org.eclipse.osbp.xtext.messagedsl/src/org/eclipse/osbp/xtext/messagedsl/internal/BasicTranslator.java

/**
 *                                                                            
 * Copyright (c) 2011, 2016 - Loetz GmbH&Co.KG (69115 Heidelberg, Germany)
 *                                                                            
 * All rights reserved. This program and the accompanying materials           
 * are made available under the terms of the Eclipse Public License v1.0       
 * which accompanies this distribution, and is available at                  
 * http://www.eclipse.org/legal/epl-v10.html                                 
 *                                                                            
 * Contributors:   
 * Christophe Loetz (Loetz GmbH&Co.KG) - initial implementation 
 */
package org.eclipse.osbp.xtext.messagedsl.internal;

import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;



/**
 */
public class BasicTranslator {
	
	@SuppressWarnings("unused")
	private static BasicTranslator INSTANCE = new BasicTranslator();

	/**
	 * get the translator key for the class and item
	 * @param clazz
	 * @param item
	 * @return translator key
	 */
	public static String getTranslatorKey(String object, String item) {
		return object+"."+item;
	}

	/**
	 * get the translator key for the class and item
	 * @param clazz
	 * @param item
	 * @return translator key
	 */
	public static String getTranslatorKey(Object object, String item) {
		return getTranslatorCanonicalName(object)+"."+item;
	}

	/**
	 * get the translator key for the class and item
	 * @param clazz
	 * @param item
	 * @return translator key
	 */
	public static String getTranslatorKey(Class<?> clazz, String item) {
		return getTranslatorCanonicalName(clazz)+"."+item;
	}
	
	/**
	 * @param object
	 * @return get the canonical class name used for the translator key
	 */
	private static String getTranslatorCanonicalName(Object object) {
		return getTranslatorCanonicalName(object.getClass());
	}

	private final static String IGNORE_IMPL_PREFIX = "Impl";
	private final static String IGNORE_IMPL_PACKAGE = ".impl.";
	private final static String IGNORE_MESSAGE_PACKAGE_NAME = "Message.";
	
	/**
	 * <ul>
	 * <li>Impl-prefix and impl-package part is removed</li>
	 * <li>Inner classes are handled with "normal" package separator</li>
	 * </ul>
	 * @param clazz the class
	 * @return get the canonical class name used for the translator key
	 */
	private static String getTranslatorCanonicalName(Class<?> clazz) {
		String result = clazz.getCanonicalName();
		if	(result.endsWith(IGNORE_IMPL_PREFIX)) {
			result = result.substring(0, result.length()-IGNORE_IMPL_PREFIX.length());
		}
		return result
				.replace('$','.')
				.replace(IGNORE_IMPL_PACKAGE,".")
				.replace(IGNORE_MESSAGE_PACKAGE_NAME,".");
	}
	
	/**
	 * one locale definition for all DSL-UI instances running in this Eclipse instance  
	 */
	private static Locale sLocale = Locale.getDefault();
	private static ResourceBundle sResourceBundle = null;
	
	/**
	 * @return the resource bundle with the translation property files of the DSL-UI-Bundle
	 */
	
	protected static ResourceBundle getResourceBundle() {
		if	((sResourceBundle == null) || !sLocale.equals(Locale.getDefault())) {
			sLocale = Locale.getDefault();
			sResourceBundle = java.util.ResourceBundle.getBundle("i18n.I18N", sLocale, BasicTranslator.class.getClassLoader());
		}
		return sResourceBundle;
	}
	
	/**
	 * Get the translated documentation for the key
	 * @param i18nKey
	 * @param i18nKeyFallBack
	 * @param warning true, if the information about missing translation or documentation should be shown
	 * @return
	 */
	public final static String translate(String i18nKey, String i18nKeyFallBack, String defaultTranslation) {
		i18nKey = i18nKey.replace('_', '.');
		// --- get the translated documentation
		try {
			String result = getResourceBundle().getString(i18nKey);
			if	((result instanceof String) && !result.isEmpty()) {
				return result;
			}
		}
		catch (MissingResourceException mre) {
		}
		if	(i18nKeyFallBack != null) {
			i18nKeyFallBack = i18nKeyFallBack.replace('_', '.');
		}
		try {
			String result = getResourceBundle().getString(i18nKeyFallBack);
			if	((result instanceof String) && !result.isEmpty()) {
				return result;
			}
		}
		catch (MissingResourceException mre) {
		}
		System.err.println("- missing translation: "+sLocale.toString()+" / "+i18nKey+" "+i18nKeyFallBack);
		return defaultTranslation;
	}
}