rainfallgraph.cpp Example File

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  #include "rainfallgraph.h"
  #include <QtDataVisualization/qcategory3daxis.h>
  #include <QtDataVisualization/qvalue3daxis.h>
  #include <QtDataVisualization/q3dscene.h>
  #include <QtDataVisualization/q3dcamera.h>
  #include <QtDataVisualization/qbar3dseries.h>
  #include <QtDataVisualization/q3dtheme.h>
  #include <QtGui/QGuiApplication>
  #include <QtGui/QFont>
  #include <QtCore/QDebug>
  #include <QtCore/QTextStream>
  #include <QtCore/QFile>

  using namespace QtDataVisualization;

  RainfallGraph::RainfallGraph(Q3DBars *rainfall)
      : m_graph(rainfall)
  {
      // In data file the months are in numeric format, so create custom list
      for (int i = 1; i <= 12; i++)
          m_numericMonths << QString::number(i);

      m_columnCount = m_numericMonths.size();

      m_proxy = new VariantBarDataProxy;
      QBar3DSeries *series = new QBar3DSeries(m_proxy);
      m_graph->addSeries(series);

      updateYearsList(2000, 2012);

      // Set up bar specifications; make the bars as wide as they are deep,
      // and add a small space between the bars
      m_graph->setBarThickness(1.0f);
      m_graph->setBarSpacing(QSizeF(1.1, 1.1));

      // Set axis labels and titles
      QStringList months;
      months << "January" << "February" << "March" << "April" << "May" << "June" << "July" << "August" << "September" << "October" << "November" << "December";
      m_graph->rowAxis()->setTitle("Year");
      m_graph->columnAxis()->setTitle("Month");
      m_graph->valueAxis()->setTitle("rainfall");
      m_graph->valueAxis()->setLabelFormat("%d mm");
      m_graph->valueAxis()->setSegmentCount(5);
      m_graph->rowAxis()->setLabels(m_years);
      m_graph->columnAxis()->setLabels(months);

      // Set bar type to cylinder
      series->setMesh(QAbstract3DSeries::MeshCylinder);

      // Set shadows to medium
      m_graph->setShadowQuality(QAbstract3DGraph::ShadowQualityMedium);

      // Set selection mode to bar and column
      m_graph->setSelectionMode(QAbstract3DGraph::SelectionItemAndColumn | QAbstract3DGraph::SelectionSlice);

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

      // Override font in theme
      m_graph->activeTheme()->setFont(QFont("Century Gothic", 30));

      // Override label background for theme
      m_graph->activeTheme()->setLabelBackgroundEnabled(false);

      // Set camera position and zoom
      m_graph->scene()->activeCamera()->setCameraPreset(Q3DCamera::CameraPresetIsometricRightHigh);

      // Set window title
      m_graph->setTitle(QStringLiteral("Monthly rainfall in Northern Finland"));

      // Set reflections on
      m_graph->setReflection(true);
  }

  RainfallGraph::~RainfallGraph()
  {
      delete m_mapping;
      delete m_dataSet;
      delete m_graph;
  }

  void RainfallGraph::start()
  {
      addDataSet();
  }

  void RainfallGraph::updateYearsList(int start, int end)
  {
      m_years.clear();
      for (int i = start; i <= end; i++)
          m_years << QString::number(i);

      m_rowCount = m_years.size();
  }

  void RainfallGraph::addDataSet()
  {
      // Create a new variant data set and data item list
      m_dataSet =  new VariantDataSet;
      VariantDataItemList *itemList = new VariantDataItemList;

      // Read data from a data file into the data item list
      QTextStream stream;
      QFile dataFile(":/data/raindata.txt");
      if (dataFile.open(QIODevice::ReadOnly | QIODevice::Text)) {
          stream.setDevice(&dataFile);
          while (!stream.atEnd()) {
              QString line = stream.readLine();
              if (line.startsWith("#")) // Ignore comments
                  continue;
              QStringList strList = line.split(",", QString::SkipEmptyParts);
              // Each line has three data items: Year, month, and rainfall value
              if (strList.size() < 3) {
                  qWarning() << "Invalid row read from data:" << line;
                  continue;
              }
              // Store year and month as strings, and rainfall value as double
              // into a variant data item and add the item to the item list.
              VariantDataItem *newItem = new VariantDataItem;
              for (int i = 0; i < 2; i++)
                  newItem->append(strList.at(i).trimmed());
              newItem->append(strList.at(2).trimmed().toDouble());
              itemList->append(newItem);
          }
      } else {
          qWarning() << "Unable to open data file:" << dataFile.fileName();
      }

      // Add items to the data set and set it to the proxy
      m_dataSet->addItems(itemList);
      m_proxy->setDataSet(m_dataSet);

      // Create new mapping for the data and set it to the proxy
      m_mapping =  new VariantBarDataMapping(0, 1, 2, m_years, m_numericMonths);
      m_proxy->setMapping(m_mapping);
  }