' Name: View.AddXYCoordToFTab
' 
' Title:  Adds X and Y coordinates of features to Attribute Table
'
' Topics:  GeoData
'
' Description:  Adds two new fields, named X-coord and Y-coord, to the table
' of the first active theme in the TOC and fills the respective fields with
' the X,Y coordinates of the selected points (or all points if no selection 
' is defined) in a point theme.  If instead the active theme is a polygon 
' theme, then the X,Y coordinates of the polygon centroid are calculated. If 
' the theme is projected, the output coordinates will also be projected.
'
' Requires:  An active point or polygon theme. This script does minimal
' error checking and assumes that there is an active theme. 
'
' Self:  
'
' Returns:  

theView = av.GetActiveDoc
'must be global to work in Calc exp below
_theProjection = theView.GetProjection 
project_flag = _theProjection.IsNull.Not  'true if projected
theTheme = theView.GetActiveThemes.Get(0)

'Check if point or polygon theme
if (((theTheme.GetSrcName.GetSubName = "point") or 
    (theTheme.GetSrcName.GetSubName = "polygon")).Not) then
  MsgBox.Info("Active theme must be polygon or point theme","")
  exit
end  

'get the theme table and current edit state
theFTab = theTheme.GetFTab
theFields = theFTab.GetFields
edit_state = theFTab.IsEditable

'make sure table is editable and that fields can be added
if (theFtab.CanEdit) then
  theFTab.SetEditable(true)
  if ((theFTab.CanAddFields).Not) then
    MsgBox.Info("Can't add fields to the table."+NL+"Check write permission.",
    "Can't add X,Y coordinates")
    exit
  end
else
  MsgBox.Info("Can't modify the feature table."+NL+
  "Check write permission.","Can't add X,Y coordinates")
  exit
end

'Check if fields named "X-coord" and Y-coord" exist
x_exists = (theFTab.FindField("X-coord") = NIL).Not
y_exists = (theFtab.FindField("Y-coord") = NIL).Not

if (x_exists or y_exists) then 
  if (MsgBox.YesNo("Overwrite existing fields?",
  "X-coord, Y-coord fields already exist", false)) then
    'if ok to overwrite, delete the fields as they may not be defined
    'as required by this script (eg., created from another script).
    if (x_exists) then
      theFTab.RemoveFields({theFTab.FindField("X-coord")})
    end
    if (y_exists) then
      theFTab.RemoveFields({theFTab.FindField("Y-coord")})
    end
  else
    exit
  end  'if (MsgBox...)
end  'if

x = Field.Make ("X-coord",#FIELD_DECIMAL,18,5)
y = Field.Make ("Y-coord",#FIELD_DECIMAL,18,5)
theFTab.AddFields({x,y})

'Get point coordinates or polygon centroid coordinates
if (theTheme.GetSrcName.GetSubName = "point") then
  if (project_flag) then
    'Projection defined
    theFTab.Calculate("[Shape].ReturnProjected(_theProjection).GetX", x)
    theFTab.Calculate("[Shape].ReturnProjected(_theProjection).GetY", y)
  else
    'No projection defined
    theFTab.Calculate("[Shape].GetX", x)
    theFTab.Calculate("[Shape].GetY", y)
  end  'if
else  'polygon case
  if (project_flag) then
    theFTab.Calculate("[Shape].ReturnCenter.ReturnProjected(_theProjection).GetX", x)
    theFTab.Calculate("[Shape].ReturnCenter.ReturnProjected(_theProjection).GetY", y)
  else
    theFTab.Calculate("[Shape].ReturnCenter.GetX", x)
    theFTab.Calculate("[Shape].ReturnCenter.GetY", y)
  end  ' if
end

'Return editing state to pre-script running state
theFTab.SetEditable(edit_state)