}
+
+void GLWidget::onResized()
+{
+    m_renderer->unlockRenderer();
+}
+
+void GLWidget::grabContext()
+{
+    m_renderer->lockRenderer();
+    QMutexLocker lock(m_renderer->grabMutex());
+    context()->moveToThread(m_thread);
+    m_renderer->grabCond()->wakeAll();
+    m_renderer->unlockRenderer();
+}
+
+Renderer::Renderer(GLWidget *w)
+    : m_inited(false),
+      m_glwidget(w),
+      m_exiting(false)
+{
+}
+
+void Renderer::paintQtLogo()
+{
+    program.enableAttributeArray(normalAttr);
+    program.enableAttributeArray(vertexAttr);
+    program.setAttributeArray(vertexAttr, vertices.constData());
+    program.setAttributeArray(normalAttr, normals.constData());
+    glDrawArrays(GL_TRIANGLES, 0, vertices.size());
+    program.disableAttributeArray(normalAttr);
+    program.disableAttributeArray(vertexAttr);
+}
+
+// Some OpenGL implementations have serious issues with compiling and linking
+// shaders on multiple threads concurrently. Avoid this.
+Q_GLOBAL_STATIC(QMutex, initMutex)
+
+void Renderer::render()
+{
+    if (m_exiting)
+        return;
+
+    QOpenGLContext *ctx = m_glwidget->context();
+    if (!ctx) // QOpenGLWidget not yet initialized
+        return;
+
+    // Grab the context.
+    m_grabMutex.lock();
+    emit contextWanted();
+    m_grabCond.wait(&m_grabMutex);
+    QMutexLocker lock(&m_renderMutex);
+    m_grabMutex.unlock();
+
+    if (m_exiting)
+        return;
+
+    Q_ASSERT(ctx->thread() == QThread::currentThread());
+
+    // Make the context (and an offscreen surface) current for this thread. The
+    // QOpenGLWidget's fbo is bound in the context.
+    m_glwidget->makeCurrent();
+
+    if (!m_inited) {
+        m_inited = true;
+        initializeOpenGLFunctions();
+
+        QMutexLocker initLock(initMutex());
+        QOpenGLShader *vshader = new QOpenGLShader(QOpenGLShader::Vertex, this);
+        const char *vsrc =
+            "attribute highp vec4 vertex;\n"
+            "attribute mediump vec3 normal;\n"
+            "uniform mediump mat4 matrix;\n"
+            "varying mediump vec4 color;\n"
+            "void main(void)\n"
+            "{\n"
+            "    vec3 toLight = normalize(vec3(0.0, 0.3, 1.0));\n"
+            "    float angle = max(dot(normal, toLight), 0.0);\n"
+            "    vec3 col = vec3(0.40, 1.0, 0.0);\n"
+            "    color = vec4(col * 0.2 + col * 0.8 * angle, 1.0);\n"
+            "    color = clamp(color, 0.0, 1.0);\n"
+            "    gl_Position = matrix * vertex;\n"
+            "}\n";
+        vshader->compileSourceCode(vsrc);
+
+        QOpenGLShader *fshader = new QOpenGLShader(QOpenGLShader::Fragment, this);
+        const char *fsrc =
+            "varying mediump vec4 color;\n"
+            "void main(void)\n"
+            "{\n"
+            "    gl_FragColor = color;\n"
+            "}\n";
+        fshader->compileSourceCode(fsrc);
+
+        program.addShader(vshader);
+        program.addShader(fshader);
+        program.link();
+
+        vertexAttr = program.attributeLocation("vertex");
+        normalAttr = program.attributeLocation("normal");
+        matrixUniform = program.uniformLocation("matrix");
+
+        m_fAngle = 0;
+        m_fScale = 1;
+        createGeometry();
+
+        m_elapsed.start();
+    }
+
+    //qDebug("%p elapsed %lld", QThread::currentThread(), m_elapsed.restart());
+
+    glClearColor(0.1f, 0.2f, 0.2f, 1.0f);
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+    glFrontFace(GL_CW);
+    glCullFace(GL_FRONT);
+    glEnable(GL_CULL_FACE);
+    glEnable(GL_DEPTH_TEST);
+
+    QMatrix4x4 modelview;
+    modelview.rotate(m_fAngle, 0.0f, 1.0f, 0.0f);
+    modelview.rotate(m_fAngle, 1.0f, 0.0f, 0.0f);
+    modelview.rotate(m_fAngle, 0.0f, 0.0f, 1.0f);
+    modelview.scale(m_fScale);
+    modelview.translate(0.0f, -0.2f, 0.0f);
+
+    program.bind();
+    program.setUniformValue(matrixUniform, modelview);
+    paintQtLogo();
+    program.release();
+
+    glDisable(GL_DEPTH_TEST);
+    glDisable(GL_CULL_FACE);
+
+    m_fAngle += 1.0f;
+
+    // Make no context current on this thread and move the QOpenGLWidget's
+    // context back to the gui thread.
+    m_glwidget->doneCurrent();
+    ctx->moveToThread(qGuiApp->thread());
+
+    // Schedule composition. Note that this will use QueuedConnection, meaning
+    // that update() will be invoked on the gui thread.
+    QMetaObject::invokeMethod(m_glwidget, "update");
+}
+
+void Renderer::createGeometry()
+{
+    vertices.clear();
+    normals.clear();
+
+    qreal x1 = +0.06f;
+    qreal y1 = -0.14f;
+    qreal x2 = +0.14f;
+    qreal y2 = -0.06f;
+    qreal x3 = +0.08f;
+    qreal y3 = +0.00f;
+    qreal x4 = +0.30f;
+    qreal y4 = +0.22f;
+
+    quad(x1, y1, x2, y2, y2, x2, y1, x1);
+    quad(x3, y3, x4, y4, y4, x4, y3, x3);
+
+    extrude(x1, y1, x2, y2);
+    extrude(x2, y2, y2, x2);
+    extrude(y2, x2, y1, x1);
+    extrude(y1, x1, x1, y1);
+    extrude(x3, y3, x4, y4);
+    extrude(x4, y4, y4, x4);
+    extrude(y4, x4, y3, x3);
+
+    const qreal Pi = 3.14159f;
+    const int NumSectors = 100;
+
+    for (int i = 0; i < NumSectors; ++i) {
+        qreal angle1 = (i * 2 * Pi) / NumSectors;
+        qreal x5 = 0.30 * sin(angle1);
+        qreal y5 = 0.30 * cos(angle1);
+        qreal x6 = 0.20 * sin(angle1);
+        qreal y6 = 0.20 * cos(angle1);
+
+        qreal angle2 = ((i + 1) * 2 * Pi) / NumSectors;
+        qreal x7 = 0.20 * sin(angle2);
+        qreal y7 = 0.20 * cos(angle2);
+        qreal x8 = 0.30 * sin(angle2);
+        qreal y8 = 0.30 * cos(angle2);
+
+        quad(x5, y5, x6, y6, x7, y7, x8, y8);
+
+        extrude(x6, y6, x7, y7);
+        extrude(x8, y8, x5, y5);
+    }
+
+    for (int i = 0;i < vertices.size();i++)
+        vertices[i] *= 2.0f;
+}
+
+void Renderer::quad(qreal x1, qreal y1, qreal x2, qreal y2, qreal x3, qreal y3, qreal x4, qreal y4)
+{
+    vertices << QVector3D(x1, y1, -0.05f);
+    vertices << QVector3D(x2, y2, -0.05f);
+    vertices << QVector3D(x4, y4, -0.05f);
+
+    vertices << QVector3D(x3, y3, -0.05f);
+    vertices << QVector3D(x4, y4, -0.05f);
+    vertices << QVector3D(x2, y2, -0.05f);
+
+    QVector3D n = QVector3D::normal
+        (QVector3D(x2 - x1, y2 - y1, 0.0f), QVector3D(x4 - x1, y4 - y1, 0.0f));
+
+    normals << n;
+    normals << n;
+    normals << n;
+
+    normals << n;
+    normals << n;
+    normals << n;
+
+    vertices << QVector3D(x4, y4, 0.05f);
+    vertices << QVector3D(x2, y2, 0.05f);
+    vertices << QVector3D(x1, y1, 0.05f);
+
+    vertices << QVector3D(x2, y2, 0.05f);
+    vertices << QVector3D(x4, y4, 0.05f);
+    vertices << QVector3D(x3, y3, 0.05f);
+
+    n = QVector3D::normal
+        (QVector3D(x2 - x4, y2 - y4, 0.0f), QVector3D(x1 - x4, y1 - y4, 0.0f));
+
+    normals << n;
+    normals << n;
+    normals << n;
+
+    normals << n;
+    normals << n;
+    normals << n;
+}
+
+void Renderer::extrude(qreal x1, qreal y1, qreal x2, qreal y2)
+{
+    vertices << QVector3D(x1, y1, +0.05f);
+    vertices << QVector3D(x2, y2, +0.05f);
+    vertices << QVector3D(x1, y1, -0.05f);
+
+    vertices << QVector3D(x2, y2, -0.05f);
+    vertices << QVector3D(x1, y1, -0.05f);
+    vertices << QVector3D(x2, y2, +0.05f);
+
+    QVector3D n = QVector3D::normal
+        (QVector3D(x2 - x1, y2 - y1, 0.0f), QVector3D(0.0f, 0.0f, -0.1f));
+
+    normals << n;
+    normals << n;
+    normals << n;
+
+    normals << n;
+    normals << n;
+    normals << n;
+}
diff --git a/examples/opengl/threadedqopenglwidget/glwidget.h b/examples/opengl/threadedqopenglwidget/glwidget.h
new file mode 100644
index 0000000000..9d746e681b
--- /dev/null
+++ b/examples/opengl/threadedqopenglwidget/glwidget.h
@@ -0,0 +1,124 @@
+/****************************************************************************
+**
+** 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.
+**
+**
+** 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,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef GLWIDGET_H
+#define GLWIDGET_H
+
+#include <QOpenGLWidget>
+#include <QOpenGLFunctions>
+#include <QOpenGLShaderProgram>
+#include <QVector3D>
+#include <QMatrix4x4>
+#include <QThread>
+#include <QMutex>
+#include <QWaitCondition>
+#include <QElapsedTimer>
+
+class GLWidget;
+
+class Renderer : public QObject, protected QOpenGLFunctions
+{
+    Q_OBJECT
+
+public:
+    Renderer(GLWidget *w);
+    void lockRenderer() { m_renderMutex.lock(); }
+    void unlockRenderer() { m_renderMutex.unlock(); }
+    QMutex *grabMutex() { return &m_grabMutex; }
+    QWaitCondition *grabCond() { return &m_grabCond; }
+    void prepareExit() { m_exiting = true; m_grabCond.wakeAll(); }
+
+signals:
+    void contextWanted();
+
+public slots:
+    void render();
+
+private:
+    void paintQtLogo();
+    void createGeometry();
+    void quad(qreal x1, qreal y1, qreal x2, qreal y2, qreal x3, qreal y3, qreal x4, qreal y4);
+    void extrude(qreal x1, qreal y1, qreal x2, qreal y2);
+
+    bool m_inited;
+    qreal m_fAngle;
+    qreal m_fScale;
+    QVector<QVector3D> vertices;
+    QVector<QVector3D> normals;
+    QOpenGLShaderProgram program;
+    int vertexAttr;
+    int normalAttr;
+    int matrixUniform;
+    GLWidget *m_glwidget;
+    QMutex m_renderMutex;
+    QElapsedTimer m_elapsed;
+    QMutex m_grabMutex;
+    QWaitCondition m_grabCond;
+    bool m_exiting;
+};
+
+class GLWidget : public QOpenGLWidget
+{
+    Q_OBJECT
+public:
+    GLWidget(QWidget *parent);
+    ~GLWidget();
+
+protected:
+    void paintEvent(QPaintEvent *) Q_DECL_OVERRIDE { }
+
+signals:
+    void renderRequested();
+
+public slots:
+    void grabContext();
+
+private slots:
+    void onAboutToCompose();
+    void onFrameSwapped();
+    void onAboutToResize();
+    void onResized();
+
+private:
+    QThread *m_thread;
+    Renderer *m_renderer;
+};
+
+#endif
diff --git a/examples/opengl/threadedqopenglwidget/main.cpp b/examples/opengl/threadedqopenglwidget/main.cpp
new file mode 100644
index 0000000000..046a24d576
--- /dev/null
+++ b/examples/opengl/threadedqopenglwidget/main.cpp
@@ -0,0 +1,69 @@
+/****************************************************************************
+**
+** 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.
+**
+**
+** 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,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QApplication>
+#include <QMainWindow>
+#include "mainwindow.h"
+#include "glwidget.h"
+
+int main( int argc, char ** argv )
+{
+    QApplication a( argc, argv );
+
+    // Two top-level windows with two QOpenGLWidget children in each.
+    // The rendering for the four QOpenGLWidgets happens on four separate threads.
+    MainWindow mw1;
+    mw1.setMinimumSize(800, 400);
+    mw1.show();
+
+    QScopedPointer<MainWindow> mw2;
+    if (!QApplication::arguments().contains(QStringLiteral("--single"))) {
+        mw2.reset(new MainWindow);
+        mw2->setMinimumSize(800, 400);
+        mw2->show();
+
+        // And a top-level.
+        GLWidget *bonus = new GLWidget(0);
+        bonus->resize(200, 200);
+        bonus->show();
+    }
+
+    return a.exec();
+}
diff --git a/examples/opengl/threadedqopenglwidget/mainwindow.cpp b/examples/opengl/threadedqopenglwidget/mainwindow.cpp
new file mode 100644
index 0000000000..29c59573cf
--- /dev/null
+++ b/examples/opengl/threadedqopenglwidget/mainwindow.cpp
@@ -0,0 +1,52 @@
+/****************************************************************************
+**
+** 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.
+**
+**
+** 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,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "mainwindow.h"
+#include "glwidget.h"
+
+MainWindow::MainWindow()
+{
+    GLWidget *glwidget1 = new GLWidget(this);
+    glwidget1->resize(400, 400);
+
+    GLWidget *glwidget2 = new GLWidget(this);
+    glwidget2->resize(400, 400);
+    glwidget2->move(400, 0);
+}
diff --git a/examples/opengl/hellogl_es2/mainwindow.h b/examples/opengl/threadedqopenglwidget/mainwindow.h
index 3f05fd4a78..91f7580717 100644
--- a/examples/opengl/hellogl_es2/mainwindow.h
+++ b/examples/opengl/threadedqopenglwidget/mainwindow.h
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** 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.
@@ -41,16 +41,14 @@
 #ifndef MAINWINDOW_H
 #define MAINWINDOW_H
 
-#include <QMainWindow>
+#include <QWidget>
 
-class MainWindow : public QMainWindow
+class MainWindow : public QWidget
 {
     Q_OBJECT
 
 public:
     MainWindow();
-
-private:
 };
 
 #endif
diff --git a/examples/opengl/threadedqopenglwidget/threadedqopenglwidget.pro b/examples/opengl/threadedqopenglwidget/threadedqopenglwidget.pro
new file mode 100644
index 0000000000..4e941b28c4
--- /dev/null
+++ b/examples/opengl/threadedqopenglwidget/threadedqopenglwidget.pro
@@ -0,0 +1,11 @@
+QT += widgets
+
+SOURCES += main.cpp \
+           glwidget.cpp \
+           mainwindow.cpp
+
+HEADERS += glwidget.h \
+           mainwindow.h
+
+target.path = $$[QT_INSTALL_EXAMPLES]/opengl/threadedqopenglwidget
+INSTALLS += target