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Thread: Possible misuse of timer?

  1. #1
    Junior Member
    Join Date
    Sep 2013
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    Default Possible misuse of timer?

    I am a bit inexperienced when it comes to using timers, especially in graphical programs.
    I am trying to code a simple Tunnel game where the player is moving through a randomly generated tunnel and has to move left and right to avoid touching the walls.
    Here is my code:
    import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;
    public class Tunnel extends JFrame{
    	public static final  boolean empty = true;
    	public static final boolean full = false;
    	public static boolean [][] board = new boolean[400][400];
    	public Tunnel(){ 
    		add(new DrawTunnel());
    	public static void main (String[] args){
    		Tunnel frame = new Tunnel();
    	static class DrawTunnel extends JPanel{
    		Timer timer;
    		int middle = 200;
    		int width = 100;
    		public DrawTunnel(){
    			//create timer
    			timer = new Timer (5, new TimerListener());
    		public void paintComponent(Graphics g){
    			for (int row= 0; row<board.length; row++){
    				for (int col=0; col<board[row].length; col++){
    					if (!board[row][col])
    						drawSquare(g, row,col);
    		public void drawSquare(Graphics g, int x, int y){
    			g.drawRect(x, y, 1, 1);
    		public void emptyBoard(){
    			for (int r=0; r<board.length; r++){
    				for (int c=0; c<board[r].length; c++){
    					board[r][c] = true;
    		class TimerListener implements ActionListener{
    			public void actionPerformed(ActionEvent e){
    				for (int r = board.length-2;r>=0;r--){
    				drawTopLine(middle, width, 0);
    			public void setRow(int rowOverwritten, int rowBeingCopied){
    				for (int c=0; c<board[rowBeingCopied].length; c++){
    					board[rowOverwritten][c] = board[rowBeingCopied][c];
    			public void setRow(boolean[][] board, int rowNum, boolean [] row){
    				for (int c=0; c<board[rowNum].length; c++){
    					board[rowNum][c] = row[rowNum];
    			public void drawTopLine(int gapMiddle, int gapWidth, int row){
    				for (int c=0; c<board[row].length; c++){
    					board[c][row] = false;
    				//forming gap
    				for (int c = gapMiddle - (gapWidth/2); c<gapMiddle + (gapWidth/2); c++){
    					board[c][row] = true;

    When I run the program, only 1 row of pixelated "tunnel" appears at the top of the screen. Since I am not quite familiar with the Timer class and uses it for repetition, I guessed that I was misusing the timer. Where do I put the code to move all "tunnel walls" down and generate a new random one at the top?

  2. #2
    Super Moderator
    Join Date
    Jun 2013
    So. Maryland, USA
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    Thanked 698 Times in 680 Posts

    Default Re: Possible misuse of timer?

    Why don't beginners comment their code? What are all of these classes and methods supposed to do? Are we supposed to read your mind?

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