/Main/src/DynamicDataDisplay/Common/RingArray.cs

  1using System;
  2using System.Collections.Generic;
  3using System.Linq;
  4using System.Text;
  5using System.Collections.ObjectModel;
  6using System.Collections;
  7using System.Collections.Specialized;
  8
  9namespace Microsoft.Research.DynamicDataDisplay.Common
 10{
 11	public class RingArray<T> : INotifyCollectionChanged, IList<T>
 12	{
 13		public RingArray(int capacity)
 14		{
 15			this.capacity = capacity;
 16			array = new T[capacity];
 17		}
 18
 19		public void Add(T item)
 20		{
 21			int index = (startIndex + count) % capacity;
 22			if (startIndex + count >= capacity)
 23			{
 24				startIndex++;
 25			}
 26			else
 27			{
 28				count++;
 29			}
 30
 31			array[index] = item;
 32
 33			CollectionChanged.Raise(this);
 34		}
 35
 36		public T this[int index]
 37		{
 38			get { return array[(startIndex + index) % capacity]; }
 39			set
 40			{
 41				array[(startIndex + index) % capacity] = value;
 42				CollectionChanged.Raise(this);
 43			}
 44		}
 45
 46		public void Clear()
 47		{
 48			count = 0;
 49			startIndex = 0;
 50			array = new T[capacity];
 51		}
 52
 53		public IEnumerator<T> GetEnumerator()
 54		{
 55			for (int i = 0; i < count; i++)
 56			{
 57				yield return this[i];
 58			}
 59		}
 60
 61		private int count;
 62		public int Count
 63		{
 64			get { return count; }
 65		}
 66
 67		private T[] array;
 68
 69		private int capacity;
 70		public int Capacity
 71		{
 72			get { return capacity; }
 73		}
 74
 75		private int startIndex = 0;
 76
 77		#region INotifyCollectionChanged Members
 78
 79		public event NotifyCollectionChangedEventHandler CollectionChanged;
 80
 81		#endregion
 82
 83		#region IList<T> Members
 84
 85		public int IndexOf(T item)
 86		{
 87			int index = Array.IndexOf(array, item);
 88
 89			if (index == -1)
 90				return -1;
 91
 92			return (index - startIndex + count) % capacity;
 93		}
 94
 95		public void Insert(int index, T item)
 96		{
 97			throw new NotImplementedException();
 98		}
 99
100		public void RemoveAt(int index)
101		{
102			throw new NotImplementedException();
103		}
104
105		#endregion
106
107		#region ICollection<T> Members
108
109		public bool Contains(T item)
110		{
111			return Array.IndexOf(array, item) > -1;
112		}
113
114		public void CopyTo(T[] array, int arrayIndex)
115		{
116			throw new NotImplementedException();
117		}
118
119		public bool IsReadOnly
120		{
121			get { throw new NotImplementedException(); }
122		}
123
124		public bool Remove(T item)
125		{
126			throw new NotImplementedException();
127		}
128
129		#endregion
130
131		#region IEnumerable Members
132
133		IEnumerator IEnumerable.GetEnumerator()
134		{
135			return GetEnumerator();
136		}
137
138		#endregion
139	}
140}