ChartDirector 6.1 (Java Edition)

Side Label Layout




This example demonstrates the "side label layout" method for positioning the sector labels. It also demonstrates metallic background colors, and sector labels with glass shading effect and rounded corners.

With "side label layout", the sector labels are positioned on the left and right sides of the chart. In contrast, all previous examples use "circular label layout", in which the labels are positioned circularly around the pie.

"Side label layout" has the advantages that the labels will automatically shift up and down to avoid overlapping. In the above chart, there are a number of small sectors at the bottom-right of the pie. Note that the labels are shifted to avoid overlapping.

This example demonstrates a technique for further improving label layout by adjusting the start angle of the first sector using PieChart.setStartAngle.

If the data have a lot of small values and are sorted, the small sectors will be crowded together. For these cases, label layout will be optimal (with the least shifting required) if the small sectors are at the left or right side of the pie, rather than at the top or bottom.

If the data are in descending order (like this example), a start angle of 135 degrees with clockwise sector layout can be used to put the small sectors at approximately 45 - 135 degrees (the right side of the pie). If the data are in ascending order, a start angle of 45 degrees with clockwise sector layout can be used to achieve similar effects.

Source Code Listing

[JSP Version] jspdemo/sidelabelpie.jsp
<%@page import="ChartDirector.*" %>
<%
// The data for the pie chart
double[] data = {35, 30, 25, 7, 6, 5, 4, 3, 2, 1};

// The labels for the pie chart
String[] labels = {"Labor", "Production", "Facilities", "Taxes", "Misc", "Legal", "Insurance",
    "Licenses", "Transport", "Interest"};

// Create a PieChart object of size 560 x 270 pixels, with a golden background and a 1 pixel 3D
// border
PieChart c = new PieChart(560, 270, Chart.goldColor(), -1, 1);

// Add a title box using 15pt Times Bold Italic font and metallic pink background color
c.addTitle("Project Cost Breakdown", "Times New Roman Bold Italic", 15).setBackground(
    Chart.metalColor(0xff9999));

// Set the center of the pie at (280, 135) and the radius to 110 pixels
c.setPieSize(280, 135, 110);

// Draw the pie in 3D with 20 pixels 3D depth
c.set3D(20);

// Use the side label layout method
c.setLabelLayout(Chart.SideLayout);

// Set the label box background color the same as the sector color, with glass effect, and with 5
// pixels rounded corners
TextBox t = c.setLabelStyle();
t.setBackground(Chart.SameAsMainColor, Chart.Transparent, Chart.glassEffect());
t.setRoundedCorners(5);

// Set the border color of the sector the same color as the fill color. Set the line color of the
// join line to black (0x0)
c.setLineColor(Chart.SameAsMainColor, 0x000000);

// Set the start angle to 135 degrees may improve layout when there are many small sectors at the
// end of the data array (that is, data sorted in descending order). It is because this makes the
// small sectors position near the horizontal axis, where the text label has the least tendency to
// overlap. For data sorted in ascending order, a start angle of 45 degrees can be used instead.
c.setStartAngle(135);

// Set the pie data and the pie labels
c.setData(data, labels);

// Output the chart
String chart1URL = c.makeSession(request, "chart1");

// Include tool tip for the chart
String imageMap1 = c.getHTMLImageMap("", "", "title='{label}: US${value}K ({percent}%)'");
%>
<html>
<body style="margin:5px 0px 0px 5px">
<div style="font-size:18pt; font-family:verdana; font-weight:bold">
    Side Label Layout
</div>
<hr color="#000080">
<div style="font-size:10pt; font-family:verdana; margin-bottom:1.5em">
    <a href="viewsource.jsp?file=<%=request.getServletPath()%>">View Source Code</a>
</div>
<img src='<%=response.encodeURL("getchart.jsp?"+chart1URL)%>'
    usemap="#map1" border="0">
<map name="map1"><%=imageMap1%></map>
</body>
</html>

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

public class sidelabelpie implements DemoModule
{
    //Name of demo program
    public String toString() { return "Side Label Layout"; }

    //Number of charts produced in this demo
    public int getNoOfCharts() { return 1; }

    //Main code for creating charts
    public void createChart(ChartViewer viewer, int chartIndex)
    {
        // The data for the pie chart
        double[] data = {35, 30, 25, 7, 6, 5, 4, 3, 2, 1};

        // The labels for the pie chart
        String[] labels = {"Labor", "Production", "Facilities", "Taxes", "Misc", "Legal",
            "Insurance", "Licenses", "Transport", "Interest"};

        // Create a PieChart object of size 560 x 270 pixels, with a golden background and a 1 pixel
        // 3D border
        PieChart c = new PieChart(560, 270, Chart.goldColor(), -1, 1);

        // Add a title box using 15pt Times Bold Italic font and metallic pink background color
        c.addTitle("Project Cost Breakdown", "Times New Roman Bold Italic", 15).setBackground(
            Chart.metalColor(0xff9999));

        // Set the center of the pie at (280, 135) and the radius to 110 pixels
        c.setPieSize(280, 135, 110);

        // Draw the pie in 3D with 20 pixels 3D depth
        c.set3D(20);

        // Use the side label layout method
        c.setLabelLayout(Chart.SideLayout);

        // Set the label box background color the same as the sector color, with glass effect, and
        // with 5 pixels rounded corners
        TextBox t = c.setLabelStyle();
        t.setBackground(Chart.SameAsMainColor, Chart.Transparent, Chart.glassEffect());
        t.setRoundedCorners(5);

        // Set the border color of the sector the same color as the fill color. Set the line color
        // of the join line to black (0x0)
        c.setLineColor(Chart.SameAsMainColor, 0x000000);

        // Set the start angle to 135 degrees may improve layout when there are many small sectors
        // at the end of the data array (that is, data sorted in descending order). It is because
        // this makes the small sectors position near the horizontal axis, where the text label has
        // the least tendency to overlap. For data sorted in ascending order, a start angle of 45
        // degrees can be used instead.
        c.setStartAngle(135);

        // Set the pie data and the pie labels
        c.setData(data, labels);

        // Output the chart
        viewer.setChart(c);

        //include tool tip for the chart
        viewer.setImageMap(c.getHTMLImageMap("clickable", "",
            "title='{label}: US${value}K ({percent}%)'"));
    }

    //Allow this module to run as standalone program for easy testing
    public static void main(String[] args)
    {
        //Instantiate an instance of this demo module
        DemoModule demo = new sidelabelpie();

        //Create and set up the main window
        JFrame frame = new JFrame(demo.toString());
        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {System.exit(0);} });
        frame.getContentPane().setBackground(Color.white);

        // Create the chart and put them in the content pane
        ChartViewer viewer = new ChartViewer();
        demo.createChart(viewer, 0);
        frame.getContentPane().add(viewer);

        // Display the window
        frame.pack();
        frame.setVisible(true);
    }
}