Set JTree root node

how do i set the root node in JTree, whereas the root node should not be the parameter in the JTree constructor. is there a methode "set root"
thanks

hi,
((DefaultTreeModel)yourtree.getModel()).setRoot(aTreeNode);

Similar Messages

Is it possible to set the root node of JTree by default close???? Pls Help

Hello frnz,
I am working on JTreeTable and rt now i am facing a problem , in which i have to keep the root of the JTree by default close,
So please suggest me to do what for this.

How about
JTree.collapseRow(0)

How to remove all nodes (except root node)from a Jtree?

How to remove all nodes (except the root node)from a Jtree?

Either:
- remove all children of root.
- save the root node, throws away the tree model, build a new TreeModel with the saved root, set the new TreeModel in the JTree.
- implement your own TreeModel, which would support an emptyExceptRoot() method.
IMHO, using the DefautlTreeModel and DefaultMutableTreeNode does lead to all sorts of small problems when the app evolves, and implementing your own TreeNode and TreeModel is not that hard and much more efficient.

Highlight root node in jtree

When I build my JTree, I have just one single node, the root node. So in order to highlight it, I basically do setSelectionRow(0);, however this is not highlighting the node as if a user clicked it with a mouse, WHEN THE APPLICATION COMES UP.
Once the application comes up, if I click on that node or for that matter any other node, they get highlighted in blue. It's only upon initialization that this doesn't work.
Here's a snippet of the sample code:
tree = new JTree();
tree.setCellRenderer(new RateManagerTreeCellRenderer());
I've also tried the setSelectionPath(TreePath path) method without any success. I think that my Custom TreeCellRenderer could be the culprit. If someone could try to duplicate this problem by using the code below of my RateManagerTreeCellRenderer, I would appreciate it.
public class RateManagerTreeCellRenderer extends DefaultTreeCellRenderer
private static Color oldColor = Color.BLACK;
private static Color newColor = Color.BLUE;
private HashMap iconMap = new HashMap();
public Component getTreeCellRendererComponent(
          JTree tree, Object value,
          boolean selected, boolean expanded,
          boolean leaf, int row,
          boolean hasFocus)
super.getTreeCellRendererComponent(tree, value, selected, expanded, leaf, row, hasFocus);
DefaultMutableTreeNode treeNode = (DefaultMutableTreeNode)value;
Object userObject = treeNode.getUserObject();
if (userObject instanceof NameAndID)
NameAndID nameAndID = (NameAndID)userObject;
int count = nameAndID.getItemCount();
if (count > 0 && !selected)
setForeground(newColor);
else if (!selected)
setForeground(oldColor);
this.setToolTipText(((NameAndID)userObject).toString());
String type = nameAndID.getType();
setIcon(type);
return this;
}

Do you mean setting the focus on that node? Or are you talking about some custom painting to put a background behind it? We can't help you much if you don't ask a more specific question with more details about what you're trying to do.

How to change icon of a node or root node of a JTree

i have a JTree with a root node, and leaf nodes. i want to change their icons. how can i do this?
thanks

Here's a search of the forums with the words 'tree', 'icon' and 'node' in the title
http://onesearch.sun.com/search/developers/index.jsp?and=jtree+icon+node&nh=10&phr=&qt=&not=&field=title&since=&col=devforums&rf=0&Search.x=28&Search.y=15
I looked at a couple and #5 seems interesting, but there are quite a few to choose from.

How do i get to display the nodes under the root node in a JTree?

In my JTree there is a root node.This root node has 4 child nodes.Each child node in turn has nodes under it.What i need to do is just display the child nodes under the root node i.e., the four child nodes and keep these child nodes in a collapsed state.How do i go sbout this?

Please try this:
tree.expandRow(0);
SwingUtilities.invokeLater(new Runnable(){
    public void run(){
        tree.setRootVisible(false);
});If you want to show the RootHandles:
tree.setShowsRootHandles(true);If you want to keep nodes in collapsed state (not expandable):
        tel = new TreeWillExpandListener() {
            public void treeWillExpand(TreeExpansionEvent event) throws ExpandVetoException {
                throw new ExpandVetoException( event, "Don't want" );
            public void treeWillCollapse(TreeExpansionEvent event) throws ExpandVetoException {
        tree.addTreeWillExpandListener(tel);Some reading material:
http://java.sun.com/docs/books/tutorial/uiswing/components/tree.html
http://java.sun.com/docs/books/tutorial/uiswing/events/treewillexpandlistener.html
Edited by: Andre_Uhres on Nov 14, 2007 5:17 PM
Edited by: Andre_Uhres on Nov 14, 2007 5:33 PM
Edited by: Andre_Uhres on Nov 14, 2007 5:39 PM

How to set a particular node selected in a JTree from within the model

I have an adapter class that provides communication between my JTree and data model. My adapter class implements TreeModel, TreeExpansionListener, TreeSelectionListener and a listener for changes to my data model.
My data model keeps reference to the currently selected node. It is working quite nicely when I select a tree node with the mouse (the data model is updated accordingly with the node selected), however my problem occurs trying to go the other way (set the selected node in my data model and have it reflected in the tree).
I know that my selection in the tree is changing correctly as when the selection changes it fires off an event to update the attributes window associated with the currently selected node. I just can't get the node to become highlighted.
Any ideas would be most welcome.
Thanks,
Beck.

Does your model really have to keep track of the selected item or can the two views (the JTree and the attributes window) not be coupled together in the user interface instead?
Failing that, you could always consider implementing TreeSelectionModel as well and calling JTree.setSelectionModel since you're keeping track of the tree selection for it already. This is quite a bit of work though.
If that's too much trouble then if you can work out the TreePath for the node that's been programmatically selected through your model then you could use JTree.getSelectionModel().setSelectionPath. Have a look at tree.getSelectionModel().setSelectedPath(new TreePath(selectedObject)).
This approach is a bit warped, though, since it implies that your model knows about the view and therefore couples them together.

JTREE: Custom TreeModel does not update non-root nodes

I have a JTree that uses a custom TreeModel that wraps over (delegates to) a data class X which keeps track of all its children. The class X maintains its own data structure internally (references to other data objects). It also implements 'equals' and 'hashcode' methods. When the data changes in X, it invokes fireTreeStructureChanged on the TreeModel. (There is a TreeModelListener registered with the TreeModel). This works very well for the root node but not for the other non-root nodes. The JTree correctly calls 'equals' and I can see that equals returns 'false' but for non-root nodes the JTree does not refresh though I can see the underlying data structure has changed.
I am wondering if I may not have fully & correctly implemented fireTreeStructureChanged as it doesn't seem to do much. Or I may be looking at the wrong place. Any pointers would be appreciated.
BTW, this question is very similar to one asked years earlier http://forums.sun.com/thread.jspa?threadID=153854 but it didn't help me :(
Thanks.
ps: working with jdk1.6.0_06 on WinXP.

I have a same problem. I got an error "Cannot Update Libray".

How to create JTree without root node

Hello;
I like to create a JTree without root node?
Any help?
Thanks!
--tony

javadocs JTree,
setRootVisible
public void setRootVisible(boolean rootVisible)
Determines whether or not the root node from the TreeModel is visible.
Parameters:
rootVisible - true if the root node of the tree is to be displayedSee Also:
rootVisible

Lining up root node and child nodes in JTree

I have a JTree that has a root node and n child nodes. There are no sub-levels - it is structured just like AOL instant messenger. What I want to do is have the child node icons line up directly under the root nodes text. For example (if you can read this), where "-" denotes the icon:
- root
- child
- child
Currently it is something like this:
- root
- child
- child
I have been messing with the setLeftChildIndent( int ) and setRightChildIndent( int ), but they are not doing much...they seem to not want to only move the leaf nodes but all of the nodes, so its not doing exactly what I want.
Any ideas? In the meantime I'll be looking more into how exactly those indent mutators work.
Thanks!

What you want is to do a setRootVisible(false) on the JTree.
All your child nodes are then your "root level" folders.
tree.setRootVisible(true):
+root
+--child1
+--child2
+--child3
+----child3a
+----child3btree.setRootVisible(false):
+child1
+child2
+child3
+--child3a
+--child3b

How to disable selection of root node in JTree

Hi all! Thanks for taking a minute to read my post!
I am writing a really basic JTree for showing a list of items.
Here is some of the code:
/** Create a basic tree **/
DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode("Title");
DefaultTreeModel treeModel = new DefaultTreeModel(rootNode);
JTree tree = new JTree(treeModel);
/** Method to return the string of the current highlighted selection **/
public String getSelectionString()
DefaultMutableTreeNode node =
tree.getSelectionPath().getLastPathComponent();
return (String)node.getUserObject();
I would like to disable selection of the root node of my JTree.
Thus, if I make a call to getSelectionString() above, it would return null instead of the string that represents the root label.
I have read the following forum on disabling various TreePaths and TreeNodes in a JTree:
http://forum.java.sun.com/thread.jsp?forum=57&thread=224691
This forum suggests implementing the TreeSelectionListener interface and the TreeSelectionModel class and over-riding the addSelectedPath() methods. I tried this suggestion, and I was able to enable and disable the different children of the Jtree, but the root of the JTree would not disable.
I suppose that I could just simply remove the visibility of the root node, but I really want to avoid that option if possible.
Wait --- let me be clear ---- I want to disable the selection of the root node only - still allowing selection of all its children.
Any suggestions?
Am I missing something really simple here?
Did I explain my problem clearly?
Thanks in advance!
jewels

simply try this..
in the
public void valueChanged(javax.swing.event.TreeSelectionEvent event);
method of TreeSelectionListener impelentation get the
TreePath tp = event.getPath();
from TreePath get the component and then remove the selection from the treePath if it is the node u were checking/root node in this case
tree.getSelectionModel().removeSelectionPath(tp);
Try out....

Setting background color to just the root node in a tree

How can I set a background color to just the root node in a tree? I got the node in the followig way in the renderer method.
IconNodeClass parentIconNode = (IconNodeClass)((IconNodeClass)value).getRoot();
Then how can I set the background for just the root node? Thanks.

You need to write ur own treeCellRenderer for that to be done

JTree no root node

how do you create a JTree with no root node?
i just want
Parent
--child
Parent
--child
--child

i think a tree must always have a root node....but I think what u can do is make that root node not visible...i've seen it done before.
good luck

Setting JTree in one class file from another class file

Hello,
I'm new to java. I recently created a project in netbeans and here is one of the java files. I used the IDE to make a split pane, with a tree structure and panel in it.
* To change this template, choose Tools | Templates
* and open the template in the editor.
* AmplifierDesignGUI.java
* Created on Jun 20, 2010, 1:18:52 PM
package AmplifierDesign;
import java.util.logging.Level;
import java.util.logging.Logger;
* @author Bugz
public class AmplifierDesignGUI extends javax.swing.JFrame {
/** Creates new form AmplifierDesignGUI */
public AmplifierDesignGUI() {
initComponents();
/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jSplitPane1 = new javax.swing.JSplitPane();
jScrollPane1 = new javax.swing.JScrollPane();
jTree1 = new javax.swing.JTree();
jPanel1 = new javax.swing.JPanel();
jMenuBar1 = new javax.swing.JMenuBar();
jMenu1 = new javax.swing.JMenu();
jMenu2 = new javax.swing.JMenu();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jScrollPane1.setViewportView(jTree1);
jSplitPane1.setLeftComponent(jScrollPane1);
org.jdesktop.layout.GroupLayout jPanel1Layout = new org.jdesktop.layout.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(0, 475, Short.MAX_VALUE)
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(0, 274, Short.MAX_VALUE)
jSplitPane1.setRightComponent(jPanel1);
jMenu1.setText("File");
jMenuBar1.add(jMenu1);
jMenu2.setText("Edit");
jMenuBar1.add(jMenu2);
setJMenuBar(jMenuBar1);
org.jdesktop.layout.GroupLayout layout = new org.jdesktop.layout.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(layout.createSequentialGroup()
.add(8, 8, 8)
.add(jSplitPane1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 571, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
.addContainerGap(32, Short.MAX_VALUE))
layout.setVerticalGroup(
layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(layout.createSequentialGroup()
.add(8, 8, 8)
.add(jSplitPane1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 278, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
.addContainerGap(org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
pack();
}// </editor-fold>
* @param args the command line arguments
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new AmplifierDesignGUI().setVisible(true);
try {
new JTreeStructure().setVisible(true);
} catch (Exception ex) {
Logger.getLogger(AmplifierDesignGUI.class.getName()).log(Level.SEVERE, null, ex);
// Variables declaration - do not modify
private javax.swing.JMenu jMenu1;
private javax.swing.JMenu jMenu2;
private javax.swing.JMenuBar jMenuBar1;
private javax.swing.JPanel jPanel1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JSplitPane jSplitPane1;
private javax.swing.JTree jTree1;
// End of variables declaration
So once this was done I wanted to link the JTree to a mysql database. So I found a sample .java file on the net:
* To change this template, choose Tools | Templates
* and open the template in the editor.
package AmplifierDesign;
import java.awt.*;
import java.sql.*;
import java.util.*;
import javax.swing.*;
import javax.swing.tree.*;
public class JTreeStructure extends JFrame {
Connection con = null;
Statement st = null;
ResultSet rs = null;
//public static void main(String args[]) throws Exception {
// new JTreeStructure();
public JTreeStructure() throws Exception {
super("Retrieving data from database ");
String driver = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:8889/";
String db = "icons";
ArrayList list = new ArrayList();
list.add("Laser Objects");
Class.forName(driver);
con = DriverManager.getConnection(url + db, "root", "root");
try {
String sql = "Select * from fiberComponents";
st = con.createStatement();
rs = st.executeQuery(sql);
while (rs.next()) {
Object value[] = {"Fiber Components",rs.getString(2) };
list.add(value);
} catch (Exception e) {
System.out.println(e);
rs.close();
st.close();
con.close();
Object hierarchy[] = list.toArray();
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container content = getContentPane();
DefaultMutableTreeNode root = processHierarchy(hierarchy);
JTree tree = new JTree(root);
content.add(new JScrollPane(tree), BorderLayout.CENTER);
setSize(275, 300);
setLocation(300, 100);
setVisible(true);
private DefaultMutableTreeNode processHierarchy(Object[] hierarchy) {
DefaultMutableTreeNode node = new DefaultMutableTreeNode(hierarchy[0]);
DefaultMutableTreeNode child;
for (int i = 1; i < hierarchy.length; i++) {
Object nodeSpecifier = hierarchy;
if (nodeSpecifier instanceof Object[]) // Ie node with children
child = processHierarchy((Object[]) nodeSpecifier);
} else {
child = new DefaultMutableTreeNode(nodeSpecifier); // Ie Leaf
node.add(child);
return (node);
The problem is when I run my program two windows open up. The original one with JTree1, and the panel and horizontal splitplane and another window with a new tree component that did get its objects from the database. My question is how do I "replace" the JTree1 with the new tree created from the second java file?
Or additionally, maybe I could set the data for JTree1 from within the second java file?

zmoddynamics wrote:
....Please excuse my post as I am not sure what is meant by code tags?To use code tags, highlight your pasted code (please be sure that it is already formatted when you paste it into the forum; the code tags don't magically format unformatted code) and then press the code button, and your code will have tags.
Another way to do this is to manually place the tags into your code by placing the tag [code] above your pasted code and the tag [code] below your pasted code like so:
[code]
// your code goes here
// notice how the top and bottom tags are different
[/code]Luck.

Setting JTree as expandable

I have a JTree and it has Parent nodes and corresponding child nodes. I edit the values of child and when i refresh the tree, I need to set the edited node in the expanded mode. The expandPath() does not seem to be working. Is there any way of making it expandable during editing???

Hello,
The expandPath()-method works fine, if you call it with the right TreePath. Make sure that the TreePath is correct (with root as first element), or use the method expandRow(int).
Hope it helps
Freddy

Set JTree root node

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