/**
 * This is example #4 out of 6, showing a sequence of improvements through
 * the progression of examples.  The six files should be viewed in order.
 * 
 * This file switches from a 'mouseClicked()' event to a 'mousePressed()'
 * event, which means that red dots will now be drawn when the mouse
 * button is pressed DOWN, instead of when the button is released UP.
 * 
 * This file has its own 'update()' method, which overrides the built-in
 * (default) method, to call the 'paint()' method.  This, along with now
 * calling the 'repaint()' method (instead of calling 'paint()' directly),
 * is the best approach, and by having the new 'update()' method contain
 * only a call to 'paint()', the applet window background is not cleared.
 * This means that every time the user presses the mouse, the previous red
 * dots are not erased.
 * 
 * This example illustrates the appropriate manner in which this program
 * should be coded, as it is efficient, yet still respectful of other
 * applets/events/programs running in a multitasking environment.  However,
 * even though one can "sort of" draw by continuously clicking the mouse,
 * this really is still not yet a drawing program.
 */

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;

public class GraphicsDrawing4 extends Applet
{
	int mouseX = -10;
	int mouseY = -10;

	public void init()
	{
		setSize(400, 400);
		setBackground(Color.yellow);
		addMouseListener(new HandleMouse());
	}

	class HandleMouse extends MouseAdapter
	{
		public void mousePressed(MouseEvent e)
		{
			mouseX = e.getX();
			mouseY = e.getY();

			// Calling the 'repaint' method is the right approach, and
			//  is better than a direct call to 'update' or 'paint'
			repaint();
		}
	}

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

	public void paint(Graphics g)
	{
		g.setColor(Color.red);
		g.fillOval(mouseX - 10, mouseY - 10, 20, 20);
	}
}