Following example shows how to use GrigBagLayout. We are going to create a Builder class which will ease the work to develop a form.

Example

The Builder class

package com.logicbig.uicommon;

import javax.swing.*;
import java.awt.*;
import java.util.function.Consumer;

public class FormBuilder {
    private final Container container;
    private int row;
    private int col = -1;
    private GridBagConstraints labelCons;

    private FormBuilder(Container container) {
        this.container = container;
        container.setLayout(new GridBagLayout());
    }

    public static FormBuilder init(Container container) {
        FormBuilder builder = new FormBuilder(container);
        return builder;
    }

    private void initLabelCons() {
        labelCons = new GridBagConstraints();
        labelCons.weightx = 0;
        labelCons.gridwidth = 1;
        labelCons.ipadx = 1;
        labelCons.anchor = GridBagConstraints.NORTHEAST;
    }

    //add component without label
    public FormBuilder add(JComponent comp) {
        this.add(null, comp, null);
        return this;
    }

    //add component without label and allow caller to set constraints
    @SafeVarargs
    public final FormBuilder add(JComponent comp, Consumer<GridBagConstraints>... consSetters) {
        this.add(null, comp, consSetters);
        return this;
    }

    //add component with label and allow caller to set constraints
    @SafeVarargs
    public final FormBuilder add(String label, JComponent comp, Consumer<GridBagConstraints>... consSetters) {
        if (label != null) {
            if (this.labelCons == null) {
                initLabelCons();
            }
            JLabel jLabel = new JLabel(label);
            labelCons.gridx = ++col;
            labelCons.gridy = row;
            container.add(jLabel, labelCons);
        }
        GridBagConstraints cons = new GridBagConstraints();
        cons.gridx = ++col;
        cons.gridy = row;
        cons.fill = GridBagConstraints.BOTH;//by default fill the available grid space
        cons.insets = new Insets(0, 5, 5, 0);
        if (consSetters != null) {//allow client side to set constraints
            for (Consumer<GridBagConstraints> cs : consSetters) {
                cs.accept(cons);
            }
        }
        container.add(comp, cons);
        return this;
    }

    //add multiple labels in current row
    public FormBuilder addLabelsAsRowHeading(String... labels) {
        GridBagConstraints cons = new GridBagConstraints();
        cons.gridy = row;
        for (String label : labels) {
            cons.gridx = ++col;
            JLabel jLabel = new JLabel(label);
            container.add(jLabel, cons);
        }
        return this;
    }

   //start new row
    public FormBuilder newRow() {
        ++row;
        col = -1;
        return this;
    }

    //skip columns
    public FormBuilder skipColumns(int columns) {
        col+=columns;
        return this;
    }

    /**
     * Methods to set constraints, Useful when used as Java 8 method reference
     */
    //horizontal span 2
    public static void spanX2(GridBagConstraints c) {
        c.gridwidth = 2;
    }

    //horizontal span 3
    public static void spanX3(GridBagConstraints c) {
        c.gridwidth = 3;
    }

    //horizontal span 4
    public static void spanX4(GridBagConstraints c) {
        c.gridwidth = 4;
    }

    //vertical span 2
    public static void spanY2(GridBagConstraints c) {
        c.gridheight = 2;
    }

    //fills horizontally if parent resized
    public static void fillParentX(GridBagConstraints c) {
        c.weightx = 1;
    }

    //fills vertically if parent resized
    public static void fillParentY(GridBagConstraints c) {
        c.weighty = 1;
    }
    //todo add more if needed
}

Main class

public class GriBagLayoutExampleMain {
    public static void main(String[] args) {
        JPanel formPanel = createFormPanel();
        JFrame frame = createFrame();
        frame.add(formPanel);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    private static JPanel createFormPanel() {
        //initialize fields
        JTextField nameField = new JTextField(10);
        JTextField streetField = new JTextField(10),
                cityField = new JTextField(5), zipCodeField = new JTextField(5);
        JTextField phoneNumberField = new JTextField();
        JTextField ageField = new JTextField();
        JTextPane descriptionField = new JTextPane();
        descriptionField.setBorder(new LineBorder(Color.gray));
        JButton submitBtn = new JButton("Submit");

        //create panel
        JPanel panel = new JPanel();
        panel.setBorder(new EmptyBorder(10, 10, 10, 10));
        //using FormBuilder
        FormBuilder.init(panel)
                   .add("Full Name", nameField, FormBuilder::spanX3)
                   .newRow()
                   .addLabelsAsRowHeading("", "Street", "City", "Zip Code")
                   .newRow()
                   .add("Address", streetField).add(cityField).add(zipCodeField)
                   .newRow()
                   .add("Phone", phoneNumberField).add("Age", ageField)
                   .newRow()
                   .add("Description", descriptionField, FormBuilder::spanX3, FormBuilder::spanY2,
                           FormBuilder::fillParentY)
                   .newRow()
                   .newRow()
                   .skipColumns(2).add(submitBtn, FormBuilder::spanX2);

        return panel;
    }

    private static JFrame createFrame() {
        JFrame frame = new JFrame("GridBagLayout Builder");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(new Dimension(400, 300));
        return frame;
    }
}

Output

Example Project

Dependencies and Technologies Used:

• JDK 10
• Maven 3.5.4