Namespace Management
 
    ''' <summary>
    ''' Test
    ''' </summary>
    ''' <typeparam name="T"></typeparam>
    ''' <remarks></remarks>
    Public Class GroupList(Of T)
        Implements IEnumerable(Of T), INotifyCollectionChanged
 
        'Implements max. Items
 
        Public Event CollectionChanged(sender As Object, e As _
          NotifyCollectionChangedEventArgs) Implements _
          INotifyCollectionChanged.CollectionChanged
 
        Private Structure EnumPointer
            Dim Group As String
            Dim Index As Integer
        End Structure
 
        Private InternalList As New List(Of CollectionItem(Of T)) 'Use 
        ' Collection
        Private SelectedItem As CollectionItem(Of T)
 
        Public Sub Add(ByVal Group As String, ByRef Item As T)
            With InternalList
                If SelectedItem.Name = Group Then
                    Dim TGroup As CollectionItem(Of T) = SelectedItem
 
                    TGroup.List.Add(Item)
                Else
                    Dim Added As Boolean = False
 
                    For Each TGroup As CollectionItem(Of T) In InternalList
 
                        If TGroup.Name = Group Then
                            TGroup.List.Add(Item)
                            SelectedItem = TGroup
 
                            Added = True
                            Exit For
                        End If
 
                    Next
 
                    If Added = False Then
                        CreateGroup(Group).Add(Item)
                    End If
 
                End If
            End With
 
            OnNotifyCollectionChanged(NotifyCollectionChangedAction.Add, Item)
        End Sub
 
        Private Function CreateGroup(ByVal Name As String) As List(Of T)
            Dim TList As New List(Of T)
            Dim TCollection As New CollectionItem(Of T)(Name)
 
            TCollection.List = TList
            InternalList.Add(TCollection)
            SelectedItem = TCollection
 
            Return TList
        End Function
 
        Public Function GetTypeEnumerator() As IEnumerator(Of T) Implements _
          IEnumerable(Of T).GetEnumerator
            Dim test As New List(Of T)
 
            For Each Item In InternalList
                test.AddRange(Item.List)
            Next
 
            Return test.GetEnumerator
        End Function
 
        Public Function GetEnumerator() As IEnumerator Implements _
          IEnumerable.GetEnumerator
            Return GetTypeEnumerator()
        End Function
 
        Private Sub OnNotifyCollectionChanged(ByVal ChangedAction As _
          NotifyCollectionChangedAction, Optional ByVal Item As Object = _
          Nothing)
            Dim EventArgs As New NotifyCollectionChangedEventArgs( _
            ChangedAction, Item)
            RaiseEvent CollectionChanged(Me, EventArgs)
        End Sub
    End Class
 
    Public Structure CollectionItem(Of T)
        Private m_Name As String
        Private m_List As List(Of T)
 
        Sub New(ByVal Group As String)
            m_Name = Group
        End Sub
 
        Public ReadOnly Property Name() As String
            Get
                Return m_Name
            End Get
        End Property
 
        Public Property List() As List(Of T)
            Get
                Return m_List
            End Get
            Set(ByVal value As List(Of T))
                m_List = value
            End Set
        End Property
    End Structure
 
End Namespace