content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   * 
   *      http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package mf.org.apache.xerces.impl.xs.util;
  
  import java.lang.reflect.Array;
  import java.util.AbstractList;
  import java.util.Iterator;
  import java.util.ListIterator;
  import java.util.NoSuchElementException;
  
  import mf.org.apache.xerces.xs.XSObject;
  import mf.org.apache.xerces.xs.XSObjectList;
  
  /**
   * Contains a list of XSObjects.
   *
   * @author Sandy Gao, IBM
   * @version $Id: XSObjectListImpl.java 776079 2009-05-18 20:22:27Z mrglavas $
   * @xerces.internal
   */
  public class XSObjectListImpl extends AbstractList implements XSObjectList {
  
      /**
       * An immutable empty list.
       */
      public static final XSObjectListImpl EMPTY_LIST = new XSObjectListImpl(new XSObject[0], 0);
      private static final ListIterator EMPTY_ITERATOR = new ListIterator() {
          @Override
          public boolean hasNext() {
              return false;
          }
  
          @Override
          public Object next() {
              throw new NoSuchElementException();
          }
  
          @Override
          public boolean hasPrevious() {
              return false;
          }
  
          @Override
          public Object previous() {
              throw new NoSuchElementException();
          }
  
          @Override
          public int nextIndex() {
              return 0;
          }
  
          @Override
          public int previousIndex() {
              return -1;
          }
  
          @Override
          public void remove() {
              throw new UnsupportedOperationException();
          }
  
          @Override
          public void set(Object object) {
              throw new UnsupportedOperationException();
          }
  
          @Override
          public void add(Object object) {
              throw new UnsupportedOperationException();
          }
      };
  
      private static final int DEFAULT_SIZE = 4;
  
      // The array to hold all data
      private XSObject[] fArray = null;
      // Number of elements in this list
      private int fLength = 0;
  
      public XSObjectListImpl() {
          fArray = new XSObject[DEFAULT_SIZE];
          fLength = 0;
      }
  
      /**
       * Construct an XSObjectList implementation
       *
       * @param array  the data array
       * @param length the number of elements
       */
      public XSObjectListImpl(XSObject[] array, int length) {
          fArray = array;
          fLength = length;
      }
  
      /**
       * The number of <code>XSObjects</code> in the list. The range of valid
       * child node indices is 0 to <code>length-1</code> inclusive.
       */
      @Override
      public int getLength() {
          return fLength;
      }
  
      /**
       * Returns the <code>index</code>th item in the collection. The index
       * starts at 0. If <code>index</code> is greater than or equal to the
       * number of nodes in the list, this returns <code>null</code>.
       *
       * @param index index into the collection.
       * @return The XSObject at the <code>index</code>th position in the
       * <code>XSObjectList</code>, or <code>null</code> if that is not a
       * valid index.
       */
      @Override
      public XSObject item(int index) {
          if (index < 0 || index >= fLength) {
              return null;
          }
          return fArray[index];
      }
  
      // clear this object
      public void clearXSObjectList() {
          for (int i = 0; i < fLength; i++) {
              fArray[i] = null;
          }
          fArray = null;
          fLength = 0;
      }
  
      public void addXSObject(XSObject object) {
          if (fLength == fArray.length) {
              XSObject[] temp = new XSObject[fLength + 4];
              System.arraycopy(fArray, 0, temp, 0, fLength);
              fArray = temp;
          }
          fArray[fLength++] = object;
      }
  
      public void addXSObject(int index, XSObject object) {
          fArray[index] = object;
      }
      
      /*
       * List methods
       */
  
      @Override
      public boolean contains(Object value) {
          return (value == null) ? containsNull() : containsObject(value);
      }
  
      @Override
      public Object get(int index) {
          if (index >= 0 && index < fLength) {
              return fArray[index];
          }
          throw new IndexOutOfBoundsException("Index: " + index);
      }
  
      @Override
      public int size() {
          return getLength();
      }
  
      @Override
      public Iterator iterator() {
          return listIterator0(0);
      }
  
      @Override
      public ListIterator listIterator() {
          return listIterator0(0);
      }
  
      @Override
      public ListIterator listIterator(int index) {
          if (index >= 0 && index < fLength) {
              return listIterator0(index);
          }
          throw new IndexOutOfBoundsException("Index: " + index);
      }
  
      private ListIterator listIterator0(int index) {
          return fLength == 0 ? EMPTY_ITERATOR : new XSObjectListIterator(index);
      }
  
      private boolean containsObject(Object value) {
          for (int i = fLength - 1; i >= 0; --i) {
              if (value.equals(fArray[i])) {
                  return true;
              }
          }
          return false;
      }
  
      private boolean containsNull() {
          for (int i = fLength - 1; i >= 0; --i) {
              if (fArray[i] == null) {
                  return true;
              }
          }
          return false;
      }
  
      @Override
      public Object[] toArray() {
          Object[] a = new Object[fLength];
          toArray0(a);
          return a;
      }
  
      @Override
      public Object[] toArray(Object[] a) {
          if (a.length < fLength) {
              Class arrayClass = a.getClass();
              Class componentType = arrayClass.getComponentType();
              a = (Object[]) Array.newInstance(componentType, fLength);
          }
          toArray0(a);
          if (a.length > fLength) {
              a[fLength] = null;
          }
          return a;
      }
  
      private void toArray0(Object[] a) {
          if (fLength > 0) {
              System.arraycopy(fArray, 0, a, 0, fLength);
          }
      }
  
      private final class XSObjectListIterator implements ListIterator {
          private int index;
  
          public XSObjectListIterator(int index) {
              this.index = index;
          }
  
          @Override
          public boolean hasNext() {
              return (index < fLength);
          }
  
          @Override
          public Object next() {
              if (index < fLength) {
                  return fArray[index++];
              }
              throw new NoSuchElementException();
          }
  
          @Override
          public boolean hasPrevious() {
              return (index > 0);
          }
  
          @Override
          public Object previous() {
              if (index > 0) {
                  return fArray[--index];
              }
              throw new NoSuchElementException();
          }
  
          @Override
          public int nextIndex() {
              return index;
          }
  
          @Override
          public int previousIndex() {
              return index - 1;
          }
  
          @Override
          public void remove() {
              throw new UnsupportedOperationException();
          }
  
          @Override
          public void set(Object o) {
              throw new UnsupportedOperationException();
          }
  
          @Override
          public void add(Object o) {
              throw new UnsupportedOperationException();
          }
      }
  
  } // class XSObjectListImpl
  