package com.darwinsys.charts;
import java.awt.*;
/**
* Simple charting bean. This version just draws a Pie Chart.
*
* It doesn't even label the pie slices; that is left as a
* (non-trivial) exercise for the reader. Please read the 1987
* Technical Report "How Hard can it be to draw a Pie Chart?"
* by D. L. Souvaine and Chris van Wyck, Rutgers Computer Science,
* LCSR-TR-90, before you decide how easy the work is going to be!
*/
public class Chart extends Component {
/** The title to print on the chart */
protected String title;
/** the data to draw */
protected ChartData data[];
/** The data to draw a Demo */
protected ChartData demoData[] = {
new ChartData(73, "Java"),
new ChartData(15, "Microsoft"),
new ChartData(10, "Macintosh"),
};
/** degrees in a circle */
public static final int CIRCLE = 360;
/** a set of colors to draw the pies in */
protected Color[] colors = {
Color.red,
Color.blue,
Color.green,
Color.pink,
Color.orange
};
/** Construct a Chart with a title */
public Chart(String s) {
title = s;
setBackground(Color.white);
}
/** Construct a Chart with no title (no-arg constructor
* required for Beans).
*/
public Chart() {
this("DarwinSys ChartBean");
}
public void setLabel(String s) {
title = s;
}
public String getLabel() {
return title;
}
public void setData(ChartData[] newStuff) {
data = newStuff;
repaint();
}
public void doDemo() {
setData(demoData);
}
public void paint(Graphics g) {
Dimension sz = getSize();
int w = sz.width, h = sz.width;
if (title != null)
g.drawString(title, w/9, (int)(h*1.1));
if (data == null || data.length == 0) {
g.drawOval(0, 0, w, h);
g.drawString("Please provide some data!", w/10, h/2);
return;
}
int total = 0;
int angle = 0;
int rad = 0; // "radians" (actually degrees) to draw
int colNum = 0;
for (int i=0; i<data.length; i++)
total += data[i].value;
for (int i=0; i<data.length; i++) {
rad = (int)(CIRCLE * ((float)data[i].value / (float)total));
// System.out.println("data: "+data[i].name+";"+data[i].value+
// ",rad="+rad);
g.setColor(colors[colNum++]);
colNum%=colors.length; // keep it in bounds
g.fillArc(0, 0, w, h, angle, rad);
angle += rad;
}
}
public Dimension getMinimumSize() {
return new Dimension(100, 120);
}
public Dimension getPreferredSize() {
return new Dimension(200, 240);
}
}
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