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diff --git a/sources/pyside6/doc/tutorials/qmlintegration/qmlintegration.rst b/sources/pyside6/doc/tutorials/qmlintegration/qmlintegration.rst new file mode 100644 index 000000000..ff6fe3e31 --- /dev/null +++ b/sources/pyside6/doc/tutorials/qmlintegration/qmlintegration.rst @@ -0,0 +1,128 @@ +Python-QML integration +====================== + +This tutorial provides a quick walk-through of a python application that loads, and interacts with +a QML file. QML is a declarative language that lets you design UIs faster than a traditional +language, such as C++. The QtQml and QtQuick modules provides the necessary infrastructure for +QML-based UIs. + +In this tutorial, you will learn how to integrate Python with a QML application. +This mechanism will help us to understand how to use Python as a backend for certain +signals from the UI elements in the QML interface. Additionally, you will learn how to provide +a modern look to your QML application using one of the features from Qt Quick Controls 2. + +The tutorial is based on an application that allow you to set many text properties, like increasing +the font size, changing the color, changing the style, and so on. Before you begin, install the +`PySide6 <https://pypi.org/project/PySide6/>`_ Python packages. + +The following step-by-step process will guide you through the key elements of the QML based +application and PySide6 integration: + +#. First, let's start with the following QML-based UI: + + .. image:: textproperties_default.png + + The design is based on a `GridLayout`, containing two `ColumnLayout`. + Inside the UI you will find many `RadioButton`, `Button`, and a `Slider`. + +#. With the QML file in place, you can load it from Python: + + .. literalinclude:: main.py + :linenos: + :lines: 63-76 + :emphasize-lines: 4,9 + + Notice that we only need a :code:`QQmlApplicationEngine` to + :code:`load` the QML file. + +#. Define the ``Bridge`` class, containing all the logic for the element + that will be register in QML: + + .. literalinclude:: main.py + :linenos: + :lines: 14-54 + :emphasize-lines: 3,4,7 + + Notice that the registration happens thanks to the :code:`QmlElement` + decorator, that underneath uses the reference to the :code:`Bridge` + class and the variables :code:`QML_IMPORT_NAME` and + :code:`QML_IMPORT_MAJOR_VERSION`. + +#. Now, go back to the QML file and connect the signals to the slots defined in the ``Bridge`` class: + + .. code:: js + + Bridge { + id: bridge + } + + Inside the :code:`ApplicationWindow` we declare a component + with the same name as the Python class, and provide an :code:`id:`. + This :code:`id` will help you to get a reference to the element + that was registered from Python. + + .. literalinclude:: view.qml + :linenos: + :lines: 45-55 + :emphasize-lines: 6-8 + + The properties *Italic*, *Bold*, and *Underline* are mutually + exclusive, this means only one can be active at any time. + To achieve this each time we select one of these options, we + check the three properties via the QML element property as you can + see in the above snippet. + Only one of the three will return *True*, while the other two + will return *False*, that is how we make sure only one is being + applied to the text. + +#. Each slot verifies if the selected option contains the text associated + to the property: + + .. literalinclude:: main.py + :linenos: + :lines: 42-47 + :emphasize-lines: 4,6 + + Returning *True* or *False* allows you to activate and deactivate + the properties of the QML UI elements. + + It is also possible to return other values that are not *Boolean*, + like the slot in charge of returning the font size: + + .. literalinclude:: main.py + :linenos: + :lines: 34-39 + +#. Now, for changing the look of our application, you have two options: + + 1. Use the command line: execute the python file adding the option, ``--style``:: + + python main.py --style material + + 2. Use a ``qtquickcontrols2.conf`` file: + + .. literalinclude:: qtquickcontrols2.conf + :linenos: + + Then add it to your ``.qrc`` file: + + .. literalinclude:: style.qrc + :linenos: + + Generate the *rc* file running, ``pyside6-rcc style.qrc -o style_rc.py`` + And finally import it from your ``main.py`` script. + + .. literalinclude:: main.py + :linenos: + :lines: 4-12 + :emphasize-lines: 9 + + You can read more about this configuration file + `here <https://doc.qt.io/qt-5/qtquickcontrols2-configuration.html>`_. + + The final look of your application will be: + + .. image:: textproperties_material.png + +You can :download:`view.qml <view.qml>` and +:download:`main.py <main.py>` to try this example. |