import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
// simple program to display and continusly run.
public class jniProgressBar {

	static JFrame frame;
	static JPanel panel;
	// initialize frame and panel at load time
	static {
		frame = new JFrame("This is a test frame ................                    .............");
		panel = new JPanel();
		BoxLayout bl = new BoxLayout( panel, BoxLayout.Y_AXIS );
		panel.setLayout( bl );		
		
		Container cont = frame.getContentPane();
		cont.setLayout( new BorderLayout() );
		cont.add( panel, BorderLayout.CENTER );
		addProgressBar();
		
		frame.validate();
		frame.pack();
		frame.setVisible( true );
		frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );	
	}
	
	// add a progress bar to the frame
	// this method is invoked from native code
	public static void addProgressBar(){

		// add a progress bar to the frame
		final JProgressBar jpb = new JProgressBar( 0 , 100 );
		panel.add( jpb );
		// thread that updates progress bar
		new Thread(){
			public void run(){
				int i = 0;
				Vector<Integer> v = new Vector<Integer>();
				while( true ){
					try{ Thread.sleep( 10 ); } catch( Exception e ){ e.printStackTrace();}
					jpb.setValue( ((i++) % 100 ) );
					v.add( new Random().nextInt() );
					
				}
			}			
		}.start();		
		panel.add( jpb );
		//frame.validate();
		frame.pack();		
		// pause for 3 seconds
		try{ Thread.sleep( 100 ); } catch ( Exception e ){ e.printStackTrace(); }
	}
}