//------------------------------------------------------------------------------
// <copyright file="ArraySubsetEnumerator.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>                                                                
//------------------------------------------------------------------------------
 
namespace System.ComponentModel {        
 
    using System;
    using System.Collections;
    using System.Diagnostics;
    using System.Security.Permissions;
 
    [HostProtection(SharedState = true)]
    internal class ArraySubsetEnumerator : IEnumerator
    {
 
        private Array array;
        private int total;
        private int current;
 
        public ArraySubsetEnumerator(Array array, int count) {
            Debug.Assert(count == 0 || array != null, "if array is null, count should be 0");
            Debug.Assert(array == null || count <= array.Length, "Trying to enumerate more than the array contains");
            this.array = array;
            this.total = count;
            current = -1;
        }
 
        public bool MoveNext() {
            if (current < total - 1) {
                current++;
                return true;
            }
            else {
                return false;
            }
        }
 
        public void Reset() {
            current = -1;
        }
 
        public object Current {
            get {
                if (current == -1) {
                    throw new InvalidOperationException();
                }
                else {
                    return array.GetValue(current);
                }
            }
        }
    }
}