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 show/hide JTree node dynamically. This example has three files: InvisibleNodeTreeExample.java, InvisibleTreeModel.java and InvisibleNode.java

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

import java.util.*;
import javax.swing.tree.*;

public class InvisibleNode extends DefaultMutableTreeNode {

protected boolean isVisible;

public InvisibleNode() {
this(null);
}

public InvisibleNode(Object userObject) {
this(userObject, true, true);
}

public InvisibleNode(Object userObject, boolean allowsChildren
, boolean isVisible) {
super(userObject, allowsChildren);
this.isVisible = isVisible;
}

public TreeNode getChildAt(int index,boolean filterIsActive) {
if (! filterIsActive) {
return super.getChildAt(index);
}
if (children == null) {
throw new ArrayIndexOutOfBoundsException("node has no children");
}

int realIndex = -1;
int visibleIndex = -1;
Enumeration menum = children.elements();
while (menum.hasMoreElements()) {
InvisibleNode node = (InvisibleNode)menum.nextElement();
if (node.isVisible()) {
visibleIndex++;
}
realIndex++;
if (visibleIndex == index) {
return (TreeNode)children.elementAt(realIndex);
}
}

throw new ArrayIndexOutOfBoundsException("index unmatched");

}

public int getChildCount(boolean filterIsActive) {
if (! filterIsActive) {
return super.getChildCount();
}
if (children == null) {
return 0;
}

int count = 0;
Enumeration menum = children.elements();
while (menum.hasMoreElements()) {
InvisibleNode node = (InvisibleNode)menum.nextElement();
if (node.isVisible()) {
count++;
}
}

return count;
}

public void setVisible(boolean visible) {
this.isVisible = visible;
}

public boolean isVisible() {
return isVisible;
}

}