main.cpp Example File

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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 Data Visualization module of the Qt Toolkit.
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  ** the Free Software Foundation and appearing in the file LICENSE.GPL3
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  #include <QtDataVisualization/q3dbars.h>
  #include <QtDataVisualization/qcategory3daxis.h>
  #include <QtDataVisualization/qitemmodelbardataproxy.h>
  #include <QtDataVisualization/qvalue3daxis.h>
  #include <QtDataVisualization/q3dscene.h>
  #include <QtDataVisualization/q3dcamera.h>
  #include <QtDataVisualization/qbar3dseries.h>
  #include <QtDataVisualization/q3dtheme.h>

  #include <QtWidgets/QApplication>
  #include <QtWidgets/QVBoxLayout>
  #include <QtWidgets/QTableWidget>
  #include <QtGui/QScreen>
  #include <QtCore/QTimer>
  #include <QtGui/QFont>
  #include <QtCore/QDebug>
  #include <QtWidgets/QHeaderView>
  #include <QtWidgets/QMessageBox>

  #define USE_STATIC_DATA

  using namespace QtDataVisualization;

  class GraphDataGenerator : public QObject
  {
  public:
      explicit GraphDataGenerator(Q3DBars *bargraph, QTableWidget *tableWidget);
      ~GraphDataGenerator();

      void setupModel();
      void addRow();
      void changeStyle();
      void changePresetCamera();
      void changeTheme();
      void start();
      void selectFromTable(const QPoint &selection);
      void selectedFromTable(int currentRow, int currentColumn, int previousRow, int previousColumn);
      void fixTableSize();

  private:
      Q3DBars *m_graph;
      QTimer *m_dataTimer;
      QTimer *m_styleTimer;
      QTimer *m_presetTimer;
      QTimer *m_themeTimer;
      int m_columnCount;
      int m_rowCount;
      QTableWidget *m_tableWidget; // not owned
  };

  GraphDataGenerator::GraphDataGenerator(Q3DBars *bargraph, QTableWidget *tableWidget)
      : m_graph(bargraph),
        m_dataTimer(0),
        m_styleTimer(0),
        m_presetTimer(0),
        m_themeTimer(0),
        m_columnCount(100),
        m_rowCount(50),
        m_tableWidget(tableWidget)
  {
      // Set up bar specifications; make the bars as wide as they are deep,
      // and add a small space between them
      m_graph->setBarThickness(1.0f);
      m_graph->setBarSpacing(QSizeF(0.2, 0.2));

  #ifndef USE_STATIC_DATA
      // Set up sample space; make it as deep as it's wide
      m_graph->rowAxis()->setRange(0, m_rowCount);
      m_graph->columnAxis()->setRange(0, m_columnCount);
      m_tableWidget->setColumnCount(m_columnCount);

      // Set selection mode to full
      m_graph->setSelectionMode(QAbstract3DGraph::SelectionItemRowAndColumn);

      // Hide axis labels by explicitly setting one empty string as label list
      m_graph->rowAxis()->setLabels(QStringList(QString()));
      m_graph->columnAxis()->setLabels(QStringList(QString()));

      m_graph->seriesList().at(0)->setItemLabelFormat(QStringLiteral("@valueLabel"));
  #else
      // Set selection mode to slice row
      m_graph->setSelectionMode(QAbstract3DGraph::SelectionItemAndRow | QAbstract3DGraph::SelectionSlice);

  #endif

      // Set theme
      m_graph->activeTheme()->setType(Q3DTheme::ThemeDigia);

      // Set font
      m_graph->activeTheme()->setFont(QFont("Impact", 20));

      // Set preset camera position
      m_graph->scene()->activeCamera()->setCameraPreset(Q3DCamera::CameraPresetFront);
  }

  GraphDataGenerator::~GraphDataGenerator()
  {
      if (m_dataTimer) {
          m_dataTimer->stop();
          delete m_dataTimer;
      }
      delete m_graph;
  }

  void GraphDataGenerator::start()
  {
  #ifndef USE_STATIC_DATA
      m_dataTimer = new QTimer();
      m_dataTimer->setTimerType(Qt::CoarseTimer);
      QObject::connect(m_dataTimer, &QTimer::timeout, this, &GraphDataGenerator::addRow);
      m_dataTimer->start(0);
      m_tableWidget->setFixedWidth(m_graph->width());
  #else
      setupModel();

      // Table needs to be shown before the size of its headers can be accurately obtained,
      // so we postpone it a bit
      m_dataTimer = new QTimer();
      m_dataTimer->setSingleShot(true);
      QObject::connect(m_dataTimer, &QTimer::timeout, this, &GraphDataGenerator::fixTableSize);
      m_dataTimer->start(0);
  #endif
  }

  void GraphDataGenerator::setupModel()
  {
      // Set up row and column names
      QStringList days;
      days << "Monday" << "Tuesday" << "Wednesday" << "Thursday" << "Friday" << "Saturday" << "Sunday";
      QStringList weeks;
      weeks << "week 1" << "week 2" << "week 3" << "week 4" << "week 5";

      // Set up data         Mon  Tue  Wed  Thu  Fri  Sat  Sun
      float hours[5][7] = {{2.0f, 1.0f, 3.0f, 0.2f, 1.0f, 5.0f, 10.0f},     // week 1
                           {0.5f, 1.0f, 3.0f, 1.0f, 2.0f, 2.0f, 3.0f},      // week 2
                           {1.0f, 1.0f, 2.0f, 1.0f, 4.0f, 4.0f, 4.0f},      // week 3
                           {0.0f, 1.0f, 0.0f, 0.0f, 2.0f, 2.0f, 0.3f},      // week 4
                           {3.0f, 3.0f, 6.0f, 2.0f, 2.0f, 1.0f, 1.0f}};     // week 5

      // Add labels
      m_graph->rowAxis()->setTitle("Week of year");
      m_graph->rowAxis()->setTitleVisible(true);
      m_graph->columnAxis()->setTitle("Day of week");
      m_graph->columnAxis()->setTitleVisible(true);
      m_graph->valueAxis()->setTitle("Hours spent on the Internet");
      m_graph->valueAxis()->setTitleVisible(true);
      m_graph->valueAxis()->setLabelFormat("%.1f h");

      m_tableWidget->setRowCount(5);
      m_tableWidget->setColumnCount(7);
      m_tableWidget->setHorizontalHeaderLabels(days);
      m_tableWidget->setVerticalHeaderLabels(weeks);
      m_tableWidget->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
      m_tableWidget->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
      m_tableWidget->setCurrentCell(-1, -1);
      m_tableWidget->setSelectionMode(QAbstractItemView::SingleSelection);

      for (int week = 0; week < weeks.size(); week++) {
          for (int day = 0; day < days.size(); day++) {
              QModelIndex index = m_tableWidget->model()->index(week, day);
              m_tableWidget->model()->setData(index, hours[week][day]);
          }
      }
  }

  void GraphDataGenerator::addRow()
  {
      m_tableWidget->model()->insertRow(0);
      if (m_tableWidget->model()->rowCount() > m_rowCount)
          m_tableWidget->model()->removeRow(m_rowCount);
      for (int i = 0; i < m_columnCount; i++) {
          QModelIndex index = m_tableWidget->model()->index(0, i);
          m_tableWidget->model()->setData(index,
              ((float)i / (float)m_columnCount) / 2.0f + (float)(rand() % 30) / 100.0f);
      }
      m_tableWidget->resizeColumnsToContents();
  }

  void GraphDataGenerator::selectFromTable(const QPoint &selection)
  {
      m_tableWidget->setFocus();
      m_tableWidget->setCurrentCell(selection.x(), selection.y());
  }

  void GraphDataGenerator::selectedFromTable(int currentRow, int currentColumn,
                                             int previousRow, int previousColumn)
  {
      Q_UNUSED(previousRow)
      Q_UNUSED(previousColumn)
      m_graph->seriesList().at(0)->setSelectedBar(QPoint(currentRow, currentColumn));
  }

  void GraphDataGenerator::fixTableSize()
  {
      int width = m_tableWidget->horizontalHeader()->length();
      width += m_tableWidget->verticalHeader()->width();
      m_tableWidget->setFixedWidth(width + 2);
      int height = m_tableWidget->verticalHeader()->length();
      height += m_tableWidget->horizontalHeader()->height();
      m_tableWidget->setFixedHeight(height + 2);
  }

  int main(int argc, char **argv)
  {
      QApplication app(argc, argv);
      Q3DBars *graph = new Q3DBars();
      QWidget *container = QWidget::createWindowContainer(graph);

      if (!graph->hasContext()) {
          QMessageBox msgBox;
          msgBox.setText("Couldn't initialize the OpenGL context.");
          msgBox.exec();
          return -1;
      }

      QSize screenSize = graph->screen()->size();
      container->setMinimumSize(QSize(screenSize.width() / 2, screenSize.height() / 2));
      container->setMaximumSize(screenSize);
      container->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
      container->setFocusPolicy(Qt::StrongFocus);

      QWidget widget;
      QVBoxLayout *layout = new QVBoxLayout(&widget);
      QTableWidget *tableWidget = new QTableWidget(&widget);
      layout->addWidget(container, 1);
      layout->addWidget(tableWidget, 1, Qt::AlignHCenter);

      tableWidget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
      tableWidget->setAlternatingRowColors(true);
      widget.setWindowTitle(QStringLiteral("Hours spent on the Internet"));

      // Since we are dealing with QTableWidget, the model will already have data sorted properly
      // into rows and columns, so we simply set useModelCategories property to true to utilize this.
      QItemModelBarDataProxy *proxy = new QItemModelBarDataProxy(tableWidget->model());
      proxy->setUseModelCategories(true);
      QBar3DSeries *series = new QBar3DSeries(proxy);
      series->setMesh(QAbstract3DSeries::MeshPyramid);
      graph->addSeries(series);

      GraphDataGenerator generator(graph, tableWidget);
      QObject::connect(series, &QBar3DSeries::selectedBarChanged, &generator,
                       &GraphDataGenerator::selectFromTable);
      QObject::connect(tableWidget, &QTableWidget::currentCellChanged, &generator,
                       &GraphDataGenerator::selectedFromTable);

      widget.show();
      generator.start();
      return app.exec();
  }