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 Wide Editor

The following code adds editor on JTree node. This example has two files: WideEditorTreeExample.java and WideCellEditor.java

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

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

public class WideCellEditor extends DefaultTreeCellEditor {

public WideCellEditor(JTree tree,
DefaultTreeCellRenderer renderer) {
this(tree, renderer, null);
}

public WideCellEditor(final JTree tree, final DefaultTreeCellRenderer renderer,
TreeCellEditor editor) {
super(tree,renderer,editor);
editingContainer = new WideEditorContainer();
}

public Component getTreeCellEditorComponent(JTree tree, Object value,
boolean isSelected, boolean expanded, boolean leaf, int row) {
Component c = super.getTreeCellEditorComponent(tree, value,
isSelected, expanded, leaf, row);
((WideEditorContainer)editingContainer).setLocalCopy(
tree,lastPath,offset,editingComponent);
return c;
}

class WideEditorContainer extends DefaultTreeCellEditor.EditorContainer {
JTree tree;
TreePath lastPath;
int offset;
Component editingComponent;

public void doLayout() {
if (editingComponent != null) {
Dimension cSize = getSize();
Dimension eSize = editingComponent.getPreferredSize();
int n = lastPath.getPathCount();
Rectangle r = new Rectangle();
r = tree.getBounds(r);
eSize.width = r.width -(offset *n);
editingComponent.setSize(eSize);
editingComponent.setLocation(offset, 0);
editingComponent.setBounds(offset, 0, eSize.width, cSize.height);
setSize(new Dimension(eSize.width + offset, cSize.height));
}
}

void setLocalCopy(JTree tree, TreePath lastPath,
int offset,Component editingComponent) {
this.tree = tree;
this.lastPath = lastPath;
this.offset = offset;
this.editingComponent = editingComponent;
}
}
}