A red blob moves randomly across the canvas. The arrow keys help move it in the desired direction. The world ends when the blob travels outside of the bounds. The clock stops when the blob falls into the black hole in the middle of the canvas. The player can change the color of the blob to green by hitting the 'G' key, to yellow by hitting the 'Y' key, and back to red by hitting the 'R' key.
To see the html code for this applet, select View Source in your browser. The Java code below is the complete code for this applet.
The code can also run as Java application. The programmer has to
remove the code for the class BlobWorldApplet, change the
import to use the impdraw package and either
comment out the main method - or run the program as a test
suite.
import java.awt.Color;
import java.util.Random;
import appletworld.*;
import tester.*;
import geometry.*;
import colors.*;
/**
* Copyright 2012 Viera K. Proulx
* This program is distributed under the terms of the
* GNU Lesser General Public License (LGPL)
*/
/**
* Applet wrapper for the BlobWorld
*
* @author Viera K. Proulx
* @since March 7 2012
*/
public class BlobWorldApplet extends WorldApplet{
/** Produce a new BlobWorld */
public World getNewWorld(){
return new BlobWorld(
new Blob(new Posn(50, 60), 20, new Red()));
}
/** Set the size of this world */
public void setWorldSize(){
this.WIDTH = 200;
this.HEIGHT = 300;
}
}
/** Class that represents a colored disk that moves around the Canvas */
class Blob{
Posn center;
int radius;
IColor col;
//ImageMaker image = new ImageMaker("shark.png");
/** The constructor */
Blob(Posn center, int radius, IColor col) {
this.center = center;
this.radius = radius;
this.col = col;
}
/** draw this blob in the given World */
void draw(Canvas c) {
//return c.drawImage(image, this.center);
c.drawDisk(this.center, this.radius, this.col);
}
/** produce the image of this blob at its current location and color */
WorldImage blobImage(){
//return new DiskImage(this.center, this.radius, this.col);
return new FromFileImage(this.center, "shark.png").
overlayImages(new CircleImage(
this.center, this.radius, this.col));
}
/** move this blob 20 pixels in the direction given by the ke
or change its color to Green, Red or Yellow */
public void moveBlob(String ke){
if (ke.equals("right")){
this.center.x = this.center.x + 5;
}
else if (ke.equals("left")){
this.center.x = this.center.x - 5;
}
else if (ke.equals("up")){
this.center.y = this.center.y - 5;
}
else if (ke.equals("down")){
this.center.y = this.center.y + 5;;
}
// change the color to Y, G, R
else if (ke.equals("Y")){
this.col = new Yellow();
}
else if (ke.equals("G")){
this.col = new Green();
}
else if (ke.equals("R")){
this.col = new Red();
}
}
/** produce a new blob moved by a random distance < n pixels */
void randomMove(int n){
this.center = new Posn(this.center.x + this.randomInt(n),
this.center.y + this.randomInt(n));
}
/** helper method to generate a random number in the range -n to n */
int randomInt(int n){
return -n + (new Random().nextInt(2 * n + 1));
}
/** is the blob outside the bounds given by the width and height */
boolean outsideBounds(int width, int height) {
return this.center.x < 0
|| this.center.x > width
|| this.center.y < 0
|| this.center.y > height;
}
/** is the blob near the center of area given by the width and height */
boolean nearCenter(int width, int height) {
return this.center.x > width / 2 - 10
&& this.center.x < width / 2 + 10
&& this.center.y > height / 2 - 10
&& this.center.y < height / 2 + 10;
}
}
/** Represent the world of a Blob */
class BlobWorld extends World {
int width = 200;
int height = 300;
Blob blob;
/** The constructor */
public BlobWorld(Blob blob) {
super();
this.blob = blob;
}
/** Move the Blob when the player presses a key */
public void onKeyEvent(String ke) {
if (ke.equals("x"))
this.endOfWorld("Goodbye");
else
this.blob.moveBlob(ke);
}
/** On tick move the Blob in a random direction.
*/
public void onTick() {
this.blob.randomMove(5);
}
/**
* On mouse click move the blob to the mouse location, make the color red.
*/
public void onMouseClicked(Posn loc){
this.blob.center = loc;
}
/**
* The entire background image for this world
* It illustrates the use of most of the WorldImage shapes
*/
public WorldImage blackHole =
new OverlayImages(new RectangleImage(new Posn(100, 150),
this.width, this.height, new Blue()),
new OverlayImages(new EllipseImage(new Posn(12, 12), 25, 25, new Green()),
new OverlayImages(new DiskImage(new Posn(100, 150), 10, new Black()),
new OverlayImages(new CircleImage(new Posn(100, 150), 10, new White()),
new OverlayImages(new RectangleImage(new Posn(100, 150), 10, 10, new White()),
new OverlayImages(new LineImage(new Posn(95, 145),
new Posn(105, 155), new Red()),
new OverlayImages(new LineImage(new Posn(95, 155),
new Posn(105, 145), new Red()),
new OvalImage(new Posn(187,287), 25, 25, new Green()))))))));
/**
* produce the image of this world by adding the moving blob
* to the background image
*/
public WorldImage makeImage(){
return new OverlayImages(this.blackHole, this.blob.blobImage());
}
/**
* produce the image of this world by adding the moving blob
* to the background image
*/
public WorldImage lastImage(String s){
return new OverlayImages(this.makeImage(),
new TextImage(new Posn(100, 40), s,
Color.red));
}
/**
* Check whether the Blob is out of bounds,
* or fell into the black hole in the middle.
*/
public WorldEnd worldEnds (){
// if the blob is outside the canvas, stop
if (this.blob.outsideBounds(this.width, this.height)){
return
new WorldEnd(true,
new OverlayImages(this.makeImage(),
new TextImage(new Posn(100, 40), "Blob is outside the bounds",
Color.red)));
}
// time ends is the blob falls into the black hole in the middle
if (this.blob.nearCenter(this.width, this.height)){
return
new WorldEnd(true,
new OverlayImages(this.makeImage(),
new TextImage(new Posn(100, 40), "Black hole ate the blob",
13, 3, Color.red)));
}
else{
return new WorldEnd(false, this.makeImage());
}
}
}
class BlobExamples{
// examples of data for the Blob class:
Blob b1 = new Blob(new Posn(100, 100), 50, new Red());
Blob b1left = new Blob(new Posn(95, 100), 50, new Red());
Blob b1right = new Blob(new Posn(105, 100), 50, new Red());
Blob b1up = new Blob(new Posn(100, 95), 50, new Red());
Blob b1down = new Blob(new Posn(100, 105), 50, new Red());
Blob b1G = new Blob(new Posn(100, 100), 50, new Green());
Blob b1Y = new Blob(new Posn(100, 100), 50, new Yellow());
// examples of data for the BlobWorld class:
BlobWorld b1w = new BlobWorld(this.b1);
BlobWorld b1leftw = new BlobWorld(this.b1left);
BlobWorld b1rightw = new BlobWorld(this.b1right);
BlobWorld b1upw = new BlobWorld(this.b1up);
BlobWorld b1downw = new BlobWorld(this.b1down);
BlobWorld b1Gw = new BlobWorld(this.b1G);
BlobWorld b1Yw = new BlobWorld(this.b1Y);
BlobWorld b1mouse50x50w =
new BlobWorld(new Blob(new Posn(50, 50), 50, new Red()));
BlobWorld bwOutOfBounds =
new BlobWorld(new Blob(new Posn(100, 350), 50, new Red()));
BlobWorld bwInTheCenter =
new BlobWorld(new Blob(new Posn(100, 150), 50, new Red()));
void reset(){
// examples of data for the Blob class:
this.b1 = new Blob(new Posn(100, 100), 50, new Red());
this.b1left = new Blob(new Posn(95, 100), 50, new Red());
this.b1right = new Blob(new Posn(105, 100), 50, new Red());
this.b1up = new Blob(new Posn(100, 95), 50, new Red());
this.b1down = new Blob(new Posn(100, 105), 50, new Red());
this.b1G = new Blob(new Posn(100, 100), 50, new Green());
this.b1Y = new Blob(new Posn(100, 100), 50, new Yellow());
// examples of data for the BlobWorld class:
this.b1w = new BlobWorld(this.b1);
this.b1leftw = new BlobWorld(this.b1left);
this.b1rightw = new BlobWorld(this.b1right);
this.b1upw = new BlobWorld(this.b1up);
this.b1downw = new BlobWorld(this.b1down);
this.b1Gw = new BlobWorld(this.b1G);
this.b1Yw = new BlobWorld(this.b1Y);
this.b1mouse50x50w =
new BlobWorld(new Blob(new Posn(50, 50), 50, new Red()));
this.bwOutOfBounds =
new BlobWorld(new Blob(new Posn(100, 350), 50, new Red()));
this.bwInTheCenter =
new BlobWorld(new Blob(new Posn(100, 150), 50, new Red()));
}
/** test the method moveBlob in the Blob class */
void testMoveBlob(Tester t){
this.reset();
this.b1.moveBlob("left");
t.checkExpect(this.b1,
this.b1left, "test moveBolb - left " + "\n");
this.reset();
this.b1.moveBlob("right");
t.checkExpect(this.b1,
this.b1right, "test movelob - right " + "\n");
this.reset();
this.b1.moveBlob("up");
t.checkExpect(this.b1,
this.b1up, "test moveBlob - up " + "\n");
this.reset();
this.b1.moveBlob("down");
t.checkExpect(this.b1,
this.b1down, "test moveBlob - down " + "\n");
this.reset();
this.b1.moveBlob("G");
t.checkExpect(this.b1,
this.b1G, "test moveBlob - G " + "\n");
this.reset();
this.b1.moveBlob("Y");
t.checkExpect(this.b1,
this.b1Y, "test moveBlob - Y " + "\n");
this.reset();
this.b1G.moveBlob("R");
t.checkExpect(this.b1G,
this.b1, "test moveBlob - R " + "\n");
}
/** test the method onKeyEvent in the BlobWorld class */
void testOnKeyEvent(Tester t){
this.reset();
this.b1w.onKeyEvent("left");
t.checkExpect(this.b1w,
this.b1leftw, "test moveBolb - left " + "\n");
this.reset();
this.b1w.onKeyEvent("right");
t.checkExpect(this.b1w,
this.b1rightw, "test movelob - right " + "\n");
this.reset();
this.b1w.onKeyEvent("up");
t.checkExpect(this.b1w,
this.b1upw, "test moveBlob - up " + "\n");
this.reset();
this.b1w.onKeyEvent("down");
t.checkExpect(this.b1w,
this.b1downw, "test moveBlob - down " + "\n");
this.reset();
this.b1w.onKeyEvent("G");
t.checkExpect(this.b1w,
this.b1Gw, "test moveBlob - G " + "\n");
this.reset();
this.b1w.onKeyEvent("Y");
t.checkExpect(this.b1w,
this.b1Yw, "test moveBlob - Y " + "\n");
this.reset();
this.b1Gw.onKeyEvent("R");
t.checkExpect(this.b1Gw,
this.b1w, "test moveBlob - R " + "\n");
}
/** test the method outsideBounds in the Blob class */
void testOutsideBounds(Tester t){
this.reset();
t.checkExpect(this.b1.outsideBounds(60, 200), true,
"test outsideBounds on the right");
this.reset();
t.checkExpect(this.b1.outsideBounds(100, 90), true,
"test outsideBounds below");
this.reset();
t.checkExpect(
new Blob(new Posn(-5, 100), 50, new Red()).outsideBounds(100, 110),
true,
"test outsideBounds above");
this.reset();
t.checkExpect(
new Blob(new Posn(80, -5), 50, new Blue()).outsideBounds(100, 90),
true,
"test outsideBounds on the left");
this.reset();
t.checkExpect(this.b1.outsideBounds(200, 400), false,
"test outsideBounds - within bounds");
}
/** test the method onMOuseClicked in the BlobWorld class */
void testOnMouseClicked(Tester t){
this.reset();
this.b1w.onMouseClicked(new Posn(50, 50));
t.checkExpect(this.b1w,
this.b1mouse50x50w);
}
/** test the method nearCenter in the Blob class */
void testNearCenter(Tester t){
this.reset();
t.checkExpect(this.b1.nearCenter(200, 200), true,
"test nearCenter - true");
this.reset();
t.checkExpect(this.b1.nearCenter(200, 100), false,
"test nearCenter - false");
}
/** the method randomInt in the Blob class */
void testRandomInt(Tester t){
this.reset();
t.checkOneOf("test randomInt",
this.b1.randomInt(3), -3, -2, -1, 0, 1, 2, 3);
this.reset();
t.checkNoneOf("test randomInt",
this.b1.randomInt(3), -5, -4, 4, 5);
}
/** test the method randomMove in the Blob class */
void testRandomMove(Tester t){
this.reset();
this.b1.randomMove(1);
t.checkOneOf("test randomMove", this.b1,
new Blob(new Posn( 99, 99), 50, new Red()),
new Blob(new Posn( 99, 100), 50, new Red()),
new Blob(new Posn( 99, 101), 50, new Red()),
new Blob(new Posn(100, 99), 50, new Red()),
new Blob(new Posn(100, 100), 50, new Red()),
new Blob(new Posn(100, 101), 50, new Red()),
new Blob(new Posn(101, 99), 50, new Red()),
new Blob(new Posn(101, 100), 50, new Red()),
new Blob(new Posn(101, 101), 50, new Red()));
}
/** test the method onTick in the BlobWorld class */
void testOnTick1(Tester t){
this.reset();
boolean result = true;
for (int i = 0; i < 20; i++){
this.reset();
this.b1w.onTick();
result = result &&
t.checkRange(this.b1w.blob.center.x, 95, 106) &&
t.checkRange(this.b1w.blob.center.y, 95, 106);
}
t.checkExpect(result);
}
/** test the method onTick in the BlobWorld class */
/*
boolean testOnTick2(Tester t){
return
// insufficient number of options ...
t.checkOneOf("test onTick2: randomMove", this.b1w.onTick(),
new BlobWorld(new Blob(new Posn( 99, 99), 50, new Red())),
new BlobWorld(new Blob(new Posn( 99, 100), 50, new Red())),
new BlobWorld(new Blob(new Posn( 99, 101), 50, new Red())),
new BlobWorld(new Blob(new Posn(100, 99), 50, new Red())),
new BlobWorld(new Blob(new Posn(100, 100), 50, new Red())),
new BlobWorld(new Blob(new Posn(100, 101), 50, new Red())),
new BlobWorld(new Blob(new Posn(101, 99), 50, new Red())),
new BlobWorld(new Blob(new Posn(101, 100), 50, new Red())),
new BlobWorld(new Blob(new Posn(101, 101), 50, new Red()))
);
}
*/
// test the method worldEnds for the class BlobWorld
void testWorldEnds(Tester t){
this.reset();
t.checkExpect(this.bwOutOfBounds.worldEnds(),
new WorldEnd(true,
new OverlayImages(this.bwOutOfBounds.makeImage(),
new TextImage(new Posn(100, 40), "Blob is outside the bounds",
Color.red))));
this.reset();
t.checkExpect(this.bwInTheCenter.worldEnds(),
new WorldEnd(true,
new OverlayImages(this.bwInTheCenter.makeImage(),
new TextImage(new Posn(100, 40), "Black hole ate the blob", 13, 3,
Color.red))));
this.reset();
t.checkExpect(this.b1w.worldEnds(),
new WorldEnd(false, this.b1w.makeImage()));
}
/** run the animation */
BlobWorld w1 =
new BlobWorld(new Blob(new Posn(100, 200), 20, new Red()));
BlobWorld w2 =
new BlobWorld(new Blob(new Posn(100, 200), 20, new Red()));
BlobWorld w3 =
new BlobWorld(new Blob(new Posn(100, 200), 20, new Red()));
/** main: an alternative way of starting the world and running the tests */
public static void main(String[] argv){
// run the tests - showing only the failed test results
BlobExamples be = new BlobExamples();
Tester.runReport(be, false, false);
}
}