Planet
navi homePPSaboutscreenshotsdownloaddevelopmentforum

source: sandbox/src/libraries/util/Scope.h @ 7324

Last change on this file since 7324 was 6038, checked in by rgrieder, 15 years ago

Synchronised sandbox with current code trunk. There should be a few bug fixes.

  • Property svn:eol-style set to native
File size: 5.6 KB
Line 
1/*
2 *   ORXONOX - the hottest 3D action shooter ever to exist
3 *                    > www.orxonox.net <
4 *
5 *
6 *   License notice:
7 *
8 *   This program is free software; you can redistribute it and/or
9 *   modify it under the terms of the GNU General Public License
10 *   as published by the Free Software Foundation; either version 2
11 *   of the License, or (at your option) any later version.
12 *
13 *   This program is distributed in the hope that it will be useful,
14 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
15 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 *   GNU General Public License for more details.
17 *
18 *   You should have received a copy of the GNU General Public License
19 *   along with this program; if not, write to the Free Software
20 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
21 *
22 *   Author:
23 *      Fabian 'x3n' Landau
24 *   Co-authors:
25 *      ...
26 *
27 */
28
29#ifndef __Util_Scope_H__
30#define __Util_Scope_H__
31
32#include "UtilPrereqs.h"
33
34#include <cassert>
35#include <map>
36#include <set>
37
38#include "Debug.h"
39#include "ScopeGuard.h"
40
41namespace orxonox
42{
43    /**
44        @brief The ScopeManager stores the variables of the scope templates in a statically linked context.
45    */
46    class _UtilExport ScopeManager
47    {
48        template <ScopeID::Value scope>
49        friend class Scope;
50        friend class ScopeListener;
51
52        private:
53            static std::map<ScopeID::Value, int> instanceCounts_s;                  //!< Counts the number of active instances (>0 means active) for a scope
54            static std::map<ScopeID::Value, std::set<ScopeListener*> > listeners_s; //!< Stores all listeners for a scope
55    };
56
57    /**
58        @brief ScopeListeners register themselves in the corresponding scope and wait for notifications.
59    */
60    class _UtilExport ScopeListener
61    {
62        template <ScopeID::Value scope>
63        friend class Scope;
64
65        protected:
66            //! Constructor: Registers the instance.
67            ScopeListener(ScopeID::Value scope) : scope_(scope), bActivated_(false)
68                { ScopeManager::listeners_s[this->scope_].insert(this); }
69            //! Destructor: Unregisters the instance.
70            virtual ~ScopeListener()
71                { ScopeManager::listeners_s[this->scope_].erase(this); }
72
73            //! Gets called if the scope is activated
74            virtual void activated() = 0;
75            //! Gets called if the scope is deactivated
76            virtual void deactivated() = 0;
77
78        private:
79            ScopeID::Value scope_; //!< Store the scope to unregister on destruction
80            bool bActivated_;
81    };
82
83    /**
84        @brief A scope for a given template argument is either active or not.
85
86        Objects inheriting from a ScopeListener are registered in a list (different for each scope).
87        If the scope gets activated or deactivated, all objects in this list are notified.
88    */
89    template <ScopeID::Value scope>
90    class Scope
91    {
92        public:
93            //! Constructor: Increases the instance counter and activates the scope if the count went from 0 to 1. Counts >1 don't change anything.
94            Scope()
95            {
96                try
97                {
98                    ScopeManager::instanceCounts_s[scope]++;
99                    assert(ScopeManager::instanceCounts_s[scope] > 0);
100                    if (ScopeManager::instanceCounts_s[scope] == 1)
101                    {
102                        Loki::ScopeGuard deactivator = Loki::MakeObjGuard(*this, &Scope::deactivateListeners);
103                        for (typename std::set<ScopeListener*>::iterator it = ScopeManager::listeners_s[scope].begin(); it != ScopeManager::listeners_s[scope].end(); )
104                        {
105                            (*it)->activated();
106                            (*(it++))->bActivated_ = true;
107                        }
108                        deactivator.Dismiss();
109                    }
110                }
111                catch (...)
112                {
113                    ScopeManager::instanceCounts_s[scope]--;
114                    throw;
115                }
116            }
117
118            //! Destructor: Decreases the instance counter and deactivates the scope if the count went from 1 to 0. Counts >0 don't change anything.
119            ~Scope()
120            {
121                ScopeManager::instanceCounts_s[scope]--;
122
123                // This shouldn't happen but just to be sure: check if the count is positive
124                assert(ScopeManager::instanceCounts_s[scope] >= 0);
125                if (ScopeManager::instanceCounts_s[scope] < 0)
126                    ScopeManager::instanceCounts_s[scope] = 0;
127
128                if (ScopeManager::instanceCounts_s[scope] == 0)
129                    this->deactivateListeners();
130            }
131
132            void deactivateListeners()
133            {
134                for (typename std::set<ScopeListener*>::iterator it = ScopeManager::listeners_s[scope].begin(); it != ScopeManager::listeners_s[scope].end(); )
135                {
136                    if ((*it)->bActivated_)
137                    {
138                        try
139                            { (*it)->deactivated(); }
140                        catch (...)
141                            { COUT(0) << "ScopeListener::deactivated() failed! This MUST NOT happen, fix it!" << std::endl; }
142                        (*(it++))->bActivated_ = false;
143                    }
144                    else
145                        ++it;
146                }
147            }
148
149            //! Returns true if the scope is active.
150            static bool isActive()
151            {
152                return (ScopeManager::instanceCounts_s[scope] > 0);
153            }
154    };
155}
156
157#endif /* __Util_Scope_H__ */
Note: See TracBrowser for help on using the repository browser.