1  /*
     2   * Copyright the original author or authors.
     3   * 
     4   * Licensed under the MOZILLA PUBLIC LICENSE, Version 1.1 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   * 
     8   *      http://www.mozilla.org/MPL/MPL-1.1.html
     9   * 
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  import org.as2lib.core.BasicClass;
    18  import org.as2lib.data.holder.Iterator;
    19  import org.as2lib.env.except.IllegalArgumentException;
    20  import org.as2lib.env.except.UnsupportedOperationException;
    21  
    22  /**
    23   * {@code ProtectedIterator} is used to iterate over any data holder
    24   * without being able to remove elements.
    25   * 
    26   * <p>This class acts as a wrapper for any class that implements the
    27   * {@code Iterator} interface and wants to be protected.
    28   *
    29   * @author Simon Wacker
    30   * @author Michael Herrmann
    31   */
    32  class org.as2lib.data.holder.ProtectedIterator extends BasicClass implements Iterator {
    33  	
    34  	/** Holds the iterator this protected iterator delegates to. */
    35  	private var iterator:Iterator;
    36  	
    37  	/**
    38  	 * Constructs a new {@code ProtectedIterator} instance.
    39  	 * 
    40  	 * <p>This iterator forwards all functionality to the wrapped passed-in
    41  	 * {@code iterator}, except the removal of the current element.
    42  	 * 
    43  	 * @param iterator the iterator to protect
    44  	 * @throws IllegalArgumentException if the passed-in {@code iterator}
    45  	 * is {@code null} or {@code undefined}
    46  	 */
    47  	public function ProtectedIterator(iterator:Iterator) {
    48  		if (!iterator) throw new IllegalArgumentException("Argument 'iterator' [" + iterator + "] to protect is not allowed to be 'null' or 'undefined'.", this, arguments);
    49  		this.iterator = iterator;
    50  	}
    51  	
    52  	/**
    53  	 * Returns whether there are more elements to iterate over.
    54  	 *
    55  	 * <p>For any special functionality that may be performed refer to the
    56  	 * wrapped iterator that has been passed-in on construction. This method
    57  	 * simply delegates to the wrapped iterator.
    58  	 *
    59  	 * @return {@code true} if there is a next element else {@code false}
    60  	 */
    61  	public function hasNext(Void):Boolean {
    62  		return iterator.hasNext();
    63  	}
    64  	
    65  	/**
    66  	 * Returns the next element.
    67  	 *
    68  	 * <p>For any special functionality that may be performed refer to the
    69  	 * wrapped iterator that has been passed-in on construction. This method
    70  	 * simply delegates to the wrapped iterator.
    71  	 *
    72  	 * @return the next element
    73  	 * @throws org.as2lib.data.holder.NoSuchElementException if there is
    74  	 * no next element
    75  	 */
    76  	public function next(Void) {
    77  		return iterator.next();
    78  	}
    79  	
    80  	/**
    81  	 * This method always throws an {@code UnsupportedOperationException}
    82  	 * because this method is not supported by this iterator and has the
    83  	 * duty to not let the removal of elements happen.
    84  	 *
    85  	 * @throws UnsupportedOperationException
    86  	 */
    87  	public function remove(Void):Void {
    88  		throw new UnsupportedOperationException("This Iterator does not support the remove() method.", this, arguments);
    89  	}
    90  	
    91  }
as2api