Support

'-- This script temporarily limits each theme to just the records

'-- in the display's extent and uses the built-in capability of a

'-- legend to return class counts to determine which classes 

'-- it can dispense with.  It is a general approach that 

'-- does not need to worry about the details of each legend. 



'-- Obtain the view's extent. It will be used to select the

'-- features for classification.

theView=av.GetActiveDoc

if (theView.Is(View).Not) then return NIL end

theExtent=theView.GetDisplay.ReturnExtent '-- Will select in the visible extents



'-- Process each active theme, if any.

sLog = "" ' Records what happens

for each theTheme in theView.GetActiveThemes

  if (theTheme.Is(FTheme) and theTheme.CanSelect and 

      theTheme.CanReturnClassCounts) then

    theFTab=theTheme.GetFtab

    '

    '-- Select visible features.

    theFTab.RememberSelection

    theTheme.SelectbyRect(theExtent,#VTAB_SELTYPE_NEW)

    '

    '-- Limit the theme to the selected features.

    theFTab.SetDefBitmap(theFTab.GetSelection.Clone)

    theFTab.UpdateDefBitmap

    '

    '-- Remove unused classes from the legend.

    lstCounts = theTheme.ReturnClassCounts

    lstClassifications = theTheme.GetLegend.GetClassifications

    lstSymbols = theTheme.GetLegend.GetSymbols

    n = 0 ' Counts the number of classes removed.

    for each i in lstClassifications.Count-2..0 by -1 ' Skip the NoData class

      if (lstCounts.Get(i) = 0) then

        lstClassifications.Remove(i)

        lstSymbols.Remove(i)

        n = n+1

      end

    end      

    theTheme.UpdateLegend ' Cause the legend to redraw in the TOC

    '

    '-- Log the changes.

    if (n = 1) then sClass = "class" else sClass = "classes" end

    sLog = sLog + NL + "[" + theTheme.GetName + "]: " + 

                       n.AsString ++ sClass ++ "removed."

    '

    '-- Restore the original definition and selection.

    theFTab.SetDefinition(theFTab.GetDefinition)

    theFTab.UpdateDefBitmap

    theFTab.SetSelection(theFTab.GetLastSelection)

    

  else '-- This is an image or grid theme, most likely.

    sLog = sLog + NL + "[" + theTheme.GetName + "] could not be modified."

  end

end



'-- Summarize results.

if (sLog <> "") then

  MsgBox.Report("Summary of changes made to legends:" + NL + sLog, Script.The.GetName)

end

'-- End of Script