Need help understanding the unexpected swing output

Question

I developed an application to create the following result:

I overridden JPanel getPrefferredSize, but why am I not seeing any changes in output when resizing. Even if I set the size to 0.0, the chart is not translated at all, and I get the same result as shown above.

Here is my complete code: -

import java.awt.BasicStroke; import java.awt.Color; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.RenderingHints; import java.awt.geom.AffineTransform; import java.awt.geom.Ellipse2D; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.SwingUtilities; public class Skeleton extends JFrame{ Skeleton() { super("Donut"); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setSize(400,400); add(new Board()); setVisible(true); } public static void main(String args[]) { SwingUtilities.invokeLater(new Runnable(){public void run(){new Skeleton();}}); } } class Board extends JPanel { public void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2=(Graphics2D)g; RenderingHints rh=new RenderingHints(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON); //the following statement has no noticeable effect. rh.put(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY); g2.setRenderingHints(rh); Ellipse2D e=new Ellipse2D.Double(0, 0, 80, 130); g2.setStroke(new BasicStroke(1)); g2.setColor(Color.RED); for(int deg=0;deg<360;deg+=5) { AffineTransform at=AffineTransform.getTranslateInstance(getWidth()/2,getHeight()/2); at.rotate(Math.toRadians(deg)); //returns a new Shape object after it has been undergone the 'at' transformation. g2.draw(at.createTransformedShape(e)); } } public Dimension getPreferredSize() { return new Dimension(100,100); } } 

Answer 1

Due to your layout manager. By default, BorderLayout ignores the preferred size, but fills all the available space. Use for example. FlowLayout and yu will see the difference.