Nullpointer avec repaint()

Version imprimable

Bonjour,

je debute avec Swing, et je suis en train de creer un jeu puissance 4.
Mon probleme est que pour actualiser l'affichage graphique je dois minimiser la fenetre puis la remaximiser. Sinon ca ne s'affiche pas.

Sur Eclipse, j'ai le probleme suivant

Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
	at uk.ac.cam.nscc2.Connect4.Game.changeGrid(Game.java:71)
	at uk.ac.cam.nscc2.Connect4.GamePanel.actionPerformed(GamePanel.java:106)
	at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2012)
	at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2335)
	at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:404)
	at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
	at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:253)
	at java.awt.Component.processMouseEvent(Component.java:6108)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
	at java.awt.Component.processEvent(Component.java:5873)
	at java.awt.Container.processEvent(Container.java:2105)
	at java.awt.Component.dispatchEventImpl(Component.java:4469)
	at java.awt.Container.dispatchEventImpl(Container.java:2163)
	at java.awt.Component.dispatchEvent(Component.java:4295)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4461)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4125)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4055)
	at java.awt.Container.dispatchEventImpl(Container.java:2149)
	at java.awt.Window.dispatchEventImpl(Window.java:2478)
	at java.awt.Component.dispatchEvent(Component.java:4295)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:604)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:275)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:200)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:190)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:185)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:177)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:138)

Merci d'avance

Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
package uk.ac.cam.nscc2.Connect4;
 
import javax.swing.JPanel;
 
public class Game {
 
	private Integer[][] grid= { {0,0,0,0,0,0,0},
								{0,0,0,0,0,0,0},
								{0,0,0,1,0,0,0},
								{0,0,1,2,0,0,0},
								{0,1,2,2,0,0,0},
								{1,2,2,2,0,0,0} } ;
 
	private GamePanel showgame;
	private Player player1;
	private Player player2;
 
	public Game() {
 
	}
 
	public static String getPlayerName() {
		// TODO Auto-generated method stub
		return null;
	}
 
	public void play() {
		showgame.repaint(); // L'ERREUR EST LA
	}
 
 
   public Integer[][] getGrid() {
	   return grid ;
   }
 
   public GamePanel getGame() {
	   return showgame;
   }
 
   public Player getPlayer1() {
	   return player1;
   }
 
   public Player getPlayer2() {
	   return player2;
   }
 
   public GamePanel getGraphics() {
		return showgame;
	}
 
	public void setGraphics(GamePanel showgame) {
		this.showgame = showgame;
	}
 
	public void changeGrid(int j) {
		for (int i = 0 ; (i<6) ; i++) {
			if (grid[i][j-1]==0) {
				grid[i][j-1]=1; // Changer pour autre joueur
				break;
			}
		}
		showgame.repaint();
	}

Je sais que showgame ici n'a pas été initialisé, mais je ne vois pas comment faire d'autant que dans les examples d'interface swing que j'ai vu, il ne l'etait pas non plus?

et l'autre classe

Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
 
package uk.ac.cam.nscc2.Connect4;
 
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
 
import javax.swing.JButton;
import javax.swing.JPanel;
 
public class GamePanel extends JPanel implements ActionListener{
 
	private Game game ;
	JButton button1;
	JButton button2;
	JButton button3 ;
	JButton button4;
	JButton button5;
	JButton button6;
	JButton button7; 
 
 
	public GamePanel(Game game) {
		super();
		this.game = game;
		//showgame = new GameGraphics(game);
		//game.setGraphics(showgame);
		FlowLayout layout = new FlowLayout();
		//GridBagLayout layout = new GridBagLayout();
		setLayout(layout);
		//GridBagConstraints c = new GridBagConstraints();
		button1 = new JButton("Here1");
		//c.gridx =0;
		//c.gridy=0;
		add(button1);
		button1.addActionListener(this);
		button2 = new JButton("Here2");
		//c.gridx=1;
		//c.gridy=0;
		add(button2);
		button2.addActionListener(this);
		button3 = new JButton("Here3");
	//	c.gridx=2;
		add(button3);
		button3.addActionListener(this);
		button4 = new JButton("Here4");
		button4.addActionListener(this);
	//	c.gridx=3;
		add(button4);
		button5 = new JButton("Here5");
		button5.addActionListener(this);
	//	c.gridx=4;
		add(button5);
		button6 = new JButton("Here6");
	//	c.gridx=5;
		add(button6);
		button6.addActionListener(this);
		button7 = new JButton("Here7");
		//c.gridx=6;
		button7.addActionListener(this);
		add(button7);
		//c.gridwidth = GridBagConstraints.REMAINDER ;
		//c.gridheight = GridBagConstraints.REMAINDER;
		//add(showgame,c);
 
	}
 
 
	protected void paintComponent(Graphics g) {
		super.paintComponent(g);
		g.setColor(Color.blue);
		g.fill3DRect(15, 70, 560, 480, true); //Size of board
		g.setColor(Color.black);
		//Each cell will be 80*80
		for (int i= 0 ; i<6 ; i++) {
			for (int j = 0 ; j<7 ; j++) {
				if ((game.getGrid())[i][j]==1) g.setColor(Color.red);
				if ((game.getGrid())[i][j]==2) g.setColor(Color.YELLOW);
				if ((game.getGrid())[i][j]==0) g.setColor(Color.white);
				g.fillOval(15 + 80*j, 70 + 80*i ,80, 80) ;
			}
		}
	}
 
 
	@Override
	public void actionPerformed(ActionEvent arg0) {
		Object source = arg0.getSource();
		if (source==button1) game.changeGrid(4); 
		if (source==button2) game.changeGrid(2);
		if (source==button3) game.changeGrid(3);
		if (source== button4)game.changeGrid(4);
		if (source== button5) game.changeGrid(5);
		if (source==button6) game.changeGrid(6);
		if (source==button7) game.changeGrid(7);
 
	} 
 
}

Code:

1
2
3
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at uk.ac.cam.nscc2.Connect4.Game.changeGrid(Game.java:71)

Code:

1
2
3
4
 
public void play() {
		showgame.repaint(); // L'ERREUR EST LA
	}

Non.

=>

Code:

1
2
3
4
5
6
7
8
9
10
 
	public void changeGrid(int j) {
		for (int i = 0 ; (i<6) ; i++) {
			if (grid[i][j-1]==0) {
				grid[i][j-1]=1; // Changer pour autre joueur
				break;
			}
		}
		showgame.repaint();
	}

Et tu fais quand un showGame = new GamePanel() ?

Je ne le fais pas. Sur le modele que j'utilisais, ils ne semblaient pas le faire (ce qui me semblait bizarre d'ailleurs :s)

Mon problème est que je ne vois pas comment faire puisque le constructeur de GamePanel appelle lui meme la classe Game (new GamePanel(Game a)). Donc je ne vois pas comment fiare pour creer une instance de GamePanel à l'intérieur de Game.

Sinon j'ai une autre classe Panel(qui etend JFrame) qui gere les autres composants

Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
 
 
public class Panel extends JFrame  {
 
	private GamePanel gamePanel;
 
 public Panel() {
	 super("Connect 4");
	 setSize(1000, 600);
	 setDefaultCloseOperation(EXIT_ON_CLOSE);
	 setLayout(new BorderLayout());
	 // Will display 1p, 2p and difficulty level
	 JComponent optionsPanel = createOptionsPanel();
	 add(optionsPanel, BorderLayout.WEST);
	 // Will display the game
	 JComponent gamePanel = gameDisplay();
	 add(gamePanel, BorderLayout.CENTER);
	 // will display statistics
	 JComponent statPanel = giveStats();
	 add(statPanel, BorderLayout.EAST);
 }
 
 
 
 private JComponent giveStats() {
	 JPanel p = new JPanel();
	 p.setLayout(new BoxLayout(p, BoxLayout.Y_AXIS)) ;
	 p.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));
	 p.setBackground(Color.BLACK);
	 p.setForeground(Color.white);
	 JLabel player = new JLabel("Game.getPlayerName()"+ "'s turn ") ;
	 player.setForeground(Color.white);
	 JLabel timeelapsed = new JLabel("Time elapsed: " + Statistics.timeElapsed());
	 timeelapsed.setForeground(Color.white);
	 JLabel numberturns = new JLabel("Number of turns: " + Statistics.numberTurns());
	 numberturns.setForeground(Color.white);
	 JLabel predicted = new JLabel("The predicted winner is: " + Statistics.predictedWinner());
	 predicted.setForeground(Color.white);
	 JLabel numberhints = new JLabel("Number of hints given: " + Statistics.numberHints());
	 numberhints.setForeground(Color.white);
	 p.add(player);
     p.add(timeelapsed);
     p.add(numberturns);
     p.add(predicted);
     p.add(numberhints);
	 return p;
}
 
private JComponent gameDisplay() {
	Game play = new Game();
	GamePanel game = new GamePanel(play);
	game.setBorder(BorderFactory.createEtchedBorder(Color.BLACK, Color.RED));
    game.setBackground(Color.black);
    game.setMinimumSize(new Dimension(400,600));
    gamePanel = game;
    game.setVisible(true);
	return game;
}
 
private JComponent createOptionsPanel() {
	JPanel p = new JPanel();
	p.setLayout(new BoxLayout(p, BoxLayout.Y_AXIS));
	p.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));
	p.setBackground(Color.BLACK);
	p.setForeground(Color.white);
    JButton oneplayer = new JButton("1 player");
    p.add(oneplayer);
    JButton twoplayer = new JButton("2 players");
    p.add(twoplayer);
    JButton rules = new JButton("Rules of the Game");
    p.add(rules);
    JButton hints = new JButton("Hints");
    p.add(hints);
	return p;
}
 
 
 
public static void main(String[] args) {
	 Panel game = new Panel();
	 game.setVisible(true);
	 game.setResizable(false);
 }
 
 
 
 
 
 
}

Merci d'avance de votre aide

24/03/2010, 22h39
bouye

showGame = new GamePanel(this) ?
25/03/2010, 00h18
nacrooks

Citation:

Envoyé par bouye

showGame = new GamePanel(this) ?

Merci beaucoup, j'ai maintenant résolu mon probleme (en effacant le showgame.repaint() et en mettant un repaint() dans la classe GamePanel au niveau de l'event handler(desolee je ne connais pas le mot francais).

Mais en tout cas merci pour l'aide :):mrgreen: