/**
     * If true the component paints every pixel within its bounds. 
     * Otherwise, the component may not paint some or all of its
     * pixels, allowing the underlying pixels to show through.
     * 

     * The default value of this property is false for JComponent.
     * However, the default value for this property on most standard
     * JComponent subclasses (such as JButton and
     * JTree) is look-and-feel dependent.
     *
     * @param isOpaque  true if this component should be opaque
     * @see #isOpaque
     * @beaninfo
     *        bound: true
     *       expert: true
     *  description: The component's opacity
     */

public class BagroundColorEnabledRenderer extends DefaultTreeCellRenderer {
    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);
	this.setOpaque(true);
	return this;
    }
}

package org.soronthar.spikes;

import javax.swing.*;
import javax.swing.event.ListSelectionListener;
import javax.swing.event.ListSelectionEvent;

public class ListSelectionSpike extends JFrame {

    public static void main(String[] args) {
        ListSelectionSpike spike = new ListSelectionSpike();
        spike.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JList jList = new JList(new String[]{"One", "Two", "Three"});
        jList.getSelectionModel().addListSelectionListener(new ListSelectionListener() {
            public void valueChanged(ListSelectionEvent e) {
                if (e.getValueIsAdjusting()) {
                    System.out.print("Adjusting ");
                }
                System.out.println("f:" + e.getFirstIndex() + " l:" + e.getLastIndex());
            }
        });
        spike.getContentPane().add(jList);
        spike.pack();
        spike.setVisible(true);
    }
}

           public void valueChanged(ListSelectionEvent e) {
                if (!e.getValueIsAdjusting()) {
                    //do my stuff
                }
            }