Item Classes

All graphical entities used to make maps and drawings (e.g. LineString, Polygon) are known as item classes. They are all sub-classes of an Item.

All item classes have properties that can be examined and edited using Properties or the Maps Control Bar.

Sub-classes of an Item inherit its properties and also include their own special properties.

For clarity and simplicity these item classes are grouped together with similar item classes into categories. These categories are reflected in the list below and on the Item menu of the main SIS Desktop 9 window.

This menu reflects the fact that some item classes have methods (i.e. commands) that can be applied to a specific item class. These methods are also available o

n the local, right mouse button menu.

The following table summarises the Cadcorp terminology for item classes.

Item class = _class$

Class name = _classLocal$ (may vary in countries using a localised language)

Category Description _class$ _classLocal$
Point Point Point Point
  Multipoint Multipoint Multipoint
  Node Node Node
  TopoPoint TopoPoint TopoPoint
LineString LineString Line LineString
  MultiLineString MultiLine MultiLineString
  TopoLineString SeedChain TopoLineString
  Link Link Link
Polygon Polygon Area Polygon
  MultiPolygon MultiArea MultiPolygon
  TopoPolygon SeedArea TopoPolygon
3D Grid Grid Grid
  Surface Surface Surface
  Tin TinSurface Tin
  Solid SolidSurface Solid
Image Bitmap Bitmap Bitmap
  Image Image Image
  MetaFile MetaFile MetaFile
  QZone QZone QZone
Text BoxText BoxText BoxText
  Label BoxLabel  
  LineText LineText LineText
  Text Text Text
Collection [user defined] Insert Insert
  Assembly Assembly Assembly
  [user defined] Group Group
  Geometry/Collection MultiGeometry Geometry/Collection
Paper Dimension DimDistance Dimension
  Dimension DimChain Dimension
  Dimension DimRun Dimension
  Dimension DimDatum Dimension
  Graticule Graticule Graticule
  Key Map KeyMap KeyMap
  North Point NorthPoint NorthPoint
  Map Frame MapFrame MapFrame
  Scale Bar ScaleBar ScaleBar
Rubber sheeting   Displace  
Miscellaneous   none  

Note: The above table is of most relevance to developers but desktop users may also need this information if they use expressions or filters, (eg class tree filter).