StoreUI + GridBagLayout

Launcher.java

package lesson5_8.shop;


public class Launcher {

    public static void main(String[] args) {

        Store store = new Store();
        new StoreUI(store);
    }
}

StoreUI.java

package lesson5_8.shop;


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

public class StoreUI {

    private Store store;

    public StoreUI(Store store) {

        this.store = store;

        JFrame frame = new JFrame("STORE");
        frame.setMinimumSize(new Dimension(800, 600));
        frame.setLocation(300, 200);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(createSellingPanel());
        frame.pack();
        frame.setVisible(true);
    }

    private JPanel createSellingPanel() {

        JPanel panel = new JPanel();
        panel.setBackground(Color.CYAN);
        GridBagLayout gbl = new GridBagLayout();
        panel.setLayout(gbl);

        GridBagConstraints c = new GridBagConstraints();
        c.anchor = GridBagConstraints.NORTHWEST;
        c.fill   = GridBagConstraints.NONE;
        c.gridheight = 1;
        c.gridwidth  = 1;
        c.gridx = GridBagConstraints.RELATIVE;
        c.gridy = GridBagConstraints.RELATIVE;
        c.insets = new Insets(10, 0, 0, 0);
        c.ipadx = 0;
        c.ipady = 0;
        c.weightx = 0.0;
        c.weighty = 0.0;

        JLabel jName = new JLabel("Enter name: ");
        JTextField jTField = new JTextField(30);
        gbl.setConstraints(jName, c);
        c.gridwidth = GridBagConstraints.REMAINDER;
        gbl.setConstraints(jTField, c);

        panel.add(jName);
        panel.add(jTField);

        JLabel jBirds = new JLabel("Birds");
        JPanel jPBirds = new JPanel();
        jPBirds.setBorder(BorderFactory.createLineBorder(Color.BLUE));
        GridLayout birdsLayout = new GridLayout(3, 0);
        jPBirds.setLayout(birdsLayout);
        JRadioButton bird1Button = new JRadioButton("bird1");
        JRadioButton bird2Button = new JRadioButton("bird2");
        JRadioButton bird3Button = new JRadioButton("bird3");

        ButtonGroup group = new ButtonGroup();
        group.add(bird1Button);
        group.add(bird2Button);
        group.add(bird3Button);
        jPBirds.add(bird1Button);
        jPBirds.add(bird2Button);
        jPBirds.add(bird3Button);

        c.gridwidth = 1;
        gbl.setConstraints(jBirds, c);
        c.gridwidth = GridBagConstraints.REMAINDER;
        gbl.setConstraints(jPBirds, c);

        panel.add(jBirds);
        panel.add(jPBirds);

        JLabel jNumber = new JLabel("Enter quantity: ");
        NumberFormat nf = NumberFormat.getInstance();
        JFormattedTextField jTField2 = new JFormattedTextField(nf);
        jTField2.setValue(1);
        c.gridwidth = 1;
        gbl.setConstraints(jNumber, c);
        c.gridwidth = GridBagConstraints.REMAINDER;
        gbl.setConstraints(jTField2, c);

        panel.add(jNumber);
        panel.add(jTField2);

        JButton buyButton = new JButton("BUY");
        c.ipadx = 100;
        c.anchor = GridBagConstraints.CENTER;
        gbl.setConstraints(buyButton, c);

        panel.add(buyButton);

        return panel;
    }
}