ChartDirector 6.1 (Java Edition)

Track Line with Data Labels (Windows)

NOTE: This section describes Track Line with Data Labels for Windows applications only. For web applications, please refer to Track Line with Data Labels (Web).

This sample program demonstrates a track cursor programmed with the following features:

The code first draws the chart. Then in the TrackCursorListener.mouseMovedPlotArea event handler, the track cursor is drawn to reflect the mouse position. The track cursor is configured to automatically hide itself when the mouse leaves the plot area.

The trackLineLabel method is the routine that draws the track cursor. Its key elements are:

Source Code Listing

[Java Version] javademo/
import ChartDirector.*;
import java.util.*;
import javax.swing.*;
import java.awt.event.*;

public class tracklabel implements DemoModule
    // The main method to allow this demo to run as a standalone program.
    public static void main(String args[]) 
        tracklabel demo = new tracklabel();

    // Display the window
    private void display() 
        // Use a JDialog as the window
           JDialog d = new JDialog((java.awt.Frame)null, toString(), true);
        // Create the ChartViewer and add it to the JDialog
        ChartViewer viewer = new ChartViewer();

        // Add a movedMovedPlotArea event listener to draw the track cursor
        viewer.addTrackCursorListener(new TrackCursorAdapter() {
            public void mouseMovedPlotArea(MouseEvent e) {
        // Draw the chart

        // Layout and display the JDialog
    // Main code for creating charts
    public void drawChart(ChartViewer viewer)
        // Data for the chart as 3 random data series
        RanSeries r = new RanSeries(127);
        double[] data0 = r.getSeries(100, 100, -15, 15);
        double[] data1 = r.getSeries(100, 150, -15, 15);
        double[] data2 = r.getSeries(100, 200, -15, 15);
        Date[] timeStamps = r.getDateSeries(100, new GregorianCalendar(2011, 0, 1).getTime(), 86400);

        // Create a XYChart object of size 640 x 400 pixels
        XYChart c = new XYChart(640, 400);

        // Add a title to the chart using 18pt Times New Roman Bold Italic font
        c.addTitle("    Product Line Global Revenue", "Times New Roman Bold Italic", 18);

        // Set the plotarea at (50, 55) with width 70 pixels less than chart width, and height 90 pixels less
        // than chart height. Use a vertical gradient from light blue (f0f6ff) to sky blue (a0c0ff) as
        // background. Set border to transparent and grid lines to white (ffffff).
        c.setPlotArea(50, 55, c.getWidth() - 70, c.getHeight() - 90, c.linearGradientColor(0, 55, 0,
            c.getHeight() - 35, 0xf0f6ff, 0xa0c0ff), -1, Chart.Transparent, 0xffffff, 0xffffff);

        // Add a legend box at (50, 25) using horizontal layout. Use 10pt Arial Bold as font. Set the
        // background and border color to Transparent.
        c.addLegend(50, 25, false, "Arial Bold", 10).setBackground(Chart.Transparent);

        // Set axis label style to 8pt Arial Bold
        c.xAxis().setLabelStyle("Arial Bold", 8);
        c.yAxis().setLabelStyle("Arial Bold", 8);

        // Set the axis stem to transparent

        // Configure x-axis label format
        c.xAxis().setMultiFormat(Chart.StartOfYearFilter(), "{value|mm/yyyy} ", Chart.StartOfMonthFilter(),

        // Add axis title using 10pt Arial Bold Italic font
        c.yAxis().setTitle("USD millions", "Arial Bold Italic", 10);

        // Add a line layer to the chart using a line width of 2 pixels.
        LineLayer layer = c.addLineLayer2();

        // Add 3 data series to the line layer
        layer.addDataSet(data0, 0xff3333, "Alpha");
        layer.addDataSet(data1, 0x008800, "Beta");
        layer.addDataSet(data2, 0x3333cc, "Gamma");

        // Assign the chart to the ChartViewer

    // Draw track cursor when mouse is moving over plotarea
    private void chartViewer1_MouseMovedPlotArea(MouseEvent e)
        ChartViewer viewer = (ChartViewer)e.getSource();
        trackLineLabel((XYChart)viewer.getChart(), viewer.getPlotAreaMouseX());

        // Hide the track cursor when the mouse leaves the plot area

    // Draw track line with data labels
    private void trackLineLabel(XYChart c, int mouseX)
        // Clear the current dynamic layer and get the DrawArea object to draw on it.
        DrawArea d = c.initDynamicLayer();

        // The plot area object
        PlotArea plotArea = c.getPlotArea();

        // Get the data x-value that is nearest to the mouse, and find its pixel coordinate.
        double xValue = c.getNearestXValue(mouseX);
        int xCoor = c.getXCoor(xValue);

        // Draw a vertical track line at the x-position
        d.vline(plotArea.getTopY(), plotArea.getBottomY(), xCoor, d.dashLineColor(0x000000, 0x0101));

        // Draw a label on the x-axis to show the track line position.
        String xlabel = "<*font,bgColor=000000*> " + c.xAxis().getFormattedLabel(xValue, "mmm dd, yyyy") +
            " <*/font*>";
        TTFText t = d.text(xlabel, "Arial Bold", 8);

        // Restrict the x-pixel position of the label to make sure it stays inside the chart image.
        int xLabelPos = Math.max(0, Math.min(xCoor - t.getWidth() / 2, c.getWidth() - t.getWidth()));
        t.draw(xLabelPos, plotArea.getBottomY() + 6, 0xffffff);

        // Iterate through all layers to draw the data labels
        for (int i = 0; i < c.getLayerCount(); ++i) {
            Layer layer = c.getLayerByZ(i);

            // The data array index of the x-value
            int xIndex = layer.getXIndexOf(xValue);

            // Iterate through all the data sets in the layer
            for (int j = 0; j < layer.getDataSetCount(); ++j) {
                ChartDirector.DataSet dataSet = layer.getDataSetByZ(j);

                // Get the color and position of the data label
                int color = dataSet.getDataColor();
                int yCoor = c.getYCoor(dataSet.getPosition(xIndex), dataSet.getUseYAxis());

                // Draw a track dot with a label next to it for visible data points in the plot area
                if ((yCoor >= plotArea.getTopY()) && (yCoor <= plotArea.getBottomY()) && (color !=
                    Chart.Transparent)) {

          , yCoor, 4, 4, color, color);

                    String label = "<*font,bgColor=" + Integer.toHexString(color) + "*> " + c.formatValue(
                        dataSet.getValue(xIndex), "{value|P4}") + " <*/font*>";
                    t = d.text(label, "Arial Bold", 8);

                    // Draw the label on the right side of the dot if the mouse is on the left side the chart,
                    // and vice versa. This ensures the label will not go outside the chart image.
                    if (xCoor <= (plotArea.getLeftX() + plotArea.getRightX()) / 2) {
                        t.draw(xCoor + 5, yCoor, 0xffffff, Chart.Left);
                    } else {
                        t.draw(xCoor - 5, yCoor, 0xffffff, Chart.Right);
    // Implementation of the DemoModule interface to allow this demo to run inside the 
    // ChartDirectorDemo browser
    // Name of demo program
    public String toString() 
        return "Track Line with Data Labels"; 

    // Number of charts produced in this demo
    public int getNoOfCharts() 
        // This demo open its own dialog instead of using the right pane of the ChartDirectorDemo 
        // for display. We just display the dialog, then return 0.
        return 0; 

    // Main code for creating charts
    public void createChart(ChartViewer viewer, int chartIndex)
        // do nothing, as the ChartDirectorDemo browser right pane is not used