Qt 5.9 | Qt Charts | Qt Charts Examples | Custom Chart Example

Qt 5.9.9 Reference Documentation

# Custom Chart Example

## Running the Example

To run the example from Qt Creator, open the Welcome mode and select the example from Examples. For more information, visit Building and Running an Example.

## Customizing Charts

We begin by creating a simple line series and a chart object.

          QLineSeries *series = new QLineSeries();
          *series << QPointF(0, 6) << QPointF(9, 4) << QPointF(15, 20) << QPointF(25, 12) << QPointF(29, 26);
          QChart *chart = new QChart();
          chart->legend()->hide();
          chart->addSeries(series);

First we customize the series and the chart's title and background.

          // Customize series
          QPen pen(QRgb(0xfdb157));
          pen.setWidth(5);
          series->setPen(pen);

          // Customize chart title
          QFont font;
          font.setPixelSize(18);
          chart->setTitleFont(font);
          chart->setTitleBrush(QBrush(Qt::white));
          chart->setTitle("Customchart example");

          // Customize chart background
          QLinearGradient backgroundGradient;
          backgroundGradient.setStart(QPointF(0, 0));
          backgroundGradient.setFinalStop(QPointF(0, 1));
          backgroundGradient.setColorAt(0.0, QRgb(0xd2d0d1));
          backgroundGradient.setColorAt(1.0, QRgb(0x4c4547));
          backgroundGradient.setCoordinateMode(QGradient::ObjectBoundingMode);
          chart->setBackgroundBrush(backgroundGradient);

          // Customize plot area background
          QLinearGradient plotAreaGradient;
          plotAreaGradient.setStart(QPointF(0, 1));
          plotAreaGradient.setFinalStop(QPointF(1, 0));
          plotAreaGradient.setColorAt(0.0, QRgb(0x555555));
          plotAreaGradient.setColorAt(1.0, QRgb(0x55aa55));
          plotAreaGradient.setCoordinateMode(QGradient::ObjectBoundingMode);
          chart->setPlotAreaBackgroundBrush(plotAreaGradient);
          chart->setPlotAreaBackgroundVisible(true);

Then we customize the axes.

          QCategoryAxis *axisX = new QCategoryAxis();
          QCategoryAxis *axisY = new QCategoryAxis();

          // Customize axis label font
          QFont labelsFont;
          labelsFont.setPixelSize(12);
          axisX->setLabelsFont(labelsFont);
          axisY->setLabelsFont(labelsFont);

          // Customize axis colors
          QPen axisPen(QRgb(0xd18952));
          axisPen.setWidth(2);
          axisX->setLinePen(axisPen);
          axisY->setLinePen(axisPen);

          // Customize axis label colors
          QBrush axisBrush(Qt::white);
          axisX->setLabelsBrush(axisBrush);
          axisY->setLabelsBrush(axisBrush);

          // Customize grid lines and shades
          axisX->setGridLineVisible(false);
          axisY->setGridLineVisible(false);
          axisY->setShadesPen(Qt::NoPen);
          axisY->setShadesBrush(QBrush(QColor(0x99, 0xcc, 0xcc, 0x55)));
          axisY->setShadesVisible(true);

Then the axis label values and ranges. Once the axes are ready, we set them to be used by the chart.

          axisX->append("low", 10);
          axisX->append("optimal", 20);
          axisX->append("high", 30);
          axisX->setRange(0, 30);

          axisY->append("slow", 10);
          axisY->append("med", 20);
          axisY->append("fast", 30);
          axisY->setRange(0, 30);

          chart->setAxisX(axisX, series);
          chart->setAxisY(axisY, series);

Finally, we create a view containing the chart.

          QChartView *chartView = new QChartView(chart);
          chartView->setRenderHint(QPainter::Antialiasing);

Now we are ready to show the chart on a main window.

          QMainWindow window;
          window.setCentralWidget(chartView);
          window.resize(400, 300);
          window.show();

Files:

- customchart/main.cpp
- customchart/customchart.pro