FryingPan/framework/Generic/ExtPropertyT.h

   1 /*
   2  * Amiga Generic Set - set of libraries and includes to ease sw development for all Amiga platforms
   3  * Copyright (C) 2001-2011 Tomasz Wiszkowski Tomasz.Wiszkowski at gmail.com.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19
  20 #ifndef _GENERIC_EXTPROPERTYT_H_
  21 #define _GENERIC_EXTPROPERTYT_H_
  22
  23 #include "Generic.h"
  24
  25 namespace GenNS
  26 {
  27    template<typename T>
  28       class ExtPropertyT : public Generic
  29    {
  30    public:
  31       class Handler
  32       {
  33       public:
  34          virtual bool   onPropSet(ExtPropertyT<T>*, const T&)     = 0;
  35          virtual T&     onPropGet(ExtPropertyT<T>*)               = 0;
  36       };
  37
  38       class Monitor
  39       {
  40       public:
  41          virtual void   onPropChange(ExtPropertyT<T>*, const T&)  = 0;
  42       };
  43
  44    protected:
  45       Handler                         *handler;
  46       VectorT<Monitor*>                monitors;
  47
  48    public:
  49       ExtPropertyT()
  50       {
  51          handler = 0;
  52       }
  53
  54       virtual ~ExtPropertyT()
  55       {
  56       }
  57
  58       virtual ExtPropertyT<T>&   operator = (const T& t)
  59       {
  60          ASSERT(handler != 0);
  61          if (handler == 0)
  62             return *this;
  63
  64          if (handler->onPropSet(this, t))
  65             NotifyAll();
  66          return *this;
  67       }
  68
  69       virtual                 operator T&()
  70       {
  71          ASSERT(handler != 0);
  72          return handler->onPropGet(this);
  73       }
  74
  75       virtual ExtPropertyT<T>&   operator << (Monitor *mon)
  76       {
  77          monitors << mon;
  78
  79          ASSERT(handler != 0);
  80          if (handler != 0)
  81             mon->onPropChange(this, handler->onPropGet(this));
  82
  83          return *this;
  84       }
  85
  86       virtual ExtPropertyT<T>&   operator >> (Monitor *mon)
  87       {
  88          monitors >> mon;
  89          return *this;
  90       }
  91
  92       virtual ExtPropertyT<T>&   SetPropHandler(Handler *f)
  93       {
  94          handler = f;
  95          return *this;
  96       }
  97
  98       virtual void            NotifyAll()
  99       {
 100          if (handler == 0)
 101             return;
 102
 103          for (int i=0; i<monitors.Count(); i++)
 104             monitors[i]->onPropChange(this, handler->onPropGet(this));
 105       }
 106    };
 107 };
 108
 109 #endif
 110