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Diffstat (limited to 'examples/declarative/referenceexamples/extended')
4 files changed, 231 insertions, 0 deletions
diff --git a/examples/declarative/referenceexamples/extended/doc/extended.rst b/examples/declarative/referenceexamples/extended/doc/extended.rst new file mode 100644 index 000000000..1f78ac1b8 --- /dev/null +++ b/examples/declarative/referenceexamples/extended/doc/extended.rst @@ -0,0 +1,41 @@ +.. _qml-extension-objects-example + +Extending QML - Extension Objects Example +========================================= + +This example builds on the the :ref:`qml-adding-types-example`. + +Shows how to use QmlExtended decorator to provide an extension object to a +QLineEdit without modifying or subclassing it. + +Firstly, the LineEditExtension class is registered with the QML system as an +extension of QLineEdit. We declare a foreign type to do this as we cannot +modify Qt's internal QLineEdit class. + +.. code-block:: python + + @QmlNamedElement("QLineEdit") + @QmlExtended(LineEditExtension) + @QmlForeign(QLineEdit) + class LineEditForeign(QObject): + + +Note the usage of ``QmlNamedElement()`` instead of ``QmlElement()``. +``QmlElement()`` uses the name of the containing type by default, +``LineEditExtension`` in this case. As the class being an extension class is +an implementation detail, we choose the more natural name ``QLineEdit`` +instead. + +The QML engine then instantiates a QLineEdit. + +In QML, a property is set on the line edit that only exists in the +``LineEditExtension`` class: + +.. code-block:: javascript + + QLineEdit { + left_margin: 20 + } + +The extension type performs calls on the ``QLineEdit`` that otherwise will not +be accessible to the QML engine. diff --git a/examples/declarative/referenceexamples/extended/example.qml b/examples/declarative/referenceexamples/extended/example.qml new file mode 100644 index 000000000..e905f7c3e --- /dev/null +++ b/examples/declarative/referenceexamples/extended/example.qml @@ -0,0 +1,55 @@ +/**************************************************************************** +** +** 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.extend 1.0 + +QLineEdit { + left_margin: 20 +} diff --git a/examples/declarative/referenceexamples/extended/extended.pyproject b/examples/declarative/referenceexamples/extended/extended.pyproject new file mode 100644 index 000000000..127a3a76a --- /dev/null +++ b/examples/declarative/referenceexamples/extended/extended.pyproject @@ -0,0 +1,3 @@ +{ + "files": ["main.py", "example.qml"] +} diff --git a/examples/declarative/referenceexamples/extended/main.py b/examples/declarative/referenceexamples/extended/main.py new file mode 100644 index 000000000..c553a1fa8 --- /dev/null +++ b/examples/declarative/referenceexamples/extended/main.py @@ -0,0 +1,132 @@ +############################################################################# +## +## 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/extended example from Qt v6.x""" + +from pathlib import Path +import sys + +from PySide6.QtCore import QObject, QUrl, Property +from PySide6.QtWidgets import QApplication, QLineEdit +from PySide6.QtQml import (QQmlComponent, QQmlEngine, QmlForeign, QmlExtended, + QmlNamedElement) + + +# To be used on the @QmlElement decorator +# (QML_IMPORT_MINOR_VERSION is optional) +QML_IMPORT_NAME = "examples.extend" +QML_IMPORT_MAJOR_VERSION = 1 + + +class LineEditExtension(QObject): + + def __init__(self, parent=None): + super().__init__(parent) + self._line_edit = parent + + @Property(int) + def left_margin(self): + return self._line_edit.textMargins().left() + + @left_margin.setter + def left_margin(self, m): + margins = self._line_edit.textMargins() + margins.setLeft(m) + self._line_edit.setTextMargins(margins) + + @Property(int) + def right_margin(self): + return self._line_edit.textMargins().right() + + @right_margin.setter + def right_margin(self, m): + margins = self._line_edit.textMargins() + margins.setRight(m) + self._line_edit.setTextMargins(margins) + + @Property(int) + def top_margin(self): + return self._line_edit.textMargins().top() + + @top_margin.setter + def top_margin(self, m): + margins = self._line_edit.textMargins() + margins.setTop(m) + self._line_edit.setTextMargins(margins) + + @Property(int) + def bottom_margin(self): + return self._line_edit.textMargins().bottom() + + @bottom_margin.setter + def bottom_margin(self, m): + margins = self._line_edit.textMargins() + margins.setBottom(m) + self._line_edit.setTextMargins(margins) + + +@QmlNamedElement("QLineEdit") +@QmlExtended(LineEditExtension) +@QmlForeign(QLineEdit) +class LineEditForeign(QObject): + + def __init__(self, parent=None): + super().__init__(parent) + + +if __name__ == '__main__': + app = QApplication(sys.argv) + + qml_file = Path(__file__).parent / "example.qml" + url = QUrl.fromLocalFile(qml_file) + engine = QQmlEngine() + component = QQmlComponent(engine, url) + widget = component.create() + if not widget: + print(component.errors()) + del engine + sys.exit(-1) + + widget.show() + r = app.exec() + # Deleting the engine before it goes out of scope is required to make sure + # all child QML instances are destroyed in the correct order. + del engine + sys.exit(r) |