/************************************************
Copyright (c) 2016-2017, 2021 by Progress Software Corporation. All rights reserved.
*************************************************/
/* ------------------------------------------------------------------------
    File        : EventArgs
    Purpose     : Generic event arguments class, including static 'Empty'
                  option. 
    Syntax      : 
    Description : 
    @author pjudge
    Created     : Mon Jul 27 11:45:09 EDT 2009
    Notes       : * Using EventArgs allows us to extend arguments without
                    changing event signatures.
                  * this class is likely to be specialised, but there's no 
                    requirement for that to happen. although outside of 
                    'empty' this is a somewhat useless class :)
  ---------------------------------------------------------------------- */
block-level on error undo, throw.

using OpenEdge.Core.EventArgs.

class OpenEdge.Core.EventArgs serializable:

    /** A single instance of this class so that we don't have
        to pass nulls around (ie we can depend on there always being
        a value if we so desire).   */
    define static public property Empty as EventArgs no-undo
        get():
            if not valid-object(EventArgs:Empty) then
                EventArgs:Empty = new EventArgs().
             
             return EventArgs:Empty.
        end.
        private set.
    
    constructor public EventArgs():
        /* Default constructor */
    end constructor.
    
end class.
