Add a QQuickWidget-based Scene3D example

Shares the QML files with the scene3d example.

Task-number: QTBUG-52132
Change-Id: I076284b66a8dfdc3308171f11528851a7e20bbce
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

examples/qt3d/qt3d.pro

@@ -29,7 +29,10 @@ qtHaveModule(multimedia): SUBDIRS += audio-visualizer-qml
 # TODO Port the old examples to new APIs
 #SUBDIRS += qt3d
 
-qtHaveModule(widgets): SUBDIRS += basicshapes-cpp
+qtHaveModule(widgets) {
+    SUBDIRS += basicshapes-cpp
+    qtHaveModule(quickwidgets): SUBDIRS += widgets-scene3d
+}
 
 EXAMPLE_FILES += \
     exampleresources

examples/qt3d/widgets-scene3d/doc/src/widgets-scene3d.qdoc

@@ -0,0 +1,56 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:FDL$
+** 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 https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Free Documentation License Usage
+** Alternatively, this file may be used under the terms of the GNU Free
+** Documentation License version 1.3 as published by the Free Software
+** Foundation and appearing in the file included in the packaging of
+** this file. Please review the following information to ensure
+** the GNU Free Documentation License version 1.3 requirements
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+    \example widgets-scene3d
+    \title Qt 3D: Scene3D QML with Widgets Example
+    \ingroup qt3d-examples-qml
+    \brief A QWidget-based application with a QML scene containing a 3D scene.
+
+    \image widgets-scene3d.png
+
+    \e {widgets-scene3D} demonstrates visualizing a 3D scene from a
+    QWidget-based application using QQuickWidget.
+
+    The actual 3D scene is the same as in the \e {scene3d} example.
+
+    This approach is different from the one based on
+    QWidget::createWindowContainer() demonstrated in \e {basicshapes-cpp}
+    because it does not create a native window for the Qt 3D content. Rather,
+    it uses QQuickWidget, a genuine QWidget subclass to compose the Qt Quick
+    and Qt 3D content together with the traditional widgets.
+
+    \note Be aware of the performance implications. While this approach is very
+    flexible in the sense that it allows mixing QML and Qt 3D with widgets
+    without clipping or stacking issues, using Scene3D in a QQuickWidget
+    involves rendering to offscreen render targets (via framebuffer objects)
+    twice. This is not always desirable for more complex scenes. For those the
+    native window based approach shown in \e {basicshapes-cpp} will likely be a
+    better choice.
+
+    \include examples-run.qdocinc
+*/

examples/qt3d/widgets-scene3d/main.cpp

@@ -0,0 +1,76 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 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
+** 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 The Qt Company Ltd 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 <QQuickWidget>
+#include <QMdiArea>
+#include <QLcdNumber>
+#include <QMenuBar>
+
+int main(int argc, char **argv)
+{
+    QApplication app(argc, argv);
+
+    QMainWindow mainWindow;
+
+    QMdiArea *centralWidget = new QMdiArea;
+
+    QLCDNumber *lcd = new QLCDNumber;
+    lcd->display(1337);
+    lcd->setMinimumSize(250, 100);
+    centralWidget->addSubWindow(lcd);
+
+    QQuickWidget *quickWidget = new QQuickWidget;
+    quickWidget->setMinimumSize(300, 300);
+    quickWidget->setResizeMode(QQuickWidget::SizeRootObjectToView);
+    quickWidget->setSource(QUrl("qrc:/main.qml"));
+    centralWidget->addSubWindow(quickWidget);
+
+    mainWindow.setCentralWidget(centralWidget);
+
+    QMenu *fileMenu = mainWindow.menuBar()->addMenu(QObject::tr("&File"));
+    fileMenu->addAction(QObject::tr("E&xit"), qApp, &QCoreApplication::quit);
+
+    mainWindow.resize(800, 600);
+    mainWindow.show();
+
+    return app.exec();
+}

examples/qt3d/widgets-scene3d/widgets-scene3d.pro

@@ -0,0 +1,15 @@
+!include( ../examples.pri ) {
+    error( "Couldn't find the examples.pri file!" )
+}
+
+QT += widgets qml quick quickwidgets 3dinput
+
+SOURCES += \
+    main.cpp
+
+OTHER_FILES += \
+    ../scene3d/AnimatedEntity.qml \
+    ../scene3d/main.qml
+
+RESOURCES += \
+    widgets-scene3d.qrc

examples/qt3d/widgets-scene3d/widgets-scene3d.qrc

@@ -0,0 +1,6 @@
+<RCC>
+    <qresource prefix="/">
+        <file alias="AnimatedEntity.qml">../scene3d/AnimatedEntity.qml</file>
+        <file alias="main.qml">../scene3d/main.qml</file>
+    </qresource>
+</RCC>