Java by API/javax.swing/LookAndFeel

LookAndFeel: makeIcon(Class baseClass, String gifFile)

import java.awt.BorderLayout;
import java.awt.Color;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.LookAndFeel;
import javax.swing.UIDefaults;
import javax.swing.UIManager;
public class MainClass {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Lazy Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Object iconObject = LookAndFeel.makeIcon(MainClass.class, "yourImage.gif");
    UIManager.put("Tree.leafIcon", iconObject);
    Integer fifteen = new Integer(15);
    Object lazyArgs[] = new Object[] { Color.GREEN, Boolean.TRUE, fifteen, fifteen };
    Object lazyDiamond = new UIDefaults.ProxyLazyValue("DiamondIcon", lazyArgs);
    UIManager.put("Tree.openIcon", lazyDiamond);
    JTree tree = new JTree();
    JScrollPane scrollPane = new JScrollPane(tree);
    frame.add(scrollPane, BorderLayout.CENTER);
    frame.setSize(200, 200);
    frame.setVisible(true);
  }
}