settingContentPane not working

Question

I asked a similar question yesterday however after further research on what I wished to accomplish I have reason to believe that the question answered was inadequate and deserves a new question in itself as the question yesterday would solve a different problem and help others but not my particular problem. Link to previous question here.

What I am trying to accomplish is to set the JFrame's contentPane to the size of 200,200, however after drawing two different rectangles you would notice the obvious difference. Please refer to the SSCCE included and the picture attached.

Simply put, I would like Canvas.getWidth()/getHeight and getContentPane.getWidth()/Height to return my specified size 200,200.

Referenced Picture

SSCCE Example

import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.image.BufferStrategy;

import javax.swing.JFrame;
import javax.swing.SwingUtilities;

@SuppressWarnings("serial")
public class SSCCE extends Canvas implements Runnable {

    private JFrame frame;
    private BufferStrategy bufferStrategy;
    private Graphics2D graphics;
    private boolean running = false;

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {             
                SSCCE game = new SSCCE();
                game.setPreferredSize(new Dimension(200,200));
                game.setFocusable(true);
                game.setIgnoreRepaint(true);
                game.frame = new JFrame("SSCCE");
                game.frame.setLayout(new BorderLayout());
                game.frame.getContentPane().setPreferredSize(new Dimension(200,200));
                game.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                game.frame.add(game, BorderLayout.CENTER);
                game.frame.pack();
                game.frame.setIgnoreRepaint(true);
                game.frame.setResizable(false);
                game.frame.setLocationRelativeTo(null);
                game.frame.setVisible(true);
                game.start();
            }
        });
    }

    public synchronized void start() {
        this.createBufferStrategy(2);
        bufferStrategy = this.getBufferStrategy();
        graphics = (Graphics2D) bufferStrategy.getDrawGraphics();
        Thread thread = new Thread(this, "main");
        thread.start();
        running = true;
    }

    @Override
    public void run() {
        while (running) {
            graphics = (Graphics2D) bufferStrategy.getDrawGraphics(); 
            graphics.setColor(Color.RED);
            graphics.fillRect(0, 0, 210, 210);
            graphics.setColor(Color.GREEN);
            graphics.fillRect(0, 0, 200, 200);
            graphics.setColor(Color.BLACK);
            graphics.drawString("Specified Width: 200", 0, 10);
            graphics.drawString("Specified Height: 200", 0, 20);
            graphics.drawString("Canvas Width: " + getWidth(), 0, 30);
            graphics.drawString("Canvas Height: " + getHeight(), 0, 40);
            graphics.drawString("Content Pane Width: " + frame.getContentPane().getWidth(), 0, 50);
            graphics.drawString("Content Pane Width: " + frame.getContentPane().getHeight(), 0, 60);
            graphics.drawString("Red Rectangle = 210,200", 0, 70);
            graphics.drawString("Green Retangle = 200,200", 0, 80);
            graphics.dispose();
            bufferStrategy.show();
        }
    }
}

Answer 1

The problem, as far as I can deduce (from examples and other posts) is the frame border. Every example I can find will either use a JWindow or a undecorated frame...

Mixing heavy and light weight components is only going to lead to tears, I'd recommend not adding a Canvas directly to the frame.

Swing is also double buffered itself. Unless you have a particular issue, I would suggest trying to simple paint within the normal Swing pipeline...

Updated

Well, I've got some bad news, I'm not sure for who though ;)

I was able to adapt the example from here and get it to work...

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (Exception ex) {
                }

                Canvas canvas = new Canvas();
                canvas.setPreferredSize(new Dimension(200, 200));

                JFrame frame = new JFrame("Test");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setIgnoreRepaint(true);
                frame.add(canvas);
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);

                canvas.createBufferStrategy(2);

                Thread t = new Thread(new Painter(canvas));
                t.setDaemon(true);
                t.start();

            }
        });
    }

    public class Painter implements Runnable {

        private Canvas canvas;

        public Painter(Canvas canvas) {
            this.canvas = canvas;
        }

        @Override
        public void run() {
            while (true) {
                BufferStrategy bs = canvas.getBufferStrategy();
                Graphics2D g2d = (Graphics2D) bs.getDrawGraphics();
                g2d.setColor(Color.RED);
                g2d.fillRect(0, 0, canvas.getWidth(), canvas.getHeight());

                int width = canvas.getWidth();
                int height = canvas.getHeight();

                FontMetrics fm = g2d.getFontMetrics();
                g2d.setColor(Color.BLACK);
                g2d.drawString("Size = " + width + "x" + height, 0, fm.getAscent());

                Window w = SwingUtilities.windowForComponent(canvas);
                g2d.drawString("Frame Size = " + w.getWidth() + "x" + w.getHeight(), 0, (fm.getHeight()) + fm.getAscent());

                g2d.dispose();
                bs.show();

                try {
                    Thread.sleep(30);
                } catch (InterruptedException ex) {
                }
            }
        }
    }
}

More Bad News

After playing around with the code a little more, I was finally able to get your example to work. I just had to remove game.frame.setResizable(false); :P

Finally, good news

Call setResizable before you call pack...