Mega Code Archive
A list implementation that is loaded the first the contents are examined
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namespace Ngs.Collections
{
// Copyright (c) Microsoft Corporation. All rights reserved.
// This source code is made available under the terms of the Microsoft Public License (MS-PL)
using System;
using System.Collections;
using System.Collections.Generic;
/// <summary>
/// A list implementation that is loaded the first the contents are examined
/// </summary>
/// <typeparam name="T"></typeparam>
public class DeferredList<T> : IList<T>, ICollection<T>, IEnumerable<T>, IList, ICollection, IEnumerable, IDeferLoadable
{
IEnumerable<T> source;
List<T> values;
public DeferredList(IEnumerable<T> source)
{
this.source = source;
}
public void Load()
{
this.values = new List<T>(this.source);
}
public bool IsLoaded
{
get { return this.values != null; }
}
private void Check()
{
if (!this.IsLoaded)
{
this.Load();
}
}
#region IList<T> Members
public int IndexOf(T item)
{
this.Check();
return this.values.IndexOf(item);
}
public void Insert(int index, T item)
{
this.Check();
this.values.Insert(index, item);
}
public void RemoveAt(int index)
{
this.Check();
this.values.RemoveAt(index);
}
public T this[int index]
{
get
{
this.Check();
return this.values[index];
}
set
{
this.Check();
this.values[index] = value;
}
}
#endregion
#region ICollection<T> Members
public void Add(T item)
{
this.Check();
this.values.Add(item);
}
public void Clear()
{
this.Check();
this.values.Clear();
}
public bool Contains(T item)
{
this.Check();
return this.values.Contains(item);
}
public void CopyTo(T[] array, int arrayIndex)
{
this.Check();
this.values.CopyTo(array, arrayIndex);
}
public int Count
{
get { this.Check(); return this.values.Count; }
}
public bool IsReadOnly
{
get { return false; }
}
public bool Remove(T item)
{
this.Check();
return this.values.Remove(item);
}
#endregion
#region IEnumerable<T> Members
public IEnumerator<T> GetEnumerator()
{
this.Check();
return this.values.GetEnumerator();
}
#endregion
#region IEnumerable Members
IEnumerator IEnumerable.GetEnumerator()
{
return this.GetEnumerator();
}
#endregion
#region IList Members
public int Add(object value)
{
this.Check();
return ((IList)this.values).Add(value);
}
public bool Contains(object value)
{
this.Check();
return ((IList)this.values).Contains(value);
}
public int IndexOf(object value)
{
this.Check();
return ((IList)this.values).IndexOf(value);
}
public void Insert(int index, object value)
{
this.Check();
((IList)this.values).Insert(index, value);
}
public bool IsFixedSize
{
get { return false; }
}
public void Remove(object value)
{
this.Check();
((IList)this.values).Remove(value);
}
object IList.this[int index]
{
get
{
this.Check();
return ((IList)this.values)[index];
}
set
{
this.Check();
((IList)this.values)[index] = value;
}
}
#endregion
#region ICollection Members
public void CopyTo(Array array, int index)
{
this.Check();
((IList)this.values).CopyTo(array, index);
}
public bool IsSynchronized
{
get { return false; }
}
public object SyncRoot
{
get { return null; }
}
#endregion
}
}
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