ChartDirector Ver 3.0 (C++ Edition)

Marks and Zones (2)




The chart in the example consists of three mark lines (one horizontal and two vertical) and one vertical zone. The mark lines are created using Axis.addMark. The zone is created using Axis.addZone.

By default, mark labels will be drawn as axis labels. In this example, the label of the red mark line is moved to the top center of the mark line using TextBox.setAlignment with TopCenter alignment.

Similarly, the labels for the brown mark lines are moved to the left and right sides of the mark lines, with the text rotated by 90 degrees. This is achieved by using TextBox.setAlignment with Left and Right alignments, and using TextBox.setFontAngle.

Source Code Listing

[The following project is available in "cppdemo/markzone2".]
#include "chartdir.h" int main(int argc, char *argv[]) { //The data for the chart double data[] = {50, 55, 47, 34, 42, 49, 63, 62, 73, 59, 56, 50, 64, 60, 67, 67, 58, 59, 73, 77, 84, 82, 80, 84, 89}; //The labels for the chart. Note the "-" means a minor tick. const char *labels[] = {"0\nJun 4", "-", "-", "3", "-", "-", "6", "-", "-", "9", "-", "-", "12", "-", "-", "15", "-", "-", "18", "-", "-", "21", "-", "-", "0\nJun 5"}; //Create a XYChart object of size 400 x 270 pixels XYChart *c = new XYChart(400, 270); //Set the plotarea at (80, 25) and of size 300 x 200 pixels. Use alternate //color background (0xe0e0e0) and (0xffffff). Set border and grid colors to //grey (0xc0c0c0). c->setPlotArea(50, 25, 300, 200, 0xe0e0e0, 0xffffff, 0xc0c0c0, 0xc0c0c0, 0xc0c0c0); //Add a title to the chart using 14 pts Times Bold Italic font c->addTitle("Server Monitor", "timesbi.ttf", 14); //Add a title to the y axis c->yAxis()->setTitle("Server Load (MBytes)"); //Set the y axis width to 2 pixels c->yAxis()->setWidth(2); //Set the labels on the x axis c->xAxis()->setLabels(StringArray(labels, sizeof(labels)/sizeof(*labels))); //Set the x axis width to 2 pixels c->xAxis()->setWidth(2); //Add a horizontal red (0x800080) mark line at y = 80 Mark *yMark = c->yAxis()->addMark(80, 0xff0000, "Critical Threshold Set Point"); //Set the mark line width to 2 pixels yMark->setLineWidth(2); //Put the mark label at the top center of the mark line yMark->setAlignment(TopCenter); //Add an orange (0xffcc66) zone from x = 18 to x = 20 c->xAxis()->addZone(18, 20, 0xffcc66); //Add a vertical brown (0x995500) mark line at x = 18 Mark *xMark1 = c->xAxis()->addMark(18, 0x995500, "Backup Start"); //Set the mark line width to 2 pixels xMark1->setLineWidth(2); //Put the mark label at the left of the mark line xMark1->setAlignment(Left); //Rotate the mark label by 90 degrees so it draws vertically xMark1->setFontAngle(90); //Add a vertical brown (0x995500) mark line at x = 20 Mark *xMark2 = c->xAxis()->addMark(20, 0x995500, "Backup End"); //Set the mark line width to 2 pixels xMark2->setLineWidth(2); //Put the mark label at the right of the mark line xMark2->setAlignment(Right); //Rotate the mark label by 90 degrees so it draws vertically xMark2->setFontAngle(90); //Add a green (0x00cc00) line layer with line width of 2 pixels c->addLineLayer(DoubleArray(data, sizeof(data)/sizeof(*data)), 0xcc00 )->setLineWidth(2); //output the chart c->makeChart("markzone2.png"); //free up resources delete c; return 0; }