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 Checkbox

The following code adds check boxes on JTree node. Checkbox selection may propogats to its children by setting customized mode. This example has three files: CheckNodeTreeExample.java,CheckRenderer.java and CheckNode.java

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

original one has bug.
*/

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

public class CheckNode extends DefaultMutableTreeNode {

public final static int SINGLE_SELECTION = 0;
public final static int DIG_IN_SELECTION = 4;
protected int selectionMode;
protected boolean isSelected;

public CheckNode() {
this(null);
}

public CheckNode(Object userObject) {
this(userObject, true, false);
}

public CheckNode(Object userObject, boolean allowsChildren
, boolean isSelected) {
super(userObject, allowsChildren);
this.isSelected = isSelected;
setSelectionMode(DIG_IN_SELECTION);
}

public void setSelectionMode(int mode) {
selectionMode = mode;
}

public int getSelectionMode() {
return selectionMode;
}

public void setSelected(boolean isSelected) {
this.isSelected = isSelected;

if ((selectionMode == DIG_IN_SELECTION)
&& (children != null)) {
Enumeration menum = children.elements();
while (menum.hasMoreElements()) {
CheckNode node = (CheckNode)menum.nextElement();
node.setSelected(isSelected);
}
}
}

public boolean isSelected() {
return isSelected;
}

// If you want to change "isSelected" by CellEditor,
/*
public void setUserObject(Object obj) {
if (obj instanceof Boolean) {
setSelected(((Boolean)obj).booleanValue());
} else {
super.setUserObject(obj);
}
}
*/

}