KeyEvent with JTree

I want to implement the hot key Ctr_c/Ctr_v for the copy/paste function in the JTree. I added a KeyListener to this JTree and implemented the keyPressed() method as following:
public void keyPressed(KeyEvent e){
if( e.isControlDown()){
if ( (e.getKeyChar() == 'c') ) {
copy();
else if(e.getKeyChar() == 'v'){
paste();
If I run this code, copy/paste doesn't work. But if I delete the " if( e.isControlDown()) " statement and only try with c/v key, then copy/paste works fine. Can anybody tell me how to make this tree recongnize two pressed keyEvents(Ctr + c and Ctr+v).
Thanks in advance!

Hi,
I too have being trying to implement the copy method in a JTree, but havent been totally sucessful.
I send a msg on this forum, but didn't help.
I'd be really glad if you could help me out, when you are through with it.
thanks

Similar Messages

Problem with JTree converting Node to string

I have a problem that I cannot slove with JTree. I have a DefaultMutalbeTreeNode and I need its parent and convert to string. I can get its parent OK but cannot convert it to string.
thisnode.getParent().toString() won't work and gives an exception
thisnode.getParent() works but how do I convert this to string to be used by a database.
Thanks
Peter Loo

You are using the wrong method to convert it to a String array.
Try replacing this line:
String[] tabStr = (String[])strList.toArray();
With this line:
String[] tabStr = (String[])strList.toArray( new String[ 0 ] );
That should work for you.

How can I open a picture with Jtree

hi,
I want to write a Filemanagerprogramm with JTree, but how can I open it, after I clickt the .jpg or .png file. Thank you for your Tip!

The java tutorial at http://java.sun.com/docs/books/tutorial/uiswing/misc/icon.html will tell you a lot of what you need to know.

Problems with JTree

Hi,
I have a few problems while working with JTree. Here is the detail:
I get the name of the required file from JFileChooser and add it to the root node of JTree using
root.add(new DefaultMutableTreeNode(fileName));
The following happens.
1) If I add it to root, it is not added(or shown,at least) there.
2) if I add it to a child of root, then if the node is collapsed before the event, after the event when it is expanded fileName is there.
3) However if it is expanded before adding the fileName,the fileName is not added (or not shown).
4) Further if I add another file(whether the node is collapsed or expanded) it is also not shown, means that it works only once during the life-time of the application.
5) I have used JFrame and call repaint() for both the JFrame and JTree but the problem is still there.
Please help me in solving this problem.
Thanks in advance,
Hamid Mukhtar,
[email protected]
H@isoft Technologies.

Try doing this...
tree.getModel().reload(node)
node here is the node to which a new node is added

Display File System With JTree

Greeting,
Are there any suggestions or example which is about displaying file system with JTree??
Thx Advanced

Just create tree model from your filesystem.
If you like to have fancier look, you may also
create renderer which would show
appropriate icons.
Look to classes
DefaultMutableTreeNode
DefaultTreeModel
( all in the javax.swing.tree )

Problemns with JTree

Hi! I'm having problems with the Tree cell renderer. I must render a tree that have leafs that is also JPanels compounded by a checkbox, an icon and a the text label. It's supposed to alter the state of the checkbox when clicked or when press the spacebar over the cell, but it isn't working...
If I set the tree as editable (down in the code, in main method), the checkbox is selected only after the second click, but the cell is not being highlighted and cannot collapse the category nodes. Otherwise, when set the Tree as NOT editable, the highlight of cell and the rest works, but obviously I cannot edit the checkboxes...
Can someone help me, please?
package test;
import com.interact.sas.ResourceLocator;
import com.interact.sas.dms.*;
import com.interact.sas.ui.UserIconLabel;
import java.awt.*;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.util.EventObject;
import java.util.Vector;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.tree.*;
public class DocumentControllerTreeTest
 static class MyTreeCellEditor extends AbstractCellEditor implements TreeCellEditor, TreeCellRenderer
 private static Icon iconCategory = ResourceLocator.getIcon( "sas/dms/tb_categories.png" );
 private static Border noFocusBorder = new EmptyBorder( 1, 1, 1, 1 );
 private JPanel cell = new JPanel();
 private JCheckBox checkRequired = new JCheckBox();
 private UserIconLabel userIconLabel = new UserIconLabel();
 private DocumentControllerTree.Item currentItem = null;
 public MyTreeCellEditor()
 userIconLabel.setOpaque( false );
 checkRequired.setOpaque( false );
 cell.setLayout( new BorderLayout() );
 cell.add( checkRequired, BorderLayout.WEST );
 cell.add( userIconLabel, BorderLayout.CENTER );
 cell.addKeyListener( new KeyAdapter()
 public void keyPressed( KeyEvent e )
 if ( e.getKeyCode() == KeyEvent.VK_SPACE )
 checkRequired.setSelected( ! checkRequired.isSelected() );
 e.consume();
 cell.addMouseListener( new java.awt.event.MouseAdapter()
 public void mouseClicked(java.awt.event.MouseEvent evt)
 checkRequired.setSelected( ! checkRequired.isSelected() );
 * getCellEditorValue
 * @return Object
 public Object getCellEditorValue()
 currentItem.getController().setRequired( checkRequired.isSelected() );
 return new Boolean( currentItem.getController().isRequired() );
 * getTreeCellEditorComponent
 * @param JTree tree,
 * @param Object value,
 * @param boolean isSelected,
 * @param boolean expanded,
 * @param boolean leaf,
 * @param int row
 * @return Component
 public Component getTreeCellEditorComponent( JTree tree,
 Object value,
 boolean isSelected,
 boolean expanded,
 boolean leaf,
 int row)
 return getTreeCellRendererComponent( tree, value, isSelected, expanded, leaf, row, true );
 * getTreeCellRendererComponent
 * @param JTree tree,
 * @param Object value,
 * @param boolean selected,
 * @param boolean expanded,
 * @param boolean leaf,
 * @param int row,
 * @param boolean hasFocus
 * @return Component
 public Component getTreeCellRendererComponent( JTree tree,
 Object value,
 boolean isSelected,
 boolean isExpanded,
 boolean isLeaf,
 int row,
 boolean hasFocus )
 DefaultMutableTreeNode node = (DefaultMutableTreeNode) value;
 Object object = node.getUserObject();
 if ( object instanceof DocumentControllerTree.Item )
 currentItem = (DocumentControllerTree.Item) object;
 checkRequired.setSelected( currentItem.getController().isRequired() );
 //checkRequired.setSelected( !checkRequired.isSelected() );
 int action = currentItem.getController().getAction();
 if ( action == DocumentController.ACTION_APROVE ||
 action == DocumentController.ACTION_VERIFY )
 checkRequired.setVisible( true );
 else
 checkRequired.setVisible( false );
 userIconLabel.setFont( tree.getFont() );
 userIconLabel.setUser( currentItem.getUser() );
 userIconLabel.setText( currentItem.getUser().getName() );
 else
 // nunca poderia chegar aqui ...
 checkRequired.setVisible( false );
 userIconLabel.setFont( tree.getFont() );
 userIconLabel.setIcon( ! isLeaf ? iconCategory : null );
 userIconLabel.setText( object.toString() );
 if ( isSelected )
 cell.setBackground( UIManager.getColor( "Tree.selectionBackground") );
 cell.setForeground( UIManager.getColor( "Tree.selectionForeground") );
 else
 cell.setBackground( tree.getBackground() );
 cell.setForeground( tree.getForeground() );
 Border border = noFocusBorder;
 if (hasFocus)
 if (isSelected)
 border = UIManager.getBorder("List.focusSelectedCellHighlightBorder");
 if (border == null)
 border = UIManager.getBorder("List.focusCellHighlightBorder");
 cell.setBorder(border);
 return cell;
 public static void main( String[] args )
 try
 DocumentControllerTree tree = new DocumentControllerTree();
 DocumentManager dm = DocumentManager.getInstance();
 DocumentCategory dc = dm.getCategory( 32 );
 Vector<DocumentController> vdc = dm.getControllers( dc );
 tree.setCellRenderer( new MyTreeCellEditor() );
 tree.setCellEditor( new MyTreeCellEditor() );
 tree.setCategory( dc );
 tree.setControllers( vdc );
 // This must be true
 //tree.setEditable( true );
 JScrollPane scroller = new JScrollPane( tree );
 scroller.setPreferredSize( new Dimension( 240, 320 ) );
 JOptionPane.showMessageDialog( null, scroller );
 catch ( Exception e )
 e.printStackTrace();
 System.exit( 0 );
}

OK, here's briefly what I'd do:
1
In your tree constructor, set a custom TreeCellRenderer. (I assume your tree extends JTree.)
2
Create a custom TreeCellRenderer by extending JPanel and implementing TreeCellRenderer. In the getTreeCellRendererComponent method, remember you don't have to use a component that you have around. You use the tree node's text: tree.convertValueToText(value, sel, expanded, leaf, row, hasFocus)); This returns a string. The string could be "true" or "false". You then create a JCheckBox based on this value. Add the JCheckBox to �this�, i.e. to the custom TreeCellRenderer that extends a JPanel. Return �this�. Remember that once �this� is returned, the value is forgotten and the JCheckBox is unclickable. (What you click actually is the TreeCellRenderer, that then decides you want to focus a node and thereafter passes focus and subsequent clicks to your panel and/or the TreeCellEditor).
3
Back to the tree constructor. Set your TreeCellEditor to a custom class of yours. Copy the code from DefaultCellEditor. There is a constructor in DefaultCellEditor that accepts a JCheckBox as sole argument. Try that one. In an inner class in DefaultCellEditor, EditorDelegate, you'll find the stopCellEditing method. Override it and make sure to convert boolean values back to "true" or "false" in the tree node, so that the renderer will have the right value to work with.
From there on, I guess things should work by themselves. (Warning: completely unchecked!!!) If not, at least the code is sufficiently separated for us to know where it fails (renderer, editor, tree...)
PS. Second thought: DefaultMutableTreeNode accepts an Object as object, not only a string. Maybe you could use a boolean value or a Boolean object directly in the tree node instead of strings...
Just my 2 cents

Checkbox with JTree

hai,
i added checkbox to each tree node and my coding is
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.ComponentOrientation;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Insets;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.awt.event.InputEvent;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import javax.swing.AbstractAction;
import javax.swing.AbstractButton;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTree;
import javax.swing.KeyStroke;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreeCellRenderer;
import javax.swing.tree.TreePath;
/** Provides checkbox-based selection of tree nodes. Override the protected
* methods to adapt this renderer's behavior to your local tree table flavor.
* No change listener notifications are provided.
public class CheckBoxTreeCellRenderer implements TreeCellRenderer {
public static final int UNSELECTABLE = 0;
public static final int FULLSELECTED = 1;
public static final int NOTSELECTED = 2;
public static final int PARTIALSELECTED = 3;
private TreeCellRenderer renderer;
public static JCheckBox checkBox;
private Point mouseLocation;
private int mouseRow = -1;
private int pressedRow = -1;
private boolean mouseInCheck;
private int state = NOTSELECTED;
private Set checkedPaths;
private JTree tree;
private MouseHandler handler;
/** Create a per-tree instance of the checkbox renderer. */
public CheckBoxTreeCellRenderer(JTree tree, TreeCellRenderer original) {
this.tree = tree;
this.renderer = original;
checkedPaths = new HashSet();
checkBox = new JCheckBox();
checkBox.setOpaque(false);
System.out.println(checkBox.isSelected());
checkBox.addActionListener(new ActionListener() {
 public void actionPerformed(ActionEvent e) {
 trace(checkBox);
// ActionListener actionListener = new ActionListener() {
// public void actionPerformed(ActionEvent actionEvent) {
// AbstractButton abstractButton = (AbstractButton) actionEvent.getSource();
// boolean selected = abstractButton.getModel().isSelected();
// System.out.println(selected);
// // abstractButton.setText(newLabel);
// checkBox.addActionListener(new ActionListener(){
// public void actionPerformed(ActionEvent actionEvent) {
// Checkbox cb = actionEvent.getSource();
// boolean selected = abstractButton.getModel().isSelected();
// System.out.println(selected);
checkBox.setSize(checkBox.getPreferredSize());
private static void trace(JCheckBox cb) {
 if (cb.isSelected())
 System.out.println(cb.getText()+" is " + cb.isSelected());
 else
 System.out.println(cb.getText()+" is " + cb.isSelected());
protected void installMouseHandler() {
if (handler == null) {
handler = new MouseHandler();
addMouseHandler(handler);
protected void addMouseHandler(MouseHandler handler) {
tree.addMouseListener(handler);
tree.addMouseMotionListener(handler);
private void updateMouseLocation(Point newLoc) {
if (mouseRow != -1) {
repaint(mouseRow);
mouseLocation = newLoc;
if (mouseLocation != null) {
mouseRow = getRow(newLoc);
repaint(mouseRow);
else {
mouseRow = -1;
if (mouseRow != -1 && mouseLocation != null) {
Point mouseLoc = new Point(mouseLocation);
Rectangle r = getRowBounds(mouseRow);
if (r != null)
mouseLoc.x -= r.x;
mouseInCheck = isInCheckBox(mouseLoc);
else {
mouseInCheck = false;
protected int getRow(Point p) {
return tree.getRowForLocation(p.x, p.y);
protected Rectangle getRowBounds(int row) {
return tree.getRowBounds(row);
protected TreePath getPathForRow(int row) {
return tree.getPathForRow(row);
protected int getRowForPath(TreePath path) {
return tree.getRowForPath(path);
public void repaint(Rectangle r) {
tree.repaint(r);
public void repaint() {
tree.repaint();
private void repaint(int row) {
Rectangle r = getRowBounds(row);
if (r != null)
repaint(r);
public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus) {
installMouseHandler();
TreePath path = getPathForRow(row);
state = UNSELECTABLE;
if (path != null) {
if (isChecked(path)) {
state = FULLSELECTED;
else if (isPartiallyChecked(path)) {
state = PARTIALSELECTED;
else if (isSelectable(path)) {
state = NOTSELECTED;
checkBox.setSelected(state == FULLSELECTED);
checkBox.getModel().setArmed(mouseRow == row && pressedRow == row && mouseInCheck);
checkBox.getModel().setPressed(pressedRow == row && mouseInCheck);
checkBox.getModel().setRollover(mouseRow == row && mouseInCheck);
Component c = renderer.getTreeCellRendererComponent(tree, value, selected, expanded, leaf, row, hasFocus);
checkBox.setForeground(c.getForeground());
if (c instanceof JLabel) {
JLabel label = (JLabel)c;
// Augment the icon to include the checkbox
Icon customOpenIcon = new ImageIcon("browse.gif");
label.setIcon(new CompoundIcon(label.getIcon()));
return c;
private boolean isInCheckBox(Point where) {
Insets insets = tree.getInsets();
int right = checkBox.getWidth();
int left = 0;
if (insets != null) {
left += insets.left;
right += insets.left;
return where.x >= left && where.x < right;
public boolean isExplicitlyChecked(TreePath path) {
return checkedPaths.contains(path);
/** Returns whether selecting the given path is allowed. The default
* returns true. You should return false if the given path represents
* a placeholder for a node that has not yet loaded, or anything else
* that doesn't represent a normal, operable object in the tree.
public boolean isSelectable(TreePath path) {
return true;
/** Returns whether the given path is currently checked. */
public boolean isChecked(TreePath path) {
if (isExplicitlyChecked(path)) {
return true;
else {
if (path.getParentPath() != null) {
return isChecked(path.getParentPath());
else {
return false;
public boolean isPartiallyChecked(TreePath path) {
Object node = path.getLastPathComponent();
for (int i = 0; i < tree.getModel().getChildCount(node); i++) {
Object child = tree.getModel().getChild(node, i);
TreePath childPath = path.pathByAddingChild(child);
if (isChecked(childPath) || isPartiallyChecked(childPath)) {
return true;
return false;
private boolean isFullyChecked(TreePath parent) {
Object node = parent.getLastPathComponent();
for (int i = 0; i < tree.getModel().getChildCount(node); i++) {
Object child = tree.getModel().getChild(node, i);
TreePath childPath = parent.pathByAddingChild(child);
if (!isExplicitlyChecked(childPath)) {
return false;
return true;
public void toggleChecked(int row) {
TreePath path = getPathForRow(row);
boolean isChecked = isChecked(path);
removeDescendants(path);
if (!isChecked) {
checkedPaths.add(path);
setParent(path);
repaint();
private void setParent(TreePath path) {
TreePath parent = path.getParentPath();
if (parent != null) {
if (isFullyChecked(parent)) {
removeChildren(parent);
checkedPaths.add(parent);
} else {
if (isChecked(parent)) {
checkedPaths.remove(parent);
addChildren(parent);
checkedPaths.remove(path);
setParent(parent);
private void addChildren(TreePath parent) {
Object node = parent.getLastPathComponent();
for (int i = 0; i < tree.getModel().getChildCount(node); i++) {
Object child = tree.getModel().getChild(node, i);
TreePath path = parent.pathByAddingChild(child);
checkedPaths.add(path);
private void removeChildren(TreePath parent) {
for (Iterator i = checkedPaths.iterator(); i.hasNext();) {
TreePath p = (TreePath) i.next();
if (p.getParentPath() != null && parent.equals(p.getParentPath())) {
i.remove();
private void removeDescendants(TreePath ancestor) {
for (Iterator i = checkedPaths.iterator(); i.hasNext();) {
TreePath path = (TreePath) i.next();
if (ancestor.isDescendant(path)) {
i.remove();
/** Returns all checked rows. */
public int[] getCheckedRows() {
TreePath[] paths = getCheckedPaths();
int[] rows = new int[checkedPaths.size()];
for (int i = 0; i < checkedPaths.size(); i++) {
rows[i] = getRowForPath(paths);
Arrays.sort(rows);
return rows;
/** Returns all checked paths. */
public TreePath[] getCheckedPaths() {
return (TreePath[]) checkedPaths.toArray(new TreePath[checkedPaths.size()]);
protected class MouseHandler extends MouseAdapter implements MouseMotionListener {
public void mouseEntered(MouseEvent e) {
updateMouseLocation(e.getPoint());
public void mouseExited(MouseEvent e) {
updateMouseLocation(null);
public void mouseMoved(MouseEvent e) {
updateMouseLocation(e.getPoint());
public void mouseDragged(MouseEvent e) {
updateMouseLocation(e.getPoint());
public void mousePressed(MouseEvent e) {
pressedRow = e.getModifiersEx() == InputEvent.BUTTON1_DOWN_MASK
? getRow(e.getPoint()) : -1;
updateMouseLocation(e.getPoint());
public void mouseReleased(MouseEvent e) {
if (pressedRow != -1) {
int row = getRow(e.getPoint());
if (row == pressedRow) {
Point p = e.getPoint();
Rectangle r = getRowBounds(row);
p.x -= r.x;
if (isInCheckBox(p)) {
toggleChecked(row);
pressedRow = -1;
updateMouseLocation(e.getPoint());
public void mouseClicked(MouseEvent e){
 if(checkBox.isSelected()){
 System.out.println(checkBox.getName());
/** Combine a JCheckBox's checkbox with another icon. */
private final class CompoundIcon implements Icon {
private final Icon icon;
private final int w;
private final int h;
private CompoundIcon(Icon icon) {
if (icon == null) {
icon = new Icon() {
public int getIconHeight() { return 0; }
public int getIconWidth() { return 0; }
public void paintIcon(Component c, Graphics g, int x, int y) { }
this.icon = icon;
this.w = icon.getIconWidth();
this.h = icon.getIconHeight();
public int getIconWidth() {
return checkBox.getPreferredSize().width + w;
public int getIconHeight() {
return Math.max(checkBox.getPreferredSize().height, h);
public void paintIcon(Component c, Graphics g, int x, int y) {
if (c.getComponentOrientation().isLeftToRight()) {
int xoffset = checkBox.getPreferredSize().width;
int yoffset = (getIconHeight()-icon.getIconHeight())/2;
icon.paintIcon(c, g, x + xoffset, y + yoffset);
if (state != UNSELECTABLE) {
paintCheckBox(g, x, y);
else {
int yoffset = (getIconHeight()-icon.getIconHeight())/2;
icon.paintIcon(c, g, x, y + yoffset);
if (state != UNSELECTABLE) {
paintCheckBox(g, x + icon.getIconWidth(), y);
private void paintCheckBox(Graphics g, int x, int y) {
int yoffset;
boolean db = checkBox.isDoubleBuffered();
checkBox.setDoubleBuffered(false);
try {
yoffset = (getIconHeight()-checkBox.getPreferredSize().height)/2;
g = g.create(x, y+yoffset, getIconWidth(), getIconHeight());
checkBox.paint(g);
if (state == PARTIALSELECTED) {
final int WIDTH = 2;
g.setColor(UIManager.getColor("CheckBox.foreground"));
Graphics2D g2d = (Graphics2D)g;
g2d.setStroke(new BasicStroke(WIDTH, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
int w = checkBox.getWidth();
int h = checkBox.getHeight();
g.drawLine(w/4+2, h/2-WIDTH/2+1, w/4+w/2-3, h/2-WIDTH/2+1);
g.dispose();
finally {
checkBox.setDoubleBuffered(db);
private static String createText(TreePath[] paths) {
if (paths.length == 0) {
return "Nothing checked";
String checked = "Checked:\n";
for (int i=0;i < paths.length;i++) {
checked += paths[i] + "\n";
return checked;
public static void main(String[] args) {
try {
final String SWITCH = "toggle-componentOrientation";
try {
 UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
 } catch (ClassNotFoundException e1) {
 e1.printStackTrace();
 } catch (InstantiationException e1) {
 e1.printStackTrace();
 } catch (IllegalAccessException e1) {
 e1.printStackTrace();
 } catch (UnsupportedLookAndFeelException e1) {
 e1.printStackTrace();
JFrame frame = new JFrame("Tree with Check Boxes");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final DefaultMutableTreeNode a = new DefaultMutableTreeNode("Node 1");
for(int i =0 ; i<3; i++ ){
 DefaultMutableTreeNode b = new DefaultMutableTreeNode("ChildNode "+i);
 a.add(b);
DefaultMutableTreeNode e = new DefaultMutableTreeNode("Node 2");
for(int i =0 ; i<3; i++ ){
 DefaultMutableTreeNode f = new DefaultMutableTreeNode("ChildNode "+i);
 e.add(f);
DefaultMutableTreeNode al = new DefaultMutableTreeNode("Sample");
al.add(a);
al.add(e);
final JTree tree = new JTree(al);
final CheckBoxTreeCellRenderer r =
new CheckBoxTreeCellRenderer(tree, tree.getCellRenderer());
tree.setCellRenderer(r);
int rc = tree.getRowCount();
tree.getActionMap().put(SWITCH, new AbstractAction(SWITCH) {
public void actionPerformed(ActionEvent e) {
ComponentOrientation o = tree.getComponentOrientation();
if (o.isLeftToRight()) {
o = ComponentOrientation.RIGHT_TO_LEFT;
else {
o = ComponentOrientation.LEFT_TO_RIGHT;
tree.setComponentOrientation(o);
tree.repaint();
int mask = InputEvent.SHIFT_MASK|Toolkit.getDefaultToolkit().getMenuShortcutKeyMask();
tree.getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_O, mask), SWITCH);
final JTextArea text = new JTextArea(createText(r.getCheckedPaths()));
text.setPreferredSize(new Dimension(200, 100));
tree.addMouseListener(new MouseAdapter() {
public void mouseReleased(MouseEvent e) {
// Invoke later to ensure all mouse handling is completed
SwingUtilities.invokeLater(new Runnable() { public void run() {
text.setText(createText(r.getCheckedPaths()));
JScrollPane pane = new JScrollPane(tree);
frame.getContentPane().add(pane);
// frame.getContentPane().add(new JScrollPane(text), BorderLayout.SOUTH);
frame.pack();
frame.setSize(600,400);
frame.setVisible(true);
catch(Exception e) {
e.printStackTrace();
System.exit(1);
now i need to get nodes names which has been selected, how can i do this
can anyone help me ...
regards,
shobi

Also, use code tags and post a SSCCE -- I'm sure more of your posted code is irrelevant to your question and few people are going to look at a code listing that long.
[http://mindprod.com/jgloss/sscce.html]

Help with JTree data by user input

I am trying to read data into a JTree without it being hardcoded.
An example of the data is:
String data[] = {"a","b","c",";","b","g","h",";","c","t",";","g","u"};
The above data is taken from user input and stored in an array and checked for errors.
I want to somehow read take the above array's data and put it into following format in some kind of loop but I am not sure how.
Object[] hierarchy = {"a", new Object[]{"b",new Object[]{"g","u"},"h"},new Object[]{"c","t"}};
This Object is then passed to a function that interpets it and prints out the appropriate JTREE structure. For the values above it would be:
a
..b
....g
......l
......u
....h
..c
....t
Tha problem is how to take the string array and put that data correctly into the Object array. I have been racking my feeble mind for quite sometime and if any one out there can see it or has a better idea of how to get my data into the JTree please let me know.
Thanks

//OutlookClient.java
//uses also Console class from Bruce Eckel
//<applet code=OutlookClient width=500 height=300>
//</applet>
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import javax.swing.event.*;
import javax.swing.tree.*;
import java.util.*;
import javax.swing.UIManager;
import javax.swing.SwingUtilities;
import BruceEckel.*;
import DynamicTree.*;
import DynamicTreeNode.*;
import java.lang.reflect.*;
/* a class creating a dialog with the version, and other details about the program*/
class AboutDialog extends JDialog {
 private JButton ok = null;
 private Container cp = null;
 private JTextField tname = null;
 public AboutDialog() {
 //System.out.println("constructor");
 ok = new JButton("OK");
 cp = getContentPane();
 cp.setLayout(new FlowLayout());
 JLabel tlab = new JLabel("Outlook - client side");
 cp.add(tlab);
 //tname.setMinimumSize(new Dimension(50,10));
 //tname.setSize(new Dimension(70,10));
 tlab = new JLabel("Author: Jiri Machotka");
 cp.add(tlab);
 tlab = new JLabel("version 1.0 (September 2001)");
 cp.add(tlab);
 tlab = new JLabel("----------------------------------------------");
 cp.add(tlab);
 ok.addActionListener( new ActionListener() {
 public void actionPerformed(ActionEvent e) {
 dispose();
 }//actionPerformed
 });//addActionListener
 cp.add(ok);
 setSize(200,150);
 setTitle("About the program");
 setModal(true);
 }//constructor
* This class more-or-less contains a graphic design object used for interaction with a user.
* Apart from all ScrollPanes, Buttons, and MenuItems, it contains also 3 interesting members:
* <ol>
* <li> protected final DefaultMutableTreeNode topNode, which is initialized with
* a potent, non-removable object of the class Node
* <li> protected final DefaultTreeModel treeModel, which is initialized with the topNode
* <li> and finally protected final DynamicTree dyn_tree, which uses the 2 objects above
* </ol>
* The OutlookClient is an applet, but it can be also processed as an application (thanks to
* a library by BruceEckel).
public class OutlookClient extends JApplet {
//------------- properties -----------------------------------------
 private Action
 newMail = new AbstractAction ("New Mail", new ImageIcon("images/NewMailIcon.gif")){
 public void actionPerformed(ActionEvent e) {
 txt.setText("NewMail");
 reply = new AbstractAction ("Reply", new ImageIcon("images/ReplyIcon.gif")){
 public void actionPerformed(ActionEvent e) {
 txt.setText("Reply");
 private JButton
 /*b1 = new JButton("Add a Node"),
 b2 = new JButton("Remove the current Node"),*/ //not used now
 tb1 = new JButton (newMail),
 tb2 = new JButton (reply);
 private JTextField
 txt = new JTextField(10);
 private Container
 leftArea = new Container(),
 rightArea = new Container();
 private JScrollPane
 left = new JScrollPane (leftArea, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS),
 right = new JScrollPane (rightArea, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
 private JSplitPane
 sp = new JSplitPane (JSplitPane.HORIZONTAL_SPLIT, left, right);
 private JToolBar
 toolBar = new JToolBar();
 private JMenuBar
 menuBar = new JMenuBar();
 /*ActionListener al = new ActionListener() {
 public void actionPerformed(ActionEvent e) {
 String name = ( (JButton)e.getSource()).getText();
 txt.setText(name);
 };*/ //not used now - used as an action listener for buttons b1, b2
 private JMenu
 mainOutlookMenu = new JMenu ("Outlook activities"),
 othersMenu = new JMenu ("Others"),
 mailMenu = new JMenu ("Mails"),
 chatMenu = new JMenu ("Chat"),
 look_and_feelMenu = new JMenu ("Look&Feel");
 private JMenuItem
 closeAppItem = new JMenuItem ("Exit",KeyEvent.VK_F3),
 newMailItem = new JMenuItem (newMail),
 replyItem = new JMenuItem (reply);
 private JRadioButtonMenuItem
 windowsLookAndFeelItem;
 protected final DefaultMutableTreeNode topNode = new DefaultMutableTreeNode(new Node ("Outlook", false, true));
 protected final DefaultTreeModel treeModel = new DefaultTreeModel(topNode);
 protected final DynamicTree dyn_tree = new DynamicTree(topNode, treeModel);
//-------------inner classes----------------------------------------
/** The class MyRenderer sets the renderer of the tree - by doing that icons can be assigned to
 * the tree's nodes. 
 * It sould be probably a standard member of a class DynamicTreeWithIcons.
 * However, it uses the knowledge that the class Node, which is the only object that can be
 * found in the dynamic tree in this application, has a method getIcon(), which returns a
 * reference to the icon object assigned to the node.
 * This is the only place, where the class Node, or its methods are called explicitely.
 protected class MyRenderer extends DefaultTreeCellRenderer {
 /** The constructor of the class.
 * - sets folders icons (opened, closed folder)
 public MyRenderer() {
 //setLeafIcon(new ImageIcon("images/middle.gif")); //for leaves' icon, all at once!
 setOpenIcon(new ImageIcon("images/folder_open.gif"));
 setClosedIcon(new ImageIcon("images/folder_close.gif"));
 /** This overridden method gets the user-specified icon for leaf nodes. */
 public Component getTreeCellRendererComponent(
 JTree tree,
 Object value,
 boolean sel,
 boolean expanded,
 boolean leaf,
 int row,
 boolean hasFocus) {
 super.getTreeCellRendererComponent(tree,value,sel,expanded,leaf,row,hasFocus);
 if (leaf)
 //workaround: test if icon not eq. null
 ImageIcon ic = getRightIcon(value);
 if (ic == null) return this;
 else
 setIcon(ic);
 return this;
 }//overridden: getTreeCellRendererComponent
 private ImageIcon getRightIcon(Object value) {
 DefaultMutableTreeNode node = (DefaultMutableTreeNode)value;
 try{
 Node node_object = (Node)(node.getUserObject());
 return (node_object.getIcon());
 catch (Exception e) { return null; }
 }// ImageIcon getRightIcon(Object value)
}//class MyRenderer
//-------------OutlookClient methods-----------------------------------------
 private void assignListeners(){
 dyn_tree.addTreeSelectionListener(new TreeSelectionListener() {
 public void valueChanged(TreeSelectionEvent e) {
 DefaultMutableTreeNode node = (DefaultMutableTreeNode)dyn_tree.getLastSelectedPathComponent();
 if (node == null) return;
 if (node.isLeaf()) { txt.setText(node.toString()); }
 }//assignListeners()
 private void createLayout(){
 leftArea.setLayout(new BoxLayout(leftArea,BoxLayout.Y_AXIS));
 rightArea.setLayout(new BoxLayout(rightArea,BoxLayout.Y_AXIS));
 //left.setMinimumSize(new Dimension(120,200));
 right.setMinimumSize(new Dimension(50,50));
 //rightArea.add(b1);
 //rightArea.add(b2);
 rightArea.add(txt);
 //leftArea.add(tree); ... not nice (why?)
 left = new JScrollPane (dyn_tree, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
 left.setMinimumSize(new Dimension(180,200));
 sp.setLeftComponent(left);
 }//createLayout()
 private void createMenu(){
 ButtonGroup group = new ButtonGroup();
 JRadioButtonMenuItem rbMenuItem;
 closeAppItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_F3, ActionEvent.ALT_MASK));
 closeAppItem.getAccessibleContext().setAccessibleDescription("Closes application");
 closeAppItem.addActionListener( new ActionListener() {
 public void actionPerformed(ActionEvent e) {System.exit(0);}
 othersMenu.setMnemonic(KeyEvent.VK_O);
 othersMenu.getAccessibleContext().setAccessibleDescription("System settings&Others");
 rbMenuItem = new JRadioButtonMenuItem("Java");
 rbMenuItem.setSelected(true);
 rbMenuItem.setMnemonic(KeyEvent.VK_J);
 group.add(rbMenuItem);
 rbMenuItem.addActionListener(new ActionListener() {
 public void actionPerformed(ActionEvent e) {setPLAF(UIManager.getCrossPlatformLookAndFeelClassName( ) );}
 look_and_feelMenu.add(rbMenuItem);
 rbMenuItem = new JRadioButtonMenuItem("Windows");
 rbMenuItem.setMnemonic(KeyEvent.VK_W);
 group.add(rbMenuItem);
 rbMenuItem.addActionListener(new ActionListener() {
 public void actionPerformed(ActionEvent e) {setPLAF("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");}
 look_and_feelMenu.add(rbMenuItem);
 windowsLookAndFeelItem = rbMenuItem;
 look_and_feelMenu.setMnemonic(KeyEvent.VK_L);
 look_and_feelMenu.getAccessibleContext().setAccessibleDescription("Look&Feel");
 JMenuItem aboutItem = new JMenuItem ("About");
 aboutItem.addActionListener(new ActionListener() {
 public void actionPerformed(ActionEvent e) {
 AboutDialog ad = new AboutDialog();
 ad.show();
 othersMenu.add(look_and_feelMenu);
 othersMenu.addSeparator();
 othersMenu.add(aboutItem);
 othersMenu.addSeparator();
 othersMenu.add(closeAppItem);
 mainOutlookMenu.setMnemonic(KeyEvent.VK_A);
 mainOutlookMenu.getAccessibleContext().setAccessibleDescription("Outlook activities");
 menuBar.add(mainOutlookMenu);
 menuBar.add(othersMenu);
 mailMenu.setMnemonic(KeyEvent.VK_M);
 mailMenu.getAccessibleContext().setAccessibleDescription("Mail activities");
 chatMenu.setMnemonic(KeyEvent.VK_C);
 chatMenu.getAccessibleContext().setAccessibleDescription("Chat");
 chatMenu.setEnabled(false);
 mainOutlookMenu.add(mailMenu);
 mainOutlookMenu.addSeparator();
 mainOutlookMenu.add(chatMenu);
 //mailMenu.add(newMail);
 //mailMenu.add(reply); //class Action has problems to catch the accelerator keys
 newMailItem.setMnemonic(KeyEvent.VK_N);
 replyItem.setMnemonic(KeyEvent.VK_R);
 mailMenu.add(newMailItem);
 mailMenu.add(replyItem);
 newMailItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_N, ActionEvent.CTRL_MASK));
 replyItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_R, ActionEvent.ALT_MASK));
 //newMail.putValue(Action.NAME, "New mail");
 //newMail.putValue(Action.SHORT_DESCRIPTION, "New mail");
 //newMail.putValue(Action.LONG_DESCRIPTION, "New mail");
 //newMail.putValue(Action.MNEMONIC_KEY, "N"); //cast an exception. why?
 //newMail.putValue(Action.ACCELERATOR_KEY, KeyStroke.getKeyStroke(KeyEvent.VK_N, ActionEvent.CTRL_MASK));
 setJMenuBar(menuBar);
 }//createMenu()
 private void createToolBar(){
 //toolBar.add(newMail);
 //toolBar.add(reply); //does not provide texts and mnemonics
 tb1.setMnemonic(KeyEvent.VK_N);
 tb2.setMnemonic(KeyEvent.VK_R);
 toolBar.add(tb1);
 toolBar.add(tb2);
 }//createToolBar()
 private void createNodes(DefaultMutableTreeNode topNode){
 //new for dynamic processing
 DefaultMutableTreeNode
 parentNode = null,
 leaveNode = null;
 parentNode = dyn_tree.addObject(null,new Node ("MailFolders", false, true));
 dyn_tree.addObject(parentNode,new Node ("Inbox","images/InboxIcon.gif", false, false));
 dyn_tree.addObject(parentNode,new Node ("Outbox","images/OutboxIcon.gif", false, false));
 dyn_tree.addObject(parentNode,new Node ("Sent","images/SentIcon.gif", false, false));
 dyn_tree.addObject(parentNode,new Node ("Deleted","images/DeletedIcon.gif", false, false));
 //leaveNode.setEnabled(false); //TODO: disable "Chat"node
 dyn_tree.addObject(null,new Node ("Chat", false, false));
 }//createcreateNodes(DefaultMutableTreeNode)
 private void setTreeSettings(){
 //one selection at one time
 dyn_tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);
 //connect nodes with a thin line - Java style only
 dyn_tree.putClientProperty("JTree.lineStyle","Angled");
 //collapse the root's children first
 //tree.setShowsRootHandles(false);
 //icon adjustment
 MyRenderer MyRen = new MyRenderer();
 dyn_tree.setCellRenderer(MyRen);
 //modifiable tree - by double click - allows modifying of nodes' names
 // but unfortunately also restores original icons
 //tree.setEditable(true);
 }//setTreeSettings()
 private boolean setPLAF(String LookAndFeelName){
 try{
 UIManager.setLookAndFeel(LookAndFeelName);
 SwingUtilities.updateComponentTreeUI(this);
 return true;
 } catch (Exception e) {
 //e.printStackTrace(System.err);
 return false;
 }//setPLAF(String LookAndFeelName)
 private void trytosetLookAndFeel(){
 if (setPLAF("com.sun.java.swing.plaf.windows.WindowsLookAndFeel"))
 windowsLookAndFeelItem.setSelected(true);
 }//trytosetLookAndFeel()
 /** The applet's init().
 * Calls methods to construct all visible objects.
 * Apart from that it also assigns the renderer to the tree.
 public void init(){
 sp.setOneTouchExpandable(true);
 //sp.setDividerLocation(150); - system puts the value to optimize the left part
 sp.setPreferredSize(new Dimension(450,200));
 Container cp = getContentPane();
 cp.setLayout(new FlowLayout());
 createLayout();
 createMenu();
 createToolBar();
 createNodes(topNode);
 setTreeSettings();
 //createPopupMenu();
 assignListeners();
 cp.add(toolBar);
 cp.add(sp);
 trytosetLookAndFeel();
 }//init()
 /** If called as an application.
 * The desired Windows Look&Feel is re-set again, when the applet is running. Otherwise, it in an application
 * it tends not to work correctly.
 public static void main(String[] args) {
 OutlookClient theApplet;
 BruceEckel.Console.run(theApplet=new OutlookClient(), 500, 300);
 theApplet.trytosetLookAndFeel();
 }//main(String[])
}///:~Take a look namely at createNodes
Hope it helps.

Problem with JTree and memory usage

I have problem with the JTree when memory usage is over the phisical memory( I have 512MB).
I use JTree to display very large data about structure organization of big company. It is working fine until memory usage is over the phisical memory - then some of nodes are not visible.
I hope somebody has an idea about this problem.

55%, it's still 1.6Gb....there shouldn't be a problem scanning something that it says will take up 300Mb, then actually only takes up 70Mb.
And not wrong, it obviously isn't releasing the memory when other applications need it because it doesn't, I have to close PS before it will release it. Yes, it probably is supposed to release it, but it isn't.
Thank you for your answer (even if it did appear to me to be a bit rude/shouty, perhaps something more polite than "Wrong!" next time) but I'm sitting at my computer, and I can see what is using how much memory and when, you can't.

Problem with Jtree to xml tranform..how to set/get parent of a node?

Hi,
I am trying to develop xml import/export module.In import wizard, I am parsing the xml file and the display it in Jtree view using xml tree model which implements TreeModel and xml tree node.I am using jaxp api..
It is workin fine.
I got stuck with removal of selected node and save it as a new xml.
I am not able to get parent node of selected node in remove process,itz throwing null.I think i missed to define parent when i load treemodel.Plz help me out..give some ideas to do it..
thanks
-bala
Edited by: r_bala on May 9, 2008 4:44 AM

there's no way anyone can help you without seeing your code.

Problem with JTree while expanding/collapsing a node

Hi,
I'm using a JTree for displaying the file system.
Here, i want that whenever a node get expanded,
it should show the latest files/directories under that node.
Now, what i'm doing is, getting all the files/dir's using files.listFiles(),
under that node and then creating a new node and adding it to parent (all in expand() method).
But, now the problem is, while doing this whenever the parent node get expanded its adding all the latest files/dirs into the previous instance
resulting the same file/dir is displaying twice,thrice.. and so on, as that node is expanded and collapsed.
i tried removeAllChildren() in collapse() method but then that node is notexpanding at all .
Can anybody help me please...
i got stuck b'coz of this only.
Thanks...

Now what i'm doing is every time expand() get called,
i'm comparing all the children of that node in the
current instance with all the children present in the
file system (because there is a possibility that some
file/dir may be added or deleted)
is this the right wy or not?it certainly is not wrong, but as usual, there is more than 1 way to implement this...
b'coz right now i'm getting all the files/dirs that
are newly added but facing some problem if somebody
deletes a file/dir.
i'm still trying to get the solutionthen you should not just compare all the children of the node with the files/dirs but also the other way round. compare the files/dirs with the children to determine if the file/dir still exists and if not remove the node.
or you could check if the file which a node represents exists and if not remove the node.
thomas

Problem with JTree custom renderer when editing

I have a JTree which uses a custom renderer to display my own icons for different types of nodes. The problem I am having is when I setEditable to true and then attept to edit a node the icon switches back to the default icon, as soon as I am done editing it goes back.
What I am doing wrong?

Here is my rendererer
public class DeviceTreeRenderer extends DefaultTreeCellRenderer implements GuiConstants {
   public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus) {
      JLabel returnValue = (JLabel)super.getTreeCellRendererComponent(tree, value, selected, expanded, leaf, row, hasFocus);
      if (value != null) {
         returnValue.setToolTipText(value.toString());
      if (value instanceof Device) {
         returnValue.setIcon(TREE_DEVICE);
         if (!((Device)value).isAlive()) {
            returnValue.setEnabled(false);
      else if (value instanceof GuiPanelGroup) {
         if (expanded) {
            returnValue.setIcon(TREE_PANEL_GROUP_OPEN);
         else {
            returnValue.setIcon(TREE_PANEL_GROUP_CLOSED);
      else if (value instanceof GuiPanel && ((GuiPanel)value).isDirty()) {
         returnValue.setIcon(TREE_PANEL_DIRTY);
      return returnValue;
}Here is my editor:
public class WwpJTreeCellEditor extends DefaultTreeCellEditor implements GuiConstants {
      private WwpJTree tree;
       * Creates a new WwpJTreeCellEditor.
       * @param tree The WwpJTree to associate with this editor.
      public WwpJTreeCellEditor(WwpJTree tree) {
         super(tree, (DefaultTreeCellRenderer)tree.getCellRenderer());
         this.tree = tree;
       * Overrides the default isCellEditable so that we check the isEditable() method
       * of the WwpJTreeNodes.
       * @param e An EventObject.
      public boolean isCellEditable(EventObject e) {
         boolean returnValue = super.isCellEditable(e);
         if (returnValue) {
            WwpJTreeNode node = this.tree.getSelectedNode();
            if (node == null || !node.isEditable() || node.isDragging()) {
               returnValue = false;
         return returnValue;
   }In my JTree I make these calls:
super.setCellRenderer(new DeviceTreeRenderer());
super.setCellEditor(new WwpJTreeCellEditor(this));
super.setEditable(true);

Problem with jtree selection

Hi all,
I've got a JTree that represents a sort of data that I'm going to change dynamically in my application. I'd like to reset the selection of the user to the leaf she has selected before the change to the tree structure.
First of all my tree uses DefaultMutableTreeNode to build each node, and each DefaultMutableTreeNode contains a SingleKeyValue object, that is a key-value object (two strings) and that has an hashcode defined as follows:
public class SingleKeyValue extends BaseKeyValue{
      * The key of the database object.
     protected String key = null;
      * The description of this object.
     protected String value = null;
     public int hashCode() {
          return this.key.hashCode();
     I hope the hashcode can help me finding the right object even when its value changes (but the key is the same). The construction of the tree is the following:
DefaultMutableTreeNode root = new DefaultMutableTreeNode("The root");
// iterate and build each node
SingleKeyValue object = new SingleKeyValue("key","value");
DefaultMutableTreeNode node = new DefaultMutableTreeNode(object);
root.add(node);
DefaultTreeModel model = new DefaultTreeModel(root);
JTree tree = new JTree(model);
            so the tree is associated to a DefaultTreeModel. Then, when I need to change something in the tree I rebuild the tree and all leafs (with the SingleKeyValues) and rebuild the model:
          TreeModel treeModel = this.myTree.getModel();
          TreeSelectionModel selectionModel = this.myTree.getSelectionModel();
          DefaultTreeModel defaultTreeModel = null;
          DefaultTreeSelectionModel defaultTreeSelectionModel = null;
          TreePath selectedPath = null;
          TreeNode root = null;
          Logger.info("SimpleTreePanel.refreshDatabaseView: treemodel "+treeModel + " selectionModel " + selectionModel);
          if( treeModel != null && treeModel instanceof DefaultTreeModel ) {
               defaultTreeModel = (DefaultTreeModel) treeModel;
               root = this.getRoot();
               // get the selection
               if( selectionModel != null && selectionModel instanceof DefaultTreeSelectionModel ){
                    defaultTreeSelectionModel = (DefaultTreeSelectionModel) selectionModel;
                    selectedPath = defaultTreeSelectionModel.getSelectionPath();
                    Logger.warn("Selection path of the tree: "+selectedPath);
               // rebuild the tree
               defaultTreeModel.setRoot(root);
               // set the selected element
               defaultTreeSelectionModel.setSelectionPath(selectedPath);The problem is that after the above code the tree is all closed, no leaf are selected. I guess the problem is with the SingleKeyValueObject because I've tried the default model and it works with, for example, simple strings. Any idea about?
Thanks,
Luca

Here's a complete test program that creates a few SingleKeyValue objetcs (objects with a key and a description) and that then places them into a JTree using the DefaultMutableTreeNode. After that, the selection of user is took and one node is changed, but while the selection is working, the reload/refresh of the tree is not.
Any idea about how to work on it?
public class SingleKeyValue extends BaseKeyValue{
      * The key of the database object.
     protected String key = null;
      * The description of this object.
     protected String value = null;
     // constants related to the type of the table this object refers to
     public static final String COMPETENCE = "competenza";
     public static final String FAMILY            = "famiglia_competenza";
     public static final String ROLE              = "ruolo";
     public static final String PROVINCE      = "provincia";
     public static final String KNOWLEDGE = "titolo_studio";
     public final static String OBJECTIVE      = "obiettivo";
     public final static String PERSON         = "persona";
     public SingleKeyValue( String key, String value, String table){
          super();
          this.key = key;
          this.value = value;
          this.SQLTable = table;
      * @return the key
     public final String getKey() {
          return key;
      * @param key the key to set
     public final void setKey(String key) {
          this.key = key;
      * @return the value
     public final String getValue() {
          return value;
      * @param value the value to set
     public final void setValue(String value) {
          this.value = value;
      * Shows this element.
     public String toString(){
          String ret;
          if( this.showKey ){
               ret = this.label + this.key +" { "+ this.value +" }";
          else
               ret = this.label + this.value;
          // trim the string
          if( ret.length() > this.maxLength )
               return ret.substring(0 , this.maxLength);
          else
               return ret;
      * The hash code of this object is the hash code of the key.
      * @return the hash code of the key of the object
     public int hashCode() {
          return this.key.hashCode();
      * Returns true if the object passed is a single key value equals (i.e., with the same key) of this one.
     public boolean equals(Object o){
          if( o== null || (! (o instanceof SingleKeyValue) ) )     return false;
          else
               return (this.hashCode() == o.hashCode());
     public static void main(String argv[]) throws Exception{
         SingleKeyValue skv1 = new SingleKeyValue("Key1","Description1", SingleKeyValue.COMPETENCE);
         SingleKeyValue skv2 = new SingleKeyValue("Key1a","Description1a", SingleKeyValue.COMPETENCE);
         SingleKeyValue skv3 = new SingleKeyValue("Key1b","Description1b", SingleKeyValue.COMPETENCE);
         SingleKeyValue skv4 = new SingleKeyValue("Key2","Description2", SingleKeyValue.COMPETENCE);
         SingleKeyValue skv5 = new SingleKeyValue("Key2a","Description2a", SingleKeyValue.COMPETENCE);
         SingleKeyValue skv6 = new SingleKeyValue("Key2b","Description2b", SingleKeyValue.COMPETENCE);
         DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode("root");
         DefaultMutableTreeNode node1 = new DefaultMutableTreeNode(skv1);
         DefaultMutableTreeNode node2 = new DefaultMutableTreeNode(skv2);
         DefaultMutableTreeNode node3 = new DefaultMutableTreeNode(skv3);
         DefaultMutableTreeNode node4 = new DefaultMutableTreeNode(skv4);
         DefaultMutableTreeNode node5 = new DefaultMutableTreeNode(skv5);
         DefaultMutableTreeNode node6 = new DefaultMutableTreeNode(skv6);
         rootNode.add(node1);
         node1.add(node2);
         node1.add(node3);
         rootNode.add(node4);
         node4.add(node5);
         node4.add(node6);
         JTree tree = new JTree(rootNode);
         JFrame f = new JFrame("Tree try");
         f.add( new JScrollPane(tree) );
         f.setSize(300,300);
         f.setVisible(true);
         System.out.println("Please select a node within 10 seconds");
         Thread.sleep(10000);
         // now get the user selection
     TreeModel treeModel = tree.getModel();
     TreeSelectionModel selectionModel = tree.getSelectionModel();
     DefaultTreeModel defaultTreeModel = null;
     DefaultTreeSelectionModel defaultTreeSelectionModel = null;
     TreePath selectedPath = null;
     TreeNode root = null;
     if( treeModel != null && treeModel instanceof DefaultTreeModel ) {
          defaultTreeModel = (DefaultTreeModel) treeModel;
          // get the selection
          if( selectionModel != null && selectionModel instanceof DefaultTreeSelectionModel ){
               defaultTreeSelectionModel = (DefaultTreeSelectionModel) selectionModel;
               selectedPath = defaultTreeSelectionModel.getSelectionPath();
          // rebuild the tree
          node1.setUserObject(new SingleKeyValue("key20","key changed",SingleKeyValue.FAMILY));
          defaultTreeModel.reload();
          // set the selected element
          defaultTreeSelectionModel.setSelectionPath(selectedPath);
}

Problem with JTree.isExpanded()

Working with a JTree, I encountered into a strange behavior - I hope someone could explain me...
For exporting a tree I need the information whether nodes are expanded or not.
The first strange thing is that the root always seems to be collapsed - but this I can handle somehow.
The problem is, that a expanded node containing a leaf, is reported as collapsed - but it is not. Why?
Here the output of a expand-checking method, which prints the state of the node and its parents.
(the "+" indicates a expanded node, the "-" indicated a collapsed node)
+ - Abasdf
+ - EP/asdf
+ - - Prosadf
+ - - - Altasdf
+ - - - - V1sadf
+ - - - - - 059asdf
+ - - - - - - 059asdf
+ - - - - - - + 059asdf
+ - - - - - - + + this_is_a_leafWhy is the expanded node containing the leaf reported as collapsed?
I'm using the following for checking if a node is expanded:
view.isExpanded(node.getIndex())I also tried this - with the same wrong result:
view.isExpanded(view.getPathForRow(node.getIndex()))Any hint is highly appretiated.

I was not able to reproduce your problemimport javax.swing.*;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreePath;
import javax.swing.tree.TreeNode;
import java.util.Random;
import java.util.Enumeration;
import java.awt.*;
import java.awt.event.ActionEvent;
public class HamsterChipsyTest extends JPanel {
 private static final Random RANDOM = new Random(System.currentTimeMillis());
 private JTree theTree;
 private DefaultTreeModel theTreeModel;
 private DefaultMutableTreeNode theRoot;
 public HamsterChipsyTest() {
 super(new BorderLayout());
 theRoot = createRandomNode();
 addNodes(theRoot, 0, 2);
 theTreeModel = new DefaultTreeModel(theRoot);
 theTree = new JTree(theTreeModel);
 add(new JScrollPane(theTree), BorderLayout.CENTER);
 add(new JButton(new AbstractAction("dump nodes' extension state") {
 public void actionPerformed(ActionEvent e) {
 dumpExtensionState(theRoot);
 }), BorderLayout.NORTH);
 private void dumpExtensionState(DefaultMutableTreeNode aTreeNode) {
 TreeNode[] path = aTreeNode.getPath();
 for (int i = 0; i < path.length; i++) {
 System.out.print('-');
 System.out.println(" " + aTreeNode.getUserObject().toString() + " " + theTree.isExpanded(new TreePath(path)));
 Enumeration children = aTreeNode.children();
 while(children.hasMoreElements()) {
 DefaultMutableTreeNode child = (DefaultMutableTreeNode)children.nextElement();
 dumpExtensionState(child);
 private static void addNodes(DefaultMutableTreeNode aParent, int aCurrentDepth, int aMaxDepth) {
 if (aCurrentDepth >= aMaxDepth) return;
 int nodeCount = RANDOM.nextInt(3);
 for (int i = 0; i < nodeCount + 1; i++) {
 DefaultMutableTreeNode child = createRandomNode();
 aParent.add(child);
 addNodes(child, aCurrentDepth + 1, aMaxDepth);
 private static DefaultMutableTreeNode createRandomNode() {
 char[] chars = new char[5];
 for (int i = 0; i < chars.length; i++) {
 chars[i] = (char)('a' + RANDOM.nextInt(26));
 return new DefaultMutableTreeNode(new String(chars));
 public static void main(String[] args) {
 final JFrame frame = new JFrame(HamsterChipsyTest.class.getName());
 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 frame.setContentPane(new HamsterChipsyTest());
 SwingUtilities.invokeLater(new Runnable() {
 public void run() {
 frame.pack();
 frame.show();
}

Focus Problem with JTree and Menus

Hi all,
I have a problem with focus when editing a JTree and selecting a menu. The problem occurs when the user single clicks on a node, invoking the countdown to edit. If the user quickly clicks on a menu item, the focus will go to the menu item, but then when the countdown finishes, the node now has keyboard focus.
Below is code to reproduce the problem. Click on the node, hover for a little bit, then quickly click on the menu item.
How would I go about fixing the problem? Thanks!
import java.awt.Container;
import java.awt.GridLayout;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
public class MyTree extends JTree {
     public MyTree(DefaultTreeModel treemodel) {
          setModel(treemodel);
          setRootVisible(true);
     public static void main(String[] args) {
          JFrame frame = new JFrame();
          JMenuBar bar = new JMenuBar();
          JMenu menu = new JMenu("Test");
          JMenuItem item = new JMenuItem("Item");
          menu.add(item);
          bar.add(menu);
          frame.setJMenuBar(bar);
          Container contentPane = frame.getContentPane();
          contentPane.setLayout(new GridLayout(1, 2));
          DefaultMutableTreeNode root1 = new DefaultMutableTreeNode("Root");
          root1.add(new DefaultMutableTreeNode("Root2"));
          DefaultTreeModel model = new DefaultTreeModel(root1);
          MyTree tree1 = new MyTree(model);
          tree1.setEditable(true);
          tree1.setCellEditor(
               new ComponentTreeCellEditor(
                    tree1,
                    new ComponentTreeCellRenderer()));
          tree1.setRowHeight(0);
          contentPane.add(tree1);
          frame.pack();
          frame.show();
import java.awt.FlowLayout;
import java.util.EventObject;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.JTree;
import javax.swing.tree.DefaultTreeCellEditor;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreeCellEditor;
import javax.swing.tree.TreeCellRenderer;
public class ComponentTreeCellEditor
     extends DefaultTreeCellEditor
     implements TreeCellEditor {
     private String m_oldValue;
     private TreeCellRenderer m_renderer = null;
     private DefaultTreeModel m_model = null;
     private JPanel m_display = null;
     private JTextField m_field = null;
     private JTree m_tree = null;
     public ComponentTreeCellEditor(
          JTree tree,
          DefaultTreeCellRenderer renderer) {
          super(tree, renderer);
          m_renderer = renderer;
          m_model = (DefaultTreeModel) tree.getModel();
          m_tree = tree;
          m_display = new JPanel(new FlowLayout(FlowLayout.LEFT));
          m_field = new JTextField();
          m_display.add(new JLabel("My Label "));
          m_display.add(m_field);
     public java.awt.Component getTreeCellEditorComponent(
          JTree tree,
          Object value,
          boolean isSelected,
          boolean expanded,
          boolean leaf,
          int row) {
          m_field.setText(value.toString());
          return m_display;
     public Object getCellEditorValue() {
          return m_field.getText();
      * The edited cell should always be selected.
      * @param anEvent the event that fired this function.
      * @return true, always.
     public boolean shouldSelectCell(EventObject anEvent) {
          return true;
      * Only edit immediately if the event is null.
      * @param event the event being studied
      * @return true if event is null, false otherwise.
     protected boolean canEditImmediately(EventObject event) {
          return (event == null);
}

You can provide a cell renderer to the JTree to paint the checkBox.
The following code checks or unchecks the box with each click also:
_tree.setCellRenderer(new DefaultTreeCellRenderer()
private JCheckBox checkBox = null;
public Component getTreeCellRendererComponent(JTree tree,
                                                Object value,
                                                boolean selected,
                                                boolean expanded,
                                                boolean leaf,
                                                int row,
                                                boolean hasFocus)
    // Each node will be drawn as a check box
    if (checkBox == null)
      checkBox = new JCheckBox();
      checkBox .setBackground(tree.getBackground());
    DefaultMutableTreeNode node = (DefaultMutableTreeNode)value;
    checkBox.setText(node.getUserObject().toString());
    checkBox.setSelected(selected);
    return checkBox;
});

KeyEvent with JTree

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