Distribution of components in GroupLayout

The example below has a GroupLayout that contains two elements, a custom search and filter bar ( JPanelSearchAndFilter ) and a JScrollPane .

When it is run and then the window is maximized you can see that these two elements are evenly distributed on the screen.

When you select any item in the combo box, the screen fills with lines of text and the search and filter bar becomes smaller on the screen, making room for lines of text.

I'd like to know how to make this toolbar smaller in size from the start of execution. Preferably without using a BorderLayout for this.

I thought about setting the size of JScrollPane or filling it with invisible items, but this seems to me to be gambiarra. I believe a solution is possible using layout managers .

GroupPanel.java

import java.awt.EventQueue;
import java.awt.Font;

import javax.swing.BoxLayout;
import javax.swing.GroupLayout.Alignment;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;

public class GroupPanel extends JPanel implements Listener   {

    private static final long serialVersionUID = 1L;

    private JPanelSearchAndFilter jPanelSearchAndFilter = new JPanelSearchAndFilter();
    private JPanel jPanelListaOrders = new JPanel();
    private JScrollPane jScrollPaneOrders = new JScrollPane(jPanelListaOrders);

    public GroupPanel() {

        javax.swing.GroupLayout jPanelMainLayout = new javax.swing.GroupLayout(this);

        jPanelMainLayout.setHorizontalGroup(jPanelMainLayout.createParallelGroup(Alignment.LEADING)
                .addGroup(jPanelMainLayout.createSequentialGroup()
                        .addGroup(jPanelMainLayout.createParallelGroup(Alignment.LEADING)
                                .addComponent(jPanelSearchAndFilter)
                                .addComponent(jScrollPaneOrders))
                        ));

        jPanelMainLayout.setVerticalGroup(jPanelMainLayout.createParallelGroup(Alignment.LEADING)
                .addGroup(jPanelMainLayout.createSequentialGroup().addGroup(
                        jPanelMainLayout.createParallelGroup(Alignment.LEADING)
                        .addGroup(jPanelMainLayout.createSequentialGroup()
                                .addComponent(jPanelSearchAndFilter)
                                .addComponent(jScrollPaneOrders)))));

        this.setLayout(jPanelMainLayout);

        jPanelListaOrders.setBackground(new java.awt.Color(254, 254, 254));
        jPanelListaOrders.setLayout(new javax.swing.BoxLayout(jPanelListaOrders, javax.swing.BoxLayout.Y_AXIS));

        jPanelSearchAndFilter.setListener(this);
    }

    private static void display() {
        JFrame f = new JFrame("GroupPanel");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setLayout(new BoxLayout(f.getContentPane(), BoxLayout.Y_AXIS));
        f.add(new GroupPanel());
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                display();
            }
        });
    }

    @Override
    public void onEvent(String event) {
        for (int i = 1; i <= 10; i++) {
            JLabel label = new JLabel(event + " " + i);
            label.setFont(new Font("Tahoma", Font.BOLD, 60));
            jPanelListaOrders.add(label);
        }

        revalidate();
        repaint();
    }
}

JPanelSearchAndFilter.java

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.util.Objects;

import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.ComboBoxModel;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class JPanelSearchAndFilter extends JPanel {

    private static final String [] ORDER_STATUSES = {
            "Todos",
            "Novos",
            "Confirmados",
            "Prontos/Enviados",
            "Entregues",
            "Cancelados"
            };

    private Listener listener = null;

    public JPanelSearchAndFilter() {

        setForeground(Color.GRAY);
        setLayout(new BoxLayout(this, BoxLayout.X_AXIS));

        setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));

        searchField = new JTextField("Pesquisar");
        searchField.setForeground(Color.GRAY);
        searchField.setFont(new Font("Tahoma", Font.PLAIN, 15));
        searchField.setToolTipText("Pesquisar");
        add(searchField);
        searchField.setColumns(10);

        // Cria um espaço vazio de tamanho fixo entre searchField e filterComboBox.
        add(Box.createRigidArea(new Dimension(20, 0)));

        ComboBoxModel<String> filterComboModel = new DefaultComboBoxModel<>(ORDER_STATUSES);
        JComboBox<String> filterComboBox = new JComboBox<>(filterComboModel);
        filterComboBox.setFont(new Font("Tahoma", Font.PLAIN, 15));
        filterComboBox.setSelectedIndex(0);

        filterComboBox.addItemListener(new ItemListener() {
            @Override
            public void itemStateChanged(ItemEvent itemEvent) {
                JPanelSearchAndFilter.this.listener.onEvent((String)itemEvent.getItem());
            }
        });

        add(filterComboBox);
    }

    public void setListener(Listener listener) {
        this.listener = listener;
    }

    private static final long serialVersionUID = 1L;
    private JTextField searchField;
}

Listener.java

public interface Listener {
    public void onEvent(String event);
}