001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.collections.primitives;
018
019/**
020 * Abstract base class for {@link IntCollection}s.
021 * <p />
022 * Read-only subclasses must override {@link #iterator}
023 * and {@link #size}.  Mutable subclasses
024 * should also override {@link #add} and 
025 * {@link IntIterator#remove IntIterator.remove}.
026 * All other methods have at least some base implementation 
027 * derived from these.  Subclasses may choose to override 
028 * these methods to provide a more efficient implementation. 
029 * 
030 * @since Commons Primitives 1.0
031 * @version $Revision: 480460 $ $Date: 2006-11-29 03:14:21 -0500 (Wed, 29 Nov 2006) $
032 * 
033 * @author Rodney Waldhoff 
034 */
035public abstract class AbstractIntCollection implements IntCollection {
036    public abstract IntIterator iterator();
037    public abstract int size();
038          
039    protected AbstractIntCollection() { }
040              
041    /** Unsupported in this base implementation. */
042    public boolean add(int element) {
043        throw new UnsupportedOperationException("add(int) is not supported.");
044    }
045
046    public boolean addAll(IntCollection c) {
047        boolean modified = false;
048        for(IntIterator iter = c.iterator(); iter.hasNext(); ) {
049            modified  |= add(iter.next());
050        }
051        return modified;
052    }
053    
054    public void clear() {
055        for(IntIterator iter = iterator(); iter.hasNext();) {
056            iter.next();
057            iter.remove();
058        }
059    }        
060
061    public boolean contains(int element) {
062        for(IntIterator iter = iterator(); iter.hasNext();) {
063            if(iter.next() == element) {
064                return true;
065            }
066        }
067        return false;
068    }
069        
070    public boolean containsAll(IntCollection c) {
071        for(IntIterator iter = c.iterator(); iter.hasNext();) {
072            if(!contains(iter.next())) {
073                return false;
074            }
075        }
076        return true;
077    }
078    
079    public boolean isEmpty() {
080        return (0 == size());
081    }
082       
083    public boolean removeElement(int element) {
084        for(IntIterator iter = iterator(); iter.hasNext();) {
085            if(iter.next() == element) {
086                iter.remove();
087                return true;
088            }
089        }
090        return false;
091    }        
092    
093    public boolean removeAll(IntCollection c) {
094        boolean modified = false;
095        for(IntIterator iter = c.iterator(); iter.hasNext(); ) {
096            modified  |= removeElement(iter.next());
097        }
098        return modified;
099    }       
100    
101    public boolean retainAll(IntCollection c) {
102        boolean modified = false;
103        for(IntIterator iter = iterator(); iter.hasNext();) {
104            if(!c.contains(iter.next())) {
105                iter.remove();
106                modified = true;
107            }
108        }
109        return modified;
110    }
111    
112    public int[] toArray() {
113        int[] array = new int[size()];
114        int i = 0;
115        for(IntIterator iter = iterator(); iter.hasNext();) {
116            array[i] = iter.next();
117            i++;
118        }
119        return array;
120    }
121        
122    public int[] toArray(int[] a) {
123        if(a.length < size()) {
124            return toArray();
125        } else {
126            int i = 0;
127            for(IntIterator iter = iterator(); iter.hasNext();) {
128                a[i] = iter.next();
129                i++;
130            }
131            return a;
132        }            
133    }
134}