Add the 'binding' example of the QML reference examples

Task-number: PYSIDE-841
Change-Id: Ie6d991b7c58148aa2963134465aaa156343f0a42
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

7 files changed, 479 insertions, 0 deletions

diff --git a/examples/declarative/referenceexamples/binding/binding.pyproject b/examples/declarative/referenceexamples/binding/binding.pyproject
new file mode 100644
index 000000000..a782d5c8a
--- /dev/null
+++ b/examples/declarative/referenceexamples/binding/binding.pyproject
@@ -0,0 +1,3 @@
+{
+    "files": ["main.py", "birthdayparty.py", "happybirthdaysong.py", "person.py", "example.qml"]
+}
diff --git a/examples/declarative/referenceexamples/binding/birthdayparty.py b/examples/declarative/referenceexamples/binding/birthdayparty.py
new file mode 100644
index 000000000..525b971d7
--- /dev/null
+++ b/examples/declarative/referenceexamples/binding/birthdayparty.py
@@ -0,0 +1,120 @@
+#############################################################################
+##
+## Copyright (C) 2022 The Qt Company Ltd.
+## Contact: http://www.qt.io/licensing/
+##
+## This file is part of the Qt for Python 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."
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+from PySide6.QtCore import QDate, QObject, ClassInfo, Property, QTime, Signal
+from PySide6.QtQml import QmlAnonymous, QmlAttached, QmlElement, ListProperty
+
+from person import Person
+
+
+# To be used on the @QmlElement decorator
+# (QML_IMPORT_MINOR_VERSION is optional)
+QML_IMPORT_NAME = "examples.binding.people"
+QML_IMPORT_MAJOR_VERSION = 1
+
+
+@QmlAnonymous
+class BirthdayPartyAttached(QObject):
+
+    rsvp_changed = Signal()
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self._rsvp = QDate()
+
+    @Property(QDate, notify=rsvp_changed)
+    def rsvp(self):
+        return self._rsvp
+
+    @rsvp.setter
+    def rsvp(self, d):
+        if self._rsvp != d:
+            self._rsvp = d
+            self.rsvp_changed.emit()
+
+
+@QmlElement
+@ClassInfo(DefaultProperty="guests")
+@QmlAttached(BirthdayPartyAttached)
+class BirthdayParty(QObject):
+
+    partyStarted = Signal(QTime)
+    host_changed = Signal()
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self._host = None
+        self._guests = []
+
+    def startParty(self):
+        self.partyStarted.emit(QTime.currentTime())
+
+    @Property(Person, notify=host_changed)
+    def host(self):
+        return self._host
+
+    @host.setter
+    def host(self, h):
+        if self._host != h:
+            self._host = h
+            self.host_changed.emit()
+
+    @Property(str)
+    def announcement(self):
+        return ""
+
+    @announcement.setter
+    def announcement(self, a):
+        print(a)
+
+    def guest(self, n):
+        return self._guests[n]
+
+    def guestCount(self):
+        return len(self._guests)
+
+    def appendGuest(self, guest):
+        self._guests.append(guest)
+
+    @staticmethod
+    def qmlAttachedProperties(self, o):
+        return BirthdayPartyAttached(o)
+
+    guests = ListProperty(Person, appendGuest)
diff --git a/examples/declarative/referenceexamples/binding/doc/binding.rst b/examples/declarative/referenceexamples/binding/doc/binding.rst
new file mode 100644
index 000000000..5c0ed21be
--- /dev/null
+++ b/examples/declarative/referenceexamples/binding/doc/binding.rst
@@ -0,0 +1,17 @@
+.. _qml-binding-example:
+
+Extending QML - Binding Example
+===============================
+
+This example builds on the :ref:`qml-adding-types-example`,
+the :ref:`qml-attached-properties-example`,
+the :ref:`qml-default-property-example`,
+the :ref:`qml-inheritance-and-coercion-example`
+the :ref:`qml-object-and-list-property-types-example`
+and the :ref:`qml-valuesource-example`.
+
+Running the Example
+-------------------
+
+The ``main.py`` file in the example includes a simple shell application that
+loads and runs the QML snippet shown below.
diff --git a/examples/declarative/referenceexamples/binding/example.qml b/examples/declarative/referenceexamples/binding/example.qml
new file mode 100644
index 000000000..46fc09e6f
--- /dev/null
+++ b/examples/declarative/referenceexamples/binding/example.qml
@@ -0,0 +1,76 @@
+/****************************************************************************
+**
+** Copyright (C) 2022 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."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import examples.binding.people
+
+BirthdayParty {
+    id: theParty
+
+    HappyBirthdaySong on announcement { name: theParty.host.name }
+
+    onPartyStarted: (time) => { console.log("This party started rockin' at " + time); }
+
+    host: Boy {
+        name: "Bob Jones"
+        shoe_size: 12
+    }
+
+    Boy {
+        name: "Leo Hodges"
+        BirthdayParty.rsvp: "2009-07-06"
+    }
+    Boy {
+        name: "Jack Smith"
+    }
+    Girl {
+        name: "Anne Brown"
+        BirthdayParty.rsvp: "2009-07-01"
+    }
+}
diff --git a/examples/declarative/referenceexamples/binding/happybirthdaysong.py b/examples/declarative/referenceexamples/binding/happybirthdaysong.py
new file mode 100644
index 000000000..cffcca3d0
--- /dev/null
+++ b/examples/declarative/referenceexamples/binding/happybirthdaysong.py
@@ -0,0 +1,84 @@
+#############################################################################
+##
+## Copyright (C) 2022 The Qt Company Ltd.
+## Contact: http://www.qt.io/licensing/
+##
+## This file is part of the Qt for Python 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."
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+from PySide6.QtCore import QObject, QTimer, Property, Slot
+from PySide6.QtQml import QmlElement, QPyQmlPropertyValueSource
+
+# To be used on the @QmlElement decorator
+# (QML_IMPORT_MINOR_VERSION is optional)
+QML_IMPORT_NAME = "examples.binding.people"
+QML_IMPORT_MAJOR_VERSION = 1
+
+
+@QmlElement
+class HappyBirthdaySong(QPyQmlPropertyValueSource):
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+
+        self.m_target = None
+        self.m_name = ""
+        self.m_line = -1
+        self.m_lyrics = []
+
+        self.m_timer = QTimer(self)
+        self.m_timer.timeout.connect(self.advance)
+        self.m_timer.start(1000)
+
+    def setTarget(self, property):
+        self.m_target = property
+
+    @Property(str)
+    def name(self):
+        return self.m_name
+
+    @name.setter
+    def name(self, n):
+        self.m_name = n
+        self.m_lyrics = ["Happy birthday to you,",
+                         "Happy birthday to you,",
+                         f"Happy birthday dear {self.m_name},",
+                         "Happy birthday to you!",
+                         ""]
+
+    @Slot()
+    def advance(self):
+        self.m_line = (self.m_line + 1) % len(self.m_lyrics)
+        self.m_target.write(self.m_lyrics[self.m_line])
diff --git a/examples/declarative/referenceexamples/binding/main.py b/examples/declarative/referenceexamples/binding/main.py
new file mode 100644
index 000000000..7e294861c
--- /dev/null
+++ b/examples/declarative/referenceexamples/binding/main.py
@@ -0,0 +1,89 @@
+#############################################################################
+##
+## Copyright (C) 2022 The Qt Company Ltd.
+## Contact: http://www.qt.io/licensing/
+##
+## This file is part of the Qt for Python 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."
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+"""PySide6 port of the qml/examples/qml/referenceexamples/binding example from Qt v6.x"""
+
+from pathlib import Path
+import sys
+
+from PySide6.QtCore import QCoreApplication, QUrl
+from PySide6.QtQml import QQmlComponent, QQmlEngine, qmlAttachedPropertiesObject
+
+from person import Boy, Girl
+from birthdayparty import BirthdayParty
+from happybirthdaysong import HappyBirthdaySong
+
+
+if __name__ == "__main__":
+    app = QCoreApplication(sys.argv)
+    qml_file = Path(__file__).parent / "example.qml"
+    url = QUrl.fromLocalFile(qml_file)
+    engine = QQmlEngine()
+    component = QQmlComponent(engine, url)
+    party = component.create()
+    if not party:
+        print(component.errors())
+        del engine
+        sys.exit(-1)
+    host = party.host
+    print(f"{host.name} is having a birthday!")
+    if isinstance(host, Boy):
+        print("He is inviting:")
+    else:
+        print("She is inviting:")
+    for g in range(party.guestCount()):
+        guest = party.guest(g)
+        name = guest.name
+
+        rsvp_date = None
+        attached = qmlAttachedPropertiesObject(BirthdayParty, guest, False)
+        if attached:
+            rsvp_date = attached.rsvp.toString()
+        if rsvp_date:
+            print(f"    {name} RSVP date: {rsvp_date}")
+        else:
+            print(f"    {name} RSVP date: Hasn't RSVP'd")
+
+    party.startParty()
+
+    r = app.exec()
+
+    del engine
+    sys.exit(r)
diff --git a/examples/declarative/referenceexamples/binding/person.py b/examples/declarative/referenceexamples/binding/person.py
new file mode 100644
index 000000000..e8f6eed62
--- /dev/null
+++ b/examples/declarative/referenceexamples/binding/person.py
@@ -0,0 +1,90 @@
+#############################################################################
+##
+## Copyright (C) 2022 The Qt Company Ltd.
+## Contact: http://www.qt.io/licensing/
+##
+## This file is part of the Qt for Python 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."
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+from PySide6.QtCore import QObject, Property, Signal
+from PySide6.QtQml import QmlAnonymous, QmlElement
+
+# To be used on the @QmlElement decorator
+# (QML_IMPORT_MINOR_VERSION is optional)
+QML_IMPORT_NAME = "examples.binding.people"
+QML_IMPORT_MAJOR_VERSION = 1
+
+
+@QmlAnonymous
+class Person(QObject):
+    name_changed = Signal()
+    shoe_size_changed = Signal()
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self._name = ''
+        self._shoe_size = 0
+
+    @Property(str, notify=name_changed)
+    def name(self):
+        return self._name
+
+    @name.setter
+    def name(self, n):
+        if self._name != n:
+            self._name = n
+            self.name_changed.emit()
+
+    @Property(int, notify=shoe_size_changed)
+    def shoe_size(self):
+        return self._shoe_size
+
+    @shoe_size.setter
+    def shoe_size(self, s):
+        if self._shoe_size != s:
+            self._shoe_size = s
+            self.shoe_size_changed.emit()
+
+
+@QmlElement
+class Boy(Person):
+    def __init__(self, parent=None):
+        super().__init__(parent)
+
+
+@QmlElement
+class Girl(Person):
+    def __init__(self, parent=None):
+        super().__init__(parent)