We Keep Coding

drawImage is not applicable for the arguments

Look I'm going to be up front about this. My assignment is due soon and i've spent way too many hours trying to fix this problem with no success at all. I'm essentially clueless at what the issue is and I really dont know where to look. I have 5 classes, I will try and post them all to ensure I get the answer, I am unable to change GameManager or Goal but I am allowed to change any other class.
The problem lines are this.canvasGraphics.drawImage(player.getCurrentImage() where drawImage says it isnt applicable for the arguments
and
this.enemies[i].getX() - (this.enemies[i].getCurrentImage().getWidth() / 2),
this.enemies[i].getY() - (this.enemies[i].getCurrentImage().getHeight() / 2), null);
where getWidth and getHeight show an almost identical error
thanks in advance
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Toolkit;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.image.BufferedImage;
import java.awt.Font;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
public class GameManager extends JFrame implements KeyListener {
private int canvasWidth;
private int canvasHeight;
private int borderLeft;
private int borderTop;
private BufferedImage canvas;
private Stage stage;
private Enemy[] enemies;
private Player player;
private Goal goal;
private Graphics gameGraphics;
private Graphics canvasGraphics;
private int numEnemies;
private boolean continueGame;
public static void main(String[] args) {
// During development, you can adjust the values provided in the brackets below
// as needed. However, your code must work with different/valid combinations
// of values.
int choice;
do{
GameManager managerObj = new GameManager(1920, 1080);
choice=JOptionPane.showConfirmDialog(null,"Play again?", "", JOptionPane.OK_CANCEL_OPTION);
}while(choice==JOptionPane.OK_OPTION);
System.exit(0);
}
public GameManager(int preferredWidth, int preferredHeight) {
int maxEnemies;
try{
maxEnemies=Integer.parseInt(JOptionPane.showInputDialog("How many enemies? (Default is 5)"));
if (maxEnemies<0)
maxEnemies=5;
}
catch (Exception e){
maxEnemies=5;
}
this.borderLeft = getInsets().left;
this.borderTop = getInsets().top;
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
if (screenSize.width < preferredWidth)
this.canvasWidth = screenSize.width - getInsets().left - getInsets().right;
else
this.canvasWidth = preferredWidth - getInsets().left - getInsets().right;
if (screenSize.height < preferredHeight)
this.canvasHeight = screenSize.height - getInsets().top - getInsets().bottom;
else
this.canvasHeight = preferredHeight - getInsets().top - getInsets().bottom;
setSize(this.canvasWidth, this.canvasHeight);
setResizable(false);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setVisible(true);
addKeyListener(this);
Random rng = new Random();
this.canvas = new BufferedImage(this.canvasWidth, this.canvasHeight, BufferedImage.TYPE_INT_RGB);
// Create a Stage object to hold the background images
this.stage = new Stage();
// Create a Goal object with its initial x and y coordinates
this.goal = new Goal((Math.abs(rng.nextInt()) % (this.canvasWidth)),
(Math.abs(rng.nextInt()) % this.canvasHeight));
// Create a Player object with its initial x and y coordinates
this.player = new Player((Math.abs(rng.nextInt()) % (this.canvasWidth)),
(Math.abs(rng.nextInt()) % this.canvasHeight));
// Create the Enemy objects, each with a reference to this (GameManager) object
// and their initial x and y coordinates.
this.numEnemies = maxEnemies;
this.enemies = new Enemy[this.numEnemies];
for (int i = 0; i < this.numEnemies; i++) {
this.enemies[i] = new Enemy(this, Math.abs(rng.nextInt()) % (this.canvasWidth),
Math.abs(rng.nextInt()) % this.canvasHeight);
}
this.gameGraphics = getGraphics();
this.canvasGraphics = this.canvas.getGraphics();
this.continueGame = true;
long gameStartTime=System.nanoTime();
while (this.continueGame) {
updateCanvas();
}
this.stage.setGameOverBackground();
double gameTime=(System.nanoTime()-gameStartTime)/1000000000.0;
updateCanvas();
this.gameGraphics.setFont(new Font(this.gameGraphics.getFont().getFontName(), Font.PLAIN, 50));
if (gameTime<1)
this.gameGraphics.drawString("Oops! Better luck next time...", this.canvasWidth/3, this.canvasHeight/2 - 50);
else
this.gameGraphics.drawString("You survived " + String.format("%.1f", gameTime)+ " seconds with "+this.numEnemies+" enemies!",
this.canvasWidth/4, this.canvasHeight/2 - 50);
return;
}
public void updateCanvas() {
long start = System.nanoTime();
this.goal.performAction();
// If the player is alive, this should move the player in the direction of the
// key that has been pressed
// Note: See keyPressed and keyReleased methods in the GameManager class.
this.player.performAction();
// If the enemy is alive, the enemy must move towards the Player. The Player object
// is obtained via the GameManager object that is given at the time of creating an Enemy
// object.
// Note: The amount that the enemy moves by must be much smaller than that of
// the player above or else the game becomes too hard to play.
for (int i = 0; i < this.numEnemies; i++) {
this.enemies[i].performAction();
}
if ((Math.abs(this.goal.getX() - this.player.getX()) < (this.goal.getCurrentImage().getWidth() / 2))
&& (Math.abs(this.goal.getY() - this.player.getY()) < (this.goal.getCurrentImage().getWidth() / 2))) {
for (int i = 0; i < this.numEnemies; i++) {
// Sets the image of the enemy to the "dead" image and sets its status to
// indicate dead
this.enemies[i].die();
}
// Sets the background of the stage to the finished game background.
this.stage.setGameOverBackground();
this.continueGame = false;
}
// If an enemy is close to the player or the goal, the player and goal die
int j = 0;
while (j < this.numEnemies) {
if ((Math.abs(this.player.getX() - this.enemies[j].getX()) < (this.player.getCurrentImage().getWidth() / 2))
&& (Math.abs(this.player.getY() - this.enemies[j].getY()) < (this.player.getCurrentImage().getWidth()
/ 2))) {
this.player.die();
this.goal.die();
this.stage.setGameOverBackground();
j = this.numEnemies;
this.continueGame = false;
}
else if ((Math.abs(this.goal.getX() - this.enemies[j].getX()) < (this.goal.getCurrentImage().getWidth() / 2))
&& (Math.abs(this.goal.getY() - this.enemies[j].getY()) < (this.goal.getCurrentImage().getWidth()
/ 2))) {
this.player.die();
this.goal.die();
this.stage.setGameOverBackground();
j = this.numEnemies;
this.continueGame = false;
}
j++;
}
try {
// Draw stage
this.canvasGraphics.drawImage(stage.getCurrentImage(), 0, 0, null);
// Draw goal
this.canvasGraphics.drawImage(this.goal.getCurrentImage(),
this.goal.getX() - (this.goal.getCurrentImage().getWidth() / 2),
this.goal.getY() - (this.goal.getCurrentImage().getHeight() / 2), null);
// Draw player
this.canvasGraphics.drawImage(player.getCurrentImage(),
this.player.getX() - (this.player.getCurrentImage().getWidth() / 2),
this.player.getY() - (this.player.getCurrentImage().getHeight() / 2), null);
// Draw enemies
for (int i = 0; i < this.numEnemies; i++) {
this.canvasGraphics.drawImage(this.enemies[i].getCurrentImage(),
this.enemies[i].getX() - (this.enemies[i].getCurrentImage().getWidth() / 2),
this.enemies[i].getY() - (this.enemies[i].getCurrentImage().getHeight() / 2), null);
}
} catch (Exception e) {
System.err.println(e.getMessage());
}
// Draw everything.
this.gameGraphics.drawImage(this.canvas, this.borderLeft, this.borderTop, this);
long end = System.nanoTime();
this.gameGraphics.setFont(new Font(this.gameGraphics.getFont().getFontName(), Font.PLAIN, 15));
this.gameGraphics.drawString("FPS: " + String.format("%2d", (int) (1000000000.0 / (end - start))),
this.borderLeft + 50, this.borderTop + 75);
return;
}
public Player getPlayer() {
return this.player;
}
public void keyPressed(KeyEvent ke) {
// Below, the setKey method is used to tell the Player object which key is
// currently pressed.
// The Player object must keep track of the pressed key and use it for
// determining the direction
// to move.
// Important: The setKey method in Player must not move the Player.
if (ke.getKeyCode() == KeyEvent.VK_LEFT)
this.player.setKey('L', true);
if (ke.getKeyCode() == KeyEvent.VK_RIGHT)
this.player.setKey('R', true);
if (ke.getKeyCode() == KeyEvent.VK_UP)
this.player.setKey('U', true);
if (ke.getKeyCode() == KeyEvent.VK_DOWN)
this.player.setKey('D', true);
if (ke.getKeyCode() == KeyEvent.VK_ESCAPE)
this.continueGame = false;
return;
}
#Override
public void keyReleased(KeyEvent ke) {
// Below, the setKey method is used to tell the Player object which key is
// currently released.
// The Player object must keep track of the pressed key and use it for
// determining the direction
// to move.
// Important: The setKey method in Player must not move the Player.
if (ke.getKeyCode() == KeyEvent.VK_LEFT)
this.player.setKey('L', false);
if (ke.getKeyCode() == KeyEvent.VK_RIGHT)
this.player.setKey('R', false);
if (ke.getKeyCode() == KeyEvent.VK_UP)
this.player.setKey('U', false);
if (ke.getKeyCode() == KeyEvent.VK_DOWN)
this.player.setKey('D', false);
return;
}
#Override
public void keyTyped(KeyEvent ke) {
return;
}
}
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import java.util.*;
public class Goal {
private int x;
private int y;
private BufferedImage imageCurrent;
private BufferedImage imageRunning;
private BufferedImage imageOver;
private int stepSize;
private Random rng; // Tip: Code that students write must not use randomness
public Goal(int x, int y) {
try {
this.imageRunning = ImageIO.read(new File("goal-alive.png"));
this.imageOver = ImageIO.read(new File("goal-dead.png"));
} catch (IOException e) {
e.printStackTrace();
}
this.x = x;
this.y = y;
this.stepSize = 10;
this.rng = new Random(x + y); // Tip: Code that students write (elsewhere) must not use any randomness.
this.imageCurrent = this.imageRunning;
return;
}
public void performAction() {
// The code below shows how the Goal can be moved by manipulating its x and y
// coordinates.
// Tip: Code that students write (elsewhere) must not use any randomness.
this.x += this.rng.nextInt() % stepSize;
this.y += this.rng.nextInt() % stepSize;
return;
}
public int getY() {
return this.y;
}
public int getX() {
return this.x;
}
public BufferedImage getCurrentImage() {
return this.imageCurrent;
}
public void die() {
this.imageCurrent = this.imageOver;
return;
}
}
import java.awt.Image;
public class Enemy {
private Image CurrentImage;
private int x;
private int y;
public Enemy(GameManager gameManager, int x, int y) {
}
public void performAction() {
}
public void die() {
}
public int getX() {
return this.x;
}
public int getY() {
return this.y;
}
public Image getCurrentImage() {
return CurrentImage;
}
}
import java.awt.Dimension;
public class Player {
private Dimension CurrentImage;
private int x;
private int y;
public Player(int x1, int y1) {
}
public void performAction() {
}
public int getX() {
return this.x;
}
public int getY() {
return this.y;
}
public Dimension getCurrentImage() {
return CurrentImage;
}
public void die() {
}
public void setKey(char c, boolean b) {
}
}
import java.awt.Image;
public class Stage {
public void setGameOverBackground() {
}
public Image getCurrentImage() {
return null;
}
}

Player.getCurrentImage() returns a Dimension, not an Image.

Java applet shows white screen despite running code to display the menu

I have an applet for a small game me and a friend are working on for our computer science class. We are attempting to make a menu that opens at the start of the applet, then after 1 second displays a class selection screen. However, after the one second, the screen just turns white, but outputs the print statement assigned to signal the class selection screen has loaded, I am unsure of why this is happening and would like to solve this.
I have tried putting the code to show the class selection screen in another thread so nothing else will be holding it back when it runs, however, this has changed nothing. I have also made sure the conditions to show the screen are true, and to show it every .2 seconds, yet nothing seems to work. I tried to make the code run in the constructor for the character, and it is supposed to run once, it runs once, but the problem with it running once is that it immediately exits the menu and goes to the next phase of the game for no reason.
import java.awt.*;
import java.applet.*;
import java.awt.event.KeyListener;
import java.awt.event.KeyEvent;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
import java.util.*;
public class FinalProjectTest extends Applet implements KeyListener, Runnable, MouseListener
{
int xCoord = 50;
int yCoord = 600;
int moveScale = 20;
int xSize = 20;
int ySize = 20;
int leftWall = 0;
int rightWall = 1000;
int topWall = 0;
int bottomWall = 650;
public volatile Graphics graphics;
boolean isInMenu = false;
boolean firstRun = true;
boolean drawMap = true;
int hostileAmount = 1000;
Character P1;
#Override
public void init()
{
addKeyListener(this);
addMouseListener( this );
}
public void Looper(Graphics g)
{
drawPlayer(g);
// Enemy 1
HostileObject enemy = new HostileObject(100, 250);
enemy.CreateHostile(g);
}
public void paint(Graphics g)
{
if (firstRun)
{
firstRun = false;
isInMenu = true;
System.out.println("Character Created");
P1 = new Character(g);
}
if (!isInMenu && !firstRun)
{
System.out.println("Game has begun!");
Map1 firstMap = new Map1(g);
Looper(g);
}
}
public void drawPlayer(Graphics g)
{
g.setColor(Util.black);
g.fillRect(xCoord - xSize, yCoord - ySize, xSize, ySize);
}
public void MovePlayer(int x, int y)
{
if (CheckPosition(xCoord + x, yCoord + y))
{
xCoord += x;
yCoord += y;
}
}
public boolean CheckPosition(int x, int y)
{
if (WallCheck1(x,y) && WallCheck2(x,y) && CheckBorders(x, y))
{
return true;
}
else
return false;
}
public boolean CheckBorders(int x, int y)
{
if (y + ySize <= bottomWall && y - ySize >= topWall && x - xSize >= leftWall && x + xSize <= rightWall)
{
return true;
}
else
return false;
}
public boolean WallCheck1(int x, int y)
{
if ((y - ySize >= Map1.wall1y1 || y + ySize <= Map1.wall1y2 + 20) || x - xSize >= Map1.wall1x2)
{
return true;
}
else
return false;
}
public boolean WallCheck2(int x, int y)
{
if ((y - ySize >= Map1.wall2y1 || y + ySize <= Map1.wall2y2 + 20) || x - xSize <= Map1.wall2x2)
{
return true;
}
else
return false;
}
boolean keyIsHeld;
char moveChar;
public void keyReleased( KeyEvent e )
{
keyIsHeld = false;
moveChar = ' ';
}
public void keyTyped( KeyEvent e ) { }
public void keyPressed( KeyEvent a )
{
char c = a.getKeyChar();
if ( c == 'w' )
{
moveChar = 'w';
keyIsHeld = true;
}
else if ( c == 'a')
{
moveChar = 'a';
keyIsHeld = true;
}
else if ( c == 's')
{
moveChar = 's';
keyIsHeld = true;
}
else if ( c == 'd')
{
moveChar = 'd';
keyIsHeld = true;
}
}
public void mouseClicked(MouseEvent e)
{
int x = e.getX();
int y = e.getY();
if (isInMenu && P1.ClassID == 0)
{
if (x < 500 && y > 100 && y < 375)
{
P1.ClassID = 1;
isInMenu = false;
System.out.println(P1.Pseudo + " has chosen class: Warrior!");
}
if (x < 500 && y >= 375)
{
P1.ClassID = 3;
isInMenu = false;
System.out.println(P1.Pseudo + " has chosen class: UO3!");
}
if (x >= 500 && y > 100 && y < 375)
{
P1.ClassID = 2;
isInMenu = false;
System.out.println(P1.Pseudo + " has chosen class: Thief!");
}
if (x >= 500 && y >= 375)
{
P1.ClassID = 4;
isInMenu = false;
System.out.println(P1.Pseudo + " has chosen class: Mage!");
}
repaint();
}
}
public void mouseEntered(MouseEvent e){}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
public boolean mouseDown(Event e, int x, int y){return true;}
public void run()
{
while (!isInMenu || !firstRun)
{
if (moveChar == 'w')
{
MovePlayer(0, -moveScale);
}
else if (moveChar == 'a')
{
MovePlayer(-moveScale, 0);
}
else if (moveChar == 's')
{
MovePlayer(0, moveScale);
}
else if (moveChar == 'd')
{
MovePlayer(moveScale, 0);
}
Util.wait(200);
repaint();
}
}
Thread moveThread;
Graphics g;
boolean increaseDecrease = false;
public void SetUpGraphics(Graphics graphics)
{
g = graphics;
}
public void start ()
{
if (moveThread == null)
{
moveThread = new Thread(this);
moveThread.start();
}
}
}
class Map1 extends FinalProjectTest
{
protected static int wall1x1 = 0;
protected static int wall1y1 = 500;
protected static int wall1x2 = 810;
protected static int wall1y2 = 440;
protected static int wall2x1 = 1000;
protected static int wall2y1 = 200;
protected static int wall2x2 = 190;
protected static int wall2y2 = 140;
public Map1(Graphics g)
{
Walls wall1 = new Walls(g, wall1x1, wall1y1, wall1x2, wall1y2);
Walls wall2 = new Walls(g, wall2x1, wall2y1, wall2x2, wall2y2);
}
}
class HostileObject
{
private int startPosX, startPosY;
private int xSize = 35;
private int ySize = 35;
public int health = 100;
public HostileObject(int x, int y)
{
startPosX = x;
startPosY = y;
}
public void CreateHostile(Graphics g)
{
g.setColor(Util.black);
//Util.fillRect(g ,startPosX,startPosY,xSize,ySize);
}
}
class Walls
{
private static int wallCount = 2;
public Walls(Graphics g, int x1, int y1, int x2, int y2)
{
Util.fillRect(g, x1, y1, x2, y2);
}
}
class Character extends FinalProjectTest implements MouseListener, Runnable
{
protected int ClassID = 0;
protected int PlayerID = 0;
protected int GP = 100;
protected String Pseudo = "Muritor";
protected boolean DebuggingMode = false;
protected Graphics menuGraphics;
Thread startMenuThread;
public Character(Graphics g)
{
g.setColor(Util.black);
Util.fillRect(g, 1, 1, 1000, 650);
Util.drawButton(g, 1, 1, 1000, 100, "3 Floors", 2);
Util.wait(1000);
menuGraphics = g;
startMenuThread = new Thread(this);
startMenuThread.start();
}
public void run()
{
while (Thread.currentThread() == startMenuThread)
{
Util.fillRect(menuGraphics, 1, 1, 1000, 650);
Util.drawButton(menuGraphics, 1, 1, 1000, 100, "Choose a Class", 2);
Util.drawButton(menuGraphics, 1, 100, 500, 375, "Warrior", 1);
Util.drawButton(menuGraphics, 501, 100, 1000, 375, "Thief", 1);
Util.drawButton(menuGraphics, 1, 376, 500, 650, "UO3", 1);
Util.drawButton(menuGraphics, 501, 376, 1000, 650, "Mage", 1);
repaint();
System.out.println("Menu loaded");
Util.wait(200);
}
}
public static void ButtonSelection(Graphics g)
{
}
}
class Util
{
static final Color black = Color.black;
static final Color white = Color.white;
public static void wait(int mil)
{
try
{
Thread.sleep((mil));
}
catch(InterruptedException ex)
{
Thread.currentThread().interrupt();
}
}
public static void fillRect(Graphics g, int x1, int y1, int x2, int y2)
{
int widthPlaceholder = x2 - x1;
int heightPlaceholder = y2 - y1;
g.fillRect(x1,y1,widthPlaceholder,heightPlaceholder);
}
public static void drawButton(Graphics g, int x1, int y1, int x2, int y2, String title, int fontType)
{
g.setColor(Util.black);
int widthPlaceholder = x2 - x1;
int heightPlaceholder = y2 - y1;
g.fillRect(x1,y1,widthPlaceholder,heightPlaceholder);
g.setColor(Util.white);
widthPlaceholder = x2 - x1;
heightPlaceholder = y2 - y1;
for (int k = 0; k < 3; k++)
{
g.drawRect(x1+k,y1+k,widthPlaceholder-k,heightPlaceholder-k);
}
switch(fontType)
{
case 1:
Font characterCreateButton = new Font("SansSerif", Font.PLAIN, 75);
g.setFont(characterCreateButton);
g.drawString(title, x1+100, y1+100);
break;
case 2:
Font characterCreateTitle = new Font("SansSerif", Font.BOLD, 100);
g.setFont(characterCreateTitle);
g.drawString(title, x1+25, y1+80);
break;
case 3:
Font mainMenu = new Font("Arial", Font.ITALIC, 50);
g.setFont(mainMenu);
break;
}
}
}
I expect it to say "Menu Loaded" every .2 seconds and refresh the actual menu screen at the same rate, I get the message, but the applet window is just white.

Problem #1
public class FinalProjectTest extends Applet implements KeyListener, Runnable, MouseListener {
I don't know about you, but when I compile your code, I get
Note: .../FinalProjectTest.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
So, if I enable the compiler flag, I get...
Compiling 1 source file to .../build/classes
.../FinalProjectTest.java:18: warning: [deprecation] Applet in java.applet has been deprecated
public class FinalProjectTest extends Applet implements KeyListener, Runnable, MouseListener {
.../FinalProjectTest.java:179: warning: [deprecation] mouseDown(Event,int,int) in Component has been deprecated
public boolean mouseDown(Event e, int x, int y) {
^
.../FinalProjectTest.java:179: warning: [deprecation] Event in java.awt has been deprecated
public boolean mouseDown(Event e, int x, int y) {
^
3 warnings
This should be raising alarm bells.
Applets have been actively been deprecated and are simply no longer supported and believe have been removed in the latest versions of the API, seriously time to move on.
In fact, when I run the code, I get:
Warning: Applet API and AppletViewer are deprecated.
Problem #2
public void paint(Graphics g) {
if (firstRun) {
firstRun = false;
isInMenu = true;
System.out.println("Character Created");
P1 = new Character(g);
}
if (!isInMenu && !firstRun) {
System.out.println("Game has begun!");
Map1 firstMap = new Map1(g);
Looper(g);
}
}
Painting should paint state, not make logical decisions or change the state, in fact, what's ever more worrying is...
P1 = new Character(g);
You should never maintain a reference to a Graphics context you did not create yourself. The painting system in AWT/Swing uses a shared context, so all components will use the same Graphics context, there's also no guarantee that the context will be the same between paint cycles.
This also highlights that you don't understand how the painting system works in AWT/Swing.
Start with Performing Custom Painting and Painting in AWT and Swing for more details about how painting actually works and how you should work with it
Problem ♾
Okay, so from there on in, every thing else is just compounding based on the above, make a bad situation infinitely worse, for example...
public void run() {
while (Thread.currentThread() == startMenuThread) {
Util.fillRect(menuGraphics, 1, 1, 1000, 650);
Util.drawButton(menuGraphics, 1, 1, 1000, 100, "Choose a Class", 2);
Util.drawButton(menuGraphics, 1, 100, 500, 375, "Warrior", 1);
Util.drawButton(menuGraphics, 501, 100, 1000, 375, "Thief", 1);
Util.drawButton(menuGraphics, 1, 376, 500, 650, "UO3", 1);
Util.drawButton(menuGraphics, 501, 376, 1000, 650, "Mage", 1);
repaint();
System.out.println("Menu loaded");
Util.wait(200);
}
}
This "might" seem okay, but if you understood how the painting, you'd understand the calling repaint will trigger and paint pass and cause paint to be called again and ... wait, hang on...
class Character extends FinalProjectTest implements MouseListener, Runnable {
Why does Character extend from FinalProjectTest?? It's not even added to any container which could paint it...oh dear ...
Answer...
Start again.
No, seriously, throw away what you've done and start again. This time start by reading (and understanding)...
Basic OO design concepts of "separation of responsibility". Rather then compounding all you logic into a single method, seperate the responsibility of each part of your program into their own class(es). The menu should be a single, stand alone component, the game canvas should be it's own, stand alone component, you should then have a "controller" which can, based on feedback from these components (via a observer pattern) decide when each should be shown (and how).
Model-View-Controller (which bleeds into the previous comment)
Performing Custom Painting and Painting in AWT and Swing
How to Use Key Bindings because KeyListener is not a good choice here
Concurrency in Swing because Swing, like most GUI frameworks, is not thread and is single threaded and you should know how to handle it.
How to Make Frames (Main Windows) because Applets are dead
How to Use CardLayout as this will help make your lives easier
Use JavaFX. At the very least you should be using Swing, but if you can, use JavaFX

How do I paint multiple objetcs that move at different speeds in Java?

I am working on homework for class, and its late because I can't seem to understand the material despite all the research that I am doing. I am a beginner and do not know much in the way of java. Also, this is my first post so please be forgiving when you are reading this.
I am building on source code from my textbook, which I updated recently for past homework, but now I am trying to generate a class that draws multiple squares and moves those objects independently and at different speeds. They will all need to rebound off the walls as well. I followed the instructions and created two arrays that will hold the random x and y values between 1 and 10. However, I struggle with arrays and I am sure that I am not doing it correctly. So, I would love some feedback to see if I have it set up correctly.
I have a the jpanel pulling up and drawing, and as long as there is 1 square it is working fine bouncing off the walls, but things change when I draw more than one. The do not move independently and they also share the same speed. Some even disappear from time to time. This has really thrown me off. I appreciate any help!
In short, I am trying to paint new squares that all travel in different directions and at different speeds. Per the instructions we are suppose create and use a two arrays that handle the x and y values.
Here is what I have so far:
public class DotsPanel extends JPanel
{
private int delay = 15;
private final int SIZE = 7, IMAGE_SIZE = 3; // radius of each dot
private Timer timer;
private int x, y, i;
private ArrayList<Point> pointList;
static int [] xarray = new int [1000];
static int [] yarray = new int [1000];
Random rand = new Random();
//-----------------------------------------------------------------
// Constructor: Sets up this panel to listen for mouse events.
//-----------------------------------------------------------------
public DotsPanel()
{
pointList = new ArrayList<Point>();
int [] xarray = new int [1000];
int [] yarray = new int [1000];
timer = new Timer(delay, new ReboundListener());
addMouseListener (new DotsListener());
addMouseMotionListener (new DotsListener());
setBackground(Color.gray);
setPreferredSize(new Dimension(700, 500));
for(int i = 0; i < xarray.length; i++)
{
xarray[i] = rand.nextInt(7);
yarray[i] = rand.nextInt(7);
}
timer.start();
}
//-----------------------------------------------------------------
// Draws all of the dots stored in the list.
//-----------------------------------------------------------------
public void paintComponent(Graphics page)
{
super.paintComponent(page);
page.setColor(Color.BLUE);
for (Point spot : pointList)
{
page.fillRect(spot.x-SIZE, spot.y-SIZE, 25, 25);
page.drawString("Count: " + pointList.size(), 5, 15);
}
}
//*****************************************************************
// Represents the listener for mouse events.
//*****************************************************************
private class DotsListener implements MouseListener, MouseMotionListener
{
//--------------------------------------------------------------
// Adds the current point to the list of points and redraws
// the panel whenever the mouse button is pressed.
//--------------------------------------------------------------
public void mousePressed(MouseEvent event)
{
pointList.add(event.getPoint());
repaint();
}
public void mouseDragged(MouseEvent event)
{
// initially I had two xarray and yarray in here just like in
// mouseClicked
// but it did not change anything when removed
}
//--------------------------------------------------------------
// Provide empty definitions for unused event methods.
//--------------------------------------------------------------
public void mouseClicked(MouseEvent event)
{
xarray[i] = rand.nextInt(7);
yarray[i] = rand.nextInt(7);
}
public void mouseReleased(MouseEvent event) {}
public void mouseEntered(MouseEvent event) {}
public void mouseExited(MouseEvent event) {}
public void mouseMoved(MouseEvent e) {}
}
private class ReboundListener implements ActionListener
{
//--------------------------------------------------------------
// Updates the position of the image and possibly the direction
// of movement whenever the timer fires an action event.
//--------------------------------------------------------------
public void actionPerformed(ActionEvent event)
{
for (Point spot : pointList)
{
spot.x += xarray[i];
spot.y += yarray[i];
if (spot.x <= 0 || spot.x >= 700)
xarray[i] = xarray[i] * -1;
if (spot.y <= 0 || spot.y >= 500)
yarray[i] = yarray[i] * -1;
repaint();
}
}
}
}

However, I struggle with arrays and I am sure that I am not doing it correctly.
I wouldn't use Arrays.
Instead, have a Ball object manage its own state. Then you can have different color, speed, size etc for each Ball. Then when the Timer fires you just calculate the new position and repaint the Ball.
Here is an example to get you started:
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.util.*;
import javax.swing.*;
import javax.swing.Timer;
public class BallAnimation4
{
private static void createAndShowUI()
{
BallPanel panel = new BallPanel();
JFrame frame = new JFrame("BallAnimation4");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( panel );
frame.setSize(800, 600);
frame.setLocationRelativeTo( null );
//frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
frame.setVisible( true );
panel.addBalls(5);
panel.startAnimation();
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
class BallPanel extends JPanel implements ActionListener
{
private ArrayList<Ball> balls = new ArrayList<Ball>();
public BallPanel()
{
setLayout( null );
setBackground( Color.BLACK );
}
public void addBalls(int ballCount)
{
Random random = new Random();
for (int i = 0; i < ballCount; i++)
{
Ball ball = new Ball();
ball.setRandomColor(true);
ball.setLocation(random.nextInt(getWidth()), random.nextInt(getHeight()));
ball.setMoveRate(32, 32, 1, 1, true);
// ball.setMoveRate(16, 16, 1, 1, true);
ball.setSize(32, 32);
balls.add( ball );
}
}
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
for (Ball ball: balls)
{
ball.draw(g);
}
}
public void startAnimation()
{
Timer timer = new Timer(75, this);
timer.start();
}
public void actionPerformed(ActionEvent e)
{
move();
repaint();
}
private void move()
{
for (Ball ball : balls)
{
ball.move(this);
}
}
class Ball
{
public Color color = Color.BLACK;
public int x = 0;
public int y = 0;
public int width = 1;
public int height = 1;
private int moveX = 1;
private int moveY = 1;
private int directionX = 1;
private int directionY = 1;
private int xScale = moveX;
private int yScale = moveY;
private boolean randomMove = false;
private boolean randomColor = false;
private Random myRand = null;
public Ball()
{
myRand = new Random();
setRandomColor(randomColor);
}
public void move(JPanel parent)
{
int iRight = parent.getSize().width;
int iBottom = parent.getSize().height;
x += 5 + (xScale * directionX);
y += 5 + (yScale * directionY);
if (x <= 0)
{
x = 0;
directionX *= (-1);
xScale = randomMove ? myRand.nextInt(moveX) : moveX;
if (randomColor) setRandomColor(randomColor);
}
if (x >= iRight - width)
{
x = iRight - width;
directionX *= (-1);
xScale = randomMove ? myRand.nextInt(moveX) : moveX;
if (randomColor) setRandomColor(randomColor);
}
if (y <= 0)
{
y = 0;
directionY *= (-1);
yScale = randomMove ? myRand.nextInt(moveY) : moveY;
if (randomColor) setRandomColor(randomColor);
}
if (y >= iBottom - height)
{
y = iBottom - height;
directionY *= (-1);
yScale = randomMove ? myRand.nextInt(moveY) : moveY;
if (randomColor) setRandomColor(randomColor);
}
}
public void draw(Graphics g)
{
g.setColor(color);
g.fillOval(x, y, width, height);
}
public void setColor(Color c)
{
color = c;
}
public void setLocation(int x, int y)
{
this.x = x;
this.y = y;
}
public void setMoveRate(int xMove, int yMove, int xDir, int yDir, boolean randMove)
{
this.moveX = xMove;
this.moveY = yMove;
directionX = xDir;
directionY = yDir;
randomMove = randMove;
}
public void setRandomColor(boolean randomColor)
{
this.randomColor = randomColor;
switch (myRand.nextInt(3))
{
case 0: color = Color.BLUE;
break;
case 1: color = Color.GREEN;
break;
case 2: color = Color.RED;
break;
default: color = Color.BLACK;
break;
}
}
public void setSize(int width, int height)
{
this.width = width;
this.height = height;
}
}
}
Since your Arrays only contain the Point you want to paint you don't have any information about the speed each point should be moved at. The best you could do is create a random amount each point should be moved each time its location is changed. This would give erratic movement as each time you move a point the distance would be random.
If you want more constant speed then you would need to create a second Array to contain the distance each point should move every time.
This starts to get messy creating a new Array every time you want a new property to be unique for the object you want to paint. That is why the approach to create a custom Object with multiple properties is easier to manage.

Menu in a simple java game [closed]

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Closed 9 years ago.
Improve this question
I created a GUI named Menu class for my Start, Help and Exit button. my problem is my game won't start, it hangs everytime I press the Start button. Can someone check my error and explain it to me because its my case study at school.
package spaceSip;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
public class Menu extends JFrame implements ActionListener
{
private JLabel titleL;
private JButton startB, helpB, exitB;
static JFrame frame1 = new JFrame();
public Menu()
{
frame1.setSize(500,250);
Container mainP = frame1.getContentPane();
mainP.setLayout(null);
titleL = new JLabel("WELCOME");
startB = new JButton("Start");
helpB = new JButton("Help");
exitB = new JButton("Exit");
mainP.add(titleL);
titleL.setFont(new Font("Chiller",Font.BOLD,50));
titleL.setBounds(100, 30, 200, 50);
mainP.add(startB);
startB.setMnemonic(KeyEvent.VK_S);
startB.setBounds(200, 80, 100, 20);
mainP.add(helpB);
helpB.setMnemonic(KeyEvent.VK_H);
helpB.setBounds(200, 100, 100, 20);
mainP.add(exitB);
exitB.setMnemonic(KeyEvent.VK_E);
exitB.setBounds(200, 120, 100, 20);
startB.addActionListener(this);
helpB.addActionListener(this);
exitB.addActionListener(this);
frame1.setVisible(true);
frame1.setResizable(false);
}
public void actionPerformed(ActionEvent e)
{
String key = e.getActionCommand();
if(key == "Start")
{
frame1.dispose();
new SpaceShipMain();
}
else if(key == "Help")
{
}
else
System.exit(0);
}
public static void main(String[]args)
{
new Menu();
}
}
package spaceSip;
import javax.swing.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
public class SpaceShipMain implements MouseListener
{
private JFrame background;
private SpaceShipPanel back;
public static boolean paused;
public static boolean crashed;
public static boolean started;
public static boolean playedOnce;
public boolean goingUp;
private double upCount;
public static int distance;
public static int maxDistance;
public final int XPOS;
public final int NUMRECS;
public final int RECHEIGHT;
public final int RECWIDTH;
private int moveIncrement;
private int numSmoke;
private ArrayList<SpaceShipImage> toprecs;
private ArrayList<SpaceShipImage> bottomrecs;
private ArrayList<SpaceShipImage> middlerecs;
private ArrayList<SpaceShipImage> smoke;
private SpaceShipImage helicopter;
public SpaceShipMain()
{
NUMRECS = 100;
RECHEIGHT = 70;
RECWIDTH = 30;
XPOS = 200;
playedOnce = false;
maxDistance = 0;
load(new File("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/Best.txt"));
initiate();
}
public void load(File file)
{
try
{
Scanner reader = new Scanner(file);
while(reader.hasNext())
{
int value = reader.nextInt();
if(value > maxDistance)
maxDistance = value;
}
}
catch(IOException i )
{
System.out.println("Error. "+i);
}
}
public void save()
{
FileWriter out;
try
{
out = new FileWriter("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/Best.txt");
out.write("" + maxDistance);
out.close();
}
catch(IOException i)
{
System.out.println("Error: "+i.getMessage());
}
}
public void initiate()
{
if(!playedOnce)
{
background = new JFrame("Space Ship Game");
background.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //closes the program when the window is closed
background.setResizable(false); //don't allow the user to resize the window
background.setSize(new Dimension(800,500));
background.setVisible(true);
back = new SpaceShipPanel("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/starfield.jpg");
background.add(back);
back.addMouseListener(this);
}
playedOnce = true;
goingUp = false;
paused = false;
crashed = false;
started = false;
distance = 0;
upCount = 0;
moveIncrement = 2;
numSmoke = 15;
toprecs = new ArrayList<SpaceShipImage>();
middlerecs = new ArrayList<SpaceShipImage>();
bottomrecs = new ArrayList<SpaceShipImage>();
smoke = new ArrayList<SpaceShipImage>();
helicopter = new SpaceShipImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/rocketship.GIF",XPOS,200);
for(int x = 0; x < NUMRECS; x++)
toprecs.add(new SpaceShipImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/rec2.JPG",RECWIDTH*x,5));
for(int x = 0; x < NUMRECS; x++)
bottomrecs.add(new SpaceShipImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/rec2.JPG",RECWIDTH*x,410));
middlerecs.add(new SpaceShipImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/asteroid2.jpg",1392,randomMidHeight()));
middlerecs.add(new SpaceShipImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/asteroid2.jpg",1972,randomMidHeight()));
drawRectangles();
}
public void drawRectangles()
{
long last = System.currentTimeMillis();
long lastCopter = System.currentTimeMillis();
long lastSmoke = System.currentTimeMillis();
long lastSound = System.currentTimeMillis();
int firstUpdates = 0;
double lastDistance = (double)System.currentTimeMillis();
while(true)
{
if(!paused && !crashed && started && (double)System.currentTimeMillis() - (double)(2900/40) > lastDistance)
{
lastDistance = System.currentTimeMillis();
distance++;
}
if(!paused && !crashed && started && System.currentTimeMillis() - 10 > lastCopter)
{
lastCopter = System.currentTimeMillis();
updateCopter();
updateMiddle();
}
if(!paused && !crashed && started && System.currentTimeMillis() - 100 > last)
{
last = System.currentTimeMillis();
updateRecs();
}
if(!paused && !crashed && started && System.currentTimeMillis() - 75 > lastSmoke)
{
lastSmoke = System.currentTimeMillis();
if (firstUpdates < numSmoke)
{
firstUpdates++;
smoke.add(new SpaceShipImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/smoke.GIF",187,helicopter.getY()));
for(int x = 0; x < firstUpdates; x++)
smoke.set(x,new SpaceShipImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/smoke.GIF",smoke.get(x).getX() - 12, smoke.get(x).getY()));
}
else
{
for(int x = 0; x < numSmoke - 1; x++)
smoke.get(x).setY(smoke.get(x+1).getY());
smoke.set(numSmoke - 1,new SpaceShipImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/smoke.GIF",187,helicopter.getY()));
}
}
back.updateImages(middlerecs,helicopter,smoke);
}
}
public void updateRecs()
{
for(int x = 0; x < (NUMRECS - 1); x++) //move all but the last rectangle 1 spot to the left
{
toprecs.set(x,new SpaceShipImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/rec2.JPG",RECWIDTH*x,toprecs.get(x+1).getY()));
bottomrecs.set(x,new SpaceShipImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/rec2.JPG",RECWIDTH*x,bottomrecs.get(x+1).getY()));
}
}
public void randomDrop()
{
toprecs.get(26).setY(toprecs.get(26).getY() + (463 - bottomrecs.get(26).getY()));
bottomrecs.get(26).setY(463);
}
public int randomMidHeight()
{
int max = 10000;
int min = 0;
for(int x = 0; x < NUMRECS; x++)
{
if(toprecs.get(x).getY() > min)
min = (int)toprecs.get(x).getY();
if(bottomrecs.get(x).getY() < max)
max = (int)bottomrecs.get(x).getY();
}
min += RECHEIGHT;
max -= (RECHEIGHT + min);
return min + (int)(Math.random() * max);
}
//moves the randomly generated middle rectangles
public void updateMiddle()
{
if(middlerecs.get(0).getX() > -1 * RECWIDTH)
{
middlerecs.set(0,new SpaceShipImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/asteroid.gif",middlerecs.get(0).getX() - (RECWIDTH/5), middlerecs.get(0).getY()));
middlerecs.set(1,new SpaceShipImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/asteroid.gif",middlerecs.get(1).getX() - (RECWIDTH/5), middlerecs.get(1).getY()));
}
else
{
middlerecs.set(0,new SpaceShipImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/asteroid.gif",middlerecs.get(1).getX() - (RECWIDTH/5), middlerecs.get(1).getY()));
middlerecs.set(1,new SpaceShipImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/asteroid.gif",middlerecs.get(0).getX() + 580,randomMidHeight()));
}
}
public boolean shoot()
{
for(int x = 3; x <= 7; x++)
if(helicopter.getY() >= bottomrecs.get(x).getY())
return true;
for(int y = 3; y <= 7; y++)
if(helicopter.getY() <= toprecs.get(y).getY())
return true;
for(int z = 0; z <= 1; z++)
if(isInMidRange(z))
return true;
return false;
}
public boolean isInMidRange(int num)
{
Rectangle middlecheck = new Rectangle((int)middlerecs.get(num).getX(),(int)middlerecs.get(num).getY(),RECWIDTH,RECHEIGHT);
Rectangle coptercheck = new Rectangle((int)helicopter.getX(),(int)helicopter.getY(),70,48); //asteroid X and y bump
return middlecheck.intersects(coptercheck);
}
public void crash()
{
crashed = true;
if(distance > maxDistance)
{
maxDistance = distance;
save();
}
int reply = JOptionPane.showConfirmDialog(null, " RESTART ?", "GAME OVER", JOptionPane.YES_NO_OPTION);
if(reply == JOptionPane.YES_OPTION)
initiate();
else
System.exit(0);
initiate();
}
//moves the spaceship
public void updateCopter()
{
upCount += .10;
if(goingUp)
{
if(upCount < 3.5)
helicopter.setPosition(XPOS,(double)(helicopter.getY() - (.3 + upCount)));
else
helicopter.setPosition(XPOS,(double)(helicopter.getY() - (1.2 + upCount)));
helicopter.setImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/rocketship.GIF");
}
else
{
if(upCount < 1)
helicopter.setPosition(XPOS,(double)(helicopter.getY() + upCount));
else
helicopter.setPosition(XPOS,(double)(helicopter.getY() + (1.2 + upCount)));
helicopter.setImage("C:\\Users/Travelmate/workspace/GAME/src/spaceSip/rocketship.GIF");
}
if(shoot())
crash();
}
//Called when the mouse exits the game window
public void mouseExited(MouseEvent e)
{
paused = true;
}
//Called when the mouse enters the game window
public void mouseEntered(MouseEvent e)
{
}
//Called when the mouse is released
public void mouseReleased(MouseEvent e)
{
goingUp = false;
upCount = -1;
if(paused)
paused = false;
}
//Called when the mouse is pressed
public void mousePressed(MouseEvent e)
{
if (!started)
started = true;
goingUp = true;
upCount = 0;
}
//Called when the mouse is released
public void mouseClicked(MouseEvent e)
{
}
}
package spaceSip;
import java.awt.Image;
import javax.swing.ImageIcon;
public class SpaceShipImage
{
private Image image; //The picture
private double x; //X position
private double y; //Y position
//Construct a new Moving Image with image, x position, and y position given
public SpaceShipImage(Image img, double xPos, double yPos)
{
image = img;
x = xPos;
y = yPos;
}
//Construct a new Moving Image with image (from file path), x position, and y position given
public SpaceShipImage(String path, double xPos, double yPos)
{
this(new ImageIcon(path).getImage(), xPos, yPos);
//easiest way to make an image from a file path in Swing
}
//They are set methods. I don't feel like commenting them.
public void setPosition(double xPos, double yPos)
{
x = xPos;
y = yPos;
}
public void setImage(String path)
{
image = new ImageIcon(path).getImage();
}
public void setY(double newY)
{
y = newY;
}
public void setX(double newX)
{
x = newX;
}
//Get methods which I'm also not commenting
public double getX()
{
return x;
}
public double getY()
{
return y;
}
public Image getImage()
{
return image;
}
}
package spaceSip;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Image;
import java.util.ArrayList;
import javax.swing.ImageIcon;
import javax.swing.JPanel;
class SpaceShipPanel extends JPanel
{
private Image background;
private ArrayList<SpaceShipImage> middle;
private SpaceShipImage copter;
private ArrayList<SpaceShipImage> smoke;
//Constructs a new ImagePanel with the background image specified by the file path given
public SpaceShipPanel(String img)
{
this(new ImageIcon(img).getImage());
//The easiest way to make images from file paths in Swing
}
//Constructs a new ImagePanel with the background image given
public SpaceShipPanel(Image img)
{
background = img;
Dimension size = new Dimension(img.getWidth(null), img.getHeight(null));
//Get the size of the image
//Thoroughly make the size of the panel equal to the size of the image
//(Various layout managers will try to mess with the size of things to fit everything)
setPreferredSize(size);
setMinimumSize(size);
setMaximumSize(size);
setSize(size);
middle = new ArrayList<SpaceShipImage>();
smoke = new ArrayList<SpaceShipImage>();
}
//This is called whenever the computer decides to repaint the window
//It's a method in JPanel that I've overwritten to paint the background and foreground images
public void paintComponent(Graphics g)
{
//Paint the background with its upper left corner at the upper left corner of the panel
g.drawImage(background, 0, 0, null);
//Paint each image in the foreground where it should go
for(SpaceShipImage img : middle)
g.drawImage(img.getImage(), (int)(img.getX()), (int)(img.getY()), null);
for(SpaceShipImage img : smoke)
g.drawImage(img.getImage(), (int)(img.getX()), (int)(img.getY()), null);
if(copter != null)
g.drawImage(copter.getImage(), (int)(copter.getX()), (int)(copter.getY()), null);
drawStrings(g);
}
public void drawStrings(Graphics g)
{
g.setColor(Color.WHITE);
g.setFont(new Font("Arial",Font.BOLD,20));
g.drawString("Distance: " + SpaceShipMain.distance,30,440);
g.setFont(new Font("Arial",Font.BOLD,20));
if (SpaceShipMain.distance > SpaceShipMain.maxDistance)
g.drawString("Best: " + SpaceShipMain.distance,650,440);
else
g.drawString("Best: " + SpaceShipMain.maxDistance,650,440);
if(SpaceShipMain.paused)
{
g.setFont(new Font("Chiller",Font.BOLD,72));
g.drawString("Paused",325,290);
g.setFont(new Font("Chiller",Font.BOLD,30));
g.drawString("Click to unpause.",320,340);
}
}
//Replaces the list of foreground images with the one given, and repaints the panel
public void updateImages(ArrayList<SpaceShipImage> newMiddle,SpaceShipImage newCopter,ArrayList<SpaceShipImage> newSmoke)
{
copter = newCopter;
middle = newMiddle;
smoke = newSmoke;
repaint(); //This repaints stuff... you don't need to know how it works
}
}

You compare Strings with equals(value equality) not with ==(reference equality). For more information read this previous question How do I compare strings in Java?
As #AndrewThompson always advice don't use NullLayout
Java GUIs might have to work on a number of platforms, on different
screen resolutions & using different PLAFs. As such they are not
conducive to exact placement of components. To organize the
components for a robust GUI, instead use layout managers, or
combinations of
them1, along
with layout padding & borders for white
space2.
As you say that your gui is blocked, that may be cause some of your execution code takes too more time and it's executed in the same thread as gui stuff (The Event Dispatch Thread). As you have a while(true) that's block the gui so use a SwingTimer for execute repeatidly task or if that code that takes long time execute it in a background thread using a Swing Worker. Here you have a complete example. When you perform custom painting you should override paintComponent and in first line you have to call super.paintComponent(..) to follow correct chaining. Read more in Painting in AWT-Swing.
Another error i see is that you are adding components after calling setVisible(true) without calling revalidate() repaint(). So i recommend to first add components to container then call setVisible(true) at final step.

Collision detection using plain arrays and rectangles--java

I am almost done with my first little java game for my final project. It is a sidescroller where you have to shoot/avoid asteroids. My last problem is figuring out how to make my array of asteroids collide with the player's lasers. Here's what I have so far, there's an "AWT-EventQueue-0" java.lang.NullPointerException" on line 137, that I can't deal with. Any help is appreciated.
Edit: I added in my other classes, I realize it would be hard to judge the functionality of my code if I didn't show you where it came from.
package ShooterGame;
import java.applet.Applet;
import java.applet.AudioClip;
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
import java.util.Random;
import javax.swing.*;
public class Board extends JPanel implements ActionListener
{
Enemy[] baddies = new Enemy[10000];
Player p;
Image img;
int y;
Timer time;
boolean lost = false;
static Font font = new Font("SanSerif", Font.BOLD, 24);
public AudioClip theme, bang, laser;
static ArrayList<Enemy> enemies;
public static int score = 0;
public static int lives = 5;
public Board()
{
p = new Player();
addKeyListener(new ActionListener());
setFocusable(true);
ImageIcon i = new ImageIcon("images/background.png");
img = i.getImage();
time = new Timer(5, this);
time.start();
for(int j = 0; j < baddies.length; j++)
{
Random ran = new Random();
y = ran.nextInt(365)+1;
baddies[j]= new Enemy((100*j + 700), y, "images/asteroid.gif");
}
theme = Applet.newAudioClip(getClass().getResource("theme.mid"));
theme.play();
bang = Applet.newAudioClip(getClass().getResource("bang.wav"));
}
public void actionPerformed(ActionEvent e)
{
checkCollisions();
ArrayList<?> bullets = Player.getBullets();
for(int i = 0; i < bullets.size(); i++)
{
Bullet b = (Bullet)bullets.get(i);
if(b.isVisible() == true)
{
b.move();
}
else
{
bullets.remove(i);
}
}
p.move();
for(int i = 0; i < baddies.length; i++)
{
if(p.x > 400)
{
baddies[i].move(p.getdx());
}
}
repaint();
}
public void paint(Graphics g)
{
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
if(lost)
{
g2d.drawString("You Lose!", 300, 300);
}
if((p.getX() - 590) % 2400 == 0 || (p.getX() - 590) % 2400 == 1)
{
p.nx = 0;
}
if((p.getX() - 1790) % 2400 == 0 ||(p.getX() - 1790) % 2400 == 1)
{
p.nx2 = 0;
}
g2d.drawImage(img, 685-p.nx2, 0, null);
if(p.getX() >= 590)
{
g2d.drawImage(img, 685-p.nx, 0, null);
}
g2d.drawImage(p.getImage(), p.edge, p.getY(), null);
ArrayList<?> bullets = Player.getBullets();
for(int i = 0; i < bullets.size(); i++)
{
Bullet b = (Bullet)bullets.get(i);
g2d.drawImage(b.getImg(), b.getX(), b.getY(), null);
}
for(int i = 0; i < baddies.length; i++)
{
if(baddies[i].isAlive == true)
{
g2d.drawImage(baddies[i].getImg(), baddies[i].getX(), baddies[i].getY(), null);
}
}
g2d.setColor(Color.white);
g2d.drawString("Score: " + score, 0, 320);
g2d.drawString("Lives: " + lives, 80, 320);
}
public void checkCollisions()
{
Rectangle[] rect = new Rectangle[baddies.length];
for(int i = 0; i < baddies.length; i++)
{
Enemy e = (Enemy)baddies[i];
rect[i] = e.getBounds();
}
ArrayList<?> bullets = Player.getBullets();
for (int i = 0; i < bullets.size(); i++)
{
Bullet b = (Bullet) bullets.get(i);
Rectangle b1 = b.getBounds();
if (rect[i].intersects(b1) && baddies[i].isAlive())
{
score++;
baddies[i].isAlive = false;
baddies[i].isVisible = false;
bang.play();
}
Rectangle h = p.getBounds();
if (h.intersects(rect[i]))
{
if(baddies[i].isAlive() == true)
{
lives--;
if(lives < 0)
{
lost = true;
theme.stop();
System.exit(1);
}
}
}
}
}
private class ActionListener extends KeyAdapter
{
public void keyReleased(KeyEvent e)
{
p.keyReleased(e);
}
public void keyPressed(KeyEvent e)
{
p.keyPressed(e);
}
}
}
Enemy
package ShooterGame;
import java.awt.*;
import javax.swing.ImageIcon;
public class Enemy
{
int x, y;
Image img;
boolean isAlive = true;
boolean isVisible = true;
public Enemy(int startX, int startY, String location)
{
x = startX;
y = startY;
ImageIcon l = new ImageIcon(location);
img = l.getImage();
}
public Rectangle getBounds()
{
return new Rectangle(x, y, 60, 60);
}
public int getX()
{
return x;
}
public int getY()
{
return y;
}
public boolean isAlive()
{
return isAlive;
}
public boolean isVisible()
{
return isVisible;
}
public Image getImg()
{
return img;
}
public void move(int dx)
{
x = x - dx;
}
}
Bullet
package ShooterGame;
import java.applet.Applet;
import java.awt.*;
import javax.swing.ImageIcon;
import java.applet.AudioClip;
public class Bullet
{
int x, y;
Image img;
boolean visible;
public Bullet(int startX, int startY)
{
x = startX;
y = startY;
ImageIcon newBullet = new ImageIcon("images/bullet.gif");
img = newBullet.getImage();
visible = true;
}
public Rectangle getBounds()
{
return new Rectangle(x, y, 9, 5);
}
public int getX()
{
return x;
}
public int getY()
{
return y;
}
public Image getImg()
{
return img;
}
public boolean isVisible()
{
return visible;
}
public void move()
{
x = x + 2;
if(x > 700)
{
visible = false;
}
}
public void setVisible(boolean isVisible)
{
visible = isVisible;
}
}
Player
package ShooterGame;
import java.applet.Applet;
import java.applet.AudioClip;
import java.awt.*;
import java.awt.event.KeyEvent;
import java.util.ArrayList;
import javax.swing.ImageIcon;
public class Player
{
int x, dx, y, dy, nx2, nx, edge, ceiling;
Image player;
ImageIcon ib = new ImageIcon("images/player1back.gif");
ImageIcon i = new ImageIcon("images/playerstill.gif");
ImageIcon f = new ImageIcon("images/playerforward.gif");
ImageIcon up = new ImageIcon("images/playerup.gif");
ImageIcon down = new ImageIcon("images/playerdown.gif");
public AudioClip laser;
static ArrayList<Bullet> bullets;
public Player()
{laser = Applet.newAudioClip(getClass().getResource("laser.wav"));
player = ib.getImage();
x = 75;
nx = 0;
nx2 = 685;
y = 172;
edge = 150;
ceiling = 0;
bullets = new ArrayList<Bullet>();
}
public static ArrayList<Bullet> getBullets()
{
return bullets;
}
public void fire()
{
Bullet z = new Bullet((edge + 60), (y+17));
bullets.add(z);
}
public Rectangle getBounds()
{
return new Rectangle(edge, y, 43, 39);
}
public void move()
{
y = y + dy;
if(y < ceiling)
{
y = ceiling;
}
if(y > 290)
{
y = 290;
}
if(dx != -1)
{
if(edge + dx <= 151)
{
edge = edge + dx;
}
else
{
x = x + dx;
nx2 = nx2 + dx;
nx = nx + dx;
}
}
else
{
if(edge + dx > 0)
{
edge = edge + dx;
}
}
}
public int getX()
{
return x;
}
public int getdx()
{
return dx;
}
public int getY()
{
return y;
}
public Image getImage()
{
return player;
}
public void keyPressed(KeyEvent e)
{
int key = e.getKeyCode();
if(key == KeyEvent.VK_RIGHT)
{
dx = 2;
player = f.getImage();
}
if(key == KeyEvent.VK_UP)
{
dy = -1;
player = up.getImage();
}
if(key == KeyEvent.VK_DOWN)
{
dy = 1;
player = down.getImage();
}
if(key == KeyEvent.VK_SPACE)
{
fire();
laser.play();
}
}
public void keyReleased(KeyEvent e)
{
int key = e.getKeyCode();
if(key == KeyEvent.VK_RIGHT)
{
dx = 1;
player = ib.getImage();
}
if(key == KeyEvent.VK_UP)
{
dy = 0;
player = ib.getImage();
}
if(key == KeyEvent.VK_DOWN)
{
dy = 0;
player = ib.getImage();
}
}
}
Frame
package ShooterGame;
import javax.swing.*;
public class Frame
{
public AudioClip theme;
public Frame()
{
JFrame frame = new JFrame();
frame.add(new Board());
frame.setTitle("SideShooter");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(700,365);
frame.setVisible(true);
frame.setLocationRelativeTo(null);
}
public static void main(String[] args)
{
new Frame();
}
}

Ok, so the problem is the line mentioned in the other answer, but I believe it is that all the enemies may not be initialised before it checks collisions. Because you are making 10000 of them to start with, I think your action performed method may be checking collisions before they have all be created.
One thing to try could be to bring down the amount of enemies you have and see if it still keeps happening, try 100 or 1000, but this still won't fix the issue.
You really want to be change your game to run in it's own loop though, at the moment you are only checking collisions when the player performs an action. so if the player stops moving, no collision detection...
I would suggest that you find a book called 'Killer Game Programming in Java', there are free ebook version, and just read the first 2 chapters about making a game loop. The book is a bit old, but the basics of the loop are very good.
This question here also contains a very simple loop, and some suggestions in the comments about how to make it better.

The error is on the line
rect[i] = e.getBounds();
Are you not initializing the bounds of your Enemy class correctly? Alternatively, the Enemy you pulled out of the array could be null.