package org.argeo.util;
   
   import java.util.Dictionary;
   import java.util.Enumeration;
   import java.util.Iterator;
   
   /**
    * Access the keys of a {@link String}-keyed {@link Dictionary} (common throughout
    * the OSGi APIs) as an {@link Iterable} so that they are easily usable in
   * for-each loops.
   */
  class DictionaryKeys implements Iterable<String> {
  	private final Dictionary<String, ?> dictionary;
  
  	public DictionaryKeys(Dictionary<String, ?> dictionary) {
  		this.dictionary = dictionary;
  	}
  
  	@Override
  	public Iterator<String> iterator() {
  		return new KeyIterator(dictionary.keys());
  	}
  
  	private static class KeyIterator implements Iterator<String> {
  		private final Enumeration<String> keys;
  
  		KeyIterator(Enumeration<String> keys) {
  			this.keys = keys;
  		}
  
  		@Override
  		public boolean hasNext() {
  			return keys.hasMoreElements();
  		}
  
  		@Override
  		public String next() {
  			return keys.nextElement();
  		}
  
  	}
  }