Java JFrame button organization

Question

How do i create a jframe that organizes the text box and jbuttons, with the textbox on top and a 3 by 4 grid layout of buttons 1-10?

"TEXT BOX HERE"
[1][2][3]
[4][5][6]
[7][8][9]
[(][0][)]

This is what I have so far:

setTitle("Test");
    setSize(400, 400);

    // Create JButton and JPanel
    JButton[] buttons = new JButton[12];
    JButton buttonLpar = new JButton("(");
    JButton buttonRpar = new JButton(")");
    JPanel panel = new JPanel();
    JPanel panel2 = new JPanel(new GridLayout(3, 4));

    // adding 10 buttons
    for(int i = 0; i < 10; i++) {
        buttons[i] = new JButton(String.valueOf(i));
    }
    buttons[11].add(buttonLpar);
    buttons[12].add(buttonRpar);

     JTextField text = new JTextField("",10);
     text.setFont(new Font("Helvetica Neue", Font.BOLD, 12));

     panel.add(text, BorderLayout.NORTH);
     panel.add(panel2, BorderLayout.CENTER);
     this.getContentPane().add(panel);

     setVisible(true);
     setDefaultCloseOperation(EXIT_ON_CLOSE);

But that's where I'm stuck.

Okay I should note that I need a for loop to populate 3 by 4 gridlayout. But I don't know what I need in the loop.

Answer 1

For this kind of grid, assuming you create it on the go, you just need to have an if-else to see if you're on the last row of data.

For example:

import java.awt.GridLayout;

import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class GridLayoutWithEmptyComponents {
    private JFrame frame;
    private JPanel pane;
    private JPanel buttonsPane;
    private JButton[] buttons;

    private void createAndShowGUI() {
        frame = new JFrame(getClass().getSimpleName());
        pane = new JPanel();
        pane.setLayout(new BoxLayout(pane, BoxLayout.PAGE_AXIS));

        buttonsPane = new JPanel();
        buttonsPane.setLayout(new GridLayout(4, 3));

        buttons = new JButton[10];
        for (int i = 0; i < buttons.length; i++) {
            buttons[i] = new JButton("" + (i + 1));
            if (i == buttons.length - 1) {
                buttonsPane.add(new JButton("("));
                buttonsPane.add(buttons[i]);
                buttonsPane.add(new JButton(")"));
            } else {
                buttonsPane.add(buttons[i]);
            }
        }

        pane.add(new JLabel("Text box"));
        pane.add(buttonsPane);

        frame.add(pane);
        frame.pack();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new GridLayoutWithEmptyComponents()::createAndShowGUI);
    }
}

Or you could have all the data in a String[] like:

String[] buttonValues = {"1", "2", "3", ..., "8", "9", "(", "0", ")"};

And then use those values as the JButtons values without the need for an if-else inside the loop.