Question

I want to do some drawing in a JPanel but the enclosing JFrame size doesn’t seem to match where I’ve asked the coordinates to be drawn.

In my example code, the JFrame size is set to (700, 700) and the last point is drawn at (600, 600). I would expect this point to be drawn 100 pixels away from the right and bottom edges but it isn’t (please see screenshot).

Here’s the code I’m using:

import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Scratch extends JPanel {

    static int frameWidth = 700;
    static int frameHeight = 700;

    public static void main(String[] args) {

    JFrame frame = new JFrame();

    frame.setSize(frameWidth, frameHeight);

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    Scratch scratch = new Scratch();

    frame.getContentPane().add(scratch);
    
    frame.setVisible(true);

    }

    @Override
    public void paintComponent(Graphics g) {

    g.drawRect(100, 100, 1, 1);

    g.drawString("100", 100, 100);

    g.drawRect(200, 200, 1, 1);

    g.drawString("200", 200, 200);

    g.drawRect(300, 300, 1, 1);

    g.drawString("300", 300, 300);

    g.drawRect(400, 400, 1, 1);

    g.drawString("400", 400, 400);

    g.drawRect(500, 500, 1, 1);

    g.drawString("500", 500, 500);

    g.drawRect(600, 600, 1, 1);

    g.drawString("600", 600, 600);


    }

}

Answer 1

Only a guess:

public class Scratch extends JPanel {

    static int frameWidth = 700;
    static int frameHeight = 700;

    public static void main(String[] args) {

    JFrame frame = new JFrame();

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    Scratch scratch = new Scratch();
    scratch.setSize(frameWidth, frameHeight);

    frame.getContentPane().add(scratch);

    frame.pack();
    frame.setVisible(true);

    }