import java.awt.Image;
import java.awt.Graphics;
import java.awt.Color;
import java.awt.Font;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseEvent;
import java.awt.Graphics2D; // Used for anti-aliasing
import java.awt.RenderingHints; // Used for anti-aliasing

import javax.swing.JFrame;

public class GraphicsMoveObjectWithMouseAndJFrame extends JFrame implements MouseMotionListener
{
	private Image image;
	private int width = 400, height = 400;
	private int dotX = 200, dotY = 200, dotSize = 50;

	public static void main(String[] args)
	{
		// Create an instance of the 'GraphicsMoveObjectWithMouseAndJFrame' class
		new GraphicsMoveObjectWithMouseAndJFrame();
	}

	// Constructor
	public GraphicsMoveObjectWithMouseAndJFrame()
	{
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setSize(width, height);
		setTitle("Object Movement with a Mouse on a JFrame");
		setLocationRelativeTo(null);
		setResizable(false);
		setVisible(true);

		addMouseMotionListener(this);
	}

	// Make sure the red dot is always positioned under the mouse pointer
	public void mouseMoved(MouseEvent event)
	{
		dotX = (int) event.getPoint().getX();
		dotY = (int) event.getPoint().getY();

		repaint();
	}

	// Redraw the red dot, even if the user holds down a mouse button
	public void mouseDragged(MouseEvent event)
	{
		mouseMoved(event);
	}

	public void update(Graphics g)
	{
		paint(g);
	}

	public void paint(Graphics g)
	{
		// Prepare to create the image on a separate 'Image' instance; this
		//  will prevent flickering while the mouse is being moved around
		//  the frame by using a "buffer" on which the frame image will
		//  first be drawn before it is displayed to the user
		image = createImage(width, height);
		Graphics graphics = image.getGraphics();

		// This line causes graphics and text to be rendered with anti-aliasing
		//  turned on, making the overall display look smoother and cleaner
		((Graphics2D) graphics).setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

		// Reset the frame background so that previous instances of the
		//  red dot are not left behind and visible on the frame
		graphics.setColor(Color.BLACK);
		graphics.fillRect(0, 0, width, height);

		// Add the text instructions to the buffer
		graphics.setColor(Color.WHITE);
		graphics.setFont(new Font("Helvetica", Font.BOLD, 16));
		graphics.drawString("Move the mouse inside the frame...", 66, 40);

		// Add the red dot in the correct location (under the mouse pointer)
		graphics.setColor(Color.RED);
		graphics.fillOval(dotX - dotSize / 2, dotY - dotSize / 2, dotSize, dotSize);

		// Display (Draw) the buffered image on the frame
		g.drawImage(image, 0, 0, null);
	}
}