Symbol Line Chart

This example demonstrates using symbols to represent data points, and putting data labels on top of the symbols.

Note that in this example, the chart title background is not a solid color but a 1 x 2 pixels pattern.

Set background color and 3D border for the chart using XYChart.XYChart.
Enable both vertical and horizontal grid lines using XYChart.setPlotArea.
Create a pattern color with a 1 x 2 pixel in-memory pattern using BaseChart.patternColor. Set it as the background color of the title box using Box.setBackground.
Enable symbols for the data points using DataSet.setDataSymbol.
Add labels on top of the symbols using Layer.setDataLabelFormat.

The following is the command line version of the code in "cppdemo/symbolline". The MFC version of the code is in "mfcdemo/mfcdemo". The Qt Widgets version of the code is in "qtdemo/qtdemo". The QML/Qt Quick version of the code is in "qmldemo/qmldemo".

#include "chartdir.h"

int main(int argc, char *argv[])
{
    // The data for the line chart
    double data0[] = {60.2, 51.7, 81.3, 48.6, 56.2, 68.9, 52.8};
    const int data0_size = (int)(sizeof(data0)/sizeof(*data0));
    double data1[] = {30.0, 32.7, 33.9, 29.5, 32.2, 28.4, 29.8};
    const int data1_size = (int)(sizeof(data1)/sizeof(*data1));
    const char* labels[] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
    const int labels_size = (int)(sizeof(labels)/sizeof(*labels));

    // Create a XYChart object of size 300 x 180 pixels, with a pale yellow (0xffffc0) background, a
    // black border, and 1 pixel 3D border effect.
    XYChart* c = new XYChart(300, 180, 0xffffc0, 0x000000, 1);

    // Set the plotarea at (45, 35) and of size 240 x 120 pixels, with white background. Turn on
    // both horizontal and vertical grid lines with light grey color (0xc0c0c0)
    c->setPlotArea(45, 35, 240, 120, 0xffffff, -1, -1, 0xc0c0c0, -1);

    // Add a legend box at (45, 12) (top of the chart) using horizontal layout and 8pt Arial font
    // Set the background and border color to Transparent.
    c->addLegend(45, 12, false, "", 8)->setBackground(Chart::Transparent);

    // Add a title to the chart using 9pt Arial Bold/white font. Use a 1 x 2 bitmap pattern as the
    // background.
    int pattern[] = {0x004000, 0x008000};
    c->addTitle("Server Load (Jun 01 - Jun 07)", "Arial Bold", 9, 0xffffff)->setBackground(
        c->patternColor(IntArray(pattern, 2), 2));

    // Set the y axis label format to nn%
    c->yAxis()->setLabelFormat("{value}%");

    // Set the labels on the x axis
    c->xAxis()->setLabels(StringArray(labels, labels_size));

    // Add a line layer to the chart
    LineLayer* layer = c->addLineLayer();

    // Add the first line. Plot the points with a 7 pixel square symbol
    layer->addDataSet(DoubleArray(data0, data0_size), 0xcf4040, "Peak")->setDataSymbol(
        Chart::SquareSymbol, 7);

    // Add the second line. Plot the points with a 9 pixel dismond symbol
    layer->addDataSet(DoubleArray(data1, data1_size), 0x40cf40, "Average")->setDataSymbol(
        Chart::DiamondSymbol, 9);

    // Enable data label on the data points. Set the label format to nn%.
    layer->setDataLabelFormat("{value|0}%");

    // Output the chart
    c->makeChart("symbolline.png");

    //free up resources
    delete c;

    return 0;
}