Best books about JAVA programming:

• Head First JAVA, Second Editon
• Effective Java Programming Language Guide
• Professional Java, JDK 5 Edition
• Ivor Horton's Beginning Java 2, JDK 5 Edition

JAVA JToolTip

This example shows how to add multiple line tooltips. It includes three files:MultiLineToolTipExample.java, MultiLineToolTipUI.java and MultiLineToolTip.java

import java.io.*;
import java.util.*;
import java.awt.*;
import javax.swing.*;
import javax.swing.plaf.metal.*;

public class MultiLineToolTipUI extends MetalToolTipUI {
private String[] strs;
private int maxWidth = 0;

public void paint(Graphics g, JComponent c) {
FontMetrics metrics = Toolkit.getDefaultToolkit().getFontMetrics(g.getFont());
Dimension size = c.getSize();
g.setColor(c.getBackground());
g.fillRect(0, 0, size.width, size.height);
g.setColor(c.getForeground());
if (strs != null) {
for (int i=0;i<strs.length;i++) {
g.drawString(strs[i], 3, (metrics.getHeight()) * (i+1));
}
}
}

public Dimension getPreferredSize(JComponent c) {
FontMetrics metrics = Toolkit.getDefaultToolkit().getFontMetrics(c.getFont());
String tipText = ((JToolTip)c).getTipText();
if (tipText == null) {
tipText = "";
}
BufferedReader br = new BufferedReader(new StringReader(tipText));
String line;
int maxWidth = 0;
Vector v = new Vector();
try {
while ((line = br.readLine()) != null) {
int width = SwingUtilities.computeStringWidth(metrics,line);
maxWidth = (maxWidth < width) ? width : maxWidth;
v.addElement(line);
}
} catch (IOException ex) {
ex.printStackTrace();
}
int lines = v.size();
if (lines < 1) {
strs = null;
lines = 1;
} else {
strs = new String[lines];
int i=0;
for (Enumeration e = v.elements(); e.hasMoreElements() ;i++) {
strs[i] = (String)e.nextElement();
}
}
int height = metrics.getHeight() * lines;
this.maxWidth = maxWidth;
return new Dimension(maxWidth + 6, height + 4);
}
}