-- File:	ParamCursor.cdl
-- Created:	Mon Oct 26 16:25:39 1992
-- Author:	Christian CAILLET
--		<cky@topsn2>
---Copyright:	 Matra Datavision 1992


class ParamCursor  from IGESData

    ---Purpose : Auxiliary class for ParamReader.
    --           It stores commands for a ParamReader to manage the current
    --           parameter number. Used by methods Read... from ParamReader.
    --           It allows to define the following commands :
    --           - read a parameter specified by a precise Number (basic case)
    --           - read a parameter then set Current Number to follow its number
    --           - read the current parameter (with Current Number) then
    --             advance Current Number by one
    --           - idem with several : read "nb" parameters from one specified,
    --             included, with or without setting Current Number to follow
    --             last parameter read
    --           - read several parameter from the current one, then advance
    --             Current Number to follow the last one read
    --           - Read several parameters (as above) but in interlaced lists,
    --             i.e. from complex items (each one including successively for
    --             instance, an Integer, a Real, an Entity ...)
    --             
    --           If commands to advance Current Number are not set, it must be
    --           set by the user (with method SetCurrent from ParamReader)
    --           ParamReader offers methods which create most useful cases
    ---See also : class ParamReader

uses Integer, Boolean

raises InterfaceError

is

    Create (num : Integer) returns ParamCursor;
    ---Purpose : Creates a Cursor to read a precise parameter of ParamReader,
    --           identified by its number, then set Current Number to "num + 1"
    --           (this constructor allows to simply give a Number to a method
    --           Read... from ParamReader, which will be translated into a
    --           ParamCursor by compiler)

    Create (num, nb : Integer; size : Integer = 1) returns ParamCursor;
    ---Purpose : Creates a Cursor to read a list of parameters (count "nb")
    --           starting from a precise one (number "num") included, then
    --           set Current Number of ParamNumber to the first following one
    --           ("num + nb")
    --           If size is given, it means that each parameter is made of more
    --           than one term. One term is the normal (default) case : for
    --           instance, a Parameter comprises one Integer, or one Entity ...
    --           Size gives the complete size of each Item if it is complex.
    --           To be used ONLY IF it is constant

    SetTerm (me : in out; size : Integer; autoadv : Boolean = Standard_True)
    	raises InterfaceError  is static;
    ---Purpose : Defines the size of a term to read in the item : this commands
    --           ParamReader to read "size" parameters for each item, then
    --           skip the remainder of the item to the same term of next Item
    --           (that is, skip "item size" - "term size")
    --           
    --           In addition, Offset from beginning of Item is managed :
    --           After being created, and for the frist call to SetTerm, the
    --           part of Item to be read begins exactly as the Item begins
    --           But after a SetTerm, the next read will add an offset which is
    --           the size of former term.
    --           
    --           autoadv commands Advance management. If it is True (default),
    --           the last SetTerm (Item size has been covered) calls SetAdvance
    --           If it is False, SetAdvance must be called directly if necessary
    --           
    --           Error if a SetTerm overpasses the size of the Item

    SetOne  (me : in out; autoadv : Boolean = Standard_True)
    	raises InterfaceError  is static;
    ---Purpose : Defines a term of one Parameter (very current case)

    SetXY   (me : in out; autoadv : Boolean = Standard_True)
    	raises InterfaceError  is static;
    ---Purpose : Defines a term of two Parameters for a XY (current case)

    SetXYZ  (me : in out; autoadv : Boolean = Standard_True)
    	raises InterfaceError  is static;
    ---Purpose : Defines a term of three Parameters for XYZ (current case)


    SetAdvance (me : in out; advance : Boolean) is static;
    ---Purpose : Changes command to advance current cursor after reading
    --           parameters. If "advance" True, sets advance, if "False",
    --           resets it. ParamCursor is created by default with True.

    Start    (me) returns Integer  is static;
    ---Purpose : Returns (included) starting number for reading parameters
    ---C++: inline

    Limit    (me) returns Integer  is static;
    ---Purpose : Returns (excluded) upper limit number for reading parameters
    ---C++ : inline

    Count    (me) returns Integer  is static;
    ---Purpose : Returns required count of items to be read
    ---C++ : inline

    ItemSize (me) returns Integer  is static;
    ---Purpose : Returns length of item (count of parameters per item)
    ---C++ : inline

    TermSize (me) returns Integer  is static;
    ---Purpose : Returns length of current term (count of parameters) in item
    ---C++ : inline

    Offset   (me) returns Integer  is static;
    ---Purpose : Returns offset from which current term must be read in item
    ---C++ : inline

    Advance  (me) returns Boolean  is static;
    ---Purpose : Returns True if Advance command has been set
    ---C++ : inline

fields

    thestart : Integer;
    thelimit : Integer;
    thecount : Integer;
    theisize : Integer;
    theoffst : Integer;
    thetsize : Integer;
    theadv   : Boolean;

end ParamCursor;