Extending QML - Plugins Example (original) (raw)

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This is the last of a series of 6 examples forming a tutorial about extending QML with Python.

This example refers to the Python version of using a QML plugin in Python. The idea of plugins in Python is non-existent because Python modules are dynamically loaded anyway. We use this idea and our QML type registration decorators - @QmlElement / @QmlNamedElement - to register the QML modules as they are imported. The pyside6-qml tool does this for you by simply pointing to the .qml file.

Running the Example¶

pyside6-qml examples/qml/tutorials/extending-qml/chapter6-plugins/app.qml -I examples/qml/tutorials/extending-qml/chapter6-plugins/Charts

Download this example

app.qml

// Copyright (C) 2022 The Qt Company Ltd. // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

import QtQuick import Charts 1.0

Item { width: 300; height: 200

PieChart {
    anchors.centerIn: parent
    width: 100; height: 100

    slices: [
        PieSlice {
            anchors.fill: parent
            color: "red"
            fromAngle: 0; angleSpan: 110
        },
        PieSlice {
            anchors.fill: parent
            color: "black"
            fromAngle: 110; angleSpan: 50
        },
        PieSlice {
            anchors.fill: parent
            color: "blue"
            fromAngle: 160; angleSpan: 100
        }
    ]
}

}

Charts/piechart.py

Copyright (C) 2022 The Qt Company Ltd.

SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

from future import annotations

from PySide6.QtCore import Property from PySide6.QtQml import QmlElement, ListProperty from PySide6.QtQuick import QQuickItem

from pieslice import PieSlice

To be used on the @QmlElement decorator

(QML_IMPORT_MINOR_VERSION is optional)

QML_IMPORT_NAME = "Charts" QML_IMPORT_MAJOR_VERSION = 1

@QmlElement class PieChart(QQuickItem): def init(self, parent=None): super().init(parent) self._slices = [] self._name = ''

@Property(str, final=True)
def name(self):
    return self._name

@name.setter
def name(self, name):
    self._name = name

def slice(self, n):
    return self._slices[n]

def sliceCount(self):
    return len(self._slices)

def append_and_setparent(self, slice):
    self._slices.append(slice)
    slice.setParentItem(self)

slices = ListProperty(PieSlice, append_and_setparent)

Charts/pieslice.py

Copyright (C) 2022 The Qt Company Ltd.

SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

from future import annotations

from PySide6.QtCore import Property, QRectF from PySide6.QtGui import QColor, QPainter, QPen from PySide6.QtQuick import QQuickPaintedItem from PySide6.QtQml import QmlElement

To be used on the @QmlElement decorator

(QML_IMPORT_MINOR_VERSION is optional)

QML_IMPORT_NAME = "Charts" QML_IMPORT_MAJOR_VERSION = 1

@QmlElement class PieSlice(QQuickPaintedItem): def init(self, parent=None): super().init(parent)

    self._color = QColor()
    self._from_angle = 0
    self._angle_span = 0

@Property(QColor, final=True)
def color(self):
    return self._color

@color.setter
def color(self, color):
    self._color = QColor(color)

@Property(int, final=True)
def fromAngle(self):
    return self._from_angle

@fromAngle.setter
def fromAngle(self, fromAngle):
    self._from_angle = fromAngle

@Property(int, final=True)
def angleSpan(self):
    return self._angle_span

@angleSpan.setter
def angleSpan(self, angleSpan):
    self._angle_span = angleSpan

def paint(self, painter):
    painter.setPen(QPen(self._color, 2))
    painter.setRenderHint(QPainter.RenderHint.Antialiasing, True)

    rect = QRectF(0, 0, self.width(), self.height()).adjusted(1, 1, -1, -1)
    painter.drawPie(rect, self._from_angle * 16, self._angle_span * 16)