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Event Handling problems


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#1 someguy127   Members   -  Reputation: 101

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Posted 15 May 2012 - 06:30 AM

Hi, I am working on one of my first games in java and I was having a big problem with the Event Handler where it would only work somewhere in the realm of 1/10 times. If anyone has any idea on how to solve this problem I'd be much obliged.

This is my game panel constructor, I have global variables called isRight, isDown etc... and in the main gameloop I check if they are true
in which case my character moves so many pixels
public GamePanel(){
  setFocusable(true);
  requestFocus();
  setPreferredSize(new Dimension(GWIDTH,GHEIGHT));
  makeGrid();
  setBackground(Color.white);
  addKeyListener(new KeyListener(){
  
   public void keyPressed(KeyEvent e) {
	switch(e.getKeyCode())
	{
	case KeyEvent.VK_RIGHT:
	 isRight = true;
	 System.out.println("Rightpressed");
	 break;
	case KeyEvent.VK_LEFT:
	 isLeft = true;
	 break;
	case KeyEvent.VK_UP:
	 isUp = true;
	 break;
	case KeyEvent.VK_DOWN:
	 isDown = true;
	default:
	 break;
	}
  
   }

   public void keyReleased(KeyEvent e) {
	switch(e.getKeyCode())
	{
	case KeyEvent.VK_RIGHT:
	 isRight = false;
	 System.out.println("Rightreleased");
	 break;
	case KeyEvent.VK_LEFT:
	 isLeft = false;
	 break;
	case KeyEvent.VK_UP:
	 isUp = false;
	 break;
	case KeyEvent.VK_DOWN:
	 isDown = false;
	default:
	 break;
	}
  
   }

   public void keyTyped(KeyEvent e) {
  
  
   }
  
  });
}
This here is the update methods and run() game loop, I don't think that the problem is in here because I put in a print statement in each of these methods and they ran consistently.
public void gameUpdate()
{
   //update game logic

   if(isRight){
	player.x += player.speed;
   }
   if(isLeft){
	player.x -=player.speed;
   }

}
public void run()
{
  while(running)
  {
  
   gameUpdate();
   gameRender();
   paintScreen();
   try{
	game.sleep(20);
   }
   catch(Exception e){}
  }
}

And Just incase it is not a problem with my constructor, here is my complete code if anyone is willing to look through it

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class GamePanel extends JPanel implements Runnable{

/**
  *
  */
private static final long serialVersionUID = 1L;
//double buffering
Image dbImage;
Graphics dbg;

Rectangle[] grid = new Rectangle[250];

//JPanel Vars
public static final int GWIDTH = 500, GHEIGHT = 500;
static final Dimension gameDim = new Dimension(GWIDTH,GHEIGHT);

public boolean isRight = false,isLeft = false, isUp = false,isDown=false;

private Thread game;
private volatile boolean running = false;

Player player = new Player();
public GamePanel(){
  setFocusable(true);
  requestFocus();
  setPreferredSize(new Dimension(GWIDTH,GHEIGHT));
  makeGrid();
  setBackground(Color.white);
  addKeyListener(new KeyListener(){
  
   public void keyPressed(KeyEvent e) {
    switch(e.getKeyCode())
    {
    case KeyEvent.VK_RIGHT:
	 isRight = true;
	 System.out.println("Rightpressed");
	 break;
    case KeyEvent.VK_LEFT:
	 isLeft = true;
	 break;
    case KeyEvent.VK_UP:
	 isUp = true;
	 break;
    case KeyEvent.VK_DOWN:
	 isDown = true;
    default:
	 break;
    }
   
   }
 
   public void keyReleased(KeyEvent e) {
    switch(e.getKeyCode())
    {
    case KeyEvent.VK_RIGHT:
	 isRight = false;
	 System.out.println("Rightreleased");
	 break;
    case KeyEvent.VK_LEFT:
	 isLeft = false;
	 break;
    case KeyEvent.VK_UP:
	 isUp = false;
	 break;
    case KeyEvent.VK_DOWN:
	 isDown = false;
    default:
	 break;
    }
   
   }

   public void keyTyped(KeyEvent e) {
   
   
   }
  
  });
  addMouseListener(new MouseListener(){
 
   public void mouseClicked(MouseEvent e) {
    // TODO Auto-generated method stub
   
   }
   @Override
   public void mouseEntered(MouseEvent e) {
    // TODO Auto-generated method stub
   
   }
   @Override
   public void mouseExited(MouseEvent e) {
    // TODO Auto-generated method stub
   
   }
   @Override
   public void mousePressed(MouseEvent e) {
    // TODO Auto-generated method stub
   
   }
   @Override
   public void mouseReleased(MouseEvent e) {
    // TODO Auto-generated method stub
   
   }
  
  });
 
}
private void makeGrid(){
  int x=0,y=0;
  for(int i = 0; i <grid.length;i++)
  {
   if(i % 16 != 0 | i ==0){
    grid[i] = new Rectangle(x,y,32,32);
    x+=32;
   }
   else{
    y+=32;
    x = 0;
    grid[i] = new Rectangle(x,y,32,32);
    x+=32;
   }
  }
}
private void startGame()
{
  if(game == null || !running){
   running = true;
   game = new Thread(this);
   game.start();
  
  }
}
public void stopGame()
{
  if(game != null || running)
  {
   running = false;
  }
}
public void addNotify()
{
  super.addNotify();
  startGame();
}
//Game Rendering
public void gameUpdate()
{
   //update game logic
 
   if(isRight){
    player.x += player.speed;
   }
   if(isLeft){
    player.x -=player.speed;
   }
 
}
private void gameRender()
{
  if(dbImage == null)
  {
   dbImage = createImage(GWIDTH,GHEIGHT);
   if(dbImage == null)
   {
    System.err.println("Error in Game Render");
    return;
   }
   else
   {
    dbg = dbImage.getGraphics();
   }
  }
  dbg.setColor(Color.WHITE);
  dbg.fillRect(0, 0, getWidth(),getHeight());
  //drawGAME
  draw(dbg);
}
public void draw(Graphics g)
{
  //draw things here
  g.setColor(Color.black);
  //player.draw(g);
  g.fillRect(player.x, player.y, player.width, player.height);
 
  g.setColor(Color.RED);
  for(int i = 0; i < grid.length; i++){
   g.drawRect(grid[i].x, grid[i].y, grid[i].width, grid[i].height);
  }
}

public void paintScreen()
{
  Graphics g;
  try{
   g = this.getGraphics();
   if(dbImage != null && g!= null){
    g.drawImage(dbImage,0,0, null);
   }
   Toolkit.getDefaultToolkit().sync();
   g.dispose();
  }
  catch(Exception e)
  {
   System.err.println("Error in paintScreen");
  }
 
}
//logic
public void run()
{
  while(running)
  {
  
   gameUpdate();
   gameRender();
   paintScreen();
   try{
    game.sleep(20);
   }
   catch(Exception e){}
  }
}
}

Edited by someguy127, 15 May 2012 - 06:33 AM.


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#2 VildNinja   Members   -  Reputation: 420

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Posted 15 May 2012 - 07:12 AM

Are you sure the panel has focus? you request focus in the constructor, but I doubt it will have any effect, since the panel is not added to any frame/applet before the entire constructor is executed any ways. Try to give it focus from the frame after you have added the panel

#3 6510   Members   -  Reputation: 151

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Posted 15 May 2012 - 07:18 AM

What exactly doesn't work ? Already set some break points and debugged ?
In any case, your direction variables should be volatile or synchronized.




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