Using this code I would like to add a button to the page that displays when the gamestate is either Dead or Win. This button will let the user either start over or go on to the next level. My action listener is not yet fully coded because I can't even get the button to be visible on the page. I have tried coding in a button using
setLayout(new FlowLayout());
this.add(sOver);
sOver = new Button("Start Over");
sOver.addActionListener(this);
But that results in a an error when the game changes state.
package androidGame;
import java.applet.Applet;
import java.awt.event.*;
import java.applet.AudioClip;
import java.awt.Button;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.ArrayList;
import java.util.Random;
import java.net.*;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.Clip;
import androidGame.framework.Animation;
import java.applet.Applet;
import java.applet.AudioClip;
import java.net.URL;
public class StartingClass extends Applet implements Runnable, KeyListener, ActionListener {
enum GameState {
Running, Dead, Win
}
GameState state = GameState.Running;
private static Robot robot;
public static Heliboy hb, hb2, hb3, hb4, hb5, hb6, hb7, hb8, hb9, hb10, hb11, hb12, hb13, hb14, hb15, hb16;
public static int score = 0;
public static int rHealth = 120;
private Font font = new Font(null, Font.BOLD, 30);
private Image image, currentSprite, character, character2, character3,
characterDown, characterJumped, background, heliboy, heliboy2,
heliboy3, heliboy4, heliboy5;
public static Image tilegrassTop, tilegrassBot, tilegrassLeft,
tilegrassRight, tiledirt, tilefire, tiledoor;
private Graphics second;
private URL base;
private static Background bg1, bg2;
private Animation anim, hanim;
int level = 1;
AudioClip clip;
Button next, sOver;
private ArrayList<Tile> tilearray = new ArrayList<Tile>();
@Override
public void init() {
setSize(800, 480);
setBackground(Color.BLACK);
setFocusable(true);
addKeyListener(this);
Frame frame = (Frame) this.getParent().getParent();
frame.setTitle("Robot Mania");
try {
base = getDocumentBase();
} catch (Exception e) {
// TODO: handle exception
}
// Image Setups
character = getImage(base, "data/character.png");
character2 = getImage(base, "data/character2.png");
character3 = getImage(base, "data/character3.png");
characterDown = getImage(base, "data/down.png");
characterJumped = getImage(base, "data/jumped.png");
heliboy = getImage(base, "data/heliboy.png");
heliboy2 = getImage(base, "data/heliboy2.png");
heliboy3 = getImage(base, "data/heliboy3.png");
heliboy4 = getImage(base, "data/heliboy4.png");
heliboy5 = getImage(base, "data/heliboy5.png");
background = getImage(base, "data/spacebackground.png");
tiledirt = getImage(base, "data/tiledirt.png");
tilegrassTop = getImage(base, "data/tilegrasstop.png");
tilegrassBot = getImage(base, "data/tilegrassbot.png");
tilegrassLeft = getImage(base, "data/tilegrassleft.png");
tilegrassRight = getImage(base, "data/tilegrassright.png");
tilefire = getImage(base, "data/tilefire.png");
tiledoor = getImage(base, "data/tiledoor.png");
anim = new Animation();
anim.addFrame(character, 1250);
anim.addFrame(character2, 50);
anim.addFrame(character3, 50);
anim.addFrame(character2, 50);
hanim = new Animation();
hanim.addFrame(heliboy, 100);
hanim.addFrame(heliboy2, 100);
hanim.addFrame(heliboy3, 100);
hanim.addFrame(heliboy4, 100);
hanim.addFrame(heliboy5, 100);
hanim.addFrame(heliboy4, 100);
hanim.addFrame(heliboy3, 100);
hanim.addFrame(heliboy2, 100);
currentSprite = anim.getImage();
}
@Override
public void start() {
//Sound.MAIN.loop();
bg1 = new Background(0, 0);
bg2 = new Background(2160, 0);
robot = new Robot();
// Initialize Tiles
try {
loadMap("data/map"+ level +".txt");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Random random = new Random();
int randomInt = random.nextInt(500);
hb = new Heliboy(700, 360);
hb2 = new Heliboy(900 + randomInt, 360);
hb3 = new Heliboy(2300 + randomInt, 360);
hb4 = new Heliboy(2900 + randomInt, 360);
hb5 = new Heliboy(3400 + randomInt, 360);
hb6 = new Heliboy(3900 + randomInt, 360);
hb7 = new Heliboy(4300 + randomInt, 360);
hb8 = new Heliboy(4700 + randomInt, 360);
hb9 = new Heliboy(5000 + randomInt, 360);
hb10 = new Heliboy(5300 + randomInt, 360);
hb11 = new Heliboy(5700 + randomInt, 360);
hb12 = new Heliboy(6000 + randomInt, 360);
hb13 = new Heliboy(6300 + randomInt, 360);
hb14 = new Heliboy(6700 + randomInt, 360);
hb15 = new Heliboy(7000 + randomInt, 360);
hb16 = new Heliboy(7200 + randomInt, 360);
Thread thread = new Thread(this);
thread.start();
}
private void loadMap(String filename) throws IOException {
ArrayList lines = new ArrayList();
int width = 0;
int height = 0;
BufferedReader reader = new BufferedReader(new FileReader(filename));
while (true) {
String line = reader.readLine();
// no more lines to read
if (line == null) {
reader.close();
break;
}
if (!line.startsWith("!")) {
lines.add(line);
width = Math.max(width, line.length());
}
}
height = lines.size();
for (int j = 0; j < 12; j++) {
String line = (String) lines.get(j);
for (int i = 0; i < width; i++) {
if (i < line.length()) {
char ch = line.charAt(i);
Tile t = new Tile(i, j, Character.getNumericValue(ch));
tilearray.add(t);
}
}
}
}
@Override
public void run() {
if (state == GameState.Running) {
while (true) {
robot.update();
if (robot.isJumped()) {
currentSprite = characterJumped;
} else if (robot.isJumped() == false
&& robot.isDucked() == false) {
currentSprite = anim.getImage();
}
ArrayList projectiles = robot.getProjectiles();
for (int i = 0; i < projectiles.size(); i++) {
Projectile p = (Projectile) projectiles.get(i);
if (p.isVisible() == true) {
p.update();
} else {
projectiles.remove(i);
}
}
updateTiles();
hb.update();
hb2.update();
hb3.update();
hb4.update();
hb5.update();
hb6.update();
hb7.update();
hb8.update();
hb9.update();
hb10.update();
hb11.update();
hb12.update();
hb13.update();
hb14.update();
hb15.update();
hb16.update();
bg1.update();
bg2.update();
animate();
repaint();
try {
Thread.sleep(17);
} catch (InterruptedException e) {
e.printStackTrace();
}
if (rHealth == 0) {
state = GameState.Dead;
Sound.MAIN.stop();
//Sound.DIE.play();
sOver = new Button("Start Over");
this.add(sOver);
sOver.addActionListener(this);
sOver.setVisible(true);
revalidate();
repaint();
}
if (robot.getCenterY() > 500) {
state = GameState.Dead;
Sound.MAIN.stop();
//Sound.DIE.play();
sOver = new Button("Start Over");
this.add(sOver);
sOver.addActionListener(this);
sOver.setVisible(true);
revalidate();
repaint();
}
if (score == 5){
state = GameState.Win;
Sound.MAIN.stop();
//Sound.WIN.play();
next = new Button("Next Level");
this.add(next);
next.addActionListener(this);
next.setVisible(true);
revalidate();
repaint();
}
}
}
}
public void animate() {
anim.update(10);
hanim.update(50);
}
@Override
public void update(Graphics g) {
if (image == null) {
image = createImage(this.getWidth(), this.getHeight());
second = image.getGraphics();
}
second.setColor(getBackground());
second.fillRect(0, 0, getWidth(), getHeight());
second.setColor(getForeground());
paint(second);
g.drawImage(image, 0, 0, this);
}
@Override
public void paint(Graphics g) {
if (state == GameState.Running) {
g.drawImage(background, bg1.getBgX(), bg1.getBgY(), this);
g.drawImage(background, bg2.getBgX(), bg2.getBgY(), this);
paintTiles(g);
ArrayList projectiles = robot.getProjectiles();
for (int i = 0; i < projectiles.size(); i++) {
Projectile p = (Projectile) projectiles.get(i);
g.setColor(Color.BLUE);
g.fillRect(p.getX(), p.getY(), 10, 5);
}
g.drawImage(currentSprite, robot.getCenterX() - 61,
robot.getCenterY() - 63, this);
g.drawImage(hanim.getImage(), hb.getCenterX() - 48,
hb.getCenterY() - 48, this);
g.drawImage(hanim.getImage(), hb2.getCenterX() - 48,
hb2.getCenterY() - 48, this);
g.drawImage(hanim.getImage(), hb3.getCenterX() - 48,
hb3.getCenterY() - 48, this);
g.drawImage(hanim.getImage(), hb4.getCenterX() - 48,
hb4.getCenterY() - 48, this);
g.drawImage(hanim.getImage(), hb5.getCenterX() - 48,
hb5.getCenterY() - 48, this);
g.drawImage(hanim.getImage(), hb6.getCenterX() - 48,
hb6.getCenterY() - 48, this);
g.drawImage(hanim.getImage(), hb7.getCenterX() - 48,
hb7.getCenterY() - 48, this);
g.drawImage(hanim.getImage(), hb8.getCenterX() - 48,
hb8.getCenterY() - 48, this);
g.drawImage(hanim.getImage(), hb9.getCenterX() - 48,
hb9.getCenterY() - 48, this);
g.drawImage(hanim.getImage(), hb10.getCenterX() - 48,
hb10.getCenterY() - 48, this);
g.drawImage(hanim.getImage(), hb11.getCenterX() - 48,
hb11.getCenterY() - 48, this);
g.drawImage(hanim.getImage(), hb12.getCenterX() - 48,
hb12.getCenterY() - 48, this);
g.drawImage(hanim.getImage(), hb13.getCenterX() - 48,
hb13.getCenterY() - 48, this);
g.drawImage(hanim.getImage(), hb14.getCenterX() - 48,
hb14.getCenterY() - 48, this);
g.drawImage(hanim.getImage(), hb15.getCenterX() - 48,
hb15.getCenterY() - 48, this);
g.drawImage(hanim.getImage(), hb16.getCenterX() - 48,
hb16.getCenterY() - 48, this);
g.setFont(font);
g.setColor(Color.WHITE);
g.drawString("Health: " + Integer.toString(rHealth), 5, 30);
g.drawString("Score: " + Integer.toString(score), 650, 30);
} else if (state == GameState.Dead) {
//setLayout(new FlowLayout());
g.setColor(Color.BLACK);
g.fillRect(0, 0, 800, 480);
g.setColor(Color.WHITE);
g.drawString("You're Dead!", 300, 200);
g.drawString("Score: " + score, 300, 250);
}
else if (state == GameState.Win) {
g.setColor(Color.BLACK);
g.fillRect(0, 0, 800, 480);
g.setColor(Color.WHITE);
g.drawString("You Beat this level!", 300, 200);
g.drawString("Score: " + score, 300, 250);
level++;
}
}
private void updateTiles() {
for (int i = 0; i < tilearray.size(); i++) {
Tile t = (Tile) tilearray.get(i);
t.update();
}
}
private void paintTiles(Graphics g) {
for (int i = 0; i < tilearray.size(); i++) {
Tile t = (Tile) tilearray.get(i);
g.drawImage(t.getTileImage(), t.getTileX(), t.getTileY(), this);
}
}
@Override
public void keyPressed(KeyEvent e) {
switch (e.getKeyCode()) {
case KeyEvent.VK_UP:
break;
case KeyEvent.VK_DOWN:
currentSprite = characterDown;
if (robot.isJumped() == false) {
robot.setDucked(true);
robot.setSpeedX(0);
}
break;
case KeyEvent.VK_LEFT:
robot.moveLeft();
robot.setMovingLeft(true);
break;
case KeyEvent.VK_RIGHT:
robot.moveRight();
robot.setMovingRight(true);
break;
case KeyEvent.VK_SPACE:
robot.jump();
break;
case KeyEvent.VK_CONTROL:
if (robot.isDucked() == false && robot.isJumped() == false
&& robot.isReadyToFire()) {
robot.shoot();
robot.setReadyToFire(false);
}
break;
}
}
@Override
public void keyReleased(KeyEvent e) {
switch (e.getKeyCode()) {
case KeyEvent.VK_UP:
break;
case KeyEvent.VK_DOWN:
currentSprite = anim.getImage();
robot.setDucked(false);
break;
case KeyEvent.VK_LEFT:
robot.stopLeft();
break;
case KeyEvent.VK_RIGHT:
robot.stopRight();
break;
case KeyEvent.VK_SPACE:
break;
case KeyEvent.VK_CONTROL:
robot.setReadyToFire(true);
Sound.GUN.play();
break;
}
}
@Override
public void keyTyped(KeyEvent e) {
// TODO Auto-generated method stub
}
public static Background getBg1() {
return bg1;
}
public static Background getBg2() {
return bg2;
}
public static Robot getRobot() {
return robot;
}
@Override
public void actionPerformed(ActionEvent evt) {
if (evt.getSource() == next)
level ++;
{
}
if (evt.getSource() == sOver)
level = 1;
{
}
}
}
The error message that I was getting is:
Exception in thread "AWT-EventQueue-1" java.lang.NullPointerException
at java.awt.Container.addImpl(Unknown Source)
at java.awt.Container.add(Unknown Source)
at androidGame.StartingClass.paint(StartingClass.java:372)
at androidGame.StartingClass.update(StartingClass.java:305)
at sun.awt.RepaintArea.updateComponent(Unknown Source)
at sun.awt.RepaintArea.paint(Unknown Source)
at sun.awt.windows.WComponentPeer.handleEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$300(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
