Add example showing the benefits of using bindable properties

Added two examples for modeling a subscription service: signal/slot
connection-based and bindable property-based. The examples are based
on the example from Fabian's Qt WS talk about the bindable properties.

Task-number: QTBUG-97655
Change-Id: I0345913b8b6e5c40b8477e128d36483598bdfcaa
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit cee89e70a6011c3fcae29ad95d5fec4b2026d055)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

24 files changed, 1492 insertions, 0 deletions

diff --git a/examples/corelib/CMakeLists.txt b/examples/corelib/CMakeLists.txt
index 08b44649b7..30e2c8cd1f 100644
--- a/examples/corelib/CMakeLists.txt
+++ b/examples/corelib/CMakeLists.txt
@@ -1,5 +1,6 @@
 # Generated from corelib.pro.
 
+add_subdirectory(bindableproperties)
 add_subdirectory(ipc)
 add_subdirectory(mimetypes)
 add_subdirectory(serialization)
diff --git a/examples/corelib/bindableproperties/CMakeLists.txt b/examples/corelib/bindableproperties/CMakeLists.txt
new file mode 100644
index 0000000000..c6d9076fd8
--- /dev/null
+++ b/examples/corelib/bindableproperties/CMakeLists.txt
@@ -0,0 +1,2 @@
+qt_internal_add_example(bindablesubscription)
+qt_internal_add_example(subscription)
diff --git a/examples/corelib/bindableproperties/bindableproperties.pro b/examples/corelib/bindableproperties/bindableproperties.pro
new file mode 100644
index 0000000000..fab8d8107a
--- /dev/null
+++ b/examples/corelib/bindableproperties/bindableproperties.pro
@@ -0,0 +1,4 @@
+TEMPLATE = subdirs
+SUBDIRS = \
+    bindablesubscription \
+    subscription
diff --git a/examples/corelib/bindableproperties/bindablesubscription/CMakeLists.txt b/examples/corelib/bindableproperties/bindablesubscription/CMakeLists.txt
new file mode 100644
index 0000000000..b2909589a5
--- /dev/null
+++ b/examples/corelib/bindableproperties/bindablesubscription/CMakeLists.txt
@@ -0,0 +1,53 @@
+cmake_minimum_required(VERSION 3.16)
+project(bindablesubscription LANGUAGES CXX)
+
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
+
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
+set(CMAKE_AUTOUIC ON)
+
+if(NOT DEFINED INSTALL_EXAMPLESDIR)
+  set(INSTALL_EXAMPLESDIR "examples")
+endif()
+
+set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/corelib/bindableproperties/bindablesubscription")
+
+find_package(Qt6 COMPONENTS Core)
+find_package(Qt6 COMPONENTS Gui)
+find_package(Qt6 COMPONENTS Widgets)
+
+qt_add_executable(bindablesubscription
+    ../shared/subscriptionwindow.cpp ../shared/subscriptionwindow.h ../shared/subscriptionwindow.ui
+    main.cpp
+    main.cpp
+    bindablesubscription.cpp bindablesubscription.h
+    bindableuser.cpp bindableuser.h
+)
+target_link_libraries(bindablesubscription PUBLIC
+    Qt::Core
+    Qt::Gui
+    Qt::Widgets
+)
+
+# Resources:
+set(countries_resource_files
+    "../shared/finland.png"
+    "../shared/germany.png"
+    "../shared/norway.png"
+)
+
+qt6_add_resources(bindablesubscription "countries"
+    PREFIX
+        "/"
+    BASE
+        "../shared"
+    FILES
+        ${countries_resource_files}
+)
+
+install(TARGETS bindablesubscription
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
+)
diff --git a/examples/corelib/bindableproperties/bindablesubscription/bindablesubscription.cpp b/examples/corelib/bindableproperties/bindablesubscription/bindablesubscription.cpp
new file mode 100644
index 0000000000..d962216cd9
--- /dev/null
+++ b/examples/corelib/bindableproperties/bindablesubscription/bindablesubscription.cpp
@@ -0,0 +1,90 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, 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 "bindablesubscription.h"
+#include "bindableuser.h"
+
+BindableSubscription::BindableSubscription(BindableUser *user) : m_user(user)
+{
+    Q_ASSERT(user);
+
+    m_price.setBinding([this] { return qRound(calculateDiscount() * m_duration * basePrice()); });
+
+    m_isValid.setBinding([this] {
+        return m_user->country() != BindableUser::None && m_user->age() > 12;
+    });
+}
+
+void BindableSubscription::setDuration(Duration newDuration)
+{
+    m_duration = newDuration;
+}
+
+double BindableSubscription::calculateDiscount() const
+{
+    switch (m_duration) {
+    case Monthly:
+        return 1;
+    case Quarterly:
+        return 0.9;
+    case Yearly:
+        return 0.6;
+    }
+    Q_ASSERT(false);
+    return -1;
+}
+
+int BindableSubscription::basePrice() const
+{
+    if (m_user->country() == BindableUser::None)
+        return 0;
+
+    return (m_user->country() == BindableUser::Norway) ? 100 : 80;
+}
diff --git a/examples/corelib/bindableproperties/bindablesubscription/bindablesubscription.h b/examples/corelib/bindableproperties/bindablesubscription/bindablesubscription.h
new file mode 100644
index 0000000000..86dd0bdf26
--- /dev/null
+++ b/examples/corelib/bindableproperties/bindablesubscription/bindablesubscription.h
@@ -0,0 +1,87 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, 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 BINDABLESUBSCRIPTION_H
+#define BINDABLESUBSCRIPTION_H
+
+#include <QPointer>
+#include <QProperty>
+
+class BindableUser;
+
+class BindableSubscription
+{
+public:
+    enum Duration { Monthly = 1, Quarterly = 4, Yearly = 12 };
+
+    BindableSubscription(BindableUser *user);
+    BindableSubscription(const BindableSubscription &) = delete;
+
+    int price() const { return m_price; }
+    QBindable<int> bindablePrice() { return &m_price; }
+
+    Duration duration() const { return m_duration; }
+    void setDuration(Duration newDuration);
+    QBindable<Duration> bindableDuration() { return &m_duration; }
+
+    bool isValid() const { return m_isValid; }
+    QBindable<bool> bindableIsValid() { return &m_isValid; }
+
+private:
+    double calculateDiscount() const;
+    int basePrice() const;
+
+    BindableUser *m_user;
+    QProperty<Duration> m_duration { Monthly };
+    QProperty<int> m_price { 0 };
+    QProperty<bool> m_isValid { false };
+};
+
+#endif // BNDABLESUBSCRIPTION_H
diff --git a/examples/corelib/bindableproperties/bindablesubscription/bindablesubscription.pro b/examples/corelib/bindableproperties/bindablesubscription/bindablesubscription.pro
new file mode 100644
index 0000000000..321a1226c4
--- /dev/null
+++ b/examples/corelib/bindableproperties/bindablesubscription/bindablesubscription.pro
@@ -0,0 +1,22 @@
+QT += widgets
+TARGET = bindablesubscription
+
+SOURCES += main.cpp \
+    bindablesubscription.cpp \
+    bindableuser.cpp \
+    ../shared/subscriptionwindow.cpp
+
+target.path = $$[QT_INSTALL_EXAMPLES]/corelib/bindableproperties/bindablesubscription
+INSTALLS += target
+
+FORMS += \
+    ../shared/subscriptionwindow.ui
+
+HEADERS += \
+    bindablesubscription.h \
+    bindableuser.h \
+    ../shared/subscriptionwindow.h
+
+RESOURCES += \
+    ../shared/countries.qrc
+
diff --git a/examples/corelib/bindableproperties/bindablesubscription/bindableuser.cpp b/examples/corelib/bindableproperties/bindablesubscription/bindableuser.cpp
new file mode 100644
index 0000000000..fc651c2579
--- /dev/null
+++ b/examples/corelib/bindableproperties/bindablesubscription/bindableuser.cpp
@@ -0,0 +1,61 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 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$
+** 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.
+**
+** BSD License Usage
+** Alternatively, 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 "bindableuser.h"
+
+void BindableUser::setCountry(Country country)
+{
+    m_country = country;
+}
+
+void BindableUser::setAge(int age)
+{
+    m_age = age;
+}
diff --git a/examples/corelib/bindableproperties/bindablesubscription/bindableuser.h b/examples/corelib/bindableproperties/bindablesubscription/bindableuser.h
new file mode 100644
index 0000000000..1c37078076
--- /dev/null
+++ b/examples/corelib/bindableproperties/bindablesubscription/bindableuser.h
@@ -0,0 +1,81 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 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$
+** 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.
+**
+** BSD License Usage
+** Alternatively, 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 BINDABLEUSER_H
+#define BINDABLEUSER_H
+
+#include <QProperty>
+
+class BindableUser
+{
+public:
+    enum Country {
+        None,
+        Finland,
+        Germany,
+        Norway,
+    };
+
+    BindableUser() = default;
+    BindableUser(const BindableUser &) = delete;
+
+    Country country() const { return m_country; }
+    void setCountry(Country country);
+    QBindable<Country> bindableCountry() { return &m_country; }
+
+    int age() const { return m_age; }
+    void setAge(int age);
+    QBindable<int> bindableAge() { return &m_age; }
+
+private:
+    QProperty<Country> m_country { None };
+    QProperty<int> m_age { 0 };
+};
+#endif // BINDABLEUSER_H
diff --git a/examples/corelib/bindableproperties/bindablesubscription/main.cpp b/examples/corelib/bindableproperties/bindablesubscription/main.cpp
new file mode 100644
index 0000000000..2ee39c5bb5
--- /dev/null
+++ b/examples/corelib/bindableproperties/bindablesubscription/main.cpp
@@ -0,0 +1,116 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 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$
+** 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.
+**
+** BSD License Usage
+** Alternatively, 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 "../shared/subscriptionwindow.h"
+#include "bindablesubscription.h"
+#include "bindableuser.h"
+
+#include <QApplication>
+#include <QButtonGroup>
+#include <QLabel>
+#include <QPushButton>
+#include <QRadioButton>
+#include <QSpinBox>
+
+int main(int argc, char *argv[])
+{
+    QApplication a(argc, argv);
+    BindableUser user;
+    BindableSubscription subscription(&user);
+
+    SubscriptionWindow w;
+
+    // Initialize subscription data
+    QRadioButton *monthly = w.findChild<QRadioButton *>("btnMonthly");
+    QObject::connect(monthly, &QRadioButton::clicked, [&] {
+        subscription.setDuration(BindableSubscription::Monthly);
+    });
+    QRadioButton *quarterly = w.findChild<QRadioButton *>("btnQuarterly");
+    QObject::connect(quarterly, &QRadioButton::clicked, [&] {
+        subscription.setDuration(BindableSubscription::Quarterly);
+    });
+    QRadioButton *yearly = w.findChild<QRadioButton *>("btnYearly");
+    QObject::connect(yearly, &QRadioButton::clicked, [&] {
+        subscription.setDuration(BindableSubscription::Yearly);
+    });
+
+    // Initialize user data
+    QPushButton *germany = w.findChild<QPushButton *>("btnGermany");
+    QObject::connect(germany, &QPushButton::clicked, [&] {
+        user.setCountry(BindableUser::Germany);
+    });
+    QPushButton *finland = w.findChild<QPushButton *>("btnFinland");
+    QObject::connect(finland, &QPushButton::clicked, [&] {
+        user.setCountry(BindableUser::Finland);
+    });
+    QPushButton *norway = w.findChild<QPushButton *>("btnNorway");
+    QObject::connect(norway, &QPushButton::clicked, [&] {
+        user.setCountry(BindableUser::Norway);
+    });
+
+    QSpinBox *ageSpinBox = w.findChild<QSpinBox *>("ageSpinBox");
+    QObject::connect(ageSpinBox, &QSpinBox::valueChanged, [&](int value) {
+        user.setAge(value);
+    });
+
+    QLabel *priceDisplay = w.findChild<QLabel *>("priceDisplay");
+
+    // Track price changes
+    auto priceChangeHandler = subscription.bindablePrice().subscribe([&] {
+        priceDisplay->setText(QString::number(subscription.price()));
+    });
+
+    auto priceValidHandler = subscription.bindableIsValid().subscribe([&] {
+        priceDisplay->setEnabled(subscription.isValid());
+    });
+
+    w.show();
+    return a.exec();
+}
diff --git a/examples/corelib/bindableproperties/shared/countries.qrc b/examples/corelib/bindableproperties/shared/countries.qrc
new file mode 100644
index 0000000000..cdf6312ebb
--- /dev/null
+++ b/examples/corelib/bindableproperties/shared/countries.qrc
@@ -0,0 +1,7 @@
+<RCC>
+    <qresource prefix="/">
+        <file>germany.png</file>
+        <file>norway.png</file>
+        <file>finland.png</file>
+    </qresource>
+</RCC>
diff --git a/examples/corelib/bindableproperties/shared/finland.png b/examples/corelib/bindableproperties/shared/finland.png
new file mode 100644
index 0000000000..92653289c1
--- /dev/null
+++ b/examples/corelib/bindableproperties/shared/finland.png
diff --git a/examples/corelib/bindableproperties/shared/germany.png b/examples/corelib/bindableproperties/shared/germany.png
new file mode 100644
index 0000000000..efc389f52a
--- /dev/null
+++ b/examples/corelib/bindableproperties/shared/germany.png
diff --git a/examples/corelib/bindableproperties/shared/norway.png b/examples/corelib/bindableproperties/shared/norway.png
new file mode 100644
index 0000000000..daee6c3c15
--- /dev/null
+++ b/examples/corelib/bindableproperties/shared/norway.png
diff --git a/examples/corelib/bindableproperties/shared/subscriptionwindow.cpp b/examples/corelib/bindableproperties/shared/subscriptionwindow.cpp
new file mode 100644
index 0000000000..03269dfa0c
--- /dev/null
+++ b/examples/corelib/bindableproperties/shared/subscriptionwindow.cpp
@@ -0,0 +1,63 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 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$
+** 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.
+**
+** BSD License Usage
+** Alternatively, 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 "subscriptionwindow.h"
+#include "ui_subscriptionwindow.h"
+
+SubscriptionWindow::SubscriptionWindow(QWidget *parent)
+    : QWidget(parent), ui(new Ui::SubscriptionWindow)
+{
+    ui->setupUi(this);
+}
+
+SubscriptionWindow::~SubscriptionWindow()
+{
+    delete ui;
+}
diff --git a/examples/corelib/bindableproperties/shared/subscriptionwindow.h b/examples/corelib/bindableproperties/shared/subscriptionwindow.h
new file mode 100644
index 0000000000..9bc3acd91a
--- /dev/null
+++ b/examples/corelib/bindableproperties/shared/subscriptionwindow.h
@@ -0,0 +1,76 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 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$
+** 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.
+**
+** BSD License Usage
+** Alternatively, 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 SUBSCRIPTIONWINDOW_H
+#define SUBSCRIPTIONWINDOW_H
+
+#include <QWidget>
+
+QT_BEGIN_NAMESPACE
+namespace Ui {
+class SubscriptionWindow;
+}
+QT_END_NAMESPACE
+
+class User;
+
+class SubscriptionWindow : public QWidget
+{
+    Q_OBJECT
+
+public:
+    explicit SubscriptionWindow(QWidget *parent = nullptr);
+    ~SubscriptionWindow();
+
+private:
+    Ui::SubscriptionWindow *ui;
+};
+
+#endif // SUBSCRIPTIONWINDOW_H
diff --git a/examples/corelib/bindableproperties/shared/subscriptionwindow.ui b/examples/corelib/bindableproperties/shared/subscriptionwindow.ui
new file mode 100644
index 0000000000..7bc2931373
--- /dev/null
+++ b/examples/corelib/bindableproperties/shared/subscriptionwindow.ui
@@ -0,0 +1,280 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>SubscriptionWindow</class>
+ <widget class="QWidget" name="SubscriptionWindow">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>639</width>
+    <height>269</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Subscription</string>
+  </property>
+  <layout class="QHBoxLayout" name="horizontalLayout_5">
+   <item>
+    <layout class="QVBoxLayout" name="verticalLayout">
+     <item>
+      <layout class="QHBoxLayout" name="horizontalLayout_4" stretch="0,0,0,0">
+       <item>
+        <spacer name="horizontalSpacer_3">
+         <property name="orientation">
+          <enum>Qt::Horizontal</enum>
+         </property>
+         <property name="sizeHint" stdset="0">
+          <size>
+           <width>40</width>
+           <height>20</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
+       <item>
+        <widget class="QPushButton" name="btnGermany">
+         <property name="toolTip">
+          <string>Germany</string>
+         </property>
+         <property name="text">
+          <string/>
+         </property>
+         <property name="icon">
+          <iconset>
+           <normaloff>:/germany.png</normaloff>:/germany.png</iconset>
+         </property>
+         <property name="iconSize">
+          <size>
+           <width>32</width>
+           <height>32</height>
+          </size>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QPushButton" name="btnNorway">
+         <property name="toolTip">
+          <string>Norway</string>
+         </property>
+         <property name="text">
+          <string/>
+         </property>
+         <property name="icon">
+          <iconset>
+           <normaloff>:/norway.png</normaloff>:/norway.png</iconset>
+         </property>
+         <property name="iconSize">
+          <size>
+           <width>32</width>
+           <height>32</height>
+          </size>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QPushButton" name="btnFinland">
+         <property name="toolTip">
+          <string>Finland</string>
+         </property>
+         <property name="text">
+          <string/>
+         </property>
+         <property name="icon">
+          <iconset>
+           <normaloff>:/finland.png</normaloff>:/finland.png</iconset>
+         </property>
+         <property name="iconSize">
+          <size>
+           <width>32</width>
+           <height>32</height>
+          </size>
+         </property>
+        </widget>
+       </item>
+      </layout>
+     </item>
+     <item>
+      <layout class="QHBoxLayout" name="horizontalLayout">
+       <item>
+        <widget class="QLabel" name="ageLabel">
+         <property name="font">
+          <font>
+           <pointsize>14</pointsize>
+           <weight>75</weight>
+           <bold>true</bold>
+          </font>
+         </property>
+         <property name="text">
+          <string>Age</string>
+         </property>
+         <property name="margin">
+          <number>3</number>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QSpinBox" name="ageSpinBox">
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Minimum" vsizetype="Fixed">
+           <horstretch>0</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+         <property name="minimumSize">
+          <size>
+           <width>80</width>
+           <height>0</height>
+          </size>
+         </property>
+         <property name="value">
+          <number>0</number>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <spacer name="horizontalSpacer">
+         <property name="orientation">
+          <enum>Qt::Horizontal</enum>
+         </property>
+         <property name="sizeHint" stdset="0">
+          <size>
+           <width>40</width>
+           <height>20</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
+      </layout>
+     </item>
+     <item>
+      <spacer name="verticalSpacer">
+       <property name="orientation">
+        <enum>Qt::Vertical</enum>
+       </property>
+       <property name="sizeHint" stdset="0">
+        <size>
+         <width>20</width>
+         <height>40</height>
+        </size>
+       </property>
+      </spacer>
+     </item>
+     <item>
+      <layout class="QHBoxLayout" name="horizontalLayout_2">
+       <item>
+        <widget class="QLabel" name="intervalLabel">
+         <property name="font">
+          <font>
+           <pointsize>14</pointsize>
+           <weight>75</weight>
+           <bold>true</bold>
+          </font>
+         </property>
+         <property name="text">
+          <string>Interval</string>
+         </property>
+         <property name="margin">
+          <number>3</number>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QRadioButton" name="btnMonthly">
+         <property name="text">
+          <string>Monthly</string>
+         </property>
+         <property name="checked">
+          <bool>true</bool>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QRadioButton" name="btnQuarterly">
+         <property name="text">
+          <string>Quarterly</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QRadioButton" name="btnYearly">
+         <property name="text">
+          <string>Yearly</string>
+         </property>
+        </widget>
+       </item>
+      </layout>
+     </item>
+     <item>
+      <spacer name="verticalSpacer_2">
+       <property name="orientation">
+        <enum>Qt::Vertical</enum>
+       </property>
+       <property name="sizeHint" stdset="0">
+        <size>
+         <width>20</width>
+         <height>40</height>
+        </size>
+       </property>
+      </spacer>
+     </item>
+     <item>
+      <layout class="QHBoxLayout" name="horizontalLayout_3">
+       <item>
+        <widget class="QLabel" name="priceLabel">
+         <property name="font">
+          <font>
+           <pointsize>14</pointsize>
+           <weight>75</weight>
+           <bold>true</bold>
+          </font>
+         </property>
+         <property name="text">
+          <string>Price/month</string>
+         </property>
+         <property name="margin">
+          <number>3</number>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QLabel" name="priceDisplay">
+         <property name="text">
+          <string>0.0</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <spacer name="horizontalSpacer_2">
+         <property name="orientation">
+          <enum>Qt::Horizontal</enum>
+         </property>
+         <property name="sizeHint" stdset="0">
+          <size>
+           <width>40</width>
+           <height>20</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
+      </layout>
+     </item>
+     <item>
+      <spacer name="verticalSpacer_3">
+       <property name="orientation">
+        <enum>Qt::Vertical</enum>
+       </property>
+       <property name="sizeHint" stdset="0">
+        <size>
+         <width>20</width>
+         <height>40</height>
+        </size>
+       </property>
+      </spacer>
+     </item>
+    </layout>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/examples/corelib/bindableproperties/subscription/CMakeLists.txt b/examples/corelib/bindableproperties/subscription/CMakeLists.txt
new file mode 100644
index 0000000000..a5480e03c7
--- /dev/null
+++ b/examples/corelib/bindableproperties/subscription/CMakeLists.txt
@@ -0,0 +1,53 @@
+cmake_minimum_required(VERSION 3.16)
+project(subscription LANGUAGES CXX)
+
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
+
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
+set(CMAKE_AUTOUIC ON)
+
+if(NOT DEFINED INSTALL_EXAMPLESDIR)
+  set(INSTALL_EXAMPLESDIR "examples")
+endif()
+
+set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/corelib/bindableproperties/subscription")
+
+find_package(Qt6 COMPONENTS Core)
+find_package(Qt6 COMPONENTS Gui)
+find_package(Qt6 COMPONENTS Widgets)
+
+qt_add_executable(subscription
+    ../shared/subscriptionwindow.cpp ../shared/subscriptionwindow.h ../shared/subscriptionwindow.ui
+    main.cpp
+    subscription.cpp subscription.h
+    user.cpp user.h
+)
+target_link_libraries(subscription PUBLIC
+    Qt::Core
+    Qt::Gui
+    Qt::Widgets
+)
+
+
+# Resources:
+set(countries_resource_files
+    "../shared/finland.png"
+    "../shared/germany.png"
+    "../shared/norway.png"
+)
+
+qt6_add_resources(subscription "countries"
+    PREFIX
+        "/"
+    BASE
+        "../shared"
+    FILES
+        ${countries_resource_files}
+)
+
+install(TARGETS subscription
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
+)
diff --git a/examples/corelib/bindableproperties/subscription/main.cpp b/examples/corelib/bindableproperties/subscription/main.cpp
new file mode 100644
index 0000000000..c987448611
--- /dev/null
+++ b/examples/corelib/bindableproperties/subscription/main.cpp
@@ -0,0 +1,128 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 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$
+** 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.
+**
+** BSD License Usage
+** Alternatively, 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 "../shared/subscriptionwindow.h"
+#include "subscription.h"
+#include "user.h"
+
+#include <QApplication>
+#include <QButtonGroup>
+#include <QLabel>
+#include <QPushButton>
+#include <QRadioButton>
+#include <QSpinBox>
+
+int main(int argc, char *argv[])
+{
+    QApplication a(argc, argv);
+    User user;
+    Subscription subscription(&user);
+
+    SubscriptionWindow w;
+
+    // Initialize subscription data
+    QRadioButton *monthly = w.findChild<QRadioButton *>("btnMonthly");
+    QObject::connect(monthly, &QRadioButton::clicked, &subscription, [&] {
+        subscription.setDuration(Subscription::Monthly);
+    });
+    QRadioButton *quarterly = w.findChild<QRadioButton *>("btnQuarterly");
+    QObject::connect(quarterly, &QRadioButton::clicked, &subscription, [&] {
+        subscription.setDuration(Subscription::Quarterly);
+    });
+    QRadioButton *yearly = w.findChild<QRadioButton *>("btnYearly");
+    QObject::connect(yearly, &QRadioButton::clicked, &subscription, [&] {
+        subscription.setDuration(Subscription::Yearly);
+    });
+
+    // Initialize user data
+    QPushButton *germany = w.findChild<QPushButton *>("btnGermany");
+    QObject::connect(germany, &QPushButton::clicked, &user, [&] {
+        user.setCountry(User::Germany);
+    });
+    QPushButton *finland = w.findChild<QPushButton *>("btnFinland");
+    QObject::connect(finland, &QPushButton::clicked, &user, [&] {
+        user.setCountry(User::Finland);
+    });
+    QPushButton *norway = w.findChild<QPushButton *>("btnNorway");
+    QObject::connect(norway, &QPushButton::clicked, &user, [&] {
+        user.setCountry(User::Norway);
+    });
+
+    QSpinBox *ageSpinBox = w.findChild<QSpinBox *>("ageSpinBox");
+    QObject::connect(ageSpinBox, &QSpinBox::valueChanged, &user, [&](int value) {
+        user.setAge(value);
+    });
+
+    // Initialize price data
+    QLabel *priceDisplay = w.findChild<QLabel *>("priceDisplay");
+    priceDisplay->setText(QString::number(subscription.price()));
+    priceDisplay->setEnabled(subscription.isValid());
+
+    // Track the price changes
+    QObject::connect(&subscription, &Subscription::priceChanged, [&] {
+        priceDisplay->setText(QString::number(subscription.price()));
+    });
+
+    QObject::connect(&subscription, &Subscription::isValidChanged, [&] {
+        priceDisplay->setEnabled(subscription.isValid());
+    });
+
+    QObject::connect(&user, &User::countryChanged, [&] {
+        subscription.calculatePrice();
+        subscription.updateValidity();
+    });
+
+    QObject::connect(&user, &User::ageChanged, [&] {
+        subscription.updateValidity();
+    });
+
+    w.show();
+    return a.exec();
+}
diff --git a/examples/corelib/bindableproperties/subscription/subscription.cpp b/examples/corelib/bindableproperties/subscription/subscription.cpp
new file mode 100644
index 0000000000..7f6da35862
--- /dev/null
+++ b/examples/corelib/bindableproperties/subscription/subscription.cpp
@@ -0,0 +1,106 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 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$
+** 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.
+**
+** BSD License Usage
+** Alternatively, 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 "subscription.h"
+#include "user.h"
+
+Subscription::Subscription(User *user) : m_user(user)
+{
+    Q_ASSERT(user);
+}
+
+void Subscription::calculatePrice()
+{
+    const auto oldPrice = m_price;
+
+    m_price = qRound(calculateDiscount() * m_duration * basePrice());
+    if (m_price != oldPrice)
+        emit priceChanged();
+}
+
+void Subscription::setDuration(Duration newDuration)
+{
+    if (newDuration != m_duration) {
+        m_duration = newDuration;
+        calculatePrice();
+        emit durationChanged();
+    }
+}
+
+double Subscription::calculateDiscount() const
+{
+    switch (m_duration) {
+    case Monthly:
+        return 1;
+    case Quarterly:
+        return 0.9;
+    case Yearly:
+        return 0.6;
+    }
+    Q_ASSERT(false);
+    return -1;
+}
+
+int Subscription::basePrice() const
+{
+    if (m_user->country() == User::None)
+        return 0;
+
+    return (m_user->country() == User::Norway) ? 100 : 80;
+}
+
+void Subscription::updateValidity()
+{
+    bool isValid = m_isValid;
+    m_isValid = m_user->country() != User::None && m_user->age() > 12;
+
+    if (m_isValid != isValid)
+        emit isValidChanged();
+}
diff --git a/examples/corelib/bindableproperties/subscription/subscription.h b/examples/corelib/bindableproperties/subscription/subscription.h
new file mode 100644
index 0000000000..95b840bbe5
--- /dev/null
+++ b/examples/corelib/bindableproperties/subscription/subscription.h
@@ -0,0 +1,91 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 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$
+** 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.
+**
+** BSD License Usage
+** Alternatively, 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 SUBSCRIPTION_H
+#define SUBSCRIPTION_H
+
+#include <QObject>
+#include <QPointer>
+
+class User;
+
+class Subscription : public QObject
+{
+    Q_OBJECT
+public:
+    enum Duration { Monthly = 1, Quarterly = 4, Yearly = 12 };
+
+    Subscription(User *user);
+
+    void calculatePrice();
+    int price() const { return m_price; }
+
+    Duration duration() const { return m_duration; }
+    void setDuration(Duration newDuration);
+
+    bool isValid() const { return m_isValid; }
+    void updateValidity();
+
+signals:
+    void priceChanged();
+    void durationChanged();
+    void isValidChanged();
+
+private:
+    double calculateDiscount() const;
+    int basePrice() const;
+
+    QPointer<User> m_user;
+    Duration m_duration = Monthly;
+    int m_price = 0;
+    bool m_isValid = false;
+};
+
+#endif // SUBSCRIPTION_H
diff --git a/examples/corelib/bindableproperties/subscription/subscription.pro b/examples/corelib/bindableproperties/subscription/subscription.pro
new file mode 100644
index 0000000000..68910904bb
--- /dev/null
+++ b/examples/corelib/bindableproperties/subscription/subscription.pro
@@ -0,0 +1,22 @@
+QT += widgets
+TARGET = subscription
+
+SOURCES += main.cpp \
+    subscription.cpp \
+    user.cpp \
+    ../shared/subscriptionwindow.cpp
+
+target.path = $$[QT_INSTALL_EXAMPLES]/corelib/bindableproperties/subscription
+INSTALLS += target
+
+FORMS += \
+    ../shared/subscriptionwindow.ui
+
+HEADERS += \
+    subscription.h \
+    user.h \
+    ../shared/subscriptionwindow.h
+
+RESOURCES += \
+    ../shared/countries.qrc
+
diff --git a/examples/corelib/bindableproperties/subscription/user.cpp b/examples/corelib/bindableproperties/subscription/user.cpp
new file mode 100644
index 0000000000..af97576cc7
--- /dev/null
+++ b/examples/corelib/bindableproperties/subscription/user.cpp
@@ -0,0 +1,67 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, 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 "user.h"
+
+void User::setCountry(Country country)
+{
+    if (m_country != country) {
+        m_country = country;
+        emit countryChanged();
+    }
+}
+
+void User::setAge(int age)
+{
+    if (m_age != age) {
+        m_age = age;
+        emit ageChanged();
+    }
+}
diff --git a/examples/corelib/bindableproperties/subscription/user.h b/examples/corelib/bindableproperties/subscription/user.h
new file mode 100644
index 0000000000..a872ecf8c8
--- /dev/null
+++ b/examples/corelib/bindableproperties/subscription/user.h
@@ -0,0 +1,82 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, 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 USER_H
+#define USER_H
+
+#include <QObject>
+
+class User : public QObject
+{
+    Q_OBJECT
+
+public:
+    enum Country {
+        None,
+        Finland,
+        Germany,
+        Norway,
+    };
+
+    Country country() const { return m_country; }
+    void setCountry(Country country);
+
+    int age() const { return m_age; }
+    void setAge(int age);
+
+signals:
+    void countryChanged();
+    void ageChanged();
+
+private:
+    Country m_country = Country::None;
+    int m_age = 0;
+};
+#endif // USER_H