| /******************************************************************************* |
| * Copyright (c) 2011, 2015 Oracle. All rights reserved. |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License v1.0, which accompanies this distribution |
| * and is available at http://www.eclipse.org/legal/epl-v10.html. |
| * |
| * Contributors: |
| * Oracle - initial API and implementation |
| ******************************************************************************/ |
| package org.eclipse.jpt.common.utility.internal.collection; |
| |
| import java.io.Serializable; |
| import java.util.Collection; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.ListIterator; |
| import org.eclipse.jpt.common.utility.internal.ArrayTools; |
| import org.eclipse.jpt.common.utility.internal.ObjectTools; |
| |
| /** |
| * A <em>read-only</em> repeating element list (i.e. the list contains only |
| * one or more references to the same element). |
| * |
| * @param <E> the type of elements maintained by the list |
| */ |
| public abstract class AbstractRepeatingElementList<E> |
| implements List<E>, Serializable |
| { |
| // never negative |
| private final int size; |
| |
| /** |
| * Construct a <em>read-only</em> list with the specified number of |
| * objects in it. |
| */ |
| protected AbstractRepeatingElementList(int size) { |
| super(); |
| if (size < 0) { |
| throw new IllegalArgumentException("Invalid size: " + size); //$NON-NLS-1$ |
| } |
| this.size = size; |
| } |
| |
| public boolean add(E o) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public void add(int index, E element) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| /** |
| * Replicate behavior of |
| * {@link java.util.AbstractCollection#addAll(Collection)}. |
| */ |
| public boolean addAll(Collection<? extends E> c) { |
| if (c.isEmpty()) { |
| return false; |
| } |
| throw new UnsupportedOperationException(); |
| } |
| |
| /** |
| * Replicate behavior of |
| * {@link java.util.AbstractList#addAll(int, Collection)}. |
| */ |
| public boolean addAll(int index, Collection<? extends E> c) { |
| return this.addAll(c); // ignore the index |
| } |
| |
| /** |
| * Replicate behavior of |
| * {@link java.util.AbstractCollection#clear()}. |
| */ |
| public void clear() { |
| if (this.size != 0) { |
| throw new UnsupportedOperationException(); |
| } |
| } |
| |
| public boolean contains(Object o) { |
| return (this.elementIs(o) && (this.size > 0)); |
| } |
| |
| /** |
| * Replicate behavior of |
| * {@link java.util.AbstractCollection#containsAll(Collection)}. |
| */ |
| public boolean containsAll(Collection<?> c) { |
| if (c.isEmpty()) { |
| return true; |
| } |
| if (this.size == 0) { |
| return false; |
| } |
| for (Iterator<?> iterator = c.iterator(); iterator.hasNext(); ) { |
| if (this.elementIsNot(iterator.next())) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| public E get(int index) { |
| this.checkIndex(index); |
| return this.getElement(); |
| } |
| |
| private void checkIndex(int index) { |
| if ((index < 0) || (index >= this.size)) { |
| throw new IndexOutOfBoundsException("Index: " + index + ", Size: " + this.size); //$NON-NLS-1$ //$NON-NLS-2$ |
| } |
| } |
| |
| public int indexOf(Object o) { |
| return (this.elementIs(o) && (this.size > 0)) ? 0 : -1; |
| } |
| |
| public boolean isEmpty() { |
| return (this.size == 0); |
| } |
| |
| public Iterator<E> iterator() { |
| return this.iterator(this.size); |
| } |
| |
| protected abstract Iterator<E> iterator(int iteratorSize); |
| |
| public int lastIndexOf(Object o) { |
| return (this.elementIs(o) && (this.size > 0)) ? (this.size - 1) : -1; |
| } |
| |
| public ListIterator<E> listIterator() { |
| return this.listIterator_(this.size); |
| } |
| |
| public ListIterator<E> listIterator(int index) { |
| return this.listIterator_(this.size - index); |
| } |
| |
| protected abstract ListIterator<E> listIterator_(int iteratorSize); |
| |
| /** |
| * Replicate behavior of |
| * {@link java.util.AbstractCollection#remove(Object)}. |
| */ |
| public boolean remove(Object o) { |
| if ((this.size > 0) && this.elementIs(o)) { |
| throw new UnsupportedOperationException(); |
| } |
| return false; |
| } |
| |
| public E remove(int index) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| /** |
| * Replicate behavior of |
| * {@link java.util.AbstractCollection#removeAll(Collection)}. |
| */ |
| public boolean removeAll(Collection<?> c) { |
| if ((this.size > 0) && c.contains(this.getElement())) { |
| throw new UnsupportedOperationException(); |
| } |
| return false; |
| } |
| |
| /** |
| * Replicate behavior of |
| * {@link java.util.AbstractCollection#retainAll(Collection)}. |
| */ |
| public boolean retainAll(Collection<?> c) { |
| if ((this.size > 0) && ! c.contains(this.getElement())) { |
| throw new UnsupportedOperationException(); |
| } |
| return false; |
| } |
| |
| public E set(int index, E element) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public int size() { |
| return this.size; |
| } |
| |
| public List<E> subList(int fromIndex, int toIndex) { |
| return this.subList(toIndex - fromIndex); |
| } |
| |
| protected abstract List<E> subList(int subListSize); |
| |
| public Object[] toArray() { |
| return ArrayTools.fill(new Object[this.size], this.getElement()); |
| } |
| |
| @SuppressWarnings("unchecked") |
| public <T> T[] toArray(T[] a) { |
| int sz = this.size; |
| return (T[]) ArrayTools.fill(((a.length >= sz) ? a : ArrayTools.newInstance(a, sz)), 0, sz, this.getElement()); |
| } |
| |
| private boolean elementIsNot(Object o) { |
| return ! this.elementIs(o); |
| } |
| |
| private boolean elementIs(Object o) { |
| return ObjectTools.equals(o, this.getElement()); |
| } |
| |
| /** |
| * Return the list's repeating element. |
| */ |
| protected abstract E getElement(); |
| |
| @Override |
| public String toString() { |
| StringBuilder sb = new StringBuilder(); |
| sb.append('['); |
| for (int i = this.size; i-- > 0; ) { |
| sb.append(this.getElement()); |
| sb.append(", "); //$NON-NLS-1$ |
| } |
| if (sb.length() > 1) { |
| sb.setLength(sb.length() - 2); |
| } |
| sb.append(']'); |
| return sb.toString(); |
| } |
| |
| private static final long serialVersionUID = 1L; |
| } |