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How can I make my game fall when off the platform I made?

I want it so when my player goes off the platform, (in checkCollision() method PlatformerPanel class) it will fall and then do something when gone off the screen, i haven't set up an end game screen yet but that's what I'm planning to do. Anyway, the problem is that it goes way too fast for some reason and falls too early, and also when an arrow key is pressed while its falling it will go back up to the platform.
Please try to help me overcome this or think of a new, easy to understand, way to do this/make this work the way i am planning.
EDIT 1:
I fixed the thing where it falls too early so don't worry about that
```
public class PlatformerMain {
public static void main(String[] args) {
PlatformerGameFrame platformerGame = new PlatformerGameFrame();
}
}
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
public class PlatformerGameFrame extends JFrame{
PlatformerGamePanel panel;
PlatformerGameFrame() {
panel = new PlatformerGamePanel();
this.add(panel);
this.setTitle("Platformer Game");
this.setResizable(false);
this.setDefaultCloseOperation(DISPOSE_ON_CLOSE);
this.pack();
this.setVisible(true);
this.setLocationRelativeTo(null);
this.getContentPane().setBackground(new Color(0,0,0));
}
}
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
public class PlatformerGamePanel extends JPanel implements Runnable{
PlatformerPlayer player1;
PlatformerMap map1;
static final int SCREEN_WIDTH = 1000;
static final int SCREEN_HEIGHT = 600;
static final int PLAYER_WIDTH = 50;
static final int PLAYER_HEIGHT = 60;
static final Dimension SCREEN_SIZE = new Dimension(SCREEN_WIDTH,SCREEN_HEIGHT);
static boolean falling = false;
Image backgroundImage;
Thread gameThread;
Image image;
Graphics graphics;
PlatformerMap map;
public PlatformerGamePanel() {
java.net.URL imgIcon = Main.class.getResource(
"/Resources/spaceImage.jpg");
backgroundImage = new ImageIcon(imgIcon).getImage();
newPlayer();
newMap();
this.setFocusable(true);
this.addKeyListener(new KeyListener() {
#Override
public void keyTyped(KeyEvent e) {}
#Override
public void keyPressed(KeyEvent e) {
player1.KeyPressed(e);
}
#Override
public void keyReleased(KeyEvent e) {
player1.KeyReleased(e);
}
});
this.setPreferredSize(SCREEN_SIZE);
this.setOpaque(true);
gameThread = new Thread(this);
gameThread.start();
}
public void paint(Graphics g) {
image = createImage(getWidth(),getHeight());
graphics = image.getGraphics();
draw(graphics);
g.drawImage(image, 0,0, null);
}
public void draw(Graphics g) {
Graphics2D g2D = (Graphics2D) g;
g2D.drawImage(backgroundImage, 0,0, null);
player1.paint(g);
map.paint(g);
}
public void newPlayer() {
player1 = new PlatformerPlayer((SCREEN_WIDTH/2)-(PLAYER_WIDTH/2), (SCREEN_HEIGHT/2)-(PLAYER_WIDTH/2), PLAYER_WIDTH, PLAYER_HEIGHT);
}
public void newMap() {
map = new PlatformerMap();
}
public void checkCollision() {
if(player1.x > SCREEN_WIDTH-PLAYER_WIDTH) {
player1.x = SCREEN_WIDTH-PLAYER_WIDTH;
}
else if(player1.x < 0) {
player1.x = 0;
}
if(!(player1.x >map.PLATFORM_WIDTH)) {
if(player1.y > SCREEN_HEIGHT-250) {
player1.y = SCREEN_HEIGHT-250;
}
} else if(player1.x > map.PLATFORM_WIDTH) {
gravity();
}
}
public void falling() {
}
public void gravity() {
player1.gravity();
}
public void move() {
player1.move();
}
public void run() {
long lastTime = System.nanoTime();
double amountOfTicks = 120.0;
double ns = 1000000000 / amountOfTicks;
double delta = 0;
while(true) {
long now = System.nanoTime();
delta += (now - lastTime)/ns;
lastTime = now;
if(delta >= 1) {
move();
checkCollision();
gravity();
repaint();
delta--;
}
}
}
}
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
public class PlatformerPlayer extends Rectangle {
/*static int playerPosX = 100;
static int playerPosY = 100;*/
static double velocityY = 0;
static double velocityX = 0;
static int vertical_position;
static final int TERMINAL_VELOCITY = 200;
static final int PLAYER_WIDTH = 50;
static final int PLAYER_HEIGHT = 50;
static int speed = 2;
protected boolean falling = true;
protected boolean jumping = false;
double gravity = 0.05;
public PlatformerPlayer(int x, int y, int PLAYERWIDTH, int PLAYERHEIGHT) {
super(x,y,PLAYERWIDTH,PLAYERHEIGHT);
}
public void KeyPressed(KeyEvent e) {
if(e.getKeyCode()==KeyEvent.VK_LEFT) {
setXDirection(-speed);
move();
}
else if(e.getKeyCode()==KeyEvent.VK_RIGHT) {
setXDirection(speed);
move();
}
}
public void KeyReleased(KeyEvent e) {
if(e.getKeyCode()==KeyEvent.VK_LEFT) {
setXDirection(0);
move();
}
else if(e.getKeyCode()==KeyEvent.VK_RIGHT) {
setXDirection(0);
move();
}
}
public void paint(Graphics g) {
Graphics2D g2D = (Graphics2D) g;
g2D.setColor(Color.red);
g2D.fillRect(x, y, PLAYER_WIDTH, PLAYER_HEIGHT);
}
public void setYDirection(int YDirection) {
velocityY = YDirection;
}
public void setXDirection(int XDirection) {
if(speed > 10) {
speed = 10;
}
velocityX = XDirection;
}
public void move() {
y += velocityY;
x += velocityX;
}
public void gravity() {
velocityY += gravity;
if (velocityY > TERMINAL_VELOCITY)
{
velocityY = TERMINAL_VELOCITY;
}
vertical_position -= velocityY;
}
}
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
public class PlatformerMap extends Rectangle {
int PLATFORM_WIDTH = 600;
int PLATFORM_HEIGHT = 150;
public PlatformerMap() {
}
public void paint(Graphics g) {
Graphics2D g2D = (Graphics2D) g;
g2D.setColor(Color.gray);
g2D.fillRect(100,400,PLATFORM_WIDTH,PLATFORM_HEIGHT);
}
}

Particles not rendering

I put in a particle system but when i run the program, when I spawn some particles, they don't render. I looked at the ArrayList and its value would always be 0 even when i added a particle to it.
heres the code for main class:
package Main;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.ArrayList;
import javax.swing.JFrame;
import javax.swing.JPanel;
import me.mango.rendering.Particle;
//do double buffering
public class Game extends JPanel {
private static final long serialVersionUID = 1L;
public static final int height = 400;
public static final int width = height * 16 / 9;
JPanel p;
Game game;
Graphics g;
JFrame frame;
KeyListener kl;
MouseListener ml;
public boolean running = true;
private ArrayList<Particle> particles = new ArrayList<Particle>(500);
public Game(){
kl = new KeyListener(){
public void keyPressed(KeyEvent e) {
}
public void keyReleased(KeyEvent e) {
}
public void keyTyped(KeyEvent e) {
}
};
ml = new MouseListener(){
public void mousePressed(MouseEvent e) {
addParticle(true);addParticle(false);addParticle(true);
addParticle(false);addParticle(true);addParticle(false);
}
public void mouseReleased(MouseEvent e) {
}
public void mouseClicked(MouseEvent e) {
}
public void mouseEntered(MouseEvent e) {
}
public void mouseExited(MouseEvent e) {
}
};
}
public void addParticle(boolean b){
int dx,dy;
int x = 100;
int y = 100;
if(b){
dx = (int) (Math.random()*5);
dy = (int) (Math.random()*5);
}else{
dx = (int) (Math.random()*-5);
dy = (int) (Math.random()*-5);
}
int size = (int) (Math.random()*12);
int life = (int) Math.random()*(120)+380;
particles.add(new Particle(x,y,dx,dy,size,life,Color.blue));
}
public void update(double delta){
for(int i = 0; i<= particles.size() - 1;i++){
if(particles.get(i).update()) particles.remove(i);
}
System.out.println(particles.size());
}
#Override
public void paint(Graphics g){
g.clearRect(0, 0, getWidth(), getHeight());
//render here
renderParticles(g);
g.dispose();
}
public void renderParticles(Graphics g){
for(int i =0;i <= particles.size() - 1;i++){
particles.get(i).render(g);
System.out.println("spawned");
}
}
public void run(){
//initialize time loop variables
long lastLoopTime = System.nanoTime();
final int TARGET_FPS = 60;
final long OPTIMAL_TIME = 1000000000 / TARGET_FPS;
double lastFpsTime = 0;
//Main game loop
while(running)
{
//Calculate since last update
long now = System.nanoTime();
long updateLength = now - lastLoopTime;
lastLoopTime = now;
double delta = updateLength / ((double)OPTIMAL_TIME);
//update frame counter
lastFpsTime += updateLength;
//update FPS counter
if(lastFpsTime >= 1000000000)
{
lastFpsTime = 0;
}
//game updates
game.update(delta);
//graphics (gameState)
game.repaint();
try{
Thread.sleep((Math.abs(lastLoopTime - System.nanoTime() + OPTIMAL_TIME)/1000000));
}catch(Exception e){
System.out.println("Error in sleep");
}
}
}
public void start(){
frame = new JFrame("Game");
game = new Game();
frame.add(game);
frame.pack();
frame.setSize(width, height);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.addKeyListener(kl);
frame.addMouseListener(ml);
frame.setVisible(true);
run();
}
public static void main(String[] args){
new Game().start();
}
}
and for the particle class:
package me.mango.rendering;
import java.awt.Color;
import java.awt.Graphics;
public class Particle {
private int x;
private int y;
private int dx;
private int dy;
private int size;
private int life;
private Color color;
public Particle(int x, int y, int dx, int dy, int size, int life, Color c){
this.x = x;
this.y = y;
this.dx = dx;
this.dy = dy;
this.size = size;
this.life = life;
this.color = c;
}
public boolean update(){
x += dx;
y += dy;
life--;
if(life <= 0){
return true;
}
return false;
}
public void render(Graphics g){
g.setColor(color);
g.fillRect(x-(size/2), y-(size/2), size, size);
g.dispose();
}
}
Thanks!

You have a thing called game inside the class Game: that's not good design at all. Apparently you dont understand the meaning of creating an object.
In main() you created an object game: that should be enough. That thing you have to manipulate.
Therefore calling game.something() inside the class game is a convolution. Get rid of it.
game = new Game();
Game game;
These things must go.
And any reference to game.someMethod()
should be replaced with just someMethod(), if you are inside Game.
Plus you have things like run() and start() etc: do you think you are creating some threads?? by just using those names for your methods?
No.

Java-2d platformer: Collision doesn't work(strange bug)

I have a very strange problem.
I am making a simple 2d platformer using Java.
The collision detection with the player and a platform, doesn't work.
But the strange thing is, when I print something to the screen to see if the collision if-statement is executed, the collision works o_O
Maybe it's a bit confusing, please see my code.
The Main class(which is good I think):
import javax.swing.*;
public class Main extends JFrame{
private static final long serialVersionUID = 1L;
GameClass gc = new GameClass();
public Main(){
setSize(gc.WIDTH,gc.HEIGHT);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setTitle("Flying GoatZ!");
add(new GameClass());
setLocationRelativeTo(null);
setVisible(true);
}
public static void main(String[] args) {
new Main();
}
}
GameClass class:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Random;
public class GameClass extends JPanel implements ActionListener, KeyListener, MouseListener{
//OBJECTS
Text text = new Text();
openImages open_img = new openImages();
Random ran = new Random();
//VARIABLES
static final long serialVersionUID = 1L;
final int WIDTH = 800;
final int HEIGHT = 600;
int goatx = WIDTH/2;
int goaty = 350;
int goatspeed = 0;
int fallspeed = 15;
int maxy = 150;
boolean up = false;
boolean flying = true;
ArrayList<Integer> xes = new ArrayList<Integer>();
ArrayList<Integer> yes = new ArrayList<Integer>();
//FPS SETTER AND KEYLISTENERS
public GameClass(){
Timer time = new Timer(15, this);
time.start();
this.addKeyListener(this);
this.setFocusable(true);
open_img.openImage();
}
public void update(){
Collision();
goatx += goatspeed;
if(up){
if(goaty > maxy){
goaty -= 5;
}else{
up = false;
}
}else
if(goaty < 350)
goaty += fallspeed;
}
public void print(String msg){
System.out.println(msg);
}
public void platformDrawing(Graphics g,int x,int y,int x1,int y1, int x2, int y2){
g.setColor(Color.RED);
g.drawImage(open_img.block,x, y, null);
g.drawImage(open_img.block,x1, y1, null);
g.drawImage(open_img.block,x2, y2, null);
xes.addAll(Arrays.asList(x,x1,x2));
yes.addAll(Arrays.asList(y,y1,y2));
}
//HERE IS THE COLLISION METHOD(I NEED THE PLAYER TO STAND STILL WHEN IT IS ON THE PLATFORM.
public void Collision(){
for(int x : xes){
for(int y : yes){
if( ( (goatx > x-20) && (goatx < (x + 150)) ) && ( (goaty+open_img.goat.getHeight(null)) <= y ) ){
//print("TEST");
fallspeed = 0;
}else{
fallspeed = 10;
}
}
}
}
//ALL TEH DRAWING
public void paintComponent(Graphics g){
//MAP
g.setColor(Color.CYAN);
g.fillRect(0,0,WIDTH,HEIGHT);
g.setColor(Color.ORANGE);
g.fillRect(0, HEIGHT-100, WIDTH, 100);
g.setColor(Color.GREEN);
g.fillRect(0, HEIGHT-125, WIDTH, 25);
//PLAYER & PLATFORMS
platformDrawing(g,50,350,300,350,600,350);
g.drawImage(open_img.goat, goatx, goaty, null);
g.dispose();
}
//THIS IS EXECUTED EVERYTIME
public void actionPerformed(ActionEvent e){
update();
repaint();
}
//KEY DETECTION
public void keyPressed(KeyEvent e){
if(e.getKeyCode() == KeyEvent.VK_LEFT){
goatspeed = -5;
}
if(e.getKeyCode() == KeyEvent.VK_RIGHT){
goatspeed = 5;
}
if(e.getKeyCode() == KeyEvent.VK_SPACE){
if(flying){
flying = false;
up = true;
}
}
}
public void keyReleased(KeyEvent e){
if(e.getKeyCode() == KeyEvent.VK_LEFT){
goatspeed = 0;
}
if(e.getKeyCode() == KeyEvent.VK_RIGHT){
goatspeed = 0;
}
if(e.getKeyCode() == KeyEvent.VK_SPACE){
flying = true;
}
}
//SOME STUFF THAT YOU HAVE TO IGNORE LEL
public void keyTyped(KeyEvent e){}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
public void mouseClicked(MouseEvent e) {}
}
I don't understand why a print statement can make the difference...
Any help is appreaciated, thanks!
Oh, and sorry for bad English or unclear question.

Java 2d Game-Very strange "bug" in game

I have a very strange bug in my 2d game made using Java.
Description of the game: the player can move a rocket sprite with the mouse, and must dodge a rectangle that is going to follow the player and kill the player(by collision). Instead of following the player, it only moves to the beginning coordinates of the player, which is 400,400. It should move to the direction the player goes to. Please help me if you know what is wrong.
Main class:
import javax.swing.*;
public class Main extends JFrame{
private static final long serialVersionUID = 1L;
final static int WW = 800;
final static int WH = 600;
public Main(){
setSize(WW,WH);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setTitle("Space Game");
add(new GameClass());
setVisible(true);
}
public static void main(String[] args) {
new Main();
}
}
GameClass class:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class GameClass extends JPanel implements ActionListener, KeyListener{
private static final long serialVersionUID = 1L;
Enemy enemy = new Enemy();
Player player = new Player();
public GameClass(){
Timer time = new Timer(15, this);
time.start();
this.addKeyListener(this);
this.setFocusable(true);
player.openImage();
}
public void update(){
player.update();
enemy.update();
}
public void paintComponent(Graphics g){
g.setColor(Color.BLACK);
g.fillRect(0,0,Main.WW,Main.WH);
player.paint(g);
enemy.paint(g);
g.dispose();
}
public void actionPerformed(ActionEvent e){
update();
repaint();
}
public void keyPressed(KeyEvent e){
if(e.getKeyCode() == KeyEvent.VK_LEFT){
player.setSpeed(-5);
}
else if(e.getKeyCode() == KeyEvent.VK_RIGHT){
player.setSpeed(5);
}
else if(e.getKeyCode() == KeyEvent.VK_UP){
player.setFly(-5);
}
else if(e.getKeyCode() == KeyEvent.VK_DOWN){
player.setFly(5);
Player.goDown = true;
}
}
public void keyReleased(KeyEvent e){
if(e.getKeyCode() == KeyEvent.VK_LEFT || e.getKeyCode() == KeyEvent.VK_RIGHT){
player.setSpeed(0);
}
if(e.getKeyCode() == KeyEvent.VK_UP || e.getKeyCode() == KeyEvent.VK_DOWN){
player.setFly(0);
Player.goDown = false;
}
}
public void keyTyped(KeyEvent e){
}
}
Enemy class:
import java.awt.*;
public class Enemy {
private int x = -100;
private int y = -100;
Player player = new Player();
public void update(){
System.out.println(player.getX());
if(player.getX() < this.x){
this.x -= 5;
}
if(player.getX() > this.x){
this.x += 5;
}
if(player.getY() > this.y){
this.y += 5;
}
if(player.getY() < this.y){
this.y -= 5;
}
}
public void paint(Graphics g){
g.setColor(Color.ORANGE);
g.fillRect(x, y, 50, 50);
}
}
Player class:
import java.awt.Image;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import java.awt.*;
public class Player {
private Image image;
private int player_x = Main.WW/2;
private int player_xspeed = 0;
private int player_y = Main.WH/2;
private int player_yspeed = 0;
private int flamey = player_y + 100;
private int flamex;
private int newx;
private int newy;
static boolean goDown = false;
public Player(){
newx = player_x;
newy = player_x;
}
public void openImage(){
try {
image = ImageIO.read(new File("spaceship.png"));
} catch (IOException e) {
e.printStackTrace();
}
}
public void paint(Graphics g){
flamex = player_x + 20;
g.drawImage(image,player_x,player_y,null);
g.setColor(Color.YELLOW);
g.fillRect(flamex, flamey+5, 6, 6);
g.fillRect(flamex+10, flamey, 6, 6);
g.fillRect(flamex+10, flamey+15, 6, 6);
g.fillRect(flamex+20, flamey+5, 6, 6);
}
public void update(){
player_x += player_xspeed;
player_y += player_yspeed;
if(flamey < (player_y + 125)){
if(goDown == false)
flamey += 5;
else
flamey += 10;
}else
flamey = player_y + 100;
newx = player_x;
newy = player_y;
}
public void setSpeed(int speed){
player_xspeed = speed;
}
public void setFly(int speed){
player_yspeed = speed;
}
public int getX(){
return newx;
}
public int getY(){
return newy;
}
}
Sorry for bad English, please help me.
Any help appreaciated :)

It's because the Player it follows is created inside Enemy via the line:
public class Enemy {
//...
Player player = new Player();
//...
}
so it's a different player instance to the one you are controlling, which is created in GameClass via:
public class GameClass extends JPanel implements ActionListener, KeyListener{
Enemy enemy = new Enemy();
Player player = new Player();
//...
}
You need to inject the controlled player instance either as a constructor parameter on Enemy, e.g.
public class GameClass extends JPanel implements ActionListener, KeyListener{
Player player = new Player();
Enemy enemy = new Enemy(player);
//...
}
public class Enemy {
//...
Player player;
public Enemy(Player player) { this.player = player; }
//...
}
or via a setter.

I'm trying to make my image move using KeyListener but it's giving me an error?

I'm trying to make Boy1 move but in the second class I'm getting redlines under setX. Anyone know what's wrong?
First Class:
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class MyGame extends JPanel implements ActionListener, KeyListener {
Timer t = new Timer(5, this);
int x = 0, y = 0, velx =0, vely =0;
public MyGame() {
t.start();
addKeyListener(this);
setFocusable(true);
setFocusTraversalKeysEnabled(false);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.RED);
g.fillRect(x,y,50,30);
}
public void actionPerformed(ActionEvent e) {
if(x < 0)
{
velx=0;
x = 0;
}
if(x > 530)
{
velx=0;
x = 530;
}
if(y < 0)
{
vely=0;
y = 0;
}
if(y > 330)
{
vely=0;
y = 330;
}
x += velx;
y += vely;
repaint();
}
public void keyPressed(KeyEvent e) {
int code = e.getKeyCode();
if (code == KeyEvent.VK_DOWN){
vely = 1;
velx = 0;
}
if (code == KeyEvent.VK_UP){
vely = -1;
velx = 0;
}
if (code == KeyEvent.VK_LEFT){
vely = 0;
velx = -1;
}
if (code == KeyEvent.VK_RIGHT){
vely = 0;
velx = 1;
}
}
public void keyTyped(KeyEvent e) {}
public void keyReleased(KeyEvent e) {
velx=0;
vely=0;
}
public static void main (String arge[]){
JFrame f = new JFrame();
MyGame s = new MyGame();
f.add(s);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(600,400);
f.setVisible(true);
}
}
Problem is with this last class. Perhaps it needs to be KeyAdapter? But I tried that and seems like that totally doesn't work.

The compiler is flagging you for a reason -- you're trying to call methods on a variable as if it were a variable that the class contains when it isn't -- it's held by a different class. And this isn't Kosher in Java.
What you should do is give the class that holds the variable public methods that outside classes can call and that will allow outside classes to be able to move the label. Then give your control object (the listener) an instance of the class that has these methods.
As an aside, you're usually better off using Key Bindings and not using a KeyListener.
I can give you an example of code that uses Key Bindings to move a JLabel around a JPanel:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.EnumMap;
import javax.imageio.ImageIO;
import javax.swing.*;
#SuppressWarnings("serial")
public class AnimateExample extends JPanel {
public static final String DUKE_IMG_PATH = // https://duke.kenai.com/iconSized/duke.gif
"https://duke.kenai.com/iconSized/duke4.gif";
private static final int PREF_W = 800;
private static final int PREF_H = 800;
private static final int TIMER_DELAY = 20;
private static final String KEY_DOWN = "key down";
private static final String KEY_RELEASE = "key release";
public static final int TRANSLATE_SCALE = 3;
private static final String BACKGROUND_STRING = "Use Arrow Keys to Move Image";
private static final Font BG_STRING_FONT = new Font(Font.SANS_SERIF,
Font.BOLD, 32);
private EnumMap<Direction, Boolean> dirMap =
new EnumMap<AnimateExample.Direction, Boolean>(Direction.class);
private BufferedImage image = null;
private int imgX = 0;
private int imgY = 0;
private int bgStringX;
private int bgStringY;
public AnimateExample() {
for (Direction dir : Direction.values()) {
dirMap.put(dir, Boolean.FALSE);
}
try {
URL imgUrl = new URL(DUKE_IMG_PATH);
image = ImageIO.read(imgUrl);
Icon icon = new ImageIcon(image);
JOptionPane.showMessageDialog(null, icon);
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
new Timer(TIMER_DELAY, new TimerListener()).start();
// here we set up our key bindings
int condition = JComponent.WHEN_IN_FOCUSED_WINDOW;
InputMap inputMap = getInputMap(condition);
ActionMap actionMap = getActionMap();
for (final Direction dir : Direction.values()) {
// for the key down key stroke
KeyStroke keyStroke = KeyStroke.getKeyStroke(dir.getKeyCode(), 0,
false);
inputMap.put(keyStroke, dir.name() + KEY_DOWN);
actionMap.put(dir.name() + KEY_DOWN, new AbstractAction() {
#Override
public void actionPerformed(ActionEvent arg0) {
dirMap.put(dir, true);
}
});
// for the key release key stroke
keyStroke = KeyStroke.getKeyStroke(dir.getKeyCode(), 0, true);
inputMap.put(keyStroke, dir.name() + KEY_RELEASE);
actionMap.put(dir.name() + KEY_RELEASE, new AbstractAction() {
#Override
public void actionPerformed(ActionEvent arg0) {
dirMap.put(dir, false);
}
});
}
FontMetrics fontMetrics = getFontMetrics(BG_STRING_FONT);
int w = fontMetrics.stringWidth(BACKGROUND_STRING);
int h = fontMetrics.getHeight();
bgStringX = (PREF_W - w) / 2;
bgStringY = (PREF_H - h) / 2;
}
#Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g.setFont(BG_STRING_FONT);
g.setColor(Color.LIGHT_GRAY);
g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
g.drawString(BACKGROUND_STRING, bgStringX, bgStringY);
if (image != null) {
g.drawImage(image, imgX, imgY, this);
}
}
private class TimerListener implements ActionListener {
public void actionPerformed(java.awt.event.ActionEvent e) {
for (Direction dir : Direction.values()) {
if (dirMap.get(dir)) {
imgX += dir.getX() * TRANSLATE_SCALE;
imgY += dir.getY() * TRANSLATE_SCALE;
}
}
repaint();
};
}
enum Direction {
Up(KeyEvent.VK_UP, 0, -1), Down(KeyEvent.VK_DOWN, 0, 1), Left(
KeyEvent.VK_LEFT, -1, 0), Right(KeyEvent.VK_RIGHT, 1, 0);
private int keyCode;
private int x;
private int y;
private Direction(int keyCode, int x, int y) {
this.keyCode = keyCode;
this.x = x;
this.y = y;
}
public int getKeyCode() {
return keyCode;
}
public int getX() {
return x;
}
public int getY() {
return y;
}
}
private static void createAndShowGui() {
AnimateExample mainPanel = new AnimateExample();
JFrame frame = new JFrame("Animate Example");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}