-- File:	IFSelect_SelectControl.cdl
-- Created:	Wed Feb 16 10:07:01 1994
-- Author:	Christian CAILLET
--		<cky@mastox>
---Copyright:	 Matra Datavision 1994


deferred class SelectControl  from IFSelect  inherits Selection

    ---Purpose : A SelectControl kind Selection works with two input Selections
    --           in a dissymmetric way : the Main Input which gives an input
    --           list of Entities, to be processed, and the Second Input which
    --           gives another list, to be used to filter the main input.
    --           
    --           e.g. : SelectDiff retains the items of the Main Input which
    --             are not in the Control Input (which acts as Diff Input)
    --           or a specific selection which retains Entities from the Main
    --             Input if and only if they are concerned by an entity from
    --             the Control Input (such as Views in IGES, etc...)
    --           
    --           The way RootResult and Label are produced are at charge of
    --           each sub-class

uses  SelectionIterator

is

    MainInput    (me) returns mutable Selection;
    ---Purpose : Returns the Main Input Selection

    HasSecondInput (me) returns Boolean;
    ---Purpose : Returns True if a Control Input is defined
    --           Thus, Result can be computed differently if there is a
    --           Control Input or if there is none

    SecondInput (me) returns mutable Selection;
    ---Purpose : Returns the Control Input Selection, or a Null Handle

    SetMainInput    (me : mutable; sel : mutable Selection);
    ---Purpose : Sets a Selection to be the Main Input

    SetSecondInput (me : mutable; sel : mutable Selection);
    ---Purpose : Sets a Selection to be the Control Input


    -- RootResult,Label remain to be defined by each class of Selection
    -- (also HasUniqueResult if it applies)

    FillIterator (me; iter : in out SelectionIterator);
    ---Purpose : Puts in an Iterator the Selections from which "me" depends
    --           That is to say, the list of Input Selections


fields

    themain   : Selection;
    thesecond : Selection;

end SelectControl;