/*
 * Copyright (c) 1987, 1988, 1989, 1990, 1991 Stanford University
 * Copyright (c) 1991 Silicon Graphics, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software and 
 * its documentation for any purpose is hereby granted without fee, provided
 * that (i) the above copyright notices and this permission notice appear in
 * all copies of the software and related documentation, and (ii) the names of
 * Stanford and Silicon Graphics may not be used in any advertising or
 * publicity relating to the software without the specific, prior written
 * permission of Stanford and Silicon Graphics.
 * 
 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
 *
 * IN NO EVENT SHALL STANFORD OR SILICON GRAPHICS BE LIABLE FOR
 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 
 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
 * OF THIS SOFTWARE.
 */

/*
 * A subject is an object that has one or more views
 * that it wishes to notify when it changes.
 */

#ifndef iv2_6_subject_h
#define iv2_6_subject_h

#include <InterViews/boolean.h>
#include <InterViews/resource.h>

class Interactor;
class SubjectRep;

//: object with one or more views to notify when it changes (iv-2.6)
// <a href=../man3.1/Subject.html>man page</a>
class Subject : virtual public Resource {
public:
    virtual ~Subject();

    virtual void Attach(Interactor*);
    virtual void Detach(Interactor*);
    virtual void Notify();
    virtual boolean IsView(Interactor*);
protected:
    Subject();
private:
    SubjectRep* rep_;
};

#endif
