jbuttons and a jtextfield that has an action listener

Question

I have a keypad made up of jbuttons and a jtextfield that has an action listener. When I press the button the number shows in the textfield but the next number overwrites it. Could anyone tell me how to append the text to the length 13 numbers and when it get's there to carriage return.

If I use the keyboard to enter numbers I can enter a String of numbers but not from the buttons.

I am using:

    JButton buttonNo2 = new JButton("2");
    buttonNo2.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            textfield.setText("2");
        }

buttonNo1.setBounds(11, 18, 50, 50);
    keyboardPanel.add(buttonNo2);
    buttonNo1.setForeground(Color.BLUE);
    buttonNo1.setFont(new Font("Perpetua", Font.BOLD, 20));

MadProgrammer · Accepted Answer · 2015-04-01T06:53:05.510

Try using something like

textfield.setText(textfield.getText() + "2");

instead of textfield.setText("2");

setText does just that, sets the text of the text field to the value you specified.

Also buttonNo1.setBounds(11, 18, 50, 50); looks like you're trying to do without a layout manager. Avoid using null layouts, pixel perfect layouts are an illusion within modern ui design. There are too many factors which affect the individual size of components, none of which you can control. Swing was designed to work with layout managers at the core, discarding these will lead to no end of issues and problems that you will spend more and more time trying to rectify

You could also make it much simpler for yourself, and use the Action API instead, which would save you a not lot of repeated typing...

public class NumberAction extends AbstractAction {

    private JTextField field;
    private int number;

    public NumberAction(JTextField field, int number) {
        this.field = field;
        this.number = number;
        putValue(NAME, Integer.toString(number));
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        Document doc = field.getDocument();
        try {
            doc.insertString(doc.getLength(), Integer.toString(number), null);
        } catch (BadLocationException ex) {
            ex.printStackTrace();
        }
    }

}

Then you would just need to add each button as required...

add(new JButton(new NumberAction(textfield, 1)));
add(new JButton(new NumberAction(textfield, 2)));
add(new JButton(new NumberAction(textfield, 3)));

See How to Use Actions for more details

score 0 · Answer 2 · answered Apr 01 '15 at 06:47

0

You have to get the text first and set the text by appending the previous and current text. public void actionPerformed(ActionEvent e) { String str = textfield.getText(); textfield.setText(str+the number printed); }

answered Apr 01 '15 at 06:47

Shriram

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score 0 · Answer 3 · answered Apr 01 '15 at 06:52

As @MadProgrammer already posted How to achieve it with JTextField , You can opt for JTextArea#append method

public void append(String str)

Appends the given text to the end of the document. Does nothing if the model is null or the string is null or empty.

Parameters: str - the text to insert

jbuttons and a jtextfield that has an action listener

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