i18n-swing

Swing bindings for the i18n-core internationalization framework.

This library provides locale-aware Swing components that automatically update their text, icons, fonts, mnemonics, tooltips, and accessibility attributes when the application locale changes.

Requirements

• Java 17 or later
• i18n-core 1.4.1 or later (pulled in transitively)

Installation

Maven

<dependency>
    <groupId>dev.javai18n</groupId>
    <artifactId>i18n-swing</artifactId>
    <version>1.2.3</version>
</dependency>

Module Declaration

module my.module
{
    requires dev.javai18n.swing;
}

Components

Localizable top-level containers

These classes serve as the locale-event source for all Resourceful components they own. They implement Localizable and dispatch locale events on the EDT when setBundleLocale() is called.

Class	Extends	Notes
LocalizableJFrame	JFrame	Standard application frame; bundle key "windowProperties" uses FramePropertyBundle
LocalizableJDialog	JDialog	Modal or non-modal dialog; bundle key "windowProperties" uses FramePropertyBundle
LocalizableJWindow	JWindow	Undecorated window; bundle key "windowProperties" uses WindowPropertyBundle

Resourceful components

All Resourceful components implement Resourceful and LocaleEventListener. Each receives an updateLocaleSpecificValues() call on the EDT whenever its source fires a locale change.

The base set of localized properties for every Resourceful component is: name, tooltip, font, accessible name, accessible description (from JComponentPropertyBundle). Additional properties are noted in the table below.

Buttons and toggles

Class	Extends	Additional Localized Properties
ResourcefulJButton	JButton	text, label, mnemonic, 7 icon types
ResourcefulJCheckBox	JCheckBox	text, label, mnemonic, 7 icon types
ResourcefulJRadioButton	JRadioButton	text, label, mnemonic, 7 icon types
ResourcefulJToggleButton	JToggleButton	text, label, mnemonic, 7 icon types

Menus

Class	Extends	Additional Localized Properties
ResourcefulJMenu	JMenu	text, label, mnemonic, 7 icon types
ResourcefulJMenuBar	JMenuBar	—
ResourcefulJMenuItem	JMenuItem	text, label, mnemonic, 7 icon types
ResourcefulJCheckBoxMenuItem	JCheckBoxMenuItem	text, label, mnemonic, 7 icon types
ResourcefulJRadioButtonMenuItem	JRadioButtonMenuItem	text, label, mnemonic, 7 icon types
ResourcefulJPopupMenu	JPopupMenu	—
ResourcefulJPopupMenuSeparator	JPopupMenu.Separator	—

Text components

Class	Extends	Additional Localized Properties
ResourcefulJTextField	JTextField	—
ResourcefulJTextArea	JTextArea	—
ResourcefulJEditorPane	JEditorPane	—
ResourcefulJTextPane	JTextPane	—
ResourcefulJPasswordField	JPasswordField	—
ResourcefulJFormattedTextField	JFormattedTextField	—

Data and selection

Class	Extends	Additional Localized Properties
ResourcefulJComboBox	JComboBox	item values (string array)
ResourcefulJList	JList	—
ResourcefulJSpinner	JSpinner	—
ResourcefulJSlider	JSlider	—
ResourcefulJTree	JTree	—
ResourcefulJTable	JTable	—
ResourcefulJTableHeader	JTableHeader	—
ResourcefulJProgressBar	JProgressBar	progress string
ResourcefulJScrollBar	JScrollBar	—
ResourcefulJColorChooser	JColorChooser	—
ResourcefulJFileChooser	JFileChooser	dialog title, approve button text, approve button tooltip

Panes and containers

Class	Extends	Additional Localized Properties
ResourcefulJPanel	JPanel	—
ResourcefulJScrollPane	JScrollPane	—
ResourcefulJSplitPane	JSplitPane	—
ResourcefulJTabbedPane	JTabbedPane	tab titles, tab tooltips, tab icons (per-tab via JTabbedPaneTabPropertyBundle)
ResourcefulJInternalFrame	JInternalFrame	title, frame icon
ResourcefulJLayeredPane	JLayeredPane	—
ResourcefulJDesktopPane	JDesktopPane	—
ResourcefulJDesktopIcon	JDesktopIcon	—
ResourcefulJRootPane	JRootPane	—
ResourcefulJViewport	JViewport	—
ResourcefulJOptionPane	JOptionPane	dialog title, button option labels

Layout helpers and decorators

Class	Extends	Additional Localized Properties
ResourcefulBox	Box	—
ResourcefulBoxFiller	Box.Filler	—
ResourcefulJLabel	JLabel	text, mnemonic, icon, disabled icon
ResourcefulJSeparator	JSeparator	—
ResourcefulJToolBar	JToolBar	—
ResourcefulJToolBarSeparator	JToolBar.Separator	—
ResourcefulJToolTip	JToolTip	tip text

Spinner editors

Class	Extends	Additional Localized Properties
ResourcefulJSpinnerDefaultEditor	JSpinner.DefaultEditor	—
ResourcefulJSpinnerDateEditor	JSpinner.DateEditor	—
ResourcefulJSpinnerNumberEditor	JSpinner.NumberEditor	—
ResourcefulJSpinnerListEditor	JSpinner.ListEditor	—

Utility menu items

Class	Extends	Description
LocaleJMenuItem	ResourcefulJMenuItem	Displays a locale name; sets the application locale when selected
LookAndFeelJMenuItem	ResourcefulJMenuItem	Displays a Look and Feel name; applies it when selected

Property Bundles

Property bundles are typed AttributeCollection implementations that carry the localized values read from a JSON or XML resource file. No code generation or compilation step is needed to add new bundle entries.

Bundle	Extends	Fields
ComponentPropertyBundle	—	name, font, accessible name, accessible description
JComponentPropertyBundle	ComponentPropertyBundle	+ tooltip
ButtonPropertyBundle	ComponentPropertyBundle	+ label
AbstractButtonPropertyBundle	JComponentPropertyBundle	+ text, label, mnemonic, icon, pressed icon, selected icon, disabled icon, disabled selected icon, rollover icon, rollover selected icon
JLabelPropertyBundle	JComponentPropertyBundle	+ text, mnemonic, icon, disabled icon
JComboBoxPropertyBundle	JComponentPropertyBundle	+ values (string array)
JProgressBarPropertyBundle	JComponentPropertyBundle	+ progress string
JInternalFramePropertyBundle	JComponentPropertyBundle	+ title, frame icon
JTabbedPaneTabPropertyBundle	—	tab title, tab tooltip, tab icon (one entry per tab)
JOptionPanePropertyBundle	JComponentPropertyBundle	+ title, options (string array)
JFileChooserPropertyBundle	JComponentPropertyBundle	+ dialog title, approve button text, approve button tooltip
JToolTipPropertyBundle	JComponentPropertyBundle	+ tip text
WindowPropertyBundle	ComponentPropertyBundle	+ icon images (list)
FramePropertyBundle	WindowPropertyBundle	+ title

Quick Start

1. Create a Localizable frame subclass

public class MyFrame extends LocalizableJFrame
{
    static
    {
        MyModuleRegistrar.ensureRegistered();
    }

    @Override
    public Locale[] getAvailableLocales()
    {
        return new Locale[]{ Locale.ROOT, Locale.FRANCE };
    }
}

2. Define a resource bundle

MyFrameBundle.json:

{
    "okButton":
    {
        "type": "dev.javai18n.swing.AbstractButtonPropertyBundle",
        "Text": "OK",
        "Mnemonic": 79
    }
}

MyFrameBundle_fr.json:

{
    "okButton":
    {
        "type": "dev.javai18n.swing.AbstractButtonPropertyBundle",
        "Text": "D'accord",
        "Mnemonic": 68
    }
}

3. Create a Resourceful component

MyFrame myFrame = MyFrame.create();
Resource okResource = new Resource(myFrame, "okButton");
ResourcefulJButton okButton = ResourcefulJButton.create(okResource);

The button displays the correct text, mnemonic, and other properties for the current locale. When myFrame.setBundleLocale(locale) is called, every attached Resourceful component updates itself on the Event Dispatch Thread.

Sample Application

A complete file explorer example is provided in the test sources to demonstrate the library end to end.

Main class: dev.javai18n.swing.test.TestSwingApp Frame class: dev.javai18n.swing.test.AppFrame

Launch it from an IDE or via Maven:

mvn test-compile exec:java -Dexec.classpathScope=test \
    -Dexec.mainClass=dev.javai18n.swing.test.TestSwingApp

The application starts with the system Look and Feel and opens at the user's home directory.

What it demonstrates

• Locale switching — Preferences > Locale menu lists the locales supported by the application logger by default, or all JVM locales when "All JVM Locales" is selected. Choosing a locale updates every label, tooltip, column header, button text, and dialog message simultaneously on the EDT.
• Look and Feel switching — Preferences > Look and Feel menu lists all installed Look and Feels; selecting one applies it immediately without restarting.
• File system navigation — a directory tree (ResourcefulJTree) on the left and a file table (ResourcefulJTable) on the right, connected by Back, Forward, Up, and Home toolbar buttons (ResourcefulJButton) and a path text field (ResourcefulJTextField).
• Sortable file table — sort by name, size, or date via View > Sort By radio menu items (ResourcefulJRadioButtonMenuItem); show or hide hidden files and file extensions via View check box menu items (ResourcefulJCheckBoxMenuItem).
• List and detail views — toggle buttons (ResourcefulJToggleButton) switch between a table view and a list view (ResourcefulJList).
• Preview tab — displays a selected text file as plain text (ResourcefulJTextArea) or as rendered HTML (ResourcefulJEditorPane), presented in a tabbed pane (ResourcefulJTabbedPane).
• Properties panel — an internal frame (ResourcefulJInternalFrame) shows the selected file's name, size, type, and modification date, all formatted for the current locale.
• Context menu — right-clicking the file table opens a popup menu (ResourcefulJPopupMenu) with localized actions.
• Localized dialogs — the New Folder and Delete Confirmation actions use ResourcefulJOptionPane instances whose title and button labels come from the resource bundle.
• Widgets tab — exercises the remaining component types: ResourcefulJPasswordField, ResourcefulJFormattedTextField (date/time), ResourcefulJSpinner (date), ResourcefulJSlider (with locale-formatted tick labels), ResourcefulJList (day-of-week names from DateFormatSymbols), and ResourcefulJTextPane (styled text).

All localized strings live in AppFrameBundle.json and its locale variants (AppFrameBundle_en.json, AppFrameBundle_fr.json, etc.).

Building

mvn clean package

To build with sources JAR, javadoc JAR, and GPG signing for release:

mvn -Prelease clean package

Testing

To execute unit tests on the classpath (default):

mvn clean test

To execute unit tests under JPMS:

mvn clean test -Ptest-modulepath

Default Locale and Surefire

LocalizationDelegate initializes its locale field from Locale.getDefault() at construction time. Passing -Duser.language=fr to Maven on the command line does not change Locale.getDefault() in the forked Surefire JVM: Surefire propagates Maven -D system properties via System.setProperty() inside the already-running JVM, after the default locale has been initialized by the JVM startup sequence.

To ensure tests pass regardless of the OS default locale, every create() factory method in test-only Localizable classes (TestComponentSource, AppWindow, AppDialog) calls setBundleLocale(Locale.ROOT) immediately after construction. Tests that call ResourceBundle.getBundle() and assert English string values pass Locale.ROOT explicitly rather than using the no-locale overload.

When writing new tests that assert string values from a bundle, always pin the locale explicitly (e.g. setBundleLocale(Locale.ROOT)) rather than relying on Locale.getDefault().

License

This project is licensed under the Apache License, Version 2.0.