How can we add JScrollPane on JTextArea in java?

Question

Can anybody tell me what is the problem in following program? I want to fit JScrollPane on JtextArea but when I add it then JTextArea is not visible.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

class Area extends JFrame
{
    private JTextArea ta;
    private JTextField tf;
    JScrollPane jp;

    public Area()
    {
       super("Text Area");
       tf=new JTextField();
       tf.setBounds(100,350,300,30);
       add(tf);
       ta=new JTextArea();
       ta.setBounds(100,100,300,200);
       jp= new JScrollPane(ta);
       add(jp);
       setLayout(null);
       setSize(500,500);
       setVisible(true);
       setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   }

   public static void main(String...s)
   {
      new Area();
   }
}

`Don't use a null layout!` - Swing was designed to be used with layout managers for too many reasons to list here. — camickr, Oct 06 '13 at 18:44

score 11 · Answer 1 · edited May 23 '17 at 12:09

I see several problems:

Don't use a null layout; do use a real layout.
The default layout of JFrame is BorderLayout; the default position is CENTER; only one component can occupy a position at a time; the example below uses NORTH & CENTER.
Use the appropriate constructor parameters to size the text components initially.
The scrollbar will appear automatically whenever the scrollpane is smaller than the enclosed component; resize the frame to see the effect.
As shown here, the frame's size is made smaller for effect.
See also Initial Threads.

import java.awt.BorderLayout;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;

/** @see https://stackoverflow.com/a/19215436/230513 */
public class Area extends JFrame {

    public Area() {
        super("Text Area");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JTextField tf = new JTextField(12);
        add(tf, BorderLayout.NORTH);
        JTextArea ta = new JTextArea(24, 12);
        JScrollPane jp = new JScrollPane(ta);
        add(jp, BorderLayout.CENTER);
        pack();
        // arbitrary size to make vertical scrollbar appear
        setSize(240, 240);
        setLocationByPlatform(true);
        setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                new Area();
            }
        });
    }
}

Sylwek · Answer 2 · 2013-10-06T18:22:47.980

0

Try this:

public Area()
{
   super("Text Area");
   tf=new JTextField();
   tf.setBounds(100,350,300,30);
   add(tf);
   ta=new JTextArea();
   jp= new JScrollPane(ta);
   jp.setBounds(5, 5, 100, 100);
   add(jp);
   setLayout(null);
   setSize(500,500);
   setVisible(true);
   setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

You have to use setBounds on JScrollPane, not on JTextArea

edited Oct 06 '13 at 18:22

answered Oct 06 '13 at 18:17

Sylwek

856
1
9
24

Oh, thank you very much. I was searching about and this "You have to use setBounds on JScrollPane, not on JTextArea" solved my problem. – Commentator Dec 05 '16 at 04:57

score 0 · Answer 3 · answered Oct 06 '13 at 18:23

0

sounds like its added but its not shown because of the policy try this:

  jp.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
  jp.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);

answered Oct 06 '13 at 18:23

Foo Bar User

2,401
3
20
26

It won't work. He has to use `setBounds` method on `jp`, not on `JTextArea`, because when he adds `textArea` to `scrollPane`, `scrollPane` is parent – Sylwek Oct 06 '13 at 18:26
2

@SylwekDerkacz actualy i run his code and theres not text area there. because of setLayoutO(null), to be honest i never used setBounds because i disagree with setBounds anyway. – Foo Bar User Oct 06 '13 at 18:32

How can we add JScrollPane on JTextArea in java?

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