org.eclipse.babel.editor/src/org/eclipse/pde/nls/internal/ui/model/ResourceBundle.java

/*******************************************************************************
 * Copyright (c) 2008 Stefan M�cke and others.
 * 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:
 *     Stefan M�cke - initial API and implementation
 *******************************************************************************/
package org.eclipse.pde.nls.internal.ui.model;

import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Locale;
import java.util.Map.Entry;
import java.util.Properties;
import java.util.Set;

import org.eclipse.babel.editor.plugin.MessagesEditorPlugin;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.jdt.core.IJarEntryResource;

/**
 * A <code>ResourceBundle</code> represents a single <code>.properties</code>
 * file.
 * <p>
 * <code>ResourceBundle</code> implements lazy loading. A bundle will be loaded
 * automatically when its entries are accessed. It can through the parent model
 * by calling {@link ResourceBundleModel#unloadBundles(Locale)} with the proper
 * locale.
 * </p>
 */
public class ResourceBundle extends ResourceBundleElement {

    private static boolean debug = false;

    /**
     * The bundle's locale.
     */
    private Locale locale;
    /**
     * The underlying resource. Either an {@link IFile} or an
     * {@link IJarEntryResource}.
     */
    private Object resource;

    private HashMap<String, String> entries;

    public ResourceBundle(ResourceBundleFamily parent, Object resource,
            Locale locale) {
        super(parent);
        this.resource = resource;
        this.locale = locale;
        if (locale == null)
            throw new IllegalArgumentException("Locale may not be null.");
    }

    /**
     * Returns the family to which this bundle belongs.
     * 
     * @return the family to which this bundle belongs
     */
    public ResourceBundleFamily getFamily() {
        return (ResourceBundleFamily) super.getParent();
    }

    /**
     * Returns the locale.
     * 
     * @return the locale
     */
    public Locale getLocale() {
        return locale;
    }

    public String getString(String key) throws CoreException {
        load();
        return entries.get(key);
    }

    /**
     * Returns the underlying resource. This may be an {@link IFile} or an
     * {@link IJarEntryResource}.
     * 
     * @return the underlying resource (an {@link IFile} or an
     *         {@link IJarEntryResource})
     */
    public Object getUnderlyingResource() {
        return resource;
    }

    protected boolean isLoaded() {
        return entries != null;
    }

    public void load() throws CoreException {
        if (isLoaded())
            return;
        entries = new HashMap<String, String>();

        if (resource instanceof IFile) {
            if (debug) {
               System.out.println("Loading " + resource + "...");
            }
            IFile file = (IFile) resource;
            InputStream inputStream = file.getContents();
            Properties properties = new Properties();
            try {
                properties.load(inputStream);
                putAll(properties);
            } catch (IOException e) {
                MessagesEditorPlugin.log("Error reading property file.", e);
            }
        } else if (resource instanceof IJarEntryResource) {
            IJarEntryResource jarEntryResource = (IJarEntryResource) resource;
            InputStream inputStream = jarEntryResource.getContents();
            Properties properties = new Properties();
            try {
                properties.load(inputStream);
                putAll(properties);
            } catch (IOException e) {
                MessagesEditorPlugin.log("Error reading property file.", e);
            }
        } else {
            MessagesEditorPlugin.log("Unknown resource type.",
                    new RuntimeException());
        }
    }

    protected void unload() {
        entries = null;
    }

    public boolean isReadOnly() {
        if (resource instanceof IJarEntryResource)
            return true;
        if (resource instanceof IFile) {
            IFile file = (IFile) resource;
            return file.isReadOnly() || file.isLinked();
        }
        return false;
    }

    protected void putAll(Properties properties) throws CoreException {
        Set<Entry<Object, Object>> entrySet = properties.entrySet();
        Iterator<Entry<Object, Object>> iter = entrySet.iterator();
        ResourceBundleFamily family = getFamily();
        while (iter.hasNext()) {
            Entry<Object, Object> next = iter.next();
            Object key = next.getKey();
            Object value = next.getValue();
            if (key instanceof String && value instanceof String) {
                String stringKey = (String) key;
                entries.put(stringKey, (String) value);
                family.addKey(stringKey);
            }
        }
    }

    public void put(String key, String value) throws CoreException {
        load();
        ResourceBundleFamily family = getFamily();
        entries.put(key, value);
        family.addKey(key);
    }

    public String[] getKeys() throws CoreException {
        load();
        Set<String> keySet = entries.keySet();
        return keySet.toArray(new String[keySet.size()]);
    }

}