Adding a Editable Text Box to a JFrame

Question

Is there any way to put a text box into a JFrame that the user can input text into? Kind of like the TextEdit or Notepad app.

Have you gone through any of the Swing tutorials yet? That's where I'd start as this sort of question is then easily and quickly answered. — Hovercraft Full Of Eels, Jan 25 '14 at 22:54
possible duplicate of [Simple JFrame program but can't see JTextfield](http://stackoverflow.com/questions/13713435/simple-jframe-program-but-cant-see-jtextfield) — jww, Jan 26 '14 at 05:23

Andrew Thompson · Accepted Answer · 2014-01-26T00:16:26.153

The closest equivalent to Notepad is a JTextArea. Wrap it in a JScrollPane for scroll-bars. Vis.

Notepad

Editpad

Tip: Make it the native PLAF for an even closer lookalike.

import java.awt.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;

public class Editpad {

    public static void main(String[] args) {
        Runnable r = new Runnable() {
            @Override
            public void run() {
                // the GUI as seen by the user (without frame)
                JPanel gui = new JPanel(new BorderLayout());
                gui.setBorder(new EmptyBorder(2,3,2,3));

                // adjust numbers for a bigger default area
                JTextArea editArea = new JTextArea(5,40);
                // adjust the font to a monospaced font.
                Font font = new Font(
                        Font.MONOSPACED, 
                        Font.PLAIN, 
                        editArea.getFont().getSize());
                editArea.setFont(font);
                gui.add(new JScrollPane(editArea,
                        JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
                        JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS));

                JFrame f = new JFrame("Editpad");
                f.add(gui);
                // Ensures JVM closes after frame(s) closed and
                // all non-daemon threads are finished
                f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                // See http://stackoverflow.com/a/7143398/418556 for demo.
                f.setLocationByPlatform(true);

                // ensures the frame is the minimum size it needs to be
                // in order display the components within it
                f.pack();
                // should be done last, to avoid flickering, moving,
                // resizing artifacts.
                f.setVisible(true);
            }
        };
        // Swing GUIs should be created and updated on the EDT
        // http://docs.oracle.com/javase/tutorial/uiswing/concurrency
        SwingUtilities.invokeLater(r);
    }
}

You have made the right choice for this use-case. – Andrew Thompson Jan 26 '14 at 00:23 — Andrew Thompson, Jan 26 '14 at 00:23

Martin Dinov · Answer 2 · 2014-01-26T00:03:29.567

1

Use a JTextField, which is a single-line "text area", or a JTextArea, which can handle multiple lines. Both work similarly. Here's a simple example with JTextField:

import java.awt.FlowLayout;

import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JTextField;

public class Foo extends JFrame {

    public Foo() {
        setLayout(new FlowLayout());
        JTextField field = new JTextField(20);
        add(field);
        setSize(500, 500);
        setVisible(true);
    }

    public static void main(String[] args) {
        Foo foo = new Foo();
    }
}

To do anything useful with such a component, you need to also add an event/action listener to a component (say a JButton) to do something with the text in it (which you can get by calling getText() on the JTextField or JTextArea)

edited Jan 26 '14 at 00:03

answered Jan 25 '14 at 22:58

Martin Dinov

8,757
3
29
41

You don't necessary need an event listener for the textfield itself; more likely a button or other event that gets and uses the text from the textfield – imulsion Jan 25 '14 at 22:59
Rushed writing that. Corrected, thanks. – Martin Dinov Jan 25 '14 at 23:02
2

Note that a `JTextField` is for a single line of text, so it is not even close to the component we would use to recreate an app. like Notepad. – Andrew Thompson Jan 26 '14 at 00:01
How can I change the size of the JTextField to be bigger (enough to fill up most of the window)? – alexsmbaratti Jan 26 '14 at 00:20

Adding a Editable Text Box to a JFrame

2 Answers2