Redraw JTree problem

I have a probram that use SAX to parse xml file and display as JTree.
I have problem redraw the tree using following code:
SAXTreeBuilder saxTree = null;
DefaultMutableTreeNode top = new DefaultMutableTreeNode(myxmlFile);
saxTree = new SAXTreeBuilder(top);
try {
SAXParser saxParser = new SAXParser();
saxParser.setContentHandler(saxTree);
saxParser.parse(new InputSource(new FileInputStream(myxmlFile)));
} catch (Exception ex) {
top.add(new DefaultMutableTreeNode(ex.getMessage()));
JFrame frame = getFrame();
JTree tree = new JTree(saxTree.getTree());
JScrollPane scrollPane = new JScrollPane(tree);
frame.getContentPane().add(ascrollPane, BorderLayout.CENTER);
frame.setVisible(true);

Swing related questions should be posted in the Swing forum.
But there is no need to repost because you can simply read the JTree API and follow the link to the Swing tutorial for an example of how to build a tree.
Don't forget to use the Code Formatting Tags so the posted code retains its original formatting. That is done by selecting the code and then clicking on the "Code" button above the question input area.

Similar Messages

Redraw order problems with paintComponent

hi,
i've got this test code below which is simply meant to overlay the scrolling transparent text "HELLO" a few times on top of a normal component
my problem is that the image in the panel, is seemingly being redrawn after the text, when it should be drawn as part of the call to super.paintComponent(g)
is having a thread calling repaint() every few milliseconds is the right way to be doing this in the first place??
any help really appreciated,
asjf
ps. pls ignore the dodgy positioning of text, and calculations of widths etc :)
import javax.swing.*;
import java.awt.*;
import java.net.URL;
class AnimTest extends JPanel {
   Font myFont;
   Color myColor;
   int x=0;
   AnimTest(URL u){
      super(new BorderLayout(8,8));
      add(new JLabel("Demo text: ajsk sdjfkl dsjfks jd aisuda siu"), BorderLayout.CENTER);
      add(new JLabel(new ImageIcon(u)), BorderLayout.EAST);
      setOpaque(true);
      setBackground(Color.white);
      myColor = new Color(255,0,0,128);
      myFont = new Font("Dialog",Font.BOLD,14);
      new Thread(new Runnable(){
         public void run() {
            try {
               while(true) {
                  repaint();
                  Thread.sleep(25);
                  x++;
            }catch(InterruptedException e) {
               e.printStackTrace();
      }).start();
   public void paintComponent(Graphics g) {
      super.paintComponent(g);
      g.setColor(myColor);
      g.setFont(myFont);
      int width = 3*(getWidth()/2);
      int mid = getHeight()/2 + 10; // sort out later
      for(int i=0; i<width; i+=width/5)
         g.drawString("HELLO",((x+i) % width)-(width/5),mid);
   public static void main(String [] arg) throws Exception {
      URL demo = new URL("http://java.sun.com/images/duke.gif");
      JFrame frame = new JFrame("AnimTest");
      frame.getContentPane().add(new AnimTest(demo));
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.pack();
      frame.show();
}

hi, thanks for the reply. I am not drawing the image myself, but am expecting it to be done as part of the redraw of my classes superclass
public void paintComponent(Graphics g) {
   super.paintComponent(g);i was expecting the call to super.paintComponent(g) to draw the contents of the JPanel that I've added (which it does do). The strange this is that the image attached to the JPanel is drawn on top the string that I paint after super.paintComponent(g) has completed. Am not sure how this could possibly happen without some complicated postponing of .drawImage coming into play??
thanks,
asjf

An Expandable JTree Problem

Hi, I'm relatively new to creating JTree components, now I have looked at many examples, and this one is nearest (i can see) to how I want my Jtree to look, however it doesn't behave in a way which I would like!
Firstly, I can set the root node to have as many folders as i want, however they only mirror whats in the first root node, I dont want this - I want to be able to create about 5/6 different roots that will yield different results - I also want after each time you click on a folder, which will ask a question about a patient i.e. "Has the patient a head injury" - click on this then it should come up with "3" more different choices, so altogther want it about 5 deep.
However, this is what I've got so far - but like I say, its not yielding the results I want, does anyone know how to modify this or can anyone point me in the right direction by starting me off a bit, that would be great!
import java.awt.*;
import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;
public class SelectableTree extends JFrame
                            implements TreeSelectionListener {
public static void main(String[] args) {
    new SelectableTree();
private JTree tree;
private JTextField currentSelectionField;
public SelectableTree() {
    super("Clinical Information Help System");
    WindowUtilities.setNativeLookAndFeel();
    addWindowListener(new ExitListener());
    Container content = getContentPane();
    DefaultMutableTreeNode root =
      new DefaultMutableTreeNode("Begin Clinical Questions");
    DefaultMutableTreeNode child = null;
    DefaultMutableTreeNode parent = null;
    DefaultMutableTreeNode grandChild = null;
    DefaultMutableTreeNode grandParent = null;
    DefaultMutableTreeNode child2 = null;
    DefaultMutableTreeNode parents = null;
    for(int grandParentIndex=1; grandParentIndex < 2; grandParentIndex++) {
      grandParent = new DefaultMutableTreeNode("[Does Patient Have Back Pains?] " + grandParentIndex);
      root.add(grandParent);
      for(int parentIndex =1; parentIndex < 3; parentIndex++) {
        parent = new DefaultMutableTreeNode("[Does the patient also have leg pain?] " + parentIndex +
                                     "." + parentIndex);
        grandParent.add(parent);
        for(int childIndex =1; childIndex < 3; childIndex++) {
         child = new DefaultMutableTreeNode("[are the pains in the lower back?] " + childIndex +
                                     "." + childIndex);
          parent.add(child);
          child2 = new DefaultMutableTreeNode("patient over 60?" + childIndex +
                "." + childIndex);
          child.add(child2);
        for(int grandChildIndex =1; grandChildIndex < 3; grandChildIndex++) {
           grandChild = new DefaultMutableTreeNode("[Does patient have bladder and/or bowel incontinence?] " + grandChildIndex +
                                        "." + grandChildIndex);
             child.add(grandChild);
        for(int childIndex = 1; childIndex < 3; childIndex++) {
            child = new DefaultMutableTreeNode("[Has Patient suffered either: appitite/wieght loss/fever?]" + childIndex +
                                         "." + childIndex);
            child = new DefaultMutableTreeNode("[Has pain been 4-6wks leg pain? OR 3-6mths low-back pain?]" + childIndex +
                    "." + childIndex);
              grandChild.add(child);
    tree = new JTree(root);
    //tree = new JTree(root2);
    tree.addTreeSelectionListener(this);
    content.add(new JScrollPane(tree), BorderLayout.CENTER);
    currentSelectionField = new JTextField("Current Selection: NONE");
    content.add(currentSelectionField, BorderLayout.SOUTH);
    setSize(400, 400);
    setVisible(true);
public void valueChanged(TreeSelectionEvent event) {
    currentSelectionField.setText
      ("Current Selection: " +
       tree.getLastSelectedPathComponent().toString());
}

I'm not really sure what your problem is, for I don't see what you mean by "mirror". If it is you have but one root node, but wanted to have many instead, then you'd simply need to call setRootVisible(false); on the tree.
As a sidenote, I don't think it's a really good UI for what you're doing, but after all, I haven't got the whole picture.
Now, what is it you mean by: its not yielding the results I want ?

JTree problem

I posted a simillar problem not long ago but didn't explain properly.
The code below displays a JFrame with a JScrollPane containing a JTree with just a root node ("root").
At the bottom of the frame is a button that when pressed re-initialises the JTree with no arguments (line 42). Hence once the button is clicked the JTree should have some elements in it (those default ones : colours, sports, food).
However, the reinitialised JTree is not displayed. What's the problem?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
class Test extends JFrame implements ActionListener {
     private JScrollPane            treeScrollPane;
     private JTree                  tree;
     private DefaultMutableTreeNode root;
     private JButton                runButton;
     public Test() {
          super("Test");
          this.tree = new JTree(this.root = new DefaultMutableTreeNode("root"));
          this.treeScrollPane = new JScrollPane(new JTree());
          this.treeScrollPane.setBorder(BorderFactory.createCompoundBorder(
               BorderFactory.createTitledBorder("Tree panel"),
               BorderFactory.createEmptyBorder(5,5,5,5)));
          this.runButton = new JButton("click me");
          this.runButton.addActionListener(this);
          Container contentPane = getContentPane();
          contentPane.setLayout(new BorderLayout());
          contentPane.add(this.treeScrollPane, BorderLayout.CENTER);
          contentPane.add(this.runButton,      BorderLayout.SOUTH);
          this.setSize(300, 400);
          this.setLocationRelativeTo(null);
          this.setDefaultCloseOperation(EXIT_ON_CLOSE);
          this.setVisible(true);
     public void actionPerformed(ActionEvent e) {
          Object source = e.getSource();
          if (source == this.runButton) {
               System.out.println("DEBUG : button clicked");
               this.tree = new JTree();
               this.tree.expandPath(new TreePath(this.tree.getModel().getRoot()));
     public static void main(String args[]) {
          try {
               UIManager.setLookAndFeel(
                    UIManager.getSystemLookAndFeelClassName());
          } catch (Exception e) {
               System.out.println(e.getMessage());
          new Test();
}

The problem is that the scrollpane is still displaying the first tree.
To fix this, you'll need to add the following line to your actionPerformed method:
treeScrollPane.setViewportView(tree);(I think you might be a litle confused by the difference between an object and a reference. The scrollpane holds a reference to the first tree you create. Then you create a new tree and assign it to your this.tree reference, but the scrollpane's reference is stil pointing to the first tree. If this explanation is all mumbled up it's because I haven't had my first cup of coffee yet :-)

JTree - problems with names of elements

I have a Jtree thats populated with expandable elements. These elements are loaded on startup, but some of the elements don't get their full names, just i.e "dem..." instead of "demo3". WHen I expand the node, the full name appears, and remains.
Anyone know what this could be?
The problem is really often associated with nodes with names containing "m" ..

By default the tree node renderer is JLabel.
It look like you are not using pack() or validate().
It depend also the layout manager you are using.
In one word, it seems the JLabel has dimension too short.
Can only show 3 to 4 char. that is why "demo3" show as "dem..."
Try have some node name like "WWWWW", if you see "WW..." or "WWW..."
Then that is the problem. ( Not as you thought: only "m" has problem )

JTree Problem again

Deat 7rst,
Sorry, I want to ask you about the same problem.
if I want to display a difference components from difference node in JTree, how the code I must use?
I already understand about the code that you give to me. But I still confuse if many nodes in JTree to perform difference panel with many components each of its. The components beside JTextField.
Thanks

I have used THE SEARCH BOX - can't find nothing about editable JList, there are only references for editable Trees and Tables.
Do anybody have concrete idea (the best would be some code), or should I reconcile myself with the JTable solution?

JTree Problem - Need help

Hi,
I am using a JTree to which I have set my own TreeModel and TreeSelectionListener (overidden all the methods for both). Wehn I add a new node to the tree, the node appears but the text for the node does not.
(e.g if the text is "ABCD", what appears is "AB..."). I called a tree.repaint(). It does not solve my problem.
A tree.updateUI() does solve my problem, but it throws a NullPointerException on every selection in the tree. I am trying to refresh the tree in the selSelection() method of the selection model.
Is there any other way?
Thanks in advance,
Achyuth

Try adding this when you add a node. Don't have time to check it so not quite sure its what you're looking for but I remember having this prob before and I think this is what I did:
EventListener[] listeners = ((DefaultTreeModel)tree.getModel()).getListeners(TreeModelListener.class);
for (int i = 0; i < listeners.length; i++) {
((TreeModelListener)listeners).treeNodesChanged(new TreeModelEvent(this, new TreePath(node.getPath())));
Alex

Re: JTree problem

You should look at the TreeSelectionListener class.
public class MyFrame extends JFrame implements TreeSelectionListner {
JTree tree = ...;
public MyFrame() {
super();
tree.addTreeSelectionListener(this);
public void valueChanged(TreeSelectionEvent evt) {
// put your code here
}

Deat 7rst,
Sorry, I want to ask you about the same problem.
if I want to display a difference components from difference node in JTree, how the code I must use?
I already understand about the code that you give to me. But I still confuse if many nodes in JTree to perform difference panel with many components each of its. The components beside JTextField.

Any component as leaf for JTree problems

hi,
I'm trying to get arbitary components as leaves in a JTree and it looks like its very nearly there, but there are two (related?) problems.
1) If you click around on the top 3 tree components then it gets stuck in a loop of rendering and causes a stack exception to be thrown.
2) For the embedded JTree component, expanding its nodes doesn't update the parent tree
both may be because current the row height is set at the wrong time (in the TreeCellRenderer)
any help would be really appreciated!
thanks,
asjf
import javax.swing.*;
import javax.swing.tree.*;
import java.awt.*;
import java.util.*;
public class ComponentTree
     public static void main(String args[])
          try{(new UIManager()).setLookAndFeel((new UIManager()).getSystemLookAndFeelClassName());}
          catch(Exception e){}
          DefaultMutableTreeNode c0 = new DefaultMutableTreeNode(new JButton("root"));
          DefaultMutableTreeNode c1 = new DefaultMutableTreeNode(new JButton("c1"));
          DefaultMutableTreeNode c2 = new DefaultMutableTreeNode(new JList(new Object [] {"A","B","C"}));
          DefaultMutableTreeNode c3 = new DefaultMutableTreeNode(new JTable(new Object [][] {{"Active","true"},{"User","root"}}, new Object [] {"Name","Value"}));
          DefaultMutableTreeNode c4 = new DefaultMutableTreeNode(new JTree());
          DefaultMutableTreeNode c5 = new DefaultMutableTreeNode(new JList(new Object [] {"D","E","F"}));
          DefaultMutableTreeNode c6 = new DefaultMutableTreeNode(new JCheckBox("Active",true));
          DefaultTreeModel dtm = new DefaultTreeModel(c0);
               dtm.insertNodeInto(c6,c0,0);
               dtm.insertNodeInto(c1,c0,0);
               dtm.insertNodeInto(c2,c0,0);
               dtm.insertNodeInto(c5,c2,0);
               dtm.insertNodeInto(c3,c1,0);
               dtm.insertNodeInto(c4,c3,0);
          JTree tree = new JTree(dtm);
               tree.setEditable(true);
               tree.setCellRenderer(new DefaultTreeCellRenderer()
                    public Component getTreeCellRendererComponent(     JTree tree,     Object value, boolean isSelected, boolean expanded, boolean leaf, int row, boolean hasFocus)
                         System.out.println("Render row "+row);
                         Component c = (Component) ((DefaultMutableTreeNode) value).getUserObject();
                         if(c instanceof JCheckBox)
                              c.setBackground(UIManager.getColor("Tree.textBackground"));
                         tree.setRowHeight(c.getHeight());
                         return c;
               tree.setCellEditor(new DefaultTreeCellEditor(tree,(DefaultTreeCellRenderer)tree.getCellRenderer())
                    public boolean isCellEditable(EventObject evt){return true;}
                    public Component getTreeCellEditorComponent(     JTree tree,     Object value, boolean isSelected, boolean expanded, boolean leaf, int row)
                         return (Component) ((DefaultMutableTreeNode) value).getUserObject();
          JFrame frame = new JFrame("ComponentTree");
               frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
               frame.getContentPane().add(tree);
               frame.pack();
               frame.show();
}

thanks!
this seems an awful lot of code to get this working - it should be possible to have a single CellEditor/Renderer??
also running the code - its very hard to select checkbox items, and the JLists seem to disable themselves when the main tree updates?
its also not general to any Component (?) (although we probably only want JComponent) so we can't add a JTree as a leaf?
I'm guessing there is a simpler way to get this working?

JTree: Problems updating the nodes size

Hi,
I'm trying to update the content of a JTree and I wonder how it
really works, since the paint() method doesn't seem to call the
renderer.
My situation: Imagine a JPanel splited in two by a JSplitPane. In
the left is the tree. Each node in the tree shows two panels, one
aligned to the left, and another to the right. I need that the panel
containing the two use all the available space in the left part of the
Split panel.
My solution: I pass the left JPanel to the tree renderer, so that
it can get the width from it (inside the
getTreeCellRendererComponent()) to build the return JPanel with the
correct size. My logic is that since each time you move the JSplitPane
the JTree paint() method is invoked the renderer can return the
correct JPanel with the correct size that will be painted then in the
screen.
My problem: Doens't work. When I render the tree, the renderer is
invoked, but it doesn't change its size (I can change the color based on the width, but not the node size). Only when I collapse & expand a node, it correctly takes into account the .setPreferredSize() and returns the JPanel with the correct size.
The only way I found to update the tree involves to catch the
JSplitPane event and call updateUI() in the tree, something that, I
think, it's certainly not the correct way to do it.
Any explanation of why this doesn't work would be really great. Any
pointer to a web resource explaining in deep how Swing components work (specially the JTree) would be a godsend.
Thanks,
- Juancho

My situation: Imagine a JPanel splited in two by a JSplitPane. Got it.
In the left is the tree. In the left side of the JSplitPane is a JTree.
Each node in the tree shows two panels,Maybe... on the right side of the JSplitPane are two Panels in which the data depends on which node is selected in the JTree???
Maybe... you have a custom TreeCellRenderer which displays a pair of panels in place of the standard JLabel???
one aligned to the left, and another to the right. To the left of what??? To the right of what???
I need that the panel containing the two use all the available
space in the left part of the Split panel.Panel containing the two what??? I thought the left part of the SplitPanel contained a JTree???

JTree problems (getting urgent)

A screen prototype that I am writing uses a JTree and a JList.
Whenever the JTree is Expanded or Colapsed, the list is updated so that is displays:
myJTree.getPathForRow(i).getPathComponent(1);
where i is the row of both the tree and the list.
My problem is that the list is always one stage behind!
ie my JTree is initialised(with root hidden):
Colour
Fruit
Sport
and the list box displays:
Colour
Fruit
Sport
if I expand Colour, the tree displays:
Colour
-Red
-Green
Fruit
Sport
and the list displays:
Colour
Fruit
Sport
then I expand Fruit, the tree displays:
Colour
-Red
-Green
Fruit
-Apple
Sport
the list displays:
Colour
Colour
Colour
Fruit
Sport
etc. etc.
why is this happening?
and how can I change my code so that the list displays what the tree is displaying and not what the tree used to display!

This is the update method:
DefaultListModel model = new DefaultListModel();
for(int i = 0; i<myJTree.getRowCount();++i) {
model.addElement(myJTree.getPathForRow(i).getPathComponent(1));
and the JTree expansion listener finds out which frame it is being called from before calling the update method on that frame.
When you say, remove all the items from the list, do you mean remove the previous model?

Jclient - Jtree problem inserting new records

I reviewed the component example of using a jtree and for display only it works fine but doesn't include any code to add new records. our example uses a polymorphic table called "levels", as:
level1
__| level2
_____| level3
inserting a record to the level1 vo works and redisplays in the jtree fine but inserts to level2 or level3 creates
display issues and other tree issues. The data is recorded correctly and the tree displays correctly if you close the app and rerun it.
We also attempted to correct this by setting
vo.setAssociationConsistent(true) in each of the level table vos. this did not help.
Is this a bug ? Can someone provide some example code if required to get this to display and insert correctly.

Robert,
I can't tell if the problem is a bug and it would require code reviews and test cases to be specific on that.
I suggest contacting customer support with this issue so the problem gets documented, addressed and solved.
See: metalink.oracle.com
Frank

Jtree - Problem creating a very large one

Hi,
I need to create a multi-level JTree that is very large (aroung 600-650 nodes all in all). At present I am doing the same by creating DefaultMutableTreeNodes and adding them one by one to the tree. It takes a very long time to complete(obviously).
Is there any way of doing this faster? The tree is being constructed from run-time data.
Thanks in advance,
Regards,
Achyuth

Two thoughts. First, I create 100's of nodes and it's pretty fast. It could be how you are creating/adding them. Make sure your code is not the bottleneck. If you are traversing the entire tree or some other odd way of doing it, it could be the problem. I only say that because I am able to create an object structre, parse XML as I create that structe and create all the nodes and its less than 1 second on a PIV 1.7Ghz system. Maybe on slower systems its a lot slower, but for me its up immediately.
Another way, however, is to keep a Map of "paths" to child items in memory. As you build your object from whever, use a Map to keep path info. Now, add listeners to the tree for expand/collapse. Each time it is about to expand, build up the nodes and add them to the expanding node at that point. If it collapses, discard them. This does one of two things. First, for large trees, you aren't wasting tons of time building the tree at the start, and more so, its probably likely that all those nodes aren't going to be expanded/shown right away. Second, it conserves resources. If your tree MUST open in a fully epxanded state, well, then you may be out of luck. But I would much prefer epxanding and building the child nodes at that moment, rather than do the whole thing first.

Simple JTree problem

Hi,
I am new to swings .. so this might be a dumb problem for you UI experts.
I have a JTree using a custom TreeRenderer. Now the getTreeCellRendererComponent() of the custom TreeRenderer is called every time the tree is clicked. I have some icons in the tree that I dynamically load / change in this method. I want the same thing to happen every second (without clicks).
So, I wrote an inner thread, and the run method is like this:
          Thread refresher = new Thread() {
               public void run() {
                    try {
                         Thread.sleep(1000);
                    } catch (InterruptedException e) {
                         e.printStackTrace();
// What shall I call here? tree.repaint() ?
The problem is that I don't know what do I need to call at the place where I've put the comment so that the getTreeCellRendererComponent() is called for all tree components just as it is called on clicks.

It may have done the trick, but it's the wrong solution. As dkrukovsky said, you
should be invoking nodeChanged() when you change a node, including
the icon. That will handle the repaint for you, ensure internal consistency
of the tree, and get rid of your totally unnecessary Thread.

Search Jtree Problem (Easy Duke dollars)

Hi all,
I know that in order to find a node is a tree I can use getNextMatch method given by JTree. However, the problem here is that I want to serach for a child node and I don't know how to... for example...
Root
- Child 1
- Child 2
- Child 3
If I search for the root node I would simply do
getNextMatch("R",0,Position.Bias.Forward);But what if I want to search for Child 1 or Child 3? What would be in my search string?

Hi,
To search for a node in a JTree, you may use the breadthFirstEnumeration() method of the DefaultMutableTreeNode and then iterate through that enumeration until the desired node is found or the node is not found.
You need to have a reference to the Root of the tree as a DefaultMutableTreeNode where the seacrh will begin.
Let's say that the desired node's data = desiredElement
DefaultMutableTreeNode root = new DefaultMutableTreeNode(.....);
java.util.Enumeration enum = root.breadthFirstEnumeration();
while(enum.hasMoreElements())
DefaultMutableTreeNode node = (DefaultMutableTreeNode) enum.nextElement();
if(node.getUserObject().equals(desiredElement))
//you have found the node in the tree
//you can get the parent using the getParent on this node as well
//if you want the search path as well
//if you reach here, the desired node is not in the tree
mail me in case of problem : [email protected]

Redraw JTree problem

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