Solved

Trouble with Java Keyboard EventDispatcher

Posted on 2014-01-06
4
353 Views
Last Modified: 2014-01-10
I'm hoping someone can help me.  I am new to Java and have this project for school where we are building a "Pacman" game using Karel Robot.  I almost have everything working but I am getting funny results with my keyboard handler which allows the user to change the direction of  the Pacman.  The game is setup so Pacman will continually move in the direction he is facing until it comes to a wall or until the user presses the UP, DOWN, LEFT or RIGHT keys.  The problem I think I am having is that when a key is pressed, depending on which direction Pacman is facing, I may need to execute multiple "turns".  Karel only has a turnLeft method so the turnRight method consists of 3 turn lefts while the turnAround method consists of 2 turnLefts.

I'm not sure what is happening.  For example, the Pacman starts out moving "West" and comes to a wall.  I hit the UP arrow key to go North and the Pacman actually turns South, East and then North.  The problem is it doesn't always happen this way.

Here is the code that I am using.  Can someone please help or give me suggestions for finding and fixing the problem.  It is already 1:00 am and the project is due at 8:00 am.

import kareltherobot.*;
import java.awt.KeyboardFocusManager;
import java.awt.event.KeyEvent;
import java.awt.KeyEventDispatcher;
import javax.swing.KeyStroke;
import java.awt.Color;

public class Pacman extends Superbot
{
   public static int currentpacmanAve;
   public static int currentpacmanSt;
   public static Directions.Direction currentpacmanDirection;
   public static boolean pacmanDied=false;
   public static boolean superpacman=false;
   public static int superpacmanCounter=0;
   private int tempA;
   private int tempS;
   private Directions.Direction tempD;

   
   public Pacman(int s, int a,Direction direction,int b)
   {
      super( s, a, direction, b);
      currentpacmanAve = a;
      currentpacmanSt = s;
      currentpacmanDirection = direction;
      World.setupThread(this);
   }
   
   public void startPacman()
   {       
      // Setup Keyboard Focus Manager
      KeyboardFocusManager focusManager = KeyboardFocusManager.getCurrentKeyboardFocusManager();
      focusManager.addKeyEventDispatcher(
            new KeyEventDispatcher() {
               @Override
                  public boolean dispatchKeyEvent(KeyEvent e) {
                  String key = KeyStroke.getKeyStrokeForEvent(e).toString();
                  if (key.equals("pressed C")) //changes world color 
                  {
                     PacmanWorld.changeLayoutColor();
                  }
                  if(key.equals("pressed A")||key.equals("pressed LEFT")) //moves pacman west 
                  {
                     if(!facingWest())
                     {
                        if(facingEast())
                        {
                           turnAround();
                              
                        }
                        else
                        {
                           if(facingSouth())
                           {
                              turnRight();
                           }
                           else
                           {
                              turnLeft();
                           }
                        }
                     }
                  }
                  if(key.equals("pressed W")||key.equals("pressed UP")) //moves pacman north
                  {
                     if(!facingNorth())
                     {
                        if(facingSouth())
                        {
                           turnAround();
                        }
                        else
                        {
                           if(facingWest())
                           {
                              turnRight();
                           }
                           else
                           {
                              turnLeft();
                           }
                        }
                     }
                  }
                  if(key.equals("pressed S")||key.equals("pressed DOWN")) //moves pacman south
                  {
                     if(!facingSouth())
                     {
                        if(facingNorth())
                        {
                           turnAround();
                        }
                        else
                        {
                           if(facingWest())
                           {
                              turnLeft();
                           }
                           else
                           {
                              turnRight();
                           }
                        }
                     }
                  }
                  if(key.equals("pressed D")||key.equals("pressed RIGHT")) //moves pacman east
                  {
                     if(!facingEast())
                     {
                        if(facingWest())
                        {
                           turnAround();
                        }
                        else
                        {
                           if(facingNorth())
                           {
                              turnRight();
                           }
                           else
                           {
                              turnLeft();
                           }
                        }
                     }
                  }
                  if(key.equals("pressed K")) //pacman dies(test only)
                  {
                     Pacman.pacmanDied=true;
                  }
                  
                  return false;
               }
            });

      int superpacmanCounter=0; 
      int beeperCounter=0;
      pacmanDied = false;
      while(!pacmanDied)
      {
         if(nextToABeeper())
         {
            pickBeeper();
            beeperCounter++;
            PacmanWorld.score+=10;
         }
         if(nextToABeeper())
         {
            pickBeeper();
            superpacman=true;
            beeperCounter++;
            PacmanWorld.score-=10;
         }
         if(beeperCounter==PacmanWorld.totalBeepers)
         {
            PacmanWorld.worldbuilder();
         }
         if(frontIsClear())
         {
            move();
            TrackPacmanPosition();
            CheckIfInWarp();
            if(superpacman==true)
            {
               superpacmanCounter++;
               if(superpacmanCounter > 20)
               {
                  superpacman=false;
                  superpacmanCounter=0;
               }
            }
            System.out.printf("score=%d\n", PacmanWorld.score);
         }
      }
      setVisible(false);
      System.out.println("Pacman Died");
   }
   
   private void TrackPacmanPosition()
   {
               if(facingWest())
            {
               currentpacmanAve--;
            }
            if(facingEast())
            {
               currentpacmanAve++;
            }
            if(facingNorth())
            {
               currentpacmanSt++;
            }
            if(facingSouth())
            {
               currentpacmanSt--;
            }
      System.out.printf("Pacman current position: Street=%d  Avenue=%d\n", currentpacmanSt, currentpacmanAve);
   }
   
   private void CheckIfInWarp()
   {
      if ((currentpacmanAve == PacmanWorld.warp1Avenue && currentpacmanSt == PacmanWorld.warp1Street) ||
          (currentpacmanAve == PacmanWorld.warp2Avenue && currentpacmanSt == PacmanWorld.warp2Street) )
      {
         //setVisible(false);
         tempA = currentpacmanAve;
         tempS = currentpacmanSt;
         tempD = currentpacmanDirection;
         // Find boundary to go to opposite side of maze
         MoveToBoundary();
         MoveToBoundary();
         MoveToBoundary();
         if (tempD == Directions.East || tempD == Directions.West)
         {
            // Move to Street where warp begins
            while (tempS < currentpacmanSt)
            {
               move();
               tempS++;            
            }
            // Turn back into warp to return to maze
            if (tempD == Directions.West)
            {
               turnLeft();
               currentpacmanAve = PacmanWorld.maxAvenues;
            }
            else
            {
               turnRight();
               currentpacmanAve = 1;
            }
         }
         else
         {
             // Move to Avenue where warp begins
            while (tempA < currentpacmanAve)
            {
               move();
               tempA++;            
            }
            // Turn back into warp to return to maze
            if (tempD == Directions.North)
            {
               turnLeft();
               currentpacmanSt = 1;
            }
            else
            {
               turnRight();
               currentpacmanSt = PacmanWorld.maxStreets;
            }
         }
         setVisible(true);
      }
   }  
   
   private void MoveToBoundary()
   {
      while (frontIsClear())
      {
         move();
      }
      if (tempD == Directions.West || tempD == Directions.North)
         turnLeft();
      else if (tempD == Directions.East || tempD == Directions.South)
         turnRight();
   }
   
   private boolean NoWallsAroundPacman()
   {
      if (!frontIsClear())
         return false;
      turnLeft();
      if (!frontIsClear())
      {
         turnRight();
         return false;
      }
      turnLeft();
      if (!frontIsClear())
      {
         turnAround();
         return false;
      }
      turnLeft();
      if (!frontIsClear())
      {
         turnLeft();
         return false;
      }
      return true;
   }
}

Open in new window


I appreciate any help I can get!
0
Comment
Question by:dyarosh
  • 2
  • 2
4 Comments
 
LVL 35

Expert Comment

by:girionis
ID: 39764604
Where is the turnRight() method?
0
 

Author Comment

by:dyarosh
ID: 39764770
turnRight is in the Superbot class and consists of  3 turnLeft statements
0
 
LVL 35

Accepted Solution

by:
girionis earned 500 total points
ID: 39764924
Then the only thing I can think of is that you probably keep the up key pressed more than once so it turns several times.  What happens if you put a system.out statement with a test message? Do you see it more than once?
0
 

Author Closing Comment

by:dyarosh
ID: 39770733
It looks like the problem is in the Karel Robot class.  I did as you suggested and the only keystrokes were the ones I pressed.  However when tracing the Robot's movements, it looked like Karel turned the Robot and moved down an avenue when it should not have.
0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

INTRODUCTION Working with files is a moderately common task in Java.  For most projects hard coding the file names, using parameters in configuration files, or using command-line arguments is sufficient.   However, when your application has vi…
Java had always been an easily readable and understandable language.  Some relatively recent changes in the language seem to be changing this pretty fast, and anyone that had not seen any Java code for the last 5 years will possibly have issues unde…
Viewers will learn one way to get user input in Java. Introduce the Scanner object: Declare the variable that stores the user input: An example prompting the user for input: Methods you need to invoke in order to properly get  user input:
This tutorial will introduce the viewer to VisualVM for the Java platform application. This video explains an example program and covers the Overview, Monitor, and Heap Dump tabs.

713 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question