/* * Copyright (c) 2000 David Flanagan.  All rights reserved. * This code is from the book Java Examples in a Nutshell, 2nd Edition. * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied. * You may study, use, and modify it for any non-commercial purpose. * You may distribute it non-commercially as long as you retain this notice. * For a commercial use license, or to purchase the book (recommended), * visit http://www.davidflanagan.com/javaexamples2. */package com.davidflanagan.examples.applet;import java.applet.*;import java.awt.*;/** * This applet lets the user scribble with the mouse. * It demonstrates the Java 1.0 event model. **/public class Scribble extends Applet {    private int lastx, lasty;    // Remember last mouse coordinates.    Button erase_button;         // The Erase button.        /** Initialize the erase button, ask for keyboard focus */    public void init() {	erase_button = new Button("Erase");  	this.add(erase_button);	this.setBackground(Color.white);  // Set background color for scribble	this.requestFocus();  // Ask for keyboard focus so we get key events    }    /** Respond to mouse clicks */    public boolean mouseDown(Event e, int x, int y) {	lastx = x; lasty = y;             // Remember where the click was	return true;    }    /** Respond to mouse drags */    public boolean mouseDrag(Event e, int x, int y) {	Graphics g = getGraphics();	g.drawLine(lastx, lasty, x, y);   // Draw from last position to here	lastx = x; lasty = y;             // And remember new last position	return true;    }    /** Respond to key presses: Erase drawing when user types 'e' */    public boolean keyDown(Event e, int key) {	if ((e.id == Event.KEY_PRESS) && (key == 'e')) {	    Graphics g = getGraphics();	    g.setColor(this.getBackground());   	    g.fillRect(0, 0, bounds().width, bounds().height);	    return true;	}	else return false;    }    /** Respond to Button clicks: erase drawing when user clicks button */    public boolean action(Event e, Object arg) {	if (e.target == erase_button) {	    Graphics g = getGraphics();	    g.setColor(this.getBackground());   	    g.fillRect(0, 0, bounds().width, bounds().height);	    return true;	}	else return false;    }}