ChartDirector Ver 3.0 (C++ Edition)

Custom Scatter Labels




This example demonstrates adding custom labels to data points.

Source Code Listing

[The following project is available in "cppdemo/scatterlabels".]
#include "chartdir.h" int main(int argc, char *argv[]) { //The XY points for the scatter chart double dataX[] = {150, 400, 300, 1500, 800}; double dataY[] = {0.6, 8, 5.4, 2, 4}; //The labels for the points const char *labels[] = {"Nano\n100", "SpeedTron\n200 Lite", "SpeedTron\n200", "Marathon\nExtra", "Marathon\n2000"}; //Create a XYChart object of size 450 x 400 pixels XYChart *c = new XYChart(450, 400); //Set the plotarea at (55, 40) and of size 350 x 300 pixels, with a light //grey border (0xc0c0c0). Turn on both horizontal and vertical grid lines //with light grey color (0xc0c0c0) c->setPlotArea(55, 40, 350, 300, 0xffffff, -1, 0xc0c0c0, 0xc0c0c0, -1); //Add a title to the chart using 18 pts Times Bold Itatic font. c->addTitle("Product Comparison Chart", "timesbi.ttf", 18); //Add a title to the y axis using 12 pts Arial Bold Italic font c->yAxis()->setTitle("Capacity (tons)", "arialbi.ttf", 12); //Add a title to the x axis using 12 pts Arial Bold Italic font c->xAxis()->setTitle("Range (miles)", "arialbi.ttf", 12); //Set the axes line width to 3 pixels c->xAxis()->setWidth(3); c->yAxis()->setWidth(3); //Add the data as a scatter chart layer, using a 15 pixel circle as the //symbol ScatterLayer *layer = c->addScatterLayer(DoubleArray(dataX, sizeof(dataX)/sizeof(*dataX)), DoubleArray(dataY, sizeof(dataY)/sizeof(*dataY)), "Server BBB", CircleSymbol, 15, 0xff3333, 0xff3333); //Add labels to the chart as an extra field layer->addExtraField(StringArray(labels, sizeof(labels)/sizeof(*labels))); //Set the data label format to display the extra field layer->setDataLabelFormat("{field0}"); //Use 8pts Arial Bold to display the labels TextBox *textbox = layer->setDataLabelStyle("arialbd.ttf", 8); //Set the background to purple with a 1 pixel 3D border textbox->setBackground(0xcc99ff, Transparent, 1); //Put the text box 4 pixels to the right of the data point textbox->setAlignment(Left); textbox->setPos(4, 0); //output the chart c->makeChart("scatterlabels.png"); //free up resources delete c; return 0; }