widget.cpp Example File | Qt Charts 5.12.8

- Qt 5.12
- Qt Charts
- Nested Donuts Example
- widget.cpp Example File
- Qt Charts | Commercial or GPLv3

# widget.cpp Example File

nesteddonuts/widget.cpp

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     ** Copyright (C) 2016 The Qt Company Ltd.
     ** Contact: https://www.qt.io/licensing/
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     ** This file is part of the Qt Charts module of the Qt Toolkit.
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     #include "widget.h"
     #include <QtCharts/QChartView>
     #include <QtCharts/QChart>
     #include <QtCharts/QLegend>
     #include <QtCharts/QPieSeries>
     #include <QtCharts/QPieSlice>
     #include <QtCore/QRandomGenerator>
     #include <QtWidgets/QGridLayout>
     #include <QtCore/QTimer>

     QT_CHARTS_USE_NAMESPACE

     Widget::Widget(QWidget *parent)
         : QWidget(parent)
     {
         setMinimumSize(800, 600);

         QChartView *chartView = new QChartView;
         chartView->setRenderHint(QPainter::Antialiasing);
         QChart *chart = chartView->chart();
         chart->legend()->setVisible(false);
         chart->setTitle("Nested donuts demo");
         chart->setAnimationOptions(QChart::AllAnimations);

         qreal minSize = 0.1;
         qreal maxSize = 0.9;
         int donutCount = 5;

         for (int i = 0; i < donutCount; i++) {
             QPieSeries *donut = new QPieSeries;
             int sliceCount =  3 + QRandomGenerator::global()->bounded(3);
             for (int j = 0; j < sliceCount; j++) {
                 qreal value = 100 + QRandomGenerator::global()->bounded(100);
                 QPieSlice *slice = new QPieSlice(QString("%1").arg(value), value);
                 slice->setLabelVisible(true);
                 slice->setLabelColor(Qt::white);
                 slice->setLabelPosition(QPieSlice::LabelInsideTangential);
                 connect(slice, &QPieSlice::hovered, this, &Widget::explodeSlice);
                 donut->append(slice);
                 donut->setHoleSize(minSize + i * (maxSize - minSize) / donutCount);
                 donut->setPieSize(minSize + (i + 1) * (maxSize - minSize) / donutCount);
             }
             m_donuts.append(donut);
             chartView->chart()->addSeries(donut);
         }

         // create main layout
         QGridLayout *mainLayout = new QGridLayout;
         mainLayout->addWidget(chartView, 1, 1);
         setLayout(mainLayout);

         updateTimer = new QTimer(this);
         connect(updateTimer, &QTimer::timeout, this, &Widget::updateRotation);
         updateTimer->start(1250);
     }

     Widget::~Widget()
     {

     }

     void Widget::updateRotation()
     {
         for (int i = 0; i < m_donuts.count(); i++) {
             QPieSeries *donut = m_donuts.at(i);
             qreal phaseShift =  -50 + QRandomGenerator::global()->bounded(100);
             donut->setPieStartAngle(donut->pieStartAngle() + phaseShift);
             donut->setPieEndAngle(donut->pieEndAngle() + phaseShift);
         }
     }

     void Widget::explodeSlice(bool exploded)
     {
         QPieSlice *slice = qobject_cast<QPieSlice *>(sender());
         if (exploded) {
             updateTimer->stop();
             qreal sliceStartAngle = slice->startAngle();
             qreal sliceEndAngle = slice->startAngle() + slice->angleSpan();

             QPieSeries *donut = slice->series();
             qreal seriesIndex = m_donuts.indexOf(donut);
             for (int i = seriesIndex + 1; i < m_donuts.count(); i++) {
                 m_donuts.at(i)->setPieStartAngle(sliceEndAngle);
                 m_donuts.at(i)->setPieEndAngle(360 + sliceStartAngle);
             }
         } else {
             for (int i = 0; i < m_donuts.count(); i++) {
                 m_donuts.at(i)->setPieStartAngle(0);
                 m_donuts.at(i)->setPieEndAngle(360);
             }
             updateTimer->start();
         }
         slice->setExploded(exploded);
     }