You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
56 lines
1.9 KiB
56 lines
1.9 KiB
14 years ago
|
/*
|
||
|
|
* Copyright (c) 2003 Patrick Julien <freak@codepimps.org>
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or modify
|
||
|
|
* it under the terms of the GNU General Public License as published by
|
||
|
|
* the Free Software Foundation; either version 2 of the License, or
|
||
|
|
* (at your option) any later version.
|
||
|
|
*
|
||
|
|
* This program is distributed in the hope that it will be useful,
|
||
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
* GNU General Public License for more details.
|
||
|
|
*
|
||
|
|
* You should have received a copy of the GNU General Public License
|
||
|
|
* along with this program; if not, write to the Free Software
|
||
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef KIS_CANVAS_OBSERVER_H_
|
||
|
|
#define KIS_CANVAS_OBSERVER_H_
|
||
|
|
|
||
|
|
class KisCanvasSubject;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* This is the base interface plugins use to implement the Observer
|
||
|
|
* design pattern. Observer can register themselves with an implementation
|
||
|
|
* of KisCanvasSubject. The KisCanvasSubject will then call update()
|
||
|
|
* on all registered observers whenever something interesting has happened.
|
||
|
|
*
|
||
|
|
* (This is something my predecessor should have done with signals and slots,
|
||
|
|
* I think...)
|
||
|
|
*/
|
||
|
|
class KisCanvasObserver {
|
||
|
|
public:
|
||
|
|
KisCanvasObserver() {};
|
||
|
|
virtual ~KisCanvasObserver() {};
|
||
|
|
|
||
|
|
public:
|
||
|
|
/**
|
||
|
|
* Implement this function to query the KisCanvasSubject implementation
|
||
|
|
* about state that may be interesting, such as current paint color and
|
||
|
|
* so on.
|
||
|
|
*
|
||
|
|
* @param subject the KisCanvasSubject that may know something that's
|
||
|
|
* interesting for us.
|
||
|
|
*/
|
||
|
|
virtual void update(KisCanvasSubject *subject) = 0;
|
||
|
|
|
||
|
|
private:
|
||
|
|
KisCanvasObserver(const KisCanvasObserver&);
|
||
|
|
KisCanvasObserver& operator=(const KisCanvasObserver&);
|
||
|
|
};
|
||
|
|
|
||
|
|
#endif // KIS_CANVAS_OBSERVER_H_
|
||
|
|
|