Attribute VB_Name = "FlipLines"
Option Explicit

Public Sub FlipLines()
'Flips all selected lines in the highlighted layer.

'This routine does not consider any network flow direction.
'If flow direction is set, it will be set to uninitalized for each selected feature in the highlighted layer.
  
On Error GoTo EH
  
  Dim pApp As IApplication
  Dim pDoc As IMxDocument
  Dim pMap As IMap
  Dim pLayer As ILayer
  Dim pFlayer As IFeatureLayer
  Dim pFC As IFeatureClass
  Dim pFSel As IFeatureSelection
  Dim pFCursor As IFeatureCursor
  Dim pQFilter As IQueryFilter
  Dim pFeature As IFeature
  Dim pGeometry As IGeometry
  Dim pPolyLine As IPolyline
  Dim pId As New UID
  Dim pEditor As IEditor
  Dim pDataset As IDataset
  Dim pELayers As IEditLayers
  Dim lCount As Long
  Dim lTotal As Long
  Dim i As Long
  Dim pNetFeature As INetworkFeature
  Dim pGeoNetwork As IGeometricNetwork
  Dim pUNetwork As IUtilityNetwork
  Dim pSEdgeFeature As ISimpleEdgeFeature
  Dim pCNetFeature As IComplexNetworkFeature
  Dim lEID As Long
  Dim pNetElements As iNetElements
  Dim pEnumNetEID As IEnumNetEID

Result = pLayer.StartEditingShapes(True)
  Set pApp = Application
  Set pDoc = pApp.Document
  Set pMap = pDoc.FocusMap
  
  ' Verify that there are layers in the table on contents
  If pMap.LayerCount < 1 Then
    MsgBox "Must have at least one layer in your map."
    Exit Sub
  End If
  
  'Get highlighted layer in the TOC
  Set pLayer = pDoc.SelectedLayer
  If pLayer Is Nothing Then
    MsgBox "You must have one higlighted layer in the TOC." & vbNewLine & _
 '         "Any selected lines in this layer will be flipped."
    Exit Sub
  End If
  
  'Verify that it is a feature layer
  If Not TypeOf pLayer Is IFeatureLayer Then
    MsgBox "The highlighted layer in the TOC must be a feature layer."
    Exit Sub
  End If
  
  'Get the Feature layer and feature class
  Set pFlayer = pLayer 'QI
  Set pFC = pFlayer.FeatureClass
  Set pFSel = pFlayer
  
  'Verify that it is a line layer
  If pFC.ShapeType <> esriGeometryPolyline Then
    MsgBox "The highlighted layer in the TOC must contain lines."
    Exit Sub
  End If
  
  'Verify it has some features selected
  If pFSel.SelectionSet.Count < 1 Then
    MsgBox "No features selected in the highlighted layer."
    Exit Sub
  End If
  
  'Verify that we are editing
  pId = "esriCore.Editor"
  Set pEditor = pApp.FindExtensionByCLSID(pId)
  If Not (pEditor.EditState = esriStateEditing) Then
    MsgBox "Must be editing."
    Exit Sub
  End If
  
  'Update Message bar
  pApp.StatusBar.Message(0) = "Flipping selected lines..."
  
  'Start edit operation (for undo)
  pEditor.StartOperation
    
  'Step through each selected line in the highlighted layer
  pFSel.SelectionSet.Search Nothing, False, pFCursor

  'Store number of selected features
  lTotal = pFSel.SelectionSet.Count
  
  'Initalize loop counter
  lCount = 0
  
  'Loop through each selected feature in the highlighted layer
  Set pFeature = pFCursor.NextFeature
  Do While Not pFeature Is Nothing
    lCount = lCount + 1
    pApp.StatusBar.Message(0) = "Flipping selected lines...   " & Str(lCount) & " of " & Str(lTotal)
    
    'Disconnect from network before flip
    If TypeOf pFeature Is INetworkFeature Then
      Set pNetFeature = pFeature
      pNetFeature.Disconnect
    End If
    
    'Flip the geometry of the feature
    Set pPolyLine = pFeature.ShapeCopy
    pPolyLine.ReverseOrientation
    Set pFeature.Shape = pPolyLine

    'Reconnect
    If TypeOf pFeature Is INetworkFeature Then
      pNetFeature.Connect
    End If

    If TypeOf pNetFeature Is IComplexEdgeFeature Then
      Dim pCEdgeFeature As IComplexEdgeFeature
      Set pCEdgeFeature = pNetFeature
      pCEdgeFeature.ConnectAtIntermediateVertices
    End If
        
    'Save changes
    pFeature.Store
    
    'Set flow to uninitalized...
    If TypeOf pFeature Is INetworkFeature Then
      Set pNetFeature = pFeature
      Set pGeoNetwork = pNetFeature.GeometricNetwork
      Set pUNetwork = pGeoNetwork.Network
  
      'for each element of a complex edge
      If TypeOf pNetFeature Is IComplexNetworkFeature Then
        Set pNetElements = pGeoNetwork.Network
        Set pEnumNetEID = pNetElements.GetEIDs(pFeature.Class.ObjectClassID, pFeature.OID, esriETEdge)
        pEnumNetEID.Reset
        lEID = pEnumNetEID.Next
        For i = 1 To pEnumNetEID.Count
          pUNetwork.SetFlowDirection lEID, esriFDUninitialized
          lEID = pEnumNetEID.Next
        Next i
      'or for the simple edge
      ElseIf TypeOf pNetFeature Is ISimpleEdgeFeature Then
        Set pSEdgeFeature = pNetFeature
        lEID = pSEdgeFeature.EID
        pUNetwork.SetFlowDirection lEID, esriFDUninitialized
      End If
    End If
    
    Set pFeature = pFCursor.NextFeature
  Loop
  
  'Stop feature editing
  pEditor.StopOperation ("Flip Lines")
  
  'Redraw the map so you'll see the new points
  pDoc.ActiveView.Refresh
  
  MsgBox lCount & " features flipped.", vbOKOnly, "Flip Lines"
  
Exit Sub
EH:
   
  MsgBox Err.Number & "  " & Err.Description



End Sub