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Diffstat (limited to 'examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties')
7 files changed, 198 insertions, 0 deletions
diff --git a/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/People/Main.qml b/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/People/Main.qml new file mode 100644 index 000000000..9971a2315 --- /dev/null +++ b/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/People/Main.qml @@ -0,0 +1,15 @@ +// Copyright (C) 2021 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause + +import People + +BirthdayParty { + host: Boy { + name: "Bob Jones" + shoe_size: 12 + } + + Boy { name: "Leo Hodges" } + Boy { name: "Jack Smith" } + Girl { name: "Anne Brown" } +} diff --git a/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/People/qmldir b/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/People/qmldir new file mode 100644 index 000000000..a2bd9515a --- /dev/null +++ b/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/People/qmldir @@ -0,0 +1,3 @@ +module People +typeinfo coercion.qmltypes +Main 1.0 Main.qml diff --git a/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/advanced3-Default-properties.pyproject b/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/advanced3-Default-properties.pyproject new file mode 100644 index 000000000..09942ebcc --- /dev/null +++ b/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/advanced3-Default-properties.pyproject @@ -0,0 +1,4 @@ +{ + "files": ["main.py", "birthdayparty.py", "person.py", + "People/Main.qml", "People/qmldir"] +} diff --git a/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/birthdayparty.py b/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/birthdayparty.py new file mode 100644 index 000000000..3f6102c66 --- /dev/null +++ b/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/birthdayparty.py @@ -0,0 +1,47 @@ +# Copyright (C) 2022 The Qt Company Ltd. +# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause + +from PySide6.QtCore import QObject, ClassInfo, Property, Signal +from PySide6.QtQml import QmlElement, ListProperty + +from person import Person + + +# To be used on the @QmlElement decorator +# (QML_IMPORT_MINOR_VERSION is optional) +QML_IMPORT_NAME = "People" +QML_IMPORT_MAJOR_VERSION = 1 + + +@QmlElement +@ClassInfo(DefaultProperty="guests") +class BirthdayParty(QObject): + host_changed = Signal() + guests_changed = Signal() + + def __init__(self, parent=None): + super().__init__(parent) + self._host = None + self._guests = [] + + @Property(Person, notify=host_changed, final=True) + def host(self): + return self._host + + @host.setter + def host(self, h): + if self._host != h: + self._host = h + self.host_changed.emit() + + def guest(self, n): + return self._guests[n] + + def guestCount(self): + return len(self._guests) + + def appendGuest(self, guest): + self._guests.append(guest) + self.guests_changed.emit() + + guests = ListProperty(Person, appendGuest, notify=guests_changed, final=True) diff --git a/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/doc/advanced3-Default-properties.rst b/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/doc/advanced3-Default-properties.rst new file mode 100644 index 000000000..0857f9d0a --- /dev/null +++ b/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/doc/advanced3-Default-properties.rst @@ -0,0 +1,40 @@ +.. _qml-advanced3-default-properties: + +Extending QML (advanced) - Default Properties +============================================= + +This is the third of a series of 6 examples forming a tutorial using the +example of a birthday party to demonstrate some of the advanced features of +QML. + +Currently, in the QML file, each property is assigned explicitly. For example, +the ``host`` property is assigned a ``Boy`` and the ``guests`` property is +assigned a list of ``Boy`` or ``Girl``. This is easy but it can be made a bit +simpler for this specific use case. Instead of assigning the ``guests`` +property explicitly, we can add ``Boy`` and ``Girl`` objects inside the party +directly and have them assigned to ``guests`` implicitly. It makes sense that +all the attendees that we specify, and that are not the host, are guests. This +change is purely syntactical but it can add a more natural feel in many +situations. + +The ``guests`` property can be designated as the default property of +``BirthdayParty``. Meaning that each object created inside of a +``BirthdayParty`` is implicitly appended to the default property ``guests``. +The resulting QML looks like this. + +.. literalinclude:: People/Main.qml + :lineno-start: 6 + :lines: 6-15 + +The only change required to enable this behavior is to add the ``DefaultProperty`` +class info annotation to ``BirthdayParty`` to designate ``guests`` as its default +property. + +.. literalinclude:: birthdayparty.py + :lineno-start: 16 + :lines: 16-18 + +You may already be familiar with this mechanism. The default property for all +descendants of ``Item`` in QML is the ``data`` property. All elements not +explicitly added to a property of an ``Item`` will be added to ``data``. This +makes the structure clear and reduces unnecessary noise in the code. diff --git a/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/main.py b/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/main.py new file mode 100644 index 000000000..020974c9b --- /dev/null +++ b/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/main.py @@ -0,0 +1,38 @@ +# Copyright (C) 2022 The Qt Company Ltd. +# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause + +"""PySide6 port of the + qml/examples/qml/tutorials/extending-qml-advanced/default advanced3-Default-properties example + from Qt v6.x""" + +from pathlib import Path +import sys + +from PySide6.QtCore import QCoreApplication +from PySide6.QtQml import QQmlComponent, QQmlEngine + +from person import Boy, Girl # noqa: F401 +from birthdayparty import BirthdayParty # noqa: F401 + + +app = QCoreApplication(sys.argv) +engine = QQmlEngine() +engine.addImportPath(Path(__file__).parent) +component = QQmlComponent(engine) +component.loadFromModule("People", "Main") +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()): + name = party.guest(g).name + print(f" {name}") +del engine +sys.exit(0) diff --git a/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/person.py b/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/person.py new file mode 100644 index 000000000..503aaf65e --- /dev/null +++ b/examples/qml/tutorials/extending-qml-advanced/advanced3-Default-properties/person.py @@ -0,0 +1,51 @@ +# Copyright (C) 2022 The Qt Company Ltd. +# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause + +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 = "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, final=True) + 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, final=True) + def shoe_size(self): + return self._shoe_size + + @shoe_size.setter + def shoe_size(self, s): + self._shoe_size = s + + +@QmlElement +class Boy(Person): + def __init__(self, parent=None): + super().__init__(parent) + + +@QmlElement +class Girl(Person): + def __init__(self, parent=None): + super().__init__(parent) |