001    /*
002     * Copyright (C) 2007 Google Inc.
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    
017    package com.google.common.collect;
018    
019    import com.google.common.annotations.GwtCompatible;
020    
021    import java.util.Iterator;
022    
023    /**
024     * An iterator which forwards all its method calls to another iterator.
025     * Subclasses should override one or more methods to modify the behavior of the
026     * backing iterator as desired per the <a
027     * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
028     *
029     * @author Kevin Bourrillion
030     * @since 2 (imported from Google Collections Library)
031     */
032    @GwtCompatible
033    public abstract class ForwardingIterator<T>
034        extends ForwardingObject implements Iterator<T> {
035    
036      /** Constructor for use by subclasses. */
037      protected ForwardingIterator() {}
038    
039      @Override protected abstract Iterator<T> delegate();
040    
041      public boolean hasNext() {
042        return delegate().hasNext();
043      }
044    
045      public T next() {
046        return delegate().next();
047      }
048    
049      public void remove() {
050        delegate().remove();
051      }
052    }