CODEWITHSUNDEEP
javaswing
DanMc
DanMc

Reputation: 848

How to create a text box that user can input a large amount of text into

I'm currently doing a Java assignment as a computer science fresher. As a part of that assignment I'm trying to bring up a secondary frame that the user can write UML code into which will then be passed into my main application and then into a class diagram.

The bit that I'm stuck with is that the JTextBox that I have put into this secondary frame is the size I want it to be, however the writing starts in the middle and does not change to a new line when it gets to the other size of the frame.

This is the image of what is currently happening:

Image of output]![The output of my current code

Code

And this is the code that I currently have for this class if it's needed.

package classdesign;
import java.awt.*;

import javax.swing.*;

 public class ClassCreation extends JFrame {

private JFrame frame;
private JLabel instructionlabel;
private JTextField inputUML;
private JButton upButton;
private String Message;

 public void ClassCreation(){

   frame = new JFrame();
   frame.setSize(300, 400);
   frame.setLocationRelativeTo(null);
   frame.setVisible(true);
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   frame.setTitle("Class Design");

   JPanel CreationPanel = new JPanel();
   CreationPanel.setLayout(new BorderLayout());

   instructionlabel = new JLabel("Fill Class details in using UML");
   CreationPanel.add(instructionlabel,BorderLayout.NORTH);

   inputUML = new JTextField("",20);
   CreationPanel.add(inputUML,BorderLayout.CENTER);

   frame.add(CreationPanel);
 }

   public Frame getFrame() {
       return frame;
   }
}

So, to summarise what I was hoping somebody could tell me how to do is to get the text input from the user to start in the top left and change to the next line when it gets to the far right, like any normal text editor etc...

Upvotes: 4

Views: 26357

Answers (3)

Andrew Thompson
Andrew Thompson

Reputation: 168825

An example of using a text area (with a few other tips thrown in free - check the comments).

ClassCreation

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

// Has an instance of frame, does not need to extend it.
public class ClassCreation { //extends JFrame {

    private JFrame frame;
    private JLabel instructionlabel;
    // as mentioned by talnicolas
    private JTextArea inputUML;

    // Don't give a method the same name as a class!!
    //public void ClassCreation(){
    public void initGui(){
        frame = new JFrame();
        //frame.setSize(300, 400);  //pack() instead!
        //frame.setLocationRelativeTo(null);    // do something better
        frame.setLocationByPlatform(true);  // better!
        //frame.setVisible(true);   // do later
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setTitle("Class Design");

        JPanel CreationPanel = new JPanel();
        CreationPanel.setLayout(new BorderLayout());

        instructionlabel = new JLabel("Fill Class details in using UML");
        CreationPanel.add(instructionlabel,BorderLayout.NORTH);

        inputUML = new JTextArea("",7,30);
        // very important next 2 lines
        inputUML.setLineWrap(true);
        inputUML.setWrapStyleWord(true);
        // add it to a scrollpane
        CreationPanel.add(new JScrollPane(inputUML),BorderLayout.CENTER);

        frame.add(CreationPanel);

        frame.pack();   // assume the natural size!
        frame.setVisible(true);

        for (int ii=0; ii<150; ii++) {
            inputUML.append(SENTENCE);
            inputUML.setCaretPosition( inputUML.getText().length() );
        }
    }

    public static void main(String[] args) {
        // Swing GUIs should be created and altered on the EDT.
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                ClassCreation cc = new ClassCreation();
                cc.initGui();
            }
        });
    }

    private static String SENTENCE = "The quick brown fox jumps over the lazy dog!  ";
}

Upvotes: 4

talnicolas
talnicolas

Reputation: 14053

JTextField is a lightweight component that allows the editing of a single line of text. (source)

As it is a single-line component, whatever its size is the cursor will always be centered and will never go to the next line.

I would suggest you use a JTextArea as it is a multi-line area and allow the user to enter input as you want him to.

Upvotes: 6

Pragalathan M
Pragalathan M

Reputation: 1781

use JTextPane or JEditorPane. Sample can be found at http://docs.oracle.com/javase/tutorial/uiswing/components/editorpane.html

Upvotes: 6

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