'View.RandomPointTheme

' Generates a point theme containing random points within a region
' defined by a selected polygon feature in the active feature theme

' May be used in a projected View

'**** get first selected polygon from first active theme

theTitle = "Random Points"
theView = av.GetActiveDoc
thePrj = theView.GetProjection
ThemeList = theView.GetActiveThemes
if (ThemeList.Count = 0) then
   MsgBox.Info("No Active Theme",theTitle)
   return nil
end
theTheme = ThemeList.Get(0)
if (theTheme.Is(FTheme).Not) then
   MsgBox.Info("Active Theme is not an FTheme",theTitle)
   return nil
end
TheFTab = theTheme.GetFTab
TheType = TheFTab.GetShapeClass.GetClassName
if (TheType <> "Polygon") then
   MsgBox.Info("Active Theme is not Polygon",theTitle)
   return nil
end
recno = theFTab.GetSelection.GetNextSet(-1)
if (recno = -1) then
   MsgBox.Info("No feature selected",theTitle)
   return nil
end
thePolygon = theFTab.ReturnValue(theFTab.FindField("Shape"),recno)
if (thePrj.IsNull.Not) then
   temp = thePolygon.ReturnProjected(thePrj)
   thePolygon = temp
end

'**** get number of points

temp = MsgBox.Input("Number of Points:",theTitle,"1")
if (temp = nil) then
   return nil
end
NumPt = temp.AsNumber

'**** get tolerances

temp = MsgBox.Input("Minimum Distance to Boundary",theTitle,"0")
if (temp = nil) then
   return nil
end
BndTol = temp.AsNumber
temp = MsgBox.Input("Minimum Distance to Another Point",theTitle,"0")
if (temp = nil) then
   return nil
end
PTol = temp.AsNumber

'**** get output shapefile

out_name = FileName.GetCWD.MakeTmp("Theme","shp")
out_name = FileDialog.Put(out_name, "*.shp", "Output Shapefile")
if (out_name = nil) then
   return nil
end

'**** let's crank it!!!!

PShape = FTab.MakeNew(out_name, Point)
fields = List.Make
fields.Add(Field.Make("ID",#FIELD_LONG,11,0))
PShape.AddFields(fields)
theExtent = thePolygon.ReturnExtent
X0 = theExtent.GetLeft
Y0 = theExtent.GetBottom
X1 = theExtent.GetRight
Y1 = theExtent.GetTop
numdec = NumPt.Log(10).Ceiling + 2
w = theExtent.GetWidth min theExtent.GetHeight
if (w < 1) then
   numdec = numdec + w.Log(10).Abs.Ceiling
end
av.ClearMsg
av.ClearStatus
av.ShowMsg("Percent Done: 0%")
av.ShowStopButton
recno = -1
for each i in 1..NumPt
   Done = false
   iteration = 0
   while (Done.Not)
      if ((iteration mod 100) = 0) then
         iteration = 0
         Cancel = av.SetWorkingStatus.Not
         if (Cancel) then
            break
         end
      end
      u = (X1 - X0) * (10 ^ numdec)
      X = (Number.MakeRandom(0,u) / (10 ^ numdec)) + X0
      u = (Y1 - Y0) * (10 ^ numdec)
      Y = (Number.MakeRandom(0,u) / (10 ^ numdec)) + Y0
      thePoint = X@Y
      Done = true
      if (thePolygon.Contains(thePoint).Not) then
         Done = false
      end
      if (thePoint.Distance(thePolygon.AsPolyline) < BndTol) then
         Done = false
      end
      PShape.SelectByPoint(thePoint,PTol,#VTAB_SELTYPE_NEW)
      if (PShape.GetSelection.GetNextSet(-1) <> -1) then
         Done = false
      end
      iteration = iteration + 1
   end
   if (Cancel) then
      break
   end
   recno = PShape.AddRecord
   PShape.SetValue(PShape.FindField("ID"),recno,i)
   if (thePrj.IsNull.Not) then
      temp = thePoint.ReturnUnprojected(thePrj)
      thePoint = temp
   end
   PShape.SetValue(PShape.FindField("Shape"),recno,thePoint)
   av.ShowMsg("Percentage Done:"++(100*i/NumPt).AsString+"%")
end
av.ClearMsg
av.ClearStatus

'**** check for null shapefile

if (recno = -1) then
   PShape.Deactivate
   PShape = nil
   av.PurgeObjects
   File.Delete(out_name)
   out_name.SetExtension("shx")
   File.Delete(out_name)
   out_name.SetExtension("dbf")
   File.Delete(out_name)
   return nil
end

'**** ask if add to View

theView = av.GetActiveDoc
if (MsgBox.YesNo("Add shapefile as theme to the view?",theTitle,true)) then
   fthm = FTheme.Make(PShape)
   theView.AddTheme(fthm)
   theView.GetWin.Activate
end