import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class RobotGetPixelColor
{
	private JFrame frame;
	private Robot robot;

	public static void main(String[] args)
	{
		new RobotGetPixelColor();
	}

	// Constructor
	public RobotGetPixelColor()
	{
		// Create and set up a JFrame and make it visible
		frame = new JFrame("Robot Demo:  getPixelColor()");
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setSize(379, 187);
		frame.setLocationRelativeTo(null);
		frame.setBackground(Color.WHITE);
		frame.add(new MainPane());
		frame.setResizable(false);
		frame.setVisible(true);
	}

	// The following claws exists because the "default" JFrame is not being
	//  extended from a class that is capable of painting; in other words,
	//  since a named JFrame ("frame") is being created, it becomes necessary
	//  to create a separate class (below), an instance of which is added to
	//  the JFrame (above), so that a 'paint' method can be overridden;
	//  otherwise, any new 'paint' method that is created will not be called
	public class MainPane extends JPanel
	{
		// Constructor
		public MainPane()
		{
			MouseAdapter mouseHandler = new MouseAdapter()
			{
				public void mousePressed(MouseEvent event)
				{
					// The 'Robot' class requires exception trapping
					try
					{
						// Note that while 'event.getX()' and 'event.getY()' return the
						//  location of the mouse on the JFrame, the 'getPixelColor()'
						//  method of the 'Robot' class applies its arguments to the
						//  entire screen; the two lines below compensate for that, as
						//  well as for the thickness of the JFrame's border and the
						//  thickness of its title bar 
						int xPos = frame.getX() + event.getX() + 4;
						int yPos = frame.getY() + event.getY() + 24;

						// Determine and display the color of the pixel on which the mouse
						//  pointer was clicked (pressed)
						robot = new Robot();
						System.out.println(robot.getPixelColor(xPos, yPos));
					}
					catch (Exception error)
					{
						System.out.println("ERROR:  " + error.getMessage());
					}
				}
			};

			addMouseListener(mouseHandler);
		}

		public void paintComponent(Graphics g)
		{
			// Draw ten filled squares to provide a variety of colors that can be clicked
			g.setColor(Color.RED);
			g.fillRect(20, 20, 50, 50);
			g.setColor(Color.GREEN);
			g.fillRect(90, 20, 50, 50);
			g.setColor(Color.BLUE);
			g.fillRect(160, 20, 50, 50);
			g.setColor(Color.BLACK);
			g.fillRect(230, 20, 50, 50);
			g.setColor(Color.YELLOW);
			g.fillRect(300, 20, 50, 50);
			g.setColor(Color.ORANGE);
			g.fillRect(20, 90, 50, 50);
			g.setColor(Color.PINK);
			g.fillRect(90, 90, 50, 50);
			g.setColor(Color.MAGENTA);
			g.fillRect(160, 90, 50, 50);
			g.setColor(Color.CYAN);
			g.fillRect(230, 90, 50, 50);
			g.setColor(Color.GRAY);
			g.fillRect(300, 90, 50, 50);
		}
	}
}