'This script will intersect an active PolyLine theme with a user-specified
'theme and produce a new third theme that shows the intersection of the
'two, with the selected fields and values of each of the original themes. 
'The script works on the selected features of each of the two themes.  
'It is particularly useful for line-on-line intersections, to combine 
'attributes from two linear themes based on the same linework.


'***********************GET FIRST LINEAR THEME**************************

theView = av.GetActiveDoc
theActiveThemes = theView.GetActiveThemes
theFirstTheme = theActiveThemes.Get(0)
theFirstFTab = theFirstTheme.GetFTab
theFirstShapeField = theFirstFTab.FindField("Shape")
theFirstSelection = theFirstFTab.GetSelection
if (theFirstSelection.Count = 0) then
  theFirstSelection = theFirstFTab
end  
theFirstFieldList = theFirstFTab.GetFields
theFirstFields = List.Make
for each theField in theFirstFieldList
  if (theField.GetAlias <> "Shape") then
    theFirstFields.Add(theField.GetAlias)
  end
end
theFirstChoices = MsgBox.MultiListAsString(theFirstFields, "Which fields from"++theFirstTheme.AsString++"would you like in the ouput file?","Select Fields from First Theme")
if (theFirstChoices = nil) then
  exit
end


'*************************GET SECOND LINEAR THEME************************

theThemeList = theView.GetThemes
theThemeListClone = theThemeList.Clone
theThemeListClone.RemoveObj(theFirstTheme)
theSecondTheme = MsgBox.List(theThemeListClone, "Choose a theme to intersect with"++theFirstTheme.AsString,"Input Dialog")
if (theSecondTheme = Nil) then
  exit
end
theSecondFtab = theSecondTheme.GetFtab
theSecondShapeField = theSecondFTab.FindField("Shape")
theSecondSelection = theSecondFTab.GetSelection
if (theSecondSelection.Count = 0) then
  theSecondSelection = theSecondFTab
end  
theSecondFieldList = theSecondFTab.GetFields
theSecondFields = List.Make
for each theField in theSecondFieldList
  if (theField.GetAlias <> "Shape") then
    theSecondFields.Add(theField.GetAlias)
  end
end
theSecondChoices = MsgBox.MultiListAsString(theSecondFields, "Which fields from"++theSecondTheme.AsString++"would you like in the ouput file?","Select Fields from Second Theme")
if (theSecondChoices = nil) then
  exit
end



'********************CREATE NEW INTERSECTION THEME************************

def = av.GetProject.MakeFileName("theme", "shp")
def = FileDialog.Put(def, "*.shp", "Specify Output Shapefile")
if (def <> nil) then
  tbl = FTab.MakeNew(def, polyline)
  if (tbl.HasError) then
     if (tbl.HasLockError) then
        MsgBox.Error("Unable to acquire Write Lock for file " + def.GetBaseName, "")
     else
        MsgBox.Error("Unable to create " + def.GetBaseName, "")
     end
     return nil
  end
  tbl.SetEditable(False)
  theNewTheme = FTheme.Make(tbl)
  theView.AddTheme(theNewTheme)
  theNewTheme.SetActive(True)
  theNewTheme.SetVisible(True)
  av.GetProject.SetModified(True)
else
  exit
end

theNewFtab = theNewTheme.GetFtab
theNewFTab.SetEditable(True)
theNewShapeField = theNewFTab.FindField("Shape")


'****************ADD FIELDS FROM ORIGINAL THEMES****************

theNewFieldList = List.Make
theNewLengthField = Field.Make("New Length",#FIELD_DECIMAL,7,2)
theNewFieldList.Add(theNewLengthField)
for each theField in theFirstFieldList
  if (theFirstChoices.FindByValue(theField.GetAlias) <> -1) then
    theNewFieldList.Add(Field.Make(theField.GetAlias,theField.GetType,theField.GetWidth,theField.GetPrecision))
  end
end
for each theField in theSecondFieldList
  if (theSecondChoices.FindByValue(theField.GetAlias) <> -1) then
    theNewFieldList.Add(Field.Make(theField.GetAlias,theField.GetType,theField.GetWidth,theField.GetPrecision))
  end
end
theNewFtab.AddFields(theNewFieldList)



'*********ADD NEW LINES TO SHAPEFILE & POPULATE ATTRIBUTES************

av.ShowMsg("Intersecting"++theFirstTheme.AsString++"with"++theSecondTheme.AsString++"...")
av.UseWaitCursor
av.ShowStopButton
if (theFirstSelection.Is(BitMap)) then
  theTotalRecs = theFirstSelection.Count
else
  theTotalRecs = theFirstSelection.GetNumRecords
end
theCurrentRecNumber = 0
for each theFirstRec in theFirstSelection     '****LOOP THROUGH RECORDS IN FIRST THEME
  theCurrentRecNumber = theCurrentRecNumber + 1
  theProgress = (theCurrentRecNumber/theTotalRecs) * 100
  GoOn = av.SetStatus(theProgress)
  if (not GoOn) then
    break
  end
  theFirstLine = theFirstFTab.ReturnValue(theFirstShapeField, theFirstRec)
  for each theSecondRec in theSecondSelection      '****LOOP THROUGH RECORDS IN SECOND THEME
    theSecondLine = theSecondFTab.ReturnValue(theSecondShapeField, theSecondRec)
    theNewLine = theFirstLine.LineIntersection(theSecondLine)
    if (theNewLine.is(Polyline) and theNewLine.IsNull.Not) then  '****CHECK IF THEMES INTERSECT AS A LINE
      theNewRec = theNewFTab.AddRecord
      theNewFTab.SetValue(theNewShapeField, theNewRec, theNewLine)
      theNewFTab.SetValue(theNewLengthField, theNewRec, Units.Convert(theNewLine.ReturnLength,#UNITS_LINEAR_METERS,#UNITS_LINEAR_MILES ))
      for each theField in theFirstFieldList
        if (theFirstChoices.FindByValue(theField.GetAlias) <> -1) then
          theValue = theFirstFTab.ReturnValue(theField,theFirstRec)
          theNewFtab.SetValue(theNewFtab.FindField(theField.GetAlias),theNewRec,theValue)
        end
      end
      for each theField in theSecondFieldList
        if (theSecondChoices.FindByValue(theField.GetAlias) <> -1) then
          theValue = theSecondFTab.ReturnValue(theField,theSecondRec)
          theNewFtab.SetValue(theNewFtab.FindField(theField.GetAlias),theNewRec,theValue)
        end
      end
    end
  end
end

av.ClearMsg
theNewFTab.SetEditable(False)
theNewTheme.Invalidate(False)