display icon/text on right of selected node in jtree

I want to display an icon or a text to the right of the selected node on the JTree. Any idea on how to implement this?
Say,
100 A
where, 100 is selected and A is beside it and not selected.
Thanks

You can easily extend DefaultTreeCellRenderer to do this and set it as the cell renderer for your JTree by calling tree.setCellRenderer() with your new cell renderer.

Nathan, I have extended defaultTreeCellRenderer. But, how to set the text so that some part of text is selected and some not selected.
say,
100 A
where 100 is selected and A is not selected.
See code below -
public Component getTreeCellRendererComponent(
JTree m_tree, Object m_value, boolean m_isSelected,
boolean m_isExpanded, boolean m_isLeaf, int m_row,
boolean m_hasFocus) {

super.getTreeCellRendererComponent( m_tree, m_value, m_isSelected,
m_isExpanded, m_isLeaf, m_row, m_hasFocus);
Component compObject = this;

if ( m_value instanceof EuamDefaultMutableTreeNode ) {
EuamDefaultMutableTreeNode node = (EuamDefaultMutableTreeNode)m_value;
setText( node.getText() );
setIcon(m_isExpanded ? node.getOpenIcon() : node.getClosedIcon() );

}
else {
setText(m_value.toString());
}
return compObject;
}

Pavan,

Here's an example of how I added the desired functionality to the renderer... Enjoy!

import javax.swing.*;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import java.awt.*;
 
public class PavanRenderer extends DefaultTreeCellRenderer {
    public Component getTreeCellRendererComponent(
            JTree m_tree, Object m_value, boolean m_isSelected,
            boolean m_isExpanded, boolean m_isLeaf, int m_row,
            boolean m_hasFocus) {
        Component compObject = super.getTreeCellRendererComponent(
                m_tree, m_value, m_isSelected,
                m_isExpanded, m_isLeaf, m_row, m_hasFocus);;
 
        if ( m_value instanceof EuamDefaultMutableTreeNode ) {
            EuamDefaultMutableTreeNode node = (EuamDefaultMutableTreeNode)m_value;
            setText( Integer.toString( node.getNumber() ) );
            setIcon(m_isExpanded ? node.getOpenIcon() : node.getClosedIcon() );
            JPanel p = new JPanel();
            p.setBackground( UIManager.getColor( "Tree.textBackground" ) );
            p.setForeground( UIManager.getColor( "Tree.textForeground" ) );
            p.setLayout( new BorderLayout() );
            p.add( compObject, BorderLayout.WEST );
            JLabel l = new JLabel( node.getText() );
            l.setFont( UIManager.getFont( "Tree.font" ) );
            p.add( l, BorderLayout.EAST );
            compObject = p;
        }
        else {
            setText(m_value.toString());
        }
        return compObject;
    }
 
    public static void main( String[] args ) {
        JFrame f = new JFrame( "Pavan Renderer Test" );
        JTree tree = new JTree( new EuamTreeModel() );
        tree.setCellRenderer( new PavanRenderer() );
        f.getContentPane().add( new JScrollPane( tree ) );
        f.setDefaultCloseOperation( WindowConstants.EXIT_ON_CLOSE );
        f.setSize( 400, 600 );
        f.show();
    }
}
 
class EuamTreeModel extends DefaultTreeModel {
 
    public EuamTreeModel() {
        super( new EuamDefaultMutableTreeNode(), true );
        initTree();
    }
 
    private void initTree() {
        EuamDefaultMutableTreeNode root = (EuamDefaultMutableTreeNode)getRoot();
        root.setText( "Root" );
        root.setNumber( 0 );
        for ( int i = 1; i <= 10; i++ ) {
            EuamDefaultMutableTreeNode node = new EuamDefaultMutableTreeNode( "Child_" + i, i );
            root.add( node );
        }
    }
}
 
class EuamDefaultMutableTreeNode extends DefaultMutableTreeNode {
 
    private String text;
    private int number;
    private Icon openIcon;
    private Icon closedIcon;
 
    public EuamDefaultMutableTreeNode() {
        this( "Default", 0 );
    }
 
    public EuamDefaultMutableTreeNode( String text, int number ) {
        this.text = text;
        this.number = number;
        this.openIcon = new RedCircle();
        this.closedIcon = new BlueCircle();
    }
 
    public String getText() {
        return text;
    }
 
    public void setText( String text ) {
        this.text = text;
    }
 
    public Icon getOpenIcon() {
        return openIcon;
    }
 
    public void setOpenIcon( Icon icon ) {
        this.openIcon = icon;
    }
 
    public Icon getClosedIcon() {
        return closedIcon;
    }
 
    public void setClosedIcon( Icon icon ) {
        this.closedIcon = icon;
    }
 
    public int getNumber() {
        return number;
    }
 
    public void setNumber( int number ) {
        this.number = number;
    }
 
    private class RedCircle implements Icon {
 
        public int getIconWidth() {
            return 16;
        }
 
        public int getIconHeight() {
            return 16;
        }
 
        public void paintIcon( Component comp, Graphics g, int x, int y ) {
            g.setColor( comp.getBackground() );
            g.fillRect( x, y, getIconWidth(), getIconHeight() );
            g.setColor( Color.red );
            g.fillOval( x, y, getIconWidth(), getIconHeight() );
        }
    }
 
    private class BlueCircle implements Icon {
 
        public int getIconWidth() {
            return 16;
        }
 
        public int getIconHeight() {
            return 16;
        }
 
        public void paintIcon( Component comp, Graphics g, int x, int y ) {
            g.setColor( comp.getBackground() );
            g.fillRect( x, y, getIconWidth(), getIconHeight() );
            g.setColor( Color.blue );
            g.fillOval( x, y, getIconWidth(), getIconHeight() );
        }
    }
}

Thanks a loot Nathan. I havent run it, but I think it will work. That was very very useful.
Thanks again.

Nathan,
Can I perform this task on node selection (in valuechanged method of TreeSelectionAdapter)?
I have a tree that is built initially, and I get the text (to be displayed next to node text) from the database only when the user selects the node.
Can I do this task?
Is node.setUserObject() do the task?
Thanks.

In the example I provided, the EuamDefaultMutableTreeNode class contains the number... so you would initially start it out at 0 (or some other default value) when you created it, and then in your selection listener you would cast the selected node to a EuamDefaultMutableTreeNode and call setNumber( int ) on it...

Nathan,
Is it possible to associate an listener (say, mouseClick) on the text displayed on the right hand side of the node data.
i.e, for the text '100 A', can I associate an listener to the text 'A' so that when the user clicks on 'A', some method is called.
Thanks

Yes... you could just add a MouseListener to the tree or the cell renderer.

I dont want the listener to be added to the text on the left hand side. MouseListener will corresponds to the whole text (left and right), isnt it?
How do I add listener to the cell renderer?

Sorry... just tried this out for real, and the tree "eats" all the events for the rendererers, so you can't add a listener on the renderer.

However, I did find some code here that shows how to differentiate areas of the renderer using a listener on the JTree.