Reputation: 37
Graphics not moving automatically and also makes copies instead of moving when pressing arrow keys
I'm working on a snake game, and I'm trying to make the snake move to the right. The issue here is the snake isn't actually moving, it just seems to copy itself to the right and also it's not going to the right automatically you have to keep pressing the key.
I am really not sure what the issue is, I made some code without any images. That should make the code run able for testing as it is.
public class Game{
static Graphics g;
public static void main(String[] args) {
JFrame b = new JFrame("Snake");
b.setBounds(300,60,905,700);
b.setBackground(Color.DARK_GRAY);
b.setResizable(false);
Snake snake = new Snake();
b.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
b.add(snake);
b.setVisible(true);
}
}
public class Snake extends JPanel implements KeyListener,ActionListener {
/**
*
*/
private static final long serialVersionUID = 1L;
private int[] snakeXlength = new int [750];
private int[] snakeYlength = new int [750];
private boolean right = true;
private boolean left = false;
private boolean up = false;
private boolean down = false;
private ImageIcon rightmouth;
private ImageIcon snakeimage;
private ImageIcon leftmouth;
private ImageIcon downmouth;
private ImageIcon upmouth;
private ImageIcon enemy;
private Timer timer;
private int snakeDelay = 100;
private int moves = 1;
private int lengtOfSnake = 3;
public Snake(){
addKeyListener(this);
setFocusable(true);
setFocusTraversalKeysEnabled(false);
timer = new Timer(snakeDelay, this);
timer.start();
}
public void paint(Graphics g) {
g.setColor(Color.WHITE);
g.drawRect (20, 24, 851, 612);
g.setColor(Color.BLACK);
g.fillRect (21, 25, 850, 610);
if (moves == 0) {
snakeXlength[2]= 63;
snakeXlength[1]= 83;
snakeXlength[0]= 100;
snakeYlength[2]= 100;
snakeYlength[1]= 100;
snakeYlength[0]= 98;
rightmouth = new ImageIcon("rightmouth.png");
rightmouth.paintIcon(this, g, snakeXlength[0], snakeYlength[0]);
}
for(int a = 0; a < lengtOfSnake; a++) {
if (a == 0 && right) {
if (a == 0 && right) {
g.setColor(Color.RED);
g.drawRect(5,10,snakeXlength[a],snakeYlength[a]);
g.fillRect (snakeXlength[a],snakeYlength[a],21,21);
g.drawRect(5,10,snakeXlength[a],snakeYlength[a]);
// rightmouth = new ImageIcon("rightmouth.png");
//rightmouth.paintIcon(this, g, snakeXlength[a], snakeYlength[a]);
}
if (a == 0 && left) {
leftmouth = new ImageIcon("leftmouth.png");
leftmouth.paintIcon(this, g, snakeXlength[a], snakeYlength[a]);
}
if (a == 0 && down) {
downmouth = new ImageIcon("downmouth.png");
downmouth.paintIcon(this, g, snakeXlength[a], snakeYlength[a]);
}
if (a == 0 && up) {
upmouth = new ImageIcon("uptmouth.png");
upmouth.paintIcon(this, g, snakeXlength[a], snakeYlength[a]);
}
if (a != 0) {
g.setColor(Color.GREEN);
g.fillOval(snakeXlength[a],snakeYlength[a],17,17);
//snakeimage = new ImageIcon("snakeimage.png");
//snakeimage.paintIcon(this, g, snakeXlength[a], snakeYlength[a]);
}
}
g.dispose();
}
public void keyPressed(KeyEvent e) {
timer.start();
if(right) {
for (int r = lengtOfSnake-1; r >= 0;r--) {
snakeYlength[r+1] = snakeYlength[r];
}
for(int r = lengtOfSnake;r >=0;r--) {
if(r==0) {
snakeXlength[r] = snakeXlength[r] +25;
}
else {
snakeXlength[r] = snakeXlength[r-1];
}
if(snakeXlength[r] > 850){
snakeXlength[r] = 25;
}
}
repaint();
}
if(left) {
}
if(up) {
}
if(down) {
}
}
@Override
public void keyTyped(KeyEvent e) {
if(e.getKeyCode() == KeyEvent.VK_RIGHT) {
moves++;
right = true;
if(left != true) {
right = true;
}
else
{
right = false;
left = true;
}
down = false;
up = false;
}
if(e.getKeyCode() == KeyEvent.VK_LEFT) {
moves++;
left = true;
if(right != true) {
left = true;
}
else
{
left = false;
right = true;
}
down = false;
up = false;
} if(e.getKeyCode() == KeyEvent.VK_UP) {
moves++;
up = true;
if(down != true) {
up = true;
}
else
{
up = false;
down = true;
}
left = false;
right = false;
}
if(e.getKeyCode() == KeyEvent.VK_DOWN) {
moves++;
down = true;
if(up != true) {
down = true;
}
else
{
up = true;
down = false;
}
left = false;
right = false;
}
}
@Override
public void keyReleased(KeyEvent e) {
// TODO Auto-generated method stub
}
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
}
}
Upvotes: 0
Views: 45
Answers (1)
Reputation: 324128
it just seems to copy itself to the right
public void paint(Graphics g)
{
g.setColor(Color.WHITE);
Custom painting should be done by overriding paintComponent(...) and then you need to invoke super.paintComponent(...):
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g.setColor(Color.WHITE);
This will make sure the background of the panel is cleared before doing the custom painting.
it's not going to the right automatically you have to keep pressing the key.
Well, that is usually the way a game is designed. You only have motion when the key is pressed as this will keep generating events. Then if you don't want motion you just don't press any keys.
If you want animation then you use a Swing Timer. Each time the Timer fires you invoke a move(...) method. This method would need to look at your "direction" variable to determine whether to move the snake left, right, up or down.
Check out:
- Motion Using the Keyboard for animation when a key is pressed and held and
- get width and height of JPanel outside of the class for continuous animation
Upvotes: 2
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