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 JTree Icon node

The following code adds icons on JTree node. Each node could have different icon. This example has four files: IconNodeTreeExample.java,IconNodeRenderer.java,IconNode.java and TextIcons.java

/*Example modified from http://www.crionics.com/products/opensource/faq/swing_ex/JTableExamples2.html
*/

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

public class TextIcons extends MetalIconFactory.TreeLeafIcon {

protected String label;
private static Hashtable labels;

protected TextIcons() {
}

public void paintIcon(Component c, Graphics g, int x, int y) {
super.paintIcon( c, g, x, y );
if (label != null) {
FontMetrics fm = g.getFontMetrics();

int offsetX = (getIconWidth() - fm.stringWidth(label)) /2;
int offsetY = (getIconHeight() - fm.getHeight()) /2 - 2;

g.drawString(label, x + offsetX ,
y + offsetY + fm.getHeight());
}
}

public static Icon getIcon(String str) {
if (labels == null) {
labels = new Hashtable();
setDefaultSet();
}
TextIcons icon = new TextIcons();
icon.label = (String)labels.get(str);
return icon;
}

public static void setLabelSet(String ext, String label) {
if (labels == null) {
labels = new Hashtable();
setDefaultSet();
}
labels.put(ext, label);
}

private static void setDefaultSet() {
labels.put("c" ,"C");
labels.put("java" ,"J");
labels.put("html" ,"H");
labels.put("htm" ,"H");

// and so on
/*
labels.put("txt" ,"TXT");
labels.put("TXT" ,"TXT");
labels.put("cc" ,"C++");
labels.put("C" ,"C++");
labels.put("cpp" ,"C++");
labels.put("exe" ,"BIN");
labels.put("class" ,"BIN");
labels.put("gif" ,"GIF");
labels.put("GIF" ,"GIF");

labels.put("", "");
*/
}

}