/source/library/Interlace/Collections/DictionaryOfLists.cs

#region Using Directives and Copyright Notice



// Copyright (c) 2007-2010, Computer Consultancy Pty Ltd

// All rights reserved.

// 

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are met:

//     * Redistributions of source code must retain the above copyright

//       notice, this list of conditions and the following disclaimer.

//     * Redistributions in binary form must reproduce the above copyright

//       notice, this list of conditions and the following disclaimer in the

//       documentation and/or other materials provided with the distribution.

//     * Neither the name of the Computer Consultancy Pty Ltd nor the

//       names of its contributors may be used to endorse or promote products

//       derived from this software without specific prior written permission.

// 

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 

// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 

// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 

// ARE DISCLAIMED. IN NO EVENT SHALL COMPUTER CONSULTANCY PTY LTD BE LIABLE 

// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 

// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 

// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 

// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 

// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 

// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH

// DAMAGE.



using System;

using System.Collections.Generic;

using System.Collections.ObjectModel;

using System.Text;



#endregion



namespace Interlace.Collections

{

    public class DictionaryOfLists<TKey, TValue> : IEnumerable<KeyValuePair<TKey, ICollection<TValue>>>

    {

        Dictionary<TKey, List<TValue>> _dictionary;

        readonly ReadOnlyCollection<TValue> _emptyCollection =

            new ReadOnlyCollection<TValue>(new List<TValue>());



        public DictionaryOfLists()

        {

            _dictionary = new Dictionary<TKey, List<TValue>>();

        }



        public IEnumerable<TKey> Keys

        {

            get { return _dictionary.Keys; }

        }



        public void Add(TKey key, TValue value)

        {

            List<TValue> list;



            bool exists = _dictionary.TryGetValue(key, out list);



            if (!exists)

            {

                list = new List<TValue>();

                _dictionary[key] = list;

            }



            list.Add(value);

        }



        public void Add(TKey key, ICollection<TValue> values)

        {

            List<TValue> list;



            bool exists = _dictionary.TryGetValue(key, out list);



            if (!exists)

            {

                list = new List<TValue>();

                _dictionary[key] = list;

            }



            foreach (TValue value in values)

            {

                list.Add(value);

            }

        }



        public void Clear()

        {

            _dictionary.Clear();

        }



        public void Clear(TKey key)

        {

            _dictionary.Remove(key);

        }



        public ICollection<TValue> this[TKey key]

        {

            get

            {

                List<TValue> list;



                bool exists = _dictionary.TryGetValue(key, out list);



                if (exists)

                {

                    return new ReadOnlyCollection<TValue>(list);

                }

                else

                {

                    return _emptyCollection;

                }

            }

        }



        public IEnumerator<KeyValuePair<TKey, ICollection<TValue>>> GetEnumerator()

        {

            return new Enumerator(_dictionary.GetEnumerator());

        }



        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()

        {

            return new Enumerator(_dictionary.GetEnumerator());

        }



        class Enumerator : IEnumerator<KeyValuePair<TKey, ICollection<TValue>>>

        {

            IEnumerator<KeyValuePair<TKey, List<TValue>>> _baseEnumerator;



            public Enumerator(IEnumerator<KeyValuePair<TKey, List<TValue>>> baseEnumerator)

            {

                _baseEnumerator = baseEnumerator;

            }



            public KeyValuePair<TKey, ICollection<TValue>> Current

            {

                get 

                { 

                    KeyValuePair<TKey, List<TValue>> pair = _baseEnumerator.Current;



                    return new KeyValuePair<TKey, ICollection<TValue>>(

                        pair.Key, new ReadOnlyCollection<TValue>(pair.Value));

                }

            }



            public void Dispose()

            {

                _baseEnumerator.Dispose();

            }



            object System.Collections.IEnumerator.Current

            {

                get

                {

                    return Current;

                }

            }



            public bool MoveNext()

            {

                return _baseEnumerator.MoveNext();

            }



            public void Reset()

            {

                _baseEnumerator.Reset();

            }

        }

    }

}