CODEWITHSUNDEEP
javaswingjtextarea
user3712626
user3712626

Reputation: 143

JTextArea won't read in text properly

I can not seem to get this to work. My assignment will only let us use JTextAreas. The issue with my code is that I can not read it text in the TextArea. The goal is to run the logic after the user types in ENTER after they type in their input.

When I run the code I can only type in one character.. and the the GUI presents the character after a zero for reasons I can not figure out. Ex: [0b ] will be in the TextArea. Please help I can't figure this out.

public class ArabicToRomanGUI extends JFrame
{
private static final long serialVersionUID = 1L;
private JTextArea enterRomanNumber = new JTextArea();
JLabel label = new JLabel();
JPanel panel = new JPanel();
JFrame frame = new JFrame();


//TestArea contructor adds jtextArea to jframe
public ArabicToRomanGUI()
{
    super("Convert a Roman Numeral");
    setLayout(new FlowLayout());

    //Text field to enter a roman numeral
    enterRomanNumber = new JTextArea(1,25);
    enterRomanNumber.setText("Delete this text and Enter a Roman Numerial Here!");
    //enterRomanNumber.setAlignmentX(0);
    //enterRomanNumber.setAlignmentY(0);

    add(enterRomanNumber);

    HandlerForTextArea handler = new HandlerForTextArea();
    enterRomanNumber.addKeyListener(handler);
}

private class HandlerForTextArea implements KeyListener
{
    //used to process text field events
    @Override
    public void keyTyped(KeyEvent e) 
    {
            String userInput = "";
            userInput = enterRomanNumber.getText();
            userInput = userInput.toUpperCase();

            ConversionLogic.ConvertFromRomanToArabic(userInput); //converts user string of Roman numerals to an int in arabic
            String arabicNumberAsString = ConversionLogic.getConvertedRomanNumeral();
            enterRomanNumber.setText(arabicNumberAsString);

            //user pressed enter in JTextField enterNumberField
            if(e.getKeyCode() == KeyEvent.VK_ENTER)
            {
                //enterRomanNumber.setText(arabicNumberAsString);
                if (ConversionLogic.getCheckFail() == true)
                {
                    JOptionPane.showMessageDialog(frame, "The Roman Numeral entered is Invalid", "Error", JOptionPane.ERROR_MESSAGE);
                }
                else
                {
                    JOptionPane.showMessageDialog(frame, "The arabic equivalent is " + arabicNumberAsString + "." , "Conversion Successful", JOptionPane.PLAIN_MESSAGE);
                }
            }
    }

    @Override
    public void keyPressed(KeyEvent e) {
        //not used

    }

    @Override
    public void keyReleased(KeyEvent e) {
        //not used

    }

}//end inner class TextFieldHandler
}//end class ArabicToRomainGUI

Upvotes: 2

Views: 135

Answers (1)

Hovercraft Full Of Eels
Hovercraft Full Of Eels

Reputation: 285430

As you'll read time and time again on this site -- don't use a KeyListener with a text component such as a JTextArea as this can mess up the functioning of the text component. Instead use a DocumentListener for when you wish to detect changes to the state of the JTextArea after it happens, or a DocumentFilter if you wish to detect (and possibly change) changes to the text component before it is posted to the text component.

I see that you're using a JTextArea(1, 25), or a single-line JTextArea, which makes me ask: why not use a JTextField? If you do this and want to trap the ENTER key press, then you can simply add an ActionListener to the JTextField.

Upvotes: 4

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