import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

public class HelloJava4 {

	public static void main( String[] args ) {

		JFrame cornice = new JFrame( "HelloJava4" );
		cornice.getContentPane().add( new HelloComponent4("Ehila`, Java!") );
		cornice.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
		cornice.setSize( 300, 300 );
		cornice.setVisible( true );

// Dopo aver costruito una prima cornice con un messaggio lampeggiante,
// costruiamone un'altra quasi uguale ma che opera indipendentemente.
// Si trattera` di un altro oggetto della stessa classe di quello di prima.

		JFrame kornice = new JFrame( "HelloJava4" );
		kornice.getContentPane().add( new HelloComponent4("Ohime`, Java!") );
		kornice.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
		kornice.setSize( 300, 300 );
		kornice.setVisible( true );
	}
}

class HelloComponent4 extends JComponent

			implements MouseMotionListener, ActionListener, Runnable {

	String theMessage;

	int messageX = 125, messageY = 95; // Coordinates of the message

	JButton theButton;

	int colorIndex; // Current index into someColors

	static Color[] someColors = {

		Color.black, Color.red, Color.green, Color.blue, Color.magenta
	};

	boolean blinkState;

	public HelloComponent4( String message ) {

		theMessage = message;

		theButton = new JButton( "Cambia Colore" );

		setLayout( new FlowLayout() );

		add( theButton );

		theButton.addActionListener( this );

		addMouseMotionListener( this );

		Thread t = new Thread( this );

		t.start( ); 
	}

	public void paintComponent( Graphics g ) {

		g.setColor( blinkState ? getBackground() : currentColor() );

		g.drawString( theMessage, messageX, messageY );
	}

	public void mouseDragged( MouseEvent e ) {

		// Save the mouse coordinates and paint the message.

		messageX = e.getX();

		messageY = e.getY();

		repaint();

	}


	public void mouseMoved( MouseEvent e ) { }

	public void actionPerformed( ActionEvent e ) {

		// Did somebody push our button?

		if ( e.getSource() == theButton )

			changeColor();

	}

	synchronized private void changeColor( ) {

		// Change the index to the next color, awkwardly.

		if ( ++colorIndex == someColors.length )

			colorIndex = 0;

		setForeground( currentColor() ); // Use the new color.

		repaint();

	}

	synchronized private Color currentColor( ) {

		return someColors[ colorIndex ];

	}

	public void run() {

		try {
			while( true ) {

				blinkState = !blinkState; // Toggle blinkState.

				repaint( ); // Show the change.

				Thread.sleep( 300 );

			}

		} catch (InterruptedException ie) { }
	}
}