Binaryworld - GetNodeRelationship - Check if two nodes are relatives ... [ VB -> Windows Common Controls ]

' Returns a value >0 if Node1 is a parent (or grandparent) of Node2
' Returns a value <0 if Node1 is a child (or grandchild) of Node2
' in both cases the number reflects the number of levels
' between the two nodes
' Returns 0 if the two Nodes are the same or
' if they belong to different subtrees

Function GetNodeRelationship(ByVal Node1 As Node, _
  ByVal Node2 As Node) As Integer

  If Node1 Is Node2 Then
    ' this is the simplest case
    Exit Function
  ElseIf Len(Node1.FullPath) > Len(Node2.FullPath) Then
    ' if the two nodes belong to the same subtree, then
    ' Node1 is a (grand)child of Node2
    If InStr(Node1.FullPath, Node2.FullPath) = 1 Then
      ' do the loop only if the two nodes appear to
      ' belong to the same subtree
      ' check that the relationship really exists
      Do Until (Node1.Parent Is Nothing)
        Set Node1 = Node1.Parent
        GetNodeRelationship = GetNodeRelationship + 1
        If Node1 Is Node2 Then Exit Function
      Loop
    End If
  Else
    ' if the two nodes belong to the same subtree, then
    ' Node1 is a (grand)parent of Node2
    If InStr(Node2.FullPath, Node1.FullPath) = 1 Then
      ' do the loop only if the two nodes appear to
      ' belong to the same subtree
      ' check that the relationship really exists
      Do Until (Node2.Parent Is Nothing)
        Set Node2 = Node2.Parent
        GetNodeRelationship = GetNodeRelationship - 1
        If Node1 Is Node2 Then Exit Function
      Loop
    End If
  End If

  ' Nodes belong to different subtrees
  GetNodeRelationship = 0

End Function