Why is this graphics component not working?

Question

I am trying to draw a rectangle in the class "Graphics", but for some reason the rectangle does not appear, but the program returns no errors. I have never experience issues such as this before so I am rather confused.

Main()

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


public class Main
{

    public Main()
    {
        JFrame window = new JFrame();

        Sound soundCall = new Sound();
        Graphics graphicsCall = new Graphics();

        final JPanel container = new JPanel();

        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        window.getContentPane().add(container);
        window.setSize(600, 400);
        window.setLocationRelativeTo(null);
        window.setVisible(true);
        window.setResizable(false);

    }

    public static void main(String args[])
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            @Override
            public void run()
            {
                new Main();
            }
        });

    }

Graphics()

import java.awt.Color;
import java.awt.Graphics2D;

import javax.swing.JPanel;

public class Graphics extends JPanel
{

    public void paintComponent(java.awt.Graphics g)
    { 
        super.paintComponent(g);
        g.setColor(Color.GRAY);
        g.drawRect(500, 500, 500, 500);
    }

}

EDIT FOR HOVERCRAFT

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


public class Main
{

    public Main()
    {
        JFrame window = new JFrame();

        Sound soundCall = new Sound();
        Draw drawCall = new Draw();

        final JPanel container = new JPanel();

        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        window.getContentPane().add(drawCall);
        window.setSize(600, 400);
        window.setLocationRelativeTo(null);
        window.setVisible(true);
        window.setResizable(false);

    }

    public static void main(String args[])
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            @Override
            public void run()
            {
                new Main();
            }
        });

    }

}

Through adding this window.getContentPane().add(drawCall); asks me to change drawCall to a Component

EDIT 2:

public class Draw 
{

    public class Graphics extends JPanel
    {

        public void paintComponent(java.awt.Graphics g)
        { 
            super.paintComponent(g);
            g.setColor(Color.GRAY);
            g.drawRect(0, 0, 500, 500);
        }

    }


}

ERROR The method add(Component) in the type Container is not applicable for the arguments (Draw)

Answer 1

You add your graphicsCall variable to nothing, and so it will not be displayed. Solution: add it to a container such as that JPanel that you just created, or perhaps directly to the JFrame's contentPane.

i.e., change this:

    JFrame window = new JFrame();

    Sound soundCall = new Sound();
    Graphics graphicsCall = new Graphics();

    final JPanel container = new JPanel();

    window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    window.getContentPane().add(container);

to this:

    JFrame window = new JFrame();

    Sound soundCall = new Sound();
    Graphics graphicsCall = new Graphics();

    // final JPanel container = new JPanel();

    window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    window.getContentPane().add(soundCall);

As an aside, you will want to re-name that class from Graphics to something else, or else you risk confusing yourself or your compiler since there already exists a critical Java class with that name.

Also, avoid using setSize(...). Better to have your drawing JPanel override getPreferredSize() and to call pack() on your JFrame.

---

Edit
As per MadProgrammer's astute observation, you're drawing outside of the bounds of your component.

---

Edit 2
Regarding your latest code, this:

public class Draw 
{
    public class Graphics extends JPanel
    {
        public void paintComponent(java.awt.Graphics g)
        { 
            super.paintComponent(g);
            g.setColor(Color.GRAY);
            g.drawRect(0, 0, 500, 500);
        }
    }
}

is useless dreck. Why are you needlessly wrapping a class inside of a class? Instead why not simply:

public class Draw extends JPanel   {

    public void paintComponent(java.awt.Graphics g)
    { 
        super.paintComponent(g);
        g.setColor(Color.GRAY);
        g.drawRect(0, 0, 500, 500);
    }

    @Override
    public Dimension getPreferredSize() {
       // return an appropriate Dimension here
    }
}