main.py

"""PySide6 port of the Chart Themes example from Qt v5.x"""

import sys
from PySide6.QtCore import QPointF, Qt
from PySide6.QtGui import QColor, QPainter, QPalette
from PySide6.QtWidgets import (QApplication, QMainWindow, QSizePolicy,
    QWidget)
from PySide6.QtCharts import QtCharts

from ui_themewidget import Ui_ThemeWidgetForm as ui

from random import random, uniform

class ThemeWidget(QWidget):
    def __init__(self, parent):
        QWidget.__init__(self, parent)
        self.charts = []

        self.ui = ui()
        self.list_count = 3
        self.value_max = 10
        self.value_count = 7
        self.data_table = self.generate_random_data(self.list_count,
            self.value_max, self.value_count)

        self.ui.setupUi(self)
        self.populate_themebox()
        self.populate_animationbox()
        self.populate_legendbox()

        # Area Chart
        chart_view =  QtCharts.QChartView(self.create_areachart())
        self.ui.gridLayout.addWidget(chart_view, 1, 0)
        self.charts.append(chart_view)

        # Pie Chart
        chart_view =  QtCharts.QChartView(self.createPieChart())
        chart_view.setSizePolicy(QSizePolicy.Ignored,
            QSizePolicy.Ignored)
        self.ui.gridLayout.addWidget(chart_view, 1, 1)
        self.charts.append(chart_view)

        # Line Chart
        chart_view =  QtCharts.QChartView(self.createLineChart())
        self.ui.gridLayout.addWidget(chart_view, 1, 2)
        self.charts.append(chart_view)

        # Bar Chart
        chart_view =  QtCharts.QChartView(self.createBarChart())
        self.ui.gridLayout.addWidget(chart_view, 2, 0)
        self.charts.append(chart_view)

        # Spline Chart
        chart_view =  QtCharts.QChartView(self.createSplineChart())
        self.ui.gridLayout.addWidget(chart_view, 2, 1)
        self.charts.append(chart_view)

        # Scatter Chart
        chart_view =  QtCharts.QChartView(self.create_scatterchart())
        self.ui.gridLayout.addWidget(chart_view, 2, 2)
        self.charts.append(chart_view)

        # Set defaults
        self.ui.antialiasCheckBox.setChecked(True)

        # Set the colors from the light theme as default ones
        pal = qApp.palette()
        pal.setColor(QPalette.Window, QColor(0xf0f0f0))
        pal.setColor(QPalette.WindowText, QColor(0x404044))
        qApp.setPalette(pal)

        self.updateUI()


    def generate_random_data(self, list_count, value_max, value_count):
        data_table = []
        for i in range(list_count):
            data_list = []
            y_value = 0
            for j in range(value_count):
                constant = value_max / float(value_count)
                y_value += uniform(0, constant)
                x_value = (j + random()) * constant
                value = QPointF(x_value, y_value)
                label = "Slice {}: {}".format(i, j)
                data_list.append((value, label))
            data_table.append(data_list)

        return data_table

    def populate_themebox(self):
        theme = self.ui.themeComboBox

        theme.addItem("Light", QtCharts.QChart.ChartThemeLight)
        theme.addItem("Blue Cerulean", QtCharts.QChart.ChartThemeBlueCerulean)
        theme.addItem("Dark", QtCharts.QChart.ChartThemeDark)
        theme.addItem("Brown Sand", QtCharts.QChart.ChartThemeBrownSand)
        theme.addItem("Blue NCS", QtCharts.QChart.ChartThemeBlueNcs)
        theme.addItem("High Contrast", QtCharts.QChart.ChartThemeHighContrast)
        theme.addItem("Blue Icy", QtCharts.QChart.ChartThemeBlueIcy)
        theme.addItem("Qt", QtCharts.QChart.ChartThemeQt)

    def populate_animationbox(self):
        animated = self.ui.animatedComboBox

        animated.addItem("No Animations", QtCharts.QChart.NoAnimation)
        animated.addItem("GridAxis Animations", QtCharts.QChart.GridAxisAnimations)
        animated.addItem("Series Animations", QtCharts.QChart.SeriesAnimations)
        animated.addItem("All Animations", QtCharts.QChart.AllAnimations)

    def populate_legendbox(self):
        legend = self.ui.legendComboBox

        legend.addItem("No Legend ", 0)
        legend.addItem("Legend Top", Qt.AlignTop)
        legend.addItem("Legend Bottom", Qt.AlignBottom)
        legend.addItem("Legend Left", Qt.AlignLeft)
        legend.addItem("Legend Right", Qt.AlignRight)

    def create_areachart(self):
        chart = QtCharts.QChart()
        chart.setTitle("Area Chart")

        # The lower series initialized to zero values
        lower_series = None
        name = "Series "
        for i in range(len(self.data_table)):
            upper_series = QtCharts.QLineSeries(chart)
            for j in range(len(self.data_table[i])):
                data = self.data_table[i][j]
                if lower_series:
                    points = lower_series.pointsVector()
                    y_value = points[i].y() + data[0].y()
                    upper_series.append(QPointF(j, y_value))
                else:
                    upper_series.append(QPointF(j, data[0].y()))
            area = QtCharts.QAreaSeries(upper_series, lower_series)
            area.setName("{}{}".format(name, i))
            chart.addSeries(area)
            lower_series = upper_series

        chart.createDefaultAxes()
        chart.axisX().setRange(0, self.value_count - 1)
        chart.axisY().setRange(0, self.value_max)
        # Add space to label to add space between labels and axis
        chart.axisY().setLabelFormat("%.1f  ")

        return chart

    def createBarChart(self):
        chart = QtCharts.QChart()
        chart.setTitle("Bar chart")

        series = QtCharts.QStackedBarSeries(chart)
        for i in range(len(self.data_table)):
            barset = QtCharts.QBarSet("Bar set {}".format(i))
            for data in self.data_table[i]:
                barset.append(data[0].y())
            series.append(barset)

        chart.addSeries(series)

        chart.createDefaultAxes()
        chart.axisY().setRange(0, self.value_max * 2)
        # Add space to label to add space between labels and axis
        chart.axisY().setLabelFormat("%.1f  ")

        return chart

    def createLineChart(self):
        chart = QtCharts.QChart()
        chart.setTitle("Line chart")

        name = "Series "
        for i, lst in enumerate(self.data_table):
            series = QtCharts.QLineSeries(chart)
            for data in lst:
                series.append(data[0])
            series.setName("{}{}".format(name, i))
            chart.addSeries(series)

        chart.createDefaultAxes()
        chart.axisX().setRange(0, self.value_max)
        chart.axisY().setRange(0, self.value_count)
        # Add space to label to add space between labels and axis
        chart.axisY().setLabelFormat("%.1f  ")

        return chart

    def createPieChart(self):
        chart = QtCharts.QChart()
        chart.setTitle("Pie chart")

        series = QtCharts.QPieSeries(chart)
        for data in self.data_table[0]:
            slc = series.append(data[1], data[0].y())
            if data == self.data_table[0][0]:
                # Show the first slice exploded with label
                slc.setLabelVisible()
                slc.setExploded()
                slc.setExplodeDistanceFactor(0.5)

        series.setPieSize(0.4)
        chart.addSeries(series)

        return chart

    def createSplineChart(self):
        chart = QtCharts.QChart()
        chart.setTitle("Spline chart")
        name = "Series "
        for i, lst in enumerate(self.data_table):
            series = QtCharts.QSplineSeries(chart)
            for data in lst:
                series.append(data[0])
            series.setName("{}{}".format(name, i))
            chart.addSeries(series)

        chart.createDefaultAxes()
        chart.axisX().setRange(0, self.value_max)
        chart.axisY().setRange(0, self.value_count)
        # Add space to label to add space between labels and axis
        chart.axisY().setLabelFormat("%.1f  ")

        return chart

    def create_scatterchart(self):
        chart = QtCharts.QChart()
        chart.setTitle("Scatter chart")
        name = "Series "
        for i, lst in enumerate(self.data_table):
            series = QtCharts.QScatterSeries(chart)
            for data in lst:
                series.append(data[0])
            series.setName("{}{}".format(name, i))
            chart.addSeries(series)

        chart.createDefaultAxes()
        chart.axisX().setRange(0, self.value_max)
        chart.axisY().setRange(0, self.value_count)
        # Add space to label to add space between labels and axis
        chart.axisY().setLabelFormat("%.1f  ")

        return chart

    def updateUI(self):
        def set_colors(window_color, text_color):
            pal = self.window().palette()
            pal.setColor(QPalette.Window, window_color)
            pal.setColor(QPalette.WindowText, text_color)
            self.window().setPalette(pal)

        idx = self.ui.themeComboBox.currentIndex()
        theme = self.ui.themeComboBox.itemData(idx)

        if len(self.charts):
            chart_theme = self.charts[0].chart().theme()
            if chart_theme != theme:
                for chart_view in self.charts:
                    if theme == 0:
                        theme_name = QtCharts.QChart.ChartThemeLight
                    elif theme == 1:
                        theme_name = QtCharts.QChart.ChartThemeBlueCerulean
                    elif theme == 2:
                        theme_name = QtCharts.QChart.ChartThemeDark
                    elif theme == 3:
                        theme_name = QtCharts.QChart.ChartThemeBrownSand
                    elif theme == 4:
                        theme_name = QtCharts.QChart.ChartThemeBlueNcs
                    elif theme == 5:
                        theme_name = QtCharts.QChart.ChartThemeHighContrast
                    elif theme == 6:
                        theme_name = QtCharts.QChart.ChartThemeBlueIcy
                    elif theme == 7:
                        theme_name = QtCharts.QChart.ChartThemeQt
                    else:
                        theme_name = QtCharts.QChart.ChartThemeLight

                    chart_view.chart().setTheme(theme_name)

                # Set palette colors based on selected theme
                if theme == QtCharts.QChart.ChartThemeLight:
                    set_colors(QColor(0xf0f0f0), QColor(0x404044))
                elif theme == QtCharts.QChart.ChartThemeDark:
                    set_colors(QColor(0x121218), QColor(0xd6d6d6))
                elif theme == QtCharts.QChart.ChartThemeBlueCerulean:
                    set_colors(QColor(0x40434a), QColor(0xd6d6d6))
                elif theme == QtCharts.QChart.ChartThemeBrownSand:
                    set_colors(QColor(0x9e8965), QColor(0x404044))
                elif theme == QtCharts.QChart.ChartThemeBlueNcs:
                    set_colors(QColor(0x018bba), QColor(0x404044))
                elif theme == QtCharts.QChart.ChartThemeHighContrast:
                    set_colors(QColor(0xffab03), QColor(0x181818))
                elif theme == QtCharts.QChart.ChartThemeBlueIcy:
                    set_colors(QColor(0xcee7f0), QColor(0x404044))
                else:
                    set_colors(QColor(0xf0f0f0), QColor(0x404044))


        # Update antialiasing
        checked = self.ui.antialiasCheckBox.isChecked()
        for chart in self.charts:
            chart.setRenderHint(QPainter.Antialiasing, checked)

        # Update animation options
        idx = self.ui.animatedComboBox.currentIndex()
        options = self.ui.animatedComboBox.itemData(idx)

        if len(self.charts):
            chart = self.charts[0].chart()
            animation_options = chart.animationOptions()
            if animation_options != options:
                for chart_view in self.charts:
                    options_name = QtCharts.QChart.NoAnimation
                    if options == 0:
                        options_name = QtCharts.QChart.NoAnimation
                    elif options == 1:
                        options_name = QtCharts.QChart.GridAxisAnimations
                    elif options == 2:
                        options_name = QtCharts.QChart.SeriesAnimations
                    elif options == 3:
                        options_name = QtCharts.QChart.AllAnimations
                    chart_view.chart().setAnimationOptions(options_name)

        # Update legend alignment
        idx = self.ui.legendComboBox.currentIndex()
        alignment = self.ui.legendComboBox.itemData(idx)

        if not alignment:
            for chart_view in self.charts:
                chart_view.chart().legend().hide()
        else:
            for chart_view in self.charts:
                alignment_name = Qt.AlignTop
                if alignment == 32:
                    alignment_name = Qt.AlignTop
                elif alignment == 64:
                    alignment_name = Qt.AlignBottom
                elif alignment == 1:
                    alignment_name = Qt.AlignLeft
                elif alignment == 2:
                    alignment_name = Qt.AlignRight
                chart_view.chart().legend().setAlignment(alignment_name)
                chart_view.chart().legend().show()


if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = QMainWindow()
    widget = ThemeWidget(None)
    window.setCentralWidget(widget)
    available_geometry = app.desktop().availableGeometry(window)
    size = available_geometry.height() * 0.75
    window.setFixedSize(size, size * 0.8)
    window.show()
    sys.exit(app.exec_())

README.md

# Chart themes

To generated the file `ui_themewidget.py`, the following
command need to be executed:

`pyside6-uic themewidget.ui > ui_themewidget.py`

Also, if you modify the UI file, then you would need
to run the previous command again.

themewidget.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>ThemeWidgetForm</class>
 <widget class="QWidget" name="ThemeWidgetForm">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>900</width>
    <height>600</height>
   </rect>
  </property>
  <layout class="QGridLayout" name="gridLayout">
   <item row="0" column="0" colspan="3">
    <layout class="QHBoxLayout" name="horizontalLayout">
     <item>
      <widget class="QLabel" name="themeLabel">
       <property name="text">
        <string>Theme:</string>
       </property>
      </widget>
     </item>
     <item>
      <widget class="QComboBox" name="themeComboBox"/>
     </item>
     <item>
      <widget class="QLabel" name="animatedLabel">
       <property name="text">
        <string>Animation:</string>
       </property>
      </widget>
     </item>
     <item>
      <widget class="QComboBox" name="animatedComboBox"/>
     </item>
     <item>
      <widget class="QLabel" name="legendLabel">
       <property name="text">
        <string>Legend:</string>
       </property>
      </widget>
     </item>
     <item>
      <widget class="QComboBox" name="legendComboBox"/>
     </item>
     <item>
      <widget class="QCheckBox" name="antialiasCheckBox">
       <property name="text">
        <string>Anti-aliasing</string>
       </property>
       <property name="checked">
        <bool>false</bool>
       </property>
      </widget>
     </item>
     <item>
      <spacer name="horizontalSpacer">
       <property name="orientation">
        <enum>Qt::Horizontal</enum>
       </property>
       <property name="sizeHint" stdset="0">
        <size>
         <width>40</width>
         <height>20</height>
        </size>
       </property>
      </spacer>
     </item>
    </layout>
   </item>
  </layout>
 </widget>
 <resources/>
 <connections>
  <connection>
   <sender>themeComboBox</sender>
   <signal>currentIndexChanged(int)</signal>
   <receiver>ThemeWidgetForm</receiver>
   <slot>updateUI()</slot>
  </connection>
  <connection>
   <sender>antialiasCheckBox</sender>
   <signal>toggled(bool)</signal>
   <receiver>ThemeWidgetForm</receiver>
   <slot>updateUI()</slot>
  </connection>
  <connection>
   <sender>legendComboBox</sender>
   <signal>currentIndexChanged(int)</signal>
   <receiver>ThemeWidgetForm</receiver>
   <slot>updateUI()</slot>
  </connection>
  <connection>
   <sender>animatedComboBox</sender>
   <signal>currentIndexChanged(int)</signal>
   <receiver>ThemeWidgetForm</receiver>
   <slot>updateUI()</slot>
  </connection>
 </connections>
 <slots>
  <slot>updateUI()</slot>
 </slots>
</ui>