Create example for geolocation in WebEngine

Task-number: QTBUG-59822
Change-Id: Iee69f10fefa223313ca112f096b65446b4156ac1
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

examples/webenginewidgets/maps/doc/src/maps.qdoc

+/****************************************************************************
+**
+** Copyright (C) 2017 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 http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://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: http://www.gnu.org/copyleft/fdl.html.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+    \example webenginewidgets/maps
+    \title WebEngine Widgets Maps Example
+    \ingroup webengine-widgetexamples
+    \brief Demonstrates how to handle geolocation requests
+
+    \image maps-example.png
+
+    \e {Maps} demonstrates how to handle geolocation requests originating from
+    a \l QWebEnginePage.
+
+    The \l {https://www.w3.org/TR/geolocation-API/}{Geolocation API} is a
+    JavaScript API that web applications can use to determine the user's
+    physical location to show on a map, for example. As Qt WebEngine relies on
+    \l {Qt Location} to power this API a viable location backend is needed for
+    the target platform.
+
+    To avoid accidentally sending location information to third parties
+    geolocation requests are denied by default. This example demonstrates the
+    steps an application must take in order to start accepting these requests.
+
+    \include examples-run.qdocinc
+
+    \section1 The Code
+
+    The example program consists of a single class, \c MainWindow, inheriting
+    from \l QMainWindow:
+
+    \quotefromfile webenginewidgets/maps/mainwindow.h
+    \skipto #include
+    \printuntil /^\}/
+
+    In the constructor we first set up the \l QWebEngineView as the central
+    widget:
+
+    \quotefromfile webenginewidgets/maps/mainwindow.cpp
+    \skipto MainWindow::MainWindow
+    \printuntil setCentralWidget
+
+    We then proceed to connect a lambda function to the \l
+    QWebEnginePage::featurePermissionRequested signal:
+
+    \skipto m_view->page()
+    \printuntil QWebEnginePage::Feature
+
+    This signal is emitted whenever a web page requests to make use of a certain
+    feature or device, including not only location services but also audio
+    capture devices or mouse locking, for example. In this example we only
+    handle requests for location services:
+
+    \printuntil return
+
+    Now comes the part where we actually ask the user for permission:
+
+    \printuntil securityOrigin
+    \printuntil });
+
+    Note that the question includes the host component of the web site's URI (\c
+    securityOrigin) to inform the user as to exactly which web site will be
+    receiving their location data.
+
+    We use the \l QWebEnginePage::setFeaturePermission method to communicate the
+    user's answer back to the web page.
+
+    Finally we ask the \l QWebEnginePage to load the web page that might want to
+    use location services:
+
+    \printuntil /^\}/
+
+    \sa {html5-geolocation}{Qt WebEngine HTML5 Geolocation}, {Qt Location}
+*/

examples/webenginewidgets/maps/main.cpp

+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://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 "mainwindow.h"
+#include <QApplication>
+
+int main(int argc, char *argv[])
+{
+    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
+    QApplication app(argc, argv);
+
+    MainWindow mainWindow;
+    mainWindow.show();
+
+    return app.exec();
+}

examples/webenginewidgets/maps/mainwindow.cpp

+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://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 "mainwindow.h"
+
+#include <QMessageBox>
+
+MainWindow::MainWindow(QWidget *parent)
+    : QMainWindow(parent)
+    , m_view(new QWebEngineView(this))
+{
+    setCentralWidget(m_view);
+
+    QWebEnginePage *page = m_view->page();
+
+    connect(page, &QWebEnginePage::featurePermissionRequested,
+            [this, page](const QUrl &securityOrigin, QWebEnginePage::Feature feature) {
+        if (feature != QWebEnginePage::Geolocation)
+            return;
+
+        QMessageBox msgBox(this);
+        msgBox.setText(tr("%1 wants to know your location").arg(securityOrigin.host()));
+        msgBox.setInformativeText(tr("Do you want to send your current location to this website?"));
+        msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
+        msgBox.setDefaultButton(QMessageBox::Yes);
+
+        if (msgBox.exec() == QMessageBox::Yes) {
+            page->setFeaturePermission(
+                securityOrigin, feature, QWebEnginePage::PermissionGrantedByUser);
+        } else {
+            page->setFeaturePermission(
+                securityOrigin, feature, QWebEnginePage::PermissionDeniedByUser);
+        }
+    });
+
+    page->load(QUrl(QStringLiteral("https://maps.google.com")));
+}

examples/webenginewidgets/maps/mainwindow.h

+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://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."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef MAINWINDOW_H
+#define MAINWINDOW_H
+
+#include <QMainWindow>
+#include <QWebEngineView>
+
+class MainWindow : public QMainWindow
+{
+    Q_OBJECT
+public:
+    explicit MainWindow(QWidget *parent = nullptr);
+
+private:
+    QWebEngineView *m_view;
+};
+
+#endif // MAINWINDOW_H

examples/webenginewidgets/maps/maps.pro

+TEMPLATE = app
+
+QT += webenginewidgets
+
+HEADERS += \
+    mainwindow.h
+
+SOURCES += main.cpp \
+    mainwindow.cpp
+
+target.path = $$[QT_INSTALL_EXAMPLES]/webenginewidgets/maps
+INSTALLS += target

examples/webenginewidgets/webenginewidgets.pro

@@ -9,6 +9,8 @@ SUBDIRS += \
     simplebrowser \
     videoplayer
 
+qtHaveModule(positioning): SUBDIRS += maps
+
 contains(WEBENGINE_CONFIG, use_spellchecker):!cross_compile {
     !contains(WEBENGINE_CONFIG, use_native_spellchecker) {
         SUBDIRS += spellchecker