CODEWITHSUNDEEP
javaswingmiglayoutconcurrencyevent-dispatch-thread
Amol Katdare
Amol Katdare

Reputation: 6760

Dynamically removing component from JPanel

Here is runnable piece of code explaining the problem -

I can remove s1 and s2 but not s3.
This does not seem MigLayout related (I happen to be using it) as I see the same behavior with default layout as well.


import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;

import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

import net.miginfocom.swing.MigLayout;

public class MyFrame2 extends JFrame {
    private JPanel main;
    private JPanel s1;
    private JPanel s2;
    private JPanel s3;

    public static void main(String[] args) throws InterruptedException {
        MyFrame2 f = new MyFrame2();
        f.setVisible(true);
        Thread.sleep(2000); //you can see all three panels for two seconds

        f.main.remove(f.s1);
        f.main.validate();
        Thread.sleep(2000);
        f.main.remove(f.s2);
        f.main.validate();
        Thread.sleep(2000);
        f.main.remove(f.s3);
        f.main.validate();
    }

    public MyFrame2() {
        main = new JPanel();

        main.setLayout(new MigLayout());

        main.add(new JLabel("Why does s3 not disappear?"),"w 200, h 100, wrap");

        s1 = new JPanel();
        s1.setBorder(BorderFactory.createTitledBorder(BorderFactory.createLineBorder(Color.GRAY,1),"s1"));
        main.add(s1,"w 90%, h 300, wrap");

        s2 = new JPanel();
        s2.setBorder(BorderFactory.createTitledBorder(BorderFactory.createLineBorder(Color.GRAY,1),"s2"));
        main.add(s2,"w 90%, h 300, wrap");

        s3 = new JPanel();
        s3.setBorder(BorderFactory.createTitledBorder(BorderFactory.createLineBorder(Color.GRAY,1),"s3"));
        main.add(s3,"w 90%, h 300, wrap");

        getContentPane().setLayout(new BorderLayout());
        getContentPane().add(main, BorderLayout.CENTER);

        setSize(new Dimension(800, 600));

    }
}

Upvotes: 5

Views: 9254

Answers (2)

Joop Eggen
Joop Eggen

Reputation: 109603

Call at the end, after the last f.validate():

f.repaint(50L);

As the last validate does not change layouting.

Upvotes: 11

trashgod
trashgod

Reputation: 205875

First, Swing GUI objects should be constructed and manipulated only on the event dispatch thread, but you mustn't sleep on the EDT. Instead use javax.swing.Timer to mark time, as shown here.

Upvotes: 5

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