JFrame not resizing when JPanel changes size

[Vas Nesterov]

Hi everyone. I am currently working on a game - Sokoban. I ran into a bit of an issue, where I want the frame to automatically resize itself when a new level begins (as most levels are different in size).
I can't seem to get it to work.
Here are parts of my code:

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.*;

public class Sokoban extends JPanel {

	private LevelReader lr;
	private Contents[][] curLevel;
	private boolean isReady;
	private boolean levelWon;
	private int levelNum;
	private int moveCounter;
	private long elapsedTime, startTime;
	private JLabel levelL, movesL, timeL, level, moves, time;
	private Timer timer;
	private int width, height;

	public Sokoban() {
		
		this.setFocusable(true);
		this.requestFocus();
		levelNum=1;
		lr = new LevelReader();
		lr.readLevels("m1.txt");		
		levelL = new JLabel("Level:");
		movesL = new JLabel("Pushes:");
		timeL = new JLabel("Elapsed Time:");
		level = new JLabel(Integer.toString(levelNum));
		moves = new JLabel(Integer.toString(moveCounter));
		time = new JLabel(Long.toString(elapsedTime));
		this.add(levelL);
		this.add(level);
		this.add(movesL);
		this.add(moves);
		this.add(timeL);
		this.add(time);
		timer = new Timer(1000, new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent arg0) {
				elapsedTime=System.currentTimeMillis()-startTime;
				time.setText(Long.toString(elapsedTime/1000));
				repaint();
			}
		});
		this.addKeyListener(new MyKeyListener());
		reset();
//		width=(curLevel.length+1)*32;
//		height=(curLevel[1].length+1)*32;
//		this.setPreferredSize(new Dimension(width, height));

		
	}

	void initLevel(int level) {

		int x = lr.getWidth(level);
		int y = lr.getHeight(level);

		curLevel = new Contents[x][];
		for (int i = 0; i < x; i++) {
			curLevel[i] = new Contents[y];
			for (int p = 0; p < y; p++) {
				curLevel[i][p] = lr.getTile(level, i, p);
			}
		}
		width=(curLevel.length+1)*32;
		height=(curLevel[1].length+1)*32;
		isReady = true;
		this.setPreferredSize(new Dimension(width,height));
		revalidate();
		repaint();
	}
	
	private boolean checkWin() {
		for (int i = 0; i < curLevel.length; i++) {
			for (int p = 0; p < curLevel[i].length; p++) {
				if (curLevel[i][p] == Contents.BOX)
					return false;
			}
		}
		reset();
		return true;
	}

	@Override
	public void paintComponent(Graphics g) {
		super.paintComponent(g);
		Graphics2D g2 = (Graphics2D) g;
		g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
//		this.setSize(width,height);

		if (isReady) {
			int x = 0, y, w = 32, h = 32;

			for (Contents i[] : curLevel) {
				y = 20;
				for (Contents p : i) {
					switch (p) {
					case BOX:
						try {
							g2.drawImage(ImageIO.read(new File("res/object.bmp")), x, y, null);
						} catch (IOException e1) {
							g2.setColor(Color.BLUE);
							g2.fill(new Rectangle2D.Double(x, y, w, h));
						}						
						break;
					case WALL:
						try {
							g2.drawImage(ImageIO.read(new File("res/wall.bmp")), x, y, null);
						} catch (IOException e) {
							g2.setColor(Color.BLACK);
							g2.fill(new Rectangle2D.Double(x, y, w, h));
						}
						break;
					case EMPTY:
						try {
							g2.drawImage(ImageIO.read(new File("res/ground.bmp")), x, y, null);
						} catch (IOException e) {
							g2.setColor(Color.WHITE);
							g2.fill(new Rectangle2D.Double(x, y, w, h));
						}						
						break;
					case GOAL:
						try {
							g2.drawImage(ImageIO.read(new File("res/store.bmp")), x, y, null);
						} catch (IOException e) {
							g2.setColor(Color.RED);
							g2.fill(new Rectangle2D.Double(x, y, w, h));
						}						
						break;
					case PLAYER:
						try {
							g2.drawImage(ImageIO.read(new File("res/mover_down.bmp")), x, y, null);
						} catch (IOException e) {
							g2.setColor(Color.GREEN);
							g2.fill(new Rectangle2D.Double(x, y, w, h));
						}						
						break;
					case BOXONGOAL:
						try {
							g2.drawImage(ImageIO.read(new File("res/object_store.bmp")), x, y, null);
						} catch (IOException e) {
							g2.setColor(Color.MAGENTA);
							g2.fill(new Rectangle2D.Double(x, y, w, h));
						}						
						break;
					case PLAYERONGOAL:
						try {
							g2.drawImage(ImageIO.read(new File("res/mover_store_down.bmp")), x, y, null);
						} catch (IOException e) {
							g2.setColor(Color.ORANGE);
							g2.fill(new Rectangle2D.Double(x, y, w, h));
						}
						break;
					}
					y += 32;
				}
				x += 32;
			}
		}
	}

	public static void main(String[] args) {
		JFrame f = new JFrame("Sokoban");
		Sokoban s = new Sokoban();
		f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
		f.setResizable(true);
		f.setLayout(new GridLayout());
		f.add(s);
		f.pack();
		f.setVisible(true);
	}
	
	public void reset() {
		try {
			initLevel(levelNum);
		} catch (IndexOutOfBoundsException e1) {
			initLevel(1);
			levelNum=1;
		}		
		moveCounter=0;
		elapsedTime=0;
		timer.stop();
		level.setText(Integer.toString(levelNum));
		moves.setText(Integer.toString(moveCounter));
		time.setText(Long.toString(elapsedTime));
//		revalidate();
		repaint();
	
	}
}

The game is essentially a JPanel that I draw inside a JFrame.
As you can see, I've been trying to revalidate the JFrame in different parts, but it doesn't appear to be working. I think it's revalidating the JPanel. How can I revalidate the JFrame to match the new coordinates of the JPanel?

Thanks!

[Kemal Sokolovic]

You should instantiate your frame from within another class, not the panel class. That's a very bad approach. In this case, revalidate() refers to panel.

Did you try to invoke pack() on your frame after you change/add new panel? That should resize it to fit its content.

[Michael Dunn]

have you tried calling
f.pack();
when new level starts?

(will need class level 'f')

[Vas Nesterov]

Great! Calling pack() at level starts worked. I had to make my JFrame class level as well as static.
I removed revalidate from my code.

Thank you very much!