JFrame not sizing correctly

Question

When I set the size of the JFrame its set the size of the frame itself including the borders. I tried creating a new content Panel and set that size instead of setting the size of the frame itself but it isn't working here is the code:

frame = new JFrame();
JPanel jp = new JPanel();
frame.setTitle(title);
//frame.setSize(width, height);
frame.setResizable(false); 
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//insets = frame.getInsets();
//frame.setSize(new Dimension(insets.left + width + insets.right, insets.top + height + insets.bottom));
jp.setPreferredSize(new Dimension(width, height));
frame.setContentPane(jp);
frame.pack();
frame.setVisible(true);

So using insets isn't working and using a new ContentPane is also not working I hope it is clear enough.

EDIT: It's working now I extended the class with Canvas set it's size to width and height and then added it to the JFrame then packed it. This works! But why I think caused it was not the sizing but the way I rendered it, I got the bufferStrategy from the JFrame instead of the canvas which is not the way it should be.

I just tried and `setPreferredSize` on the `ContentPane` is definitely working. — Gabriel Negut, Aug 16 '14 at 15:23
Welcome to Stack Overflow, please take the [Tour](http://stackoverflow.com/tour). — DavidPostill, Aug 16 '14 at 16:23

score 1 · Accepted Answer · edited May 23 '17 at 12:12

Override getPreferredSize() to set the preferred size of the JPanel.

Sample code:

JPanel panel =new JPanel (){

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(..., ...);
    }
}

See Should I avoid the use of set(Preferred|Maximum|Minimum)Size methods in Java Swing?

Use SwingUtilities.invokeLater() or EventQueue.invokeLater() to make sure that EDT is initialized properly.

sample code:

public static void main(String args[]) {
    SwingUtilities.invokeLater(new Runnable() {

        @Override
        public void run() {
            // GUI related code goes here (not heavy task)
        }
    });
}

See SwingUtilities.invokeLater

Why are you setting new content pane of JFrame? Just add in the default content pane using frame.getContentPane().add(panel) or frame.add(panel)

Call frame.setResizable(false) in the end after making it visible to make sure that all the components are fit properly.

JFrame not sizing correctly

1 Answers1