widget.cpp Example File

nesteddonuts/widget.cpp
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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);
 }