Frame size clipping pixels off right side with Absolute Positioning

[Psyclone]

I made a frame that is 1280x800. I'm using Absolute Positioning and when I add a panel or label that is 1280 pixels wide, it doesn't show about 8 pixels on the right side.

Why is the frame drawing at only 1272 pixels wide? I don't think it's the panel drawing at the wrong size, because I also have multiple panels across the middle and bottom of the frame that are lining up properly with the top panel.

        JFrame lobbyFrame = new JFrame("Welcome to ...");
        lobbyFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        lobbyFrame.setSize(1280, 800);
 
        JPanel lobbyPanelTop = new JPanel();
        lobbyFrame.add(lobbyPanelTop);
        lobbyPanelTop.setLayout(null);
        lobbyPanelTop.setOpaque(true);
        lobbyPanelTop.setBackground(new Color(202, 102, 202));
        lobbyPanelTop.setPreferredSize(new Dimension(1280, 120));
        Dimension size = lobbyPanelTop.getPreferredSize();
        lobbyPanelTop.setBounds(0, 0, size.width, size.height);

And yes, I am intentionally using Absolute Positioning instead of a Layout Manager.

[Fubarable]

You may be forgetting the JFrame's insets. Call getInsets on the JFrame and print it out to see what they are.

e.g.,

import java.awt.Dimension;
import javax.swing.*;

public class FuSwing {
  private static final Dimension SIZE = new Dimension(400, 400);

  private static void createAndShowUI() {
    JPanel panel = new JPanel();
    
    
    JFrame frame = new JFrame("FuSwing");
    frame.setPreferredSize(SIZE);
    frame.getContentPane().add(panel);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.pack();
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
    System.out.println(panel.getSize());
    System.out.println(frame.getInsets());
  }

  public static void main(String[] args) {
    java.awt.EventQueue.invokeLater(new Runnable() {
      public void run() {
        createAndShowUI();
      }
    });
  }
}

Myself, I would set the preferred size of the JFrame's contentPane not the JFrame itself.

[Psyclone]

OK, thanks. I think I set both of them.