JFrame maximum size

Question

Hi! I'm using a JFrame in a game I'm developing, and this should be resizeable within some bounds. This works fine for the minimum size, the user is unable to even try to resize the frame smaller than what I've set as the minimum size. But it seems like maximum size is a different issue - I can't find a way to bound how large the user may expand the frame. Of course, when it's extended to a larger size than my specified maximum, it's resized back to the maximum size (using a ComponentListener to detect resize attempts - this has to be done because I need a constant aspect ratio - and a maximum size). But I don't like this solution very much, I would rather find it impossible to even try to extend the frame larger than the bounds - in the same way one can set the bounds for the minimum size. Please help me!
Any suggestions anyone?

Answer 1

See [http://forums.sun.com/thread.jspa?threadID=5342801]
The real issue is that setMinimumSize is declared in Window whereas setMaximumSize is declared in Component. Thus the two methods do not have complementary connotations.
Experimenting with workarounds posted on those bug report pages, I think this is the cleanest solution, even if it does involve using a painting method for something other than painting -- normally to be avoided. SSCCE:import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
public class MaxSizeFrame {
   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         @Override
         public void run() {
            new MaxSizeFrame().makeUI();
   public void makeUI() {
      final JFrame frame = new JFrame("") {
         @Override
         public void paint(Graphics g) {
            Dimension d = getSize();
            Dimension m = getMaximumSize();
            boolean resize = d.width > m.width || d.height > m.height;
            d.width = Math.min(m.width, d.width);
            d.height = Math.min(m.height, d.height);
            if (resize) {
               Point p = getLocation();
               setVisible(false);
               setSize(d);
               setLocation(p);
               setVisible(true);
            super.paint(g);
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.setSize(400, 400);
      frame.setMaximumSize(new Dimension(500, 500));
      frame.setMinimumSize(new Dimension(300, 300));
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
}This way, instead of repeated flickering, there is just one flicker as the specified maximum size is crossed.
db