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using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Reflection;
using System.Diagnostics.CodeAnalysis;
namespace System.Data.Linq {
internal class EntitySetBindingList<TEntity> : SortableBindingList<TEntity>
where TEntity : class {
private EntitySet<TEntity> data;
private TEntity addNewInstance;
private TEntity cancelNewInstance;
private bool addingNewInstance;
internal EntitySetBindingList(IList<TEntity> sequence, EntitySet<TEntity> data)
: base(sequence) {
if (sequence == null) {
throw Error.ArgumentNull("sequence");
}
if (data == null) {
throw Error.ArgumentNull("data");
}
this.data = data;
}
[SuppressMessage("Microsoft.Performance", "CA1822:MarkMembersAsStatic", Justification="Unknown reason.")]
private void ThrowEntitySetErrorsIfTypeInappropriate() {
Type type = typeof(TEntity);
if (type.IsAbstract) {
throw Error.EntitySetDataBindingWithAbstractBaseClass(type.Name);
}
if (type.GetConstructor(System.Type.EmptyTypes) == null) {
throw Error.EntitySetDataBindingWithNonPublicDefaultConstructor(type.Name);
}
}
protected override object AddNewCore() {
ThrowEntitySetErrorsIfTypeInappropriate();
addingNewInstance = true;
addNewInstance = (TEntity)base.AddNewCore();
return addNewInstance;
}
protected override void InsertItem(int index, TEntity item) {
base.InsertItem(index, item);
if (!addingNewInstance && index >= 0 && index <= Count) {
this.data.Insert(index, item);
}
}
protected override void RemoveItem(int index) {
if (index >= 0 && index < Count && this[index] == cancelNewInstance) {
cancelNewInstance = null;
}
else {
this.data.Remove(this[index]);
}
base.RemoveItem(index);
}
protected override void SetItem(int index, TEntity item) {
TEntity removedItem = this[index];
base.SetItem(index, item);
if (index >= 0 && index < Count) {
//Check to see if the user is trying to set an item that is currently being added via AddNew
//If so then the list should not continue the AddNew; but instead add the item
//that is being passed in.
if (removedItem == addNewInstance) {
addNewInstance = null;
addingNewInstance = false;
}
else {
this.data.Remove(removedItem);
}
this.data.Insert(index,item);
}
}
protected override void ClearItems() {
this.data.Clear();
base.ClearItems();
}
public override void EndNew(int itemIndex) {
if (itemIndex >= 0 && itemIndex < Count && this[itemIndex] == addNewInstance) {
this.data.Add(addNewInstance);
addNewInstance = null;
addingNewInstance = false;
}
base.EndNew(itemIndex);
}
public override void CancelNew(int itemIndex) {
if (itemIndex >= 0 && itemIndex < Count && this[itemIndex] == addNewInstance) {
cancelNewInstance = addNewInstance;
addNewInstance = null;
addingNewInstance = false;
}
base.CancelNew(itemIndex);
}
}
}
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