csevcord.h Source File

00001 /*
00002     Copyright (C) 2000 by Jorrit Tyberghein
00003     Written by Michael Dale Long.
00004 
00005     This library is free software; you can redistribute it and/or
00006     modify it under the terms of the GNU Library General Public
00007     License as published by the Free Software Foundation; either
00008     version 2 of the License, or (at your option) any later version.
00009 
00010     This library is distributed in the hope that it will be useful,
00011     but WITHOUT ANY WARRANTY; without even the implied warranty of
00012     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013     Library General Public License for more details.
00014 
00015     You should have received a copy of the GNU Library General Public
00016     License along with this library; if not, write to the Free
00017     Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00018 */
00019 
00020 #ifndef __CS_CSEVCORD__
00021 #define __CS_CSEVCORD__
00022 
00023 #include "csutil/scf.h"
00024 #include "iutil/event.h"
00025 struct iEventHandler;
00026 class csEventOutlet;
00027 
00028 class csEventCord : public iEventCord
00029 {
00030 protected:
00031   // Pass events to the system queue?
00032   volatile bool pass;
00033 
00034   // The category and subcategory of this events on this cord
00035   int category, subcategory;
00036 
00037   // Linked list of plugins
00038   struct PluginData
00039   {
00040     iEventHandler *plugin;
00041     int priority;
00042     PluginData *next;
00043   };
00044 
00045   // The cord itself
00046   PluginData *plugins;
00047 
00048   // Protection against multiple threads accessing the same cord
00049   volatile int SpinLock;
00050 
00051   // Lock the queue for modifications: NESTED CALLS TO LOCK/UNLOCK NOT ALLOWED!
00052   inline void Lock() { while (SpinLock) {} SpinLock++; }
00053   // Unlock the queue
00054   inline void Unlock() { SpinLock--; }
00055 
00056   // iEventOutlet places events into cords.
00057   friend class csEventOutlet;
00058   bool Post(iEvent*);
00059 
00060 public:
00061   SCF_DECLARE_IBASE;
00062 
00064   csEventCord(int category, int subcategory);
00065 
00067   virtual int Insert(iEventHandler*, int priority);
00068 
00070   virtual void Remove(iEventHandler*);
00071 
00073   virtual bool GetPass() const { return pass; }
00074 
00076   virtual void SetPass(bool flag) { pass = flag; }
00077 
00079   virtual int GetCategory() const { return category; }
00080 
00081   // Get the subcategory of this cord.
00082   virtual int GetSubcategory() const { return subcategory; }
00083 };
00084 
00085 #endif // ! __CS_CSEVCORD__