resourcebundlesupport.java

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package org.jfree.util;

import java.awt.Image;
import java.awt.Toolkit;
import java.awt.event.InputEvent;
import java.awt.event.KeyEvent;
import java.awt.image.BufferedImage;
import java.lang.reflect.Field;
import java.net.URL;
import java.text.MessageFormat;
import java.util.Arrays;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import java.util.TreeMap;
import java.util.TreeSet;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JMenu;
import javax.swing.KeyStroke;

/**
 * An utility class to ease up using property-file resource bundles.
 * <p/>
 * The class support references within the resource bundle set to minimize the occurence
 * of duplicate keys. References are given in the format:
 * <pre>
 * a.key.name=@referenced.key
 * </pre>
 * <p/>
 * A lookup to a key in an other resource bundle should be written by
 * <pre>
 * a.key.name=@@[e-mail]
 * </pre>
 *
 * @author Thomas Morgner
 */
public class ResourceBundleSupport {
    /**
     * The resource bundle that will be used for local lookups.
     */
    private ResourceBundle resources;

    /**
     * A cache for string values, as looking up the cache is faster than looking up the
     * value in the bundle.
     */
    private TreeMap cache;
    /**
     * The current lookup path when performing non local lookups. This prevents infinite
     * loops during such lookups.
     */
    private TreeSet lookupPath;

    /**
     * The name of the local resource bundle.
     */
    private String resourceBase;

    /** The locale for this bundle. */
    private Locale locale;

    /**
     * Creates a new instance.
     *
     * @param baseName the base name of the resource bundle, a fully qualified class name
     */
    public ResourceBundleSupport(final Locale locale, final String baseName) {
        this(locale, ResourceBundle.getBundle(baseName, locale), baseName);
    }

    /**
     * Creates a new instance.
     *
     * @param locale         the locale for which this resource bundle is created.
     * @param resourceBundle the resourcebundle
     * @param baseName       the base name of the resource bundle, a fully qualified class name
     */
    protected ResourceBundleSupport(final Locale locale,
                                    final ResourceBundle resourceBundle,
                                    final String baseName) {
        if (locale == null) {
            throw new NullPointerException("Locale must not be null");
        }
        if (resourceBundle == null) {
            throw new NullPointerException("Resources must not be null");
        }
        if (baseName == null) {
            throw new NullPointerException("BaseName must not be null");
        }
        this.locale = locale;
        this.resources = resourceBundle;
        this.resourceBase = baseName;
        this.cache = new TreeMap();
        this.lookupPath = new TreeSet();
    }

    /**
     * Creates a new instance.
     *
     * @param locale         the locale for which the resource bundle is created.
     * @param resourceBundle the resourcebundle
     */
    public ResourceBundleSupport(final Locale locale, final ResourceBundle resourceBundle) {
        this(locale, resourceBundle, resourceBundle.toString());
    }

    /**
     * Creates a new instance.
     *
     * @param baseName the base name of the resource bundle, a fully qualified class name
     */
    public ResourceBundleSupport(final String baseName) {
        this(Locale.getDefault(), ResourceBundle.getBundle(baseName), baseName);
    }

    /**
     * Creates a new instance.
     *
     * @param resourceBundle the resourcebundle
     * @param baseName       the base name of the resource bundle, a fully qualified class name
     */
    protected ResourceBundleSupport(final ResourceBundle resourceBundle,
                                    final String baseName) {
        this(Locale.getDefault(), resourceBundle, baseName);
    }

    /**
     * Creates a new instance.
     *
     * @param resourceBundle the resourcebundle
     */
    public ResourceBundleSupport(final ResourceBundle resourceBundle) {
        this(Locale.getDefault(), resourceBundle, resourceBundle.toString());
    }

    /**
     * The base name of the resource bundle.
     *
     * @return the resource bundle's name.
     */
    protected final String getResourceBase() {
        return this.resourceBase;
    }

    /**
     * Gets a string for the given key from this resource bundle or one of its parents. If
     * the key is a link, the link is resolved and the referenced string is returned
     * instead.
     *
     * @param key the key for the desired string
     * @return the string for the given key
     * @throws NullPointerException     if <code>key</code> is <code>null</code>
     * @throws MissingResourceException if no object for the given key can be found
     * @throws ClassCastException       if the object found for the given key is not a
     *                                  string
     */
    public synchronized String getString(final String key) {
        final String retval = (String) this.cache.get(key);
        if (retval != null) {
            return retval;
        }
        this.lookupPath.clear();
        return internalGetString(key);
    }

    /**
     * Performs the lookup for the given key. If the key points to a link the link is
     * resolved and that key is looked up instead.
     *
     * @param key the key for the string
     * @return the string for the given key
     */
    protected String internalGetString(final String key) {
        if (this.lookupPath.contains(key)) {
            throw new MissingResourceException
                ("InfiniteLoop in resource lookup",
                    getResourceBase(), this.lookupPath.toString());
        }
        final String fromResBundle = this.resources.getString(key);
        if (fromResBundle.startsWith("@@")) {
            // global forward ...
            final int idx = fromResBundle.indexOf('@', 2);
            if (idx == -1) {
                throw new MissingResourceException
                    ("Invalid format for global lookup key.", getResourceBase(), key);
            }
            try {
                final ResourceBundle res = ResourceBundle.getBundle
                    (fromResBundle.substring(2, idx));
                return res.getString(fromResBundle.substring(idx + 1));
            }
            catch (Exception e) {
                Log.error("Error during global lookup", e);
                throw new MissingResourceException
                    ("Error during global lookup", getResourceBase(), key);
            }
        }
        else if (fromResBundle.startsWith("@")) {
            // local forward ...
            final String newKey = fromResBundle.substring(1);
            this.lookupPath.add(key);
            final String retval = internalGetString(newKey);

            this.cache.put(key, retval);
            return retval;
        }
        else {
            this.cache.put(key, fromResBundle);
            return fromResBundle;
        }
    }

    /**
     * Returns an scaled icon suitable for buttons or menus.
     *
     * @param key   the name of the resource bundle key
     * @param large true, if the image should be scaled to 24x24, or false for 16x16
     * @return the icon.
     */
    public Icon getIcon(final String key, final boolean large) {
        final String name = getString(key);
        return createIcon(name, true, large);
    }

    /**
     * Returns an unscaled icon.
     *
     * @param key the name of the resource bundle key
     * @return the icon.
     */
    public Icon getIcon(final String key) {
        final String name = getString(key);
        return createIcon(name, false, false);
    }

    /**
     * Returns the mnemonic stored at the given resourcebundle key. The mnemonic should be
     * either the symbolic name of one of the KeyEvent.VK_* constants (without the 'VK_') or
     * the character for that key.
     * <p/>
     * For the enter key, the resource bundle would therefore either contain "ENTER" or
     * "\n".
     * <pre>
     * a.resourcebundle.key=ENTER