ChartDirector 6.0 (C++ Edition)

Stacked Bar Chart




This example demonstrates creating a stacked bar chart, completed with bar labels and legend box.

The key features demonstrated in this example are:

For bar labels, Layer.setDataLabelStyle and Layer.setAggregateLabelStyle control the styles (fonts, colors, backgrounds, etc), while Layer.setDataLabelFormat and Layer.setAggregateLabelFormat control the formats (the label text, number of decimal points, etc). You can also add custom labels to the bars using Layer.addCustomDataLabel, Layer.addCustomAggregateLabel and Layer.addCustomGroupLabel.

Source Code Listing

[The following code is available in "cppdemo/stackedbar". A MFC version of the code is available in "mfcdemo/mfcdemo" (Windows edition only). A QT version of the code is available in "qtdemo/qtdemo".]
#include "chartdir.h"

int main(int argc, char *argv[])
{
    // The data for the bar chart
    double data0[] = {100, 115, 165, 107, 67};
    double data1[] = {85, 106, 129, 161, 123};
    double data2[] = {67, 87, 86, 167, 157};

    // The labels for the bar chart
    const char *labels[] = {"Mon", "Tue", "Wed", "Thu", "Fri"};

    // Create a XYChart object of size 600 x 360 pixels
    XYChart *c = new XYChart(600, 360);

    // Set the plotarea at (70, 20) and of size 400 x 300 pixels, with transparent background and
    // border and light grey (0xcccccc) horizontal grid lines
    c->setPlotArea(70, 20, 400, 300, Chart::Transparent, -1, Chart::Transparent, 0xcccccc);

    // Add a legend box at (480, 20) using vertical layout and 12pt Arial font. Set background and
    // border to transparent and key icon border to the same as the fill color.
    LegendBox *b = c->addLegend(480, 20, true, "arial.ttf", 12);
    b->setBackground(Chart::Transparent, Chart::Transparent);
    b->setKeyBorder(Chart::SameAsMainColor);

    // Set the x and y axis stems to transparent and the label font to 12pt Arial
    c->xAxis()->setColors(Chart::Transparent);
    c->yAxis()->setColors(Chart::Transparent);
    c->xAxis()->setLabelStyle("arial.ttf", 12);
    c->yAxis()->setLabelStyle("arial.ttf", 12);

    // Add a stacked bar layer
    BarLayer *layer = c->addBarLayer(Chart::Stack);

    // Add the three data sets to the bar layer
    layer->addDataSet(DoubleArray(data0, (int)(sizeof(data0) / sizeof(data0[0]))), 0xaaccee,
        "Server # 1");
    layer->addDataSet(DoubleArray(data1, (int)(sizeof(data1) / sizeof(data1[0]))), 0xbbdd88,
        "Server # 2");
    layer->addDataSet(DoubleArray(data2, (int)(sizeof(data2) / sizeof(data2[0]))), 0xeeaa66,
        "Server # 3");

    // Set the bar border to transparent
    layer->setBorderColor(Chart::Transparent);

    // Enable labelling for the entire bar and use 12pt Arial font
    layer->setAggregateLabelStyle("arial.ttf", 12);

    // Enable labelling for the bar segments and use 12pt Arial font with center alignment
    layer->setDataLabelStyle("arial.ttf", 10)->setAlignment(Chart::Center);

    // For a vertical stacked bar with positive data, the first data set is at the bottom. For the
    // legend box, by default, the first entry at the top. We can reverse the legend order to make
    // the legend box consistent with the stacked bar.
    layer->setLegendOrder(Chart::ReverseLegend);

    // Set the labels on the x axis.
    c->xAxis()->setLabels(StringArray(labels, (int)(sizeof(labels) / sizeof(labels[0]))));

    // For the automatic y-axis labels, set the minimum spacing to 40 pixels.
    c->yAxis()->setTickDensity(40);

    // Add a title to the y axis using dark grey (0x555555) 14pt Arial Bold font
    c->yAxis()->setTitle("Y-Axis Title Placeholder", "arialbd.ttf", 14, 0x555555);

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

    //free up resources
    delete c;
    return 0;
}