CODEWITHSUNDEEP
javaswingjscrollpane
AR7
AR7

Reputation: 71

How can we add JScrollPane on JTextArea in java?

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();
   }
}

Upvotes: 3

Views: 29143

Answers (3)

trashgod
trashgod

Reputation: 205775

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.

image

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();
            }
        });
    }
}

Upvotes: 12

Foo Bar User
Foo Bar User

Reputation: 2491

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);

Upvotes: 0

Sylwek
Sylwek

Reputation: 866

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

Upvotes: 0

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