clsItemColl

'The main reason the class stores items in a collection
'rather than an array, linked list, or some other data
'structures is to provide the For Each operator. To do
'that, the class must provide a NewEnum function that
'returns an IUnknown interface object. The class can get
'such an object from a normal collection like this:
Public Function NewEnum() As IUnknown
    Set NewEnum = m_Items.[_NewEnum]
End Function

'To register this function as the class enumerator,
'you must:
'1. Open the SortedCollection's class editor window.
'2. Select the Tools menu's Procedure Attributes command.
'a. Select NewEnum in the Name box.
'b. Click Advanced >>
'c. Click on the Procedure ID box and type -4.
'd. Check the "Hide this member" box so the user cannot see
'   this method(really only useful indirectly via For each)
'e. Click Ok.
'The Count, Remove, and Item methods are simply delegated
'to the m_Items collection.
'Return the number of items.
Public Function Count() As Integer
    Count = m_Items.Count
End Function

'Remove an item.
Public Sub Remove(ByVal Index As Integer)
    m_Items.Remove Index
End Sub

'Return an item.
Public Function Item(ByVal Index As Integer) As String
    Item = m_Items(Index)
End Function

'The class makes its Item method its default method.
'That allows a program using it to refer to items as in:
sorted_collection(K)
'in addition to:
sorted_collection.Item(K)
'To make Item be the default method, you must:
'1. Open the SortedCollection's class editor window.
'2. Select the Tools menu's Procedure Attributes command.
'a. Select Item in the Name box.
'b. Click Advanced >>
'c. Select (Default) in the Procedure ID box.
'd. Click Ok.

'Add an item at its correct position.

Public Sub AddItem(ByVal new_item As String)
Dim i As Integer
'See where the item belongs.

For i = 1 To m_Items.Count
If m_Items(i) >= new_item Then Exit For
Next i
'Insert the item.

If i > m_Items.Count Then
'Add at the end.

m_Items.Add new_item
Else
'Add at the right position.

m_Items.Add new_item, , i
End If
End Sub

'The main reason the class stores items in a collection

'rather than an array, linked list, or some other data

'structures is to provide the For Each operator. To do

'that, the class must provide a NewEnum function that

'returns an IUnknown interface object. The class can get

'such an object from a normal collection like this:

Public Function NewEnum() As IUnknown
Set NewEnum = m_Items.[_NewEnum]
End Function

'To register this function as the class enumerator,

'you must:

'1. Open the SortedCollection's class editor window.

'2. Select the Tools menu's Procedure Attributes command.

'a. Select NewEnum in the Name box.

'b. Click Advanced >>

'c. Click on the Procedure ID box and type -4.

'd. Check the "Hide this member" box so the user cannot see

' this method(really only useful indirectly via For each)

'e. Click Ok.

'The Count, Remove, and Item methods are simply delegated

'to the m_Items collection.

'Return the number of items.

Public Function Count() As Integer
Count = m_Items.Count
End Function

'Remove an item.

Public Sub Remove(ByVal Index As Integer)
m_Items.Remove Index
End Sub

'Return an item.

Public Function Item(ByVal Index As Integer) As String
Item = m_Items(Index)
End Function

'The class makes its Item method its default method.

'That allows a program using it to refer to items as in:

sorted_collection(K)
'in addition to:

sorted_collection.Item(K)
'To make Item be the default method, you must:

'1. Open the SortedCollection's class editor window.

'2. Select the Tools menu's Procedure Attributes command.

'a. Select Item in the Name box.

'b. Click Advanced >>

'c. Select (Default) in the Procedure ID box.

'd. Click Ok.