-- File:	TDF_DeltaOnModification.cdl
--      	---------------------------
-- Author:	DAUTRY Philippe
--		<fid@fox.paris1.matra-dtv.fr>
---Copyright:	 MATRA DATAVISION 1997

---Version:	0.0
---History:	Version	Date		Purpose
--		0.0	Oct 10 1997	Creation


deferred class DeltaOnModification from TDF
    inherits AttributeDelta from TDF

	---Purpose: This class provides default services for an
	--          AttributeDelta on a MODIFICATION action.
	--          
	--          Applying this AttributeDelta means GOING BACK to
	--          the attribute previously registered state.

uses

    Attribute from TDF

-- raises

is

    Initialize(anAttribute: Attribute from TDF)
    	returns mutable DeltaOnModification from TDF;
	---Purpose: Initializes a TDF_DeltaOnModification.

    Apply (me : mutable)
    	is redefined virtual;
    	---Purpose: Applies the delta to the attribute.

end DeltaOnModification;