chapter3-bindings

(You can also check this code in the repository)

//![0]
import Charts
import QtQuick

Item {
    width: 300; height: 200

    Row {
        anchors.centerIn: parent
        spacing: 20

        PieChart {
            id: chartA
            width: 100; height: 100
            color: "red"
        }

        PieChart {
            id: chartB
            width: 100; height: 100
            color: chartA.color
        }
    }

    MouseArea {
        anchors.fill: parent
        onClicked: { chartA.color = "blue" }
    }

    Text {
        anchors {
            bottom: parent.bottom;
            horizontalCenter: parent.horizontalCenter;
            bottomMargin: 20
        }
        text: "Click anywhere to change the chart color"
    }
}
//![0]
"""PySide6 port of the qml/tutorials/extending-qml/chapter3-bindings example from Qt v5.x"""

import os
from pathlib import Path
import sys

from PySide6.QtCore import Property, Signal, Slot, QUrl, Qt
from PySide6.QtGui import QGuiApplication, QPen, QPainter, QColor
from PySide6.QtQml import qmlRegisterType
from PySide6.QtQuick import QQuickPaintedItem, QQuickView


class PieChart (QQuickPaintedItem):

    chartCleared = Signal()
    nameChanged = Signal()
    colorChanged = Signal()

    def __init__(self, parent=None):
        QQuickPaintedItem.__init__(self, parent)
        self._name = u''
        self._color = QColor()

    def paint(self, painter):
        pen = QPen(self._color, 2)
        painter.setPen(pen)
        painter.setRenderHints(QPainter.Antialiasing, True)
        painter.drawPie(self.boundingRect().adjusted(1, 1, -1, -1), 90 * 16, 290 * 16)

    @Property(QColor, notify=colorChanged)
    def color(self):
        return self._color

    @color.setter
    def color(self, value):
        if value != self._color:
            self._color = value
            self.update()
            self.colorChanged.emit()

    @Property(str, notify=nameChanged)
    def name(self):
        return self._name

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

    @Slot()  # This should be something like @Invokable
    def clearChart(self):
        self.color = Qt.transparent
        self.update()
        self.chartCleared.emit()


if __name__ == '__main__':
    app = QGuiApplication(sys.argv)

    qmlRegisterType(PieChart, 'Charts', 1, 0, 'PieChart')

    view = QQuickView()
    view.setResizeMode(QQuickView.SizeRootObjectToView)
    qml_file = os.fspath(Path(__file__).resolve().parent / 'app.qml')
    view.setSource(QUrl.fromLocalFile(qml_file))
    if view.status() == QQuickView.Error:
        sys.exit(-1)
    view.show()
    res = app.exec()
    # Deleting the view before it goes out of scope is required to make sure all child QML instances
    # are destroyed in the correct order.
    del view
    sys.exit(res)