JavaHelp with JTree

I have just started using JavaHelp today, and I've figured out the general opening of the help window with F1 and the help broker, and also triggering context-sensitive help.... However, I can't seem to figure the correct way that I could register context-sensitive help for tree nodes. I have a tree that will have a specific set of named nodes, and there will be help topics for each type of node, so I'd like to have help linkable to the type of node. Can anyone point me in the right direction? Thanks,

Hi,
I am facing exactly the same issue. Did you get some solution for this?
Since JTree is a component and DefaultMutableTreeNodes inside it are not (extend directly from java.lang.Object), we can attach CSH only to the overall tree and not to the separate nodes is it?
I have to solve this As Soon As Possible. Somebody please reply soon.
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

Best way to bundle JavaHelp with application

What is the best way to bundle JavaHelp with an application....
At present I have to run the application that uses JavaHelp as follows
java -classpath ;lib/jhall.jar HelpMenu
Is there a better way? so that when the application is moved to a client machine the classpath to the javaHelp jhall.jar does not have to be supplied as above?
Cheers :)

If you don't want to specify the classpath you can
1> either create a batch/shell script with lauches the app with the appropriate classpath
2> You jar your app and specify the classpath in your jars's MANIFEST.MF file like this.
Main-Class: main class name which will launch the app
Class-Path: jhall.jar
The above entries assume jhall.jar is in the same dir as your main jar. You can put more jars in the classpath above by separating them with space.
With this the app can be just lauched by typing: java -jar filaname.jar

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 )

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;
});

Problem with JTree and JPopupMenu

Hi,
I'm using a JPopupMenu with a JPanel in it. In the panel
I want to have a JTree. I can build the tree without
problems but when I try to "go down" in the tree it
vanishes. This happens only the first time that I
access a node. When I initialize the menu a second
time the node I just pressed works fine.
What is the problem????
Here is a sample of my code.
popUpMenu = new JPopupMenu();
thePanel = new JPanel();
thePanel .setLayout(new GridBagLayout());
popUpMenu .add(thePanel );
DefaultMutableTreeNode top = new DefaultMutableTreeNode("The top");
DefaultMutableTreeNode secondNode = null;
DefaultMutableTreeNode firstNode = null;
firstNode = new DefaultMutableTreeNode("One node");
top.add(firstNode);
secondNode= new DefaultMutableTreeNode("One node");
firstNode.add(secondNode);
buildConstraints(gbc, 1, 0, 1, 5, 5, 5, 5, 2, 1); //My contraintsmethod
JTree tree = new JTree(top);
thePanel .add(tree, gbc);

Mate, why are you putting a JPanel in a JPopupMenu? I'd be interested to look at a screenshot of this.
Mitch

Problem with Jtree and a checkbox

Hello,
I have a problem with my tree implementation.
I create a tree and i want to add a checkbox in each node.
this is my code :
DefaultMutableTreeNode root;
root = new DefaultMutableTreeNode(new JCheckBox());
DefaultTreeModel model = new DefaultTreeModel(root);
_tree = new JTree(model);
eastpane.add(tree);
THe problem is that my checkbox doesn't appear. And a message appears
instead of my checkbox.
But my tree appears.
Can anyone help me .
Thanks

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;
});

JavaHelp with JTree

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