-- Created on: 1993-10-19
-- Created by: Christian CAILLET
-- Copyright (c) 1993-1999 Matra Datavision
-- Copyright (c) 1999-2014 OPEN CASCADE SAS
--
-- This file is part of Open CASCADE Technology software library.
--
-- This library is free software; you can redistribute it and/or modify it under
-- the terms of the GNU Lesser General Public License version 2.1 as published
-- by the Free Software Foundation, with special exception defined in the file
-- OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
-- distribution for complete text of the license and disclaimer of any warranty.
--
-- Alternatively, this file may be used under the terms of Open CASCADE
-- commercial license or contractual agreement.

deferred class GeneralModifier  from IFSelect  inherits TShared

    ---Purpose : This class gives a frame for Actions which modify the effect
    --           of a Dispatch, i.e. :
    --           By Selections and Dispatches, an original Model can be
    --           splitted into one or more "target" Models : these Models
    --           contain Entities copied from the original one (that is, a
    --           part of it). Basically, these dispatched Entities are copied
    --           as identical to their original counterparts. Also the copied
    --           Models reproduce the Header of the original one.
    --           
    --           Modifiers allow to change this copied content : this is the
    --           way to be used for any kind of alterations, adaptations ...
    --           They are exploited by a ModelCopier, which firstly performs
    --           the copy operation described by Dispatches, then invokes the
    --           Modifiers to work on the result.
    --           
    --           Each GeneralModifier can be attached to :
    --           - all the Models produced
    --           - a Dispatch (it will be applied to all the Models obtained
    --             from this Dispatch) designated by its Ident in a ShareOut
    --           - in addition, to a Selection (facultative) : this adds a
    --             criterium, the Modifier is invoked on a produced Model only
    --             if this Model contains an Entity copied from one of the
    --             Entities designated by this Selection.
    --             (for special Modifiers from IFAdapt, while they must work on
    --             definite Entities, this Selection is mandatory to run)
    --             
    --             Remark : this class has no action attached, it only provides
    --             a frame to work on criteria. Then, sub-classes will define
    --             their kind of action, which can be applied at a precise step
    --             of the production of a File : see Modifier, and in the
    --             package IFAdapt, EntityModifier and EntityCopier


uses AsciiString from TCollection, Selection, Dispatch

is

    Initialize (maychangegraph : Boolean);
    ---Purpose : Sets the Modifier criteria to default Values
    --           (i.e. "always applies")
    --           <maychangegraph> must be provided at creation time, to :
    --           - False if this GeneralModifier surely lets the graph of
    --             dependencies unchanged (NO edition of any reference, BUT
    --             also NO entity added or replaced or removed)
    --           - True if there is a possibility of changing the graph of
    --             dependencies when this modifier is applied

    MayChangeGraph (me) returns Boolean;
    ---Purpose : Returns True if this modifier may change the graph of
    --           dependences (aknowledged at creation time)

    SetDispatch (me : mutable; disp : any Dispatch);
    ---Purpose : Attaches to a Dispatch. If <disp> is Null, Resets it
    --           (to apply the Modifier on every Dispatch)

    Dispatch (me) returns any Dispatch;
    ---Purpose : Returns the Dispatch to be matched, Null if not set

    Applies (me; disp : Dispatch) returns Boolean;
    ---Purpose : Returns True if a Model obtained from the Dispatch <disp>
    --           is to be treated (apart from the Selection criterium)
    --           If Dispatch(me) is Null, returns True. Else, checks <disp>


    SetSelection (me : mutable; sel : Selection);
    ---Purpose : Sets a Selection : a Model is treated if it contains one or
    --           more Entities designated by the Selection

    ResetSelection (me : mutable);
    ---Purpose : Resets the Selection : this criterium is not longer active

    HasSelection (me) returns Boolean;
    ---Purpose : Returns True if a Selection is set as an additionnal criterium

    Selection (me) returns Selection;
    ---Purpose : Returns the Selection, or a Null Handle if not set


    Label (me) returns AsciiString from TCollection  is deferred;
    ---Purpose : Returns a short text which defines the operation performed

fields

    thesel  : Selection;
    thedisp : Dispatch;
    thechgr : Boolean;

end GeneralModifier;