Bar Labels

This example extends the Simple Bar Chart (1) example by including bar labels on the bars, and decorating the bars with rounded corners and gradient shading.

Use Layer.setAggregateLabelStyle to include labels on top of the bars. There is an alternative method Layer.setDataLabelStyle for including the labels inside the bars.
Use BarLayer.setRoundedCorners to configure the bars to have rounded corners.
Use Layer.setBorderColor with Chart::barLighting to apply a gradient shading effect to the bars.

The following is the command line version of the code in "cppdemo/barlabel". 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 bar chart
    double data[] = {85, 156, 179, 211, 123, 189, 166};
    const int data_size = (int)(sizeof(data)/sizeof(*data));

    // The labels for the bar chart
    const char* labels[] = {"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};
    const int labels_size = (int)(sizeof(labels)/sizeof(*labels));

    // 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 500 x 300 pixels, with transparent background and
    // border and light grey (0xcccccc) horizontal grid lines
    c->setPlotArea(70, 20, 500, 300, Chart::Transparent, -1, Chart::Transparent, 0xcccccc);

    // 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", 12);
    c->yAxis()->setLabelStyle("Arial", 12);

    // Add a blue (0x6699bb) bar chart layer using the given data
    BarLayer* layer = c->addBarLayer(DoubleArray(data, data_size), 0x6699bb);

    // Use bar gradient lighting with the light intensity from 0.8 to 1.3
    layer->setBorderColor(Chart::Transparent, Chart::barLighting(0.8, 1.3));

    // Set rounded corners for bars
    layer->setRoundedCorners();

    // Display labela on top of bars using 12pt Arial font
    layer->setAggregateLabelStyle("Arial", 12);

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

    // 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", "Arial Bold", 14, 0x555555);

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

    //free up resources
    delete c;

    return 0;
}