JScrollpane only visible after maximising window Java Swing

Question

I'm using JScrollPane to put inside a JTable with some values, but the JScrollPane has to be invisible until user clicks on a button. But the JScrollPane remains not visible until I maximise the window manually. I've tried almost everything, .validate(); .revalidate(); .repaint()... I'm using Netbeans, and on the Custom Code of the JScrollPane I've wrote this:

scrollPane = new javax.swing.JScrollPane();
this.scrollPane.setVisible(false);
// El código de los subcomponentes y del gestor de distribución - no se muestra aquí

// El código que agrega el componente al contenedor superior - no se muestra aquí

Then, on MouseReleased:

private void botoGeneraLlistatMouseReleased(java.awt.event.MouseEvent evt) {
    this.generaLlistat();
}

And on the end of generaLlistat():

public void generaLlistat(){{
   ...(Some code requesting data from DB)
   JTable table = new JTable(rows, headings);
   scrollPane.setViewportView(table);
   this.scrollPane.setVisible(true);
   statement.close();
   connection.close();
}

I will appreciate any help :) Thank you all, and sorry about my english grammar and spelling.

Answer 1

Try doing this way:

package stack;

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;

public class Aitor extends JFrame implements ActionListener{
    JTable table;
    JPanel panel = new JPanel();
    JButton button = new JButton("Add"); 

    String data[][]={{"hey","hey"},{"hey","hey"},{"hey","hey"},{"hey","hey"},                        {"hey","hey"},{"hey","hey"}
,{"hey","hey"},{"hey","hey"},{"hey","hey"},{"hey","hey"},{"hey","hey"},{"hey","hey"},{"hey","hey"},{"hey","hey"}
,{"hey","hey"},{"hey","hey"}};
    String columns[] = {"First","Second"};

    public Aitor(){
        setLayout(new BorderLayout());
        panel.setLayout(new BorderLayout());
        panel.setPreferredSize(new Dimension(500,400));
        button.addActionListener(this);
        add(panel,BorderLayout.CENTER);
        add(button, BorderLayout.SOUTH);

    }

    public static void main(String [] a){
        Aitor aitor = new Aitor();
        aitor.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        aitor.pack();
        aitor.setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent arg0) {
        panel.removeAll();
        table =new JTable(data,columns);
        panel.add(new JScrollPane(table),BorderLayout.CENTER);
        repaint();
        revalidate();
    }
}

Answer 2

You can just call pack() on your container after calling setVisible(true) and and your scrollpane will appear.

Answer 3

You can use setPreferredScrollableViewportSize(), as shown here and here, although it has some of the same drawbacks mentioned here.

Answer 4

Try this coding if youu arer using jframe.

In constructor method, give

Jscrollpane.setVisible (false);

Give the particular jscrollpane which is associated with your jtable in jframe.

Then in actionperformed method give

Jscrollpane. setvisible (true); 
pack (); 

It would help.....