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CICA 1993 April
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CICA MS Windows - April 1993.iso
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misc
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iv26_w30
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intervie
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subject.h
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C/C++ Source or Header
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1980-01-03
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75 lines
/*
* Copyright (c) 1987, 1988, 1989 Stanford University
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided
* that the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name of Stanford not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. Stanford makes no representations about
* the suitability of this software for any purpose. It is provided "as is"
* without express or implied warranty.
*
* STANFORD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
* IN NO EVENT SHALL STANFORD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
* OTHER TORTIOUS ACTION, 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 subject_h
#define subject_h
#include <InterViews/resource.h>
class Interactor;
class ViewList {
friend class Subject;
friend class InteractorItr;
Interactor* element;
ViewList* next;
};
class Subject : public Resource {
public:
Subject();
~Subject();
virtual void Attach(Interactor*);
virtual void Detach(Interactor*);
void all(InteractorItr&);
virtual void Notify();
boolean IsView(Interactor*);
protected:
ViewList* views;
private:
friend class InteractorItr;
};
class InteractorItr {
public:
InteractorItr() { cur = nil; }
InteractorItr(Subject* s) { s->all(*this); }
protected:
boolean more() { return cur != nil; }
InteractorItr& next() { cur = cur->next; return *this; }
Interactor* view() { return cur->element; }
private:
friend class Subject;
ViewList* cur;
};
#endif