I'm developing a JavaFX application with multiple language support. My app sometimes shows an alert box, for example:
package application;
import java.util.Locale;
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.control.Button;
import javafx.scene.control.Alert.AlertType;
import javafx.scene.layout.BorderPane;
public class Main extends Application {
@Override
public void start(Stage primaryStage) {
try {
Button btn = new Button("Show alert");
btn.setOnAction(this::handleButton);
BorderPane root = new BorderPane();
root.setCenter(btn);
Scene scene = new Scene(root,200, 200);
primaryStage.setScene(scene);
primaryStage.show();
} catch(Exception e) {
e.printStackTrace();
}
}
void handleButton(ActionEvent e){
Alert alert = new Alert(AlertType.CONFIRMATION);
alert.showAndWait();
}
static Locale getLocaleSettingFromConfigurationFile(){
return Locale.FRENCH;
//return new Locale("vi");
}
public static void main(String[] args) {
Locale appLocale = getLocaleSettingFromConfigurationFile();
Locale.setDefault(appLocale);
launch(args);
}
}
The language setting is obtained via getLocaleSettingFromConfigurationFile() method
In the code above, I used Locale.FRENCH as app language and everything works file:
Two confirm buttons have been translated to French.
Now I want my app to support Vietnamese as well (uncomment return new Locale("vi") from the code above). After digging into details, I found that:
->Two confirm button "Ok", "Cancel" are constructed from:
package javafx.scene.control;
import com.sun.javafx.scene.control.skin.resources.ControlResources;
import javafx.beans.NamedArg;
import javafx.scene.control.Button;
import javafx.scene.control.ButtonBar.ButtonData;
/**
* The ButtonType class is used as part of the JavaFX {@link Dialog} API (more
* specifically, the {@link DialogPane} API) to specify which buttons should be
* shown to users in the dialogs. Refer to the {@link DialogPane} class javadoc
* for more information on how to use this class.
*
* @see Alert
* @see Dialog
* @see DialogPane
* @since JavaFX 8u40
*/
public final class ButtonType {
/**
* A pre-defined {@link ButtonType} that displays "Apply" and has a
* {@link ButtonData} of {@link ButtonData#APPLY}.
*/
public static final ButtonType APPLY = new ButtonType(
"Dialog.apply.button", null, ButtonData.APPLY);
/**
* A pre-defined {@link ButtonType} that displays "OK" and has a
* {@link ButtonData} of {@link ButtonData#OK_DONE}.
*/
public static final ButtonType OK = new ButtonType(
"Dialog.ok.button", null, ButtonData.OK_DONE);
/**
* A pre-defined {@link ButtonType} that displays "Cancel" and has a
* {@link ButtonData} of {@link ButtonData#CANCEL_CLOSE}.
*/
public static final ButtonType CANCEL = new ButtonType(
"Dialog.cancel.button", null, ButtonData.CANCEL_CLOSE);
/**
* A pre-defined {@link ButtonType} that displays "Close" and has a
* {@link ButtonData} of {@link ButtonData#CANCEL_CLOSE}.
*/
public static final ButtonType CLOSE = new ButtonType(
"Dialog.close.button", null, ButtonData.CANCEL_CLOSE);
/**
* A pre-defined {@link ButtonType} that displays "Yes" and has a
* {@link ButtonData} of {@link ButtonData#YES}.
*/
public static final ButtonType YES = new ButtonType(
"Dialog.yes.button", null, ButtonData.YES);
/**
* A pre-defined {@link ButtonType} that displays "No" and has a
* {@link ButtonData} of {@link ButtonData#NO}.
*/
public static final ButtonType NO = new ButtonType(
"Dialog.no.button", null, ButtonData.NO);
/**
* A pre-defined {@link ButtonType} that displays "Finish" and has a
* {@link ButtonData} of {@link ButtonData#FINISH}.
*/
public static final ButtonType FINISH = new ButtonType(
"Dialog.finish.button", null, ButtonData.FINISH);
/**
* A pre-defined {@link ButtonType} that displays "Next" and has a
* {@link ButtonData} of {@link ButtonData#NEXT_FORWARD}.
*/
public static final ButtonType NEXT = new ButtonType(
"Dialog.next.button", null, ButtonData.NEXT_FORWARD);
/**
* A pre-defined {@link ButtonType} that displays "Previous" and has a
* {@link ButtonData} of {@link ButtonData#BACK_PREVIOUS}.
*/
public static final ButtonType PREVIOUS = new ButtonType(
"Dialog.previous.button", null, ButtonData.BACK_PREVIOUS);
private final String key;
private final String text;
private final ButtonData buttonData;
/**
* Creates a ButtonType instance with the given text, and the ButtonData set
* as {@link ButtonData#OTHER}.
*
* @param text The string to display in the text property of controls such
* as {@link Button#textProperty() Button}.
*/
public ButtonType(@NamedArg("text") String text) {
this(text, ButtonData.OTHER);
}
/**
* Creates a ButtonType instance with the given text, and the ButtonData set
* as specified.
*
* @param text The string to display in the text property of controls such
* as {@link Button#textProperty() Button}.
* @param buttonData The type of button that should be created from this ButtonType.
*/
public ButtonType(@NamedArg("text") String text,
@NamedArg("buttonData") ButtonData buttonData) {
this(null, text, buttonData);
}
/**
* Provide key or text. The other one should be null.
*/
private ButtonType(String key, String text, ButtonData buttonData) {
this.key = key;
this.text = text;
this.buttonData = buttonData;
}
/**
* Returns the ButtonData specified for this ButtonType in the constructor.
*/
public final ButtonData getButtonData() { return this.buttonData; }
/**
* Returns the text specified for this ButtonType in the constructor;
*/
public final String getText() {
if (text == null && key != null) {
return ControlResources.getString(key);
} else {
return text;
}
}
/** {@inheritDoc} */
@Override public String toString() {
return "ButtonType [text=" + getText() + ", buttonData=" + getButtonData() + "]";
}
}
->The button displaying text is rendered from ControlResources.getString(key), its source code:
package com.sun.javafx.scene.control.skin.resources;
import java.util.ResourceBundle;
public final class ControlResources {
// Translatable properties
private static final String BASE_NAME = "com/sun/javafx/scene/control/skin/resources/controls";
// Non-translateable properties
private static final String NT_BASE_NAME = "com/sun/javafx/scene/control/skin/resources/controls-nt";
// Do not cache the bundle here. It is cached by the ResourceBundle
// class and may be updated if the default locale changes.
private ControlResources() {
// no-op
}
/*
* Look up a string in the properties file corresponding to the
* default locale (i.e. the application's locale). If not found, the
* search then falls back to the base controls.properties file,
* containing the default string (usually English).
*/
public static String getString(String key) {
return ResourceBundle.getBundle(BASE_NAME).getString(key);
}
/*
* Look up a non-translatable string in the properties file
* corresponding to the default locale (i.e. the application's
* locale). If not found, the search then falls back to the base
* controls-nt.properties file, containing the default string.
*
* Note that property values may be set in locale-specific files,
* e.g. when a property value is defined for a country rather than
* a language. However, there are no such files included with
* JavaFX 8, but may be added to the classpath by developers or
* users.
*/
public static String getNonTranslatableString(String key) {
return ResourceBundle.getBundle(NT_BASE_NAME).getString(key);
}
}
Now, I tried my solution as follow:
Step 1: create Vietnamese resource file com/sun/javafx/scene/control/skin/resources/controls_vi.properties in the project
### Dialogs ###
Dialog.apply.button = Áp d\u1EE5ng
Dialog.ok.button = OK
Dialog.close.button = \u0110óng
Dialog.cancel.button = H\u1EE7y b\u1ECF
Dialog.yes.button = Có
Dialog.no.button = Không
Dialog.finish.button = Hoàn thành
Dialog.next.button = Ti\u1EBFp
Dialog.previous.button = Tr\u01B0\u1EDBc
After lauching the app, the button language still English.
Step 2: I figured out that the class loader to load JavaFx resource file is differ from my app class loader (see ResourceBundle.getBundle(BASE_NAME) API). This is resource inside jfxrt.jar:
I tried to load the ControlResources class with application class loader but still no result:
public static void main(String[] args) throws Exception {
List<Locale> fxSupported = Arrays.asList(Locale.ENGLISH, Locale.FRENCH); // Add later ....
Locale appLocale = getLocaleSettingFromConfigurationFile();
Locale.setDefault(appLocale);
// Load class from current class loader
if (!fxSupported.contains(appLocale)){
ClassLoader loader = Main.class.getClassLoader();
Class<?> loadedCls = Class.forName("com.sun.javafx.scene.control.skin.resources.ControlResources", true, loader);
System.out.printf("Loader 1: %s\nloader 2: %s\n", loader, loadedCls.getClassLoader());
// Loader 1: sun.misc.Launcher$AppClassLoader@73d16e93
// loader 2: sun.misc.Launcher$ExtClassLoader@6d06d69c
}
launch(args);
}
Fallback solution
I can create my own ButtonType "OK", "Cancel" and load my own resource string, the set created button list to the Alert object, but I want to use the system provided resource instead.
ResourceBundle res = ResourceBundle.getBundle("application.myownres");
ButtonType OK = new ButtonType(res.getString("btn.ok"), ButtonData.OK_DONE);
ButtonType CANCEL = new ButtonType(res.getString("btn.cancel"), ButtonData.CANCEL_CLOSE);
Alert alert = new Alert(AlertType.CONFIRMATION, "Are you sure", OK, CANCEL);
alert.showAndWait();
So, anyone has solution that does not need to create new ButtonType object.
Thanks
java -Xbootclasspath/a:my-translations.jar -cp .... Whether it is worth it over the custom button type... I don't know! – Alluvial