src_base_timer.hh

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/*
 * LEGAL:   COPYRIGHT (C) 2006 JIM E. BROOKS
 *          THIS SOURCE CODE IS RELEASED UNDER THE TERMS
 *          OF THE GNU GENERAL PUBLIC LICENSE VERSION 2 (GPL 2).
 *****************************************************************************/

#ifndef BASE_TIMER_HH
#define BASE_TIMER_HH 1

#define GET_TIMER() (base::Timer::GetInstance())

#include "base/time.hh"  // Milliseconds etc

namespace base {

const bool TIMER_ENABLED = true;
const bool TIMER_DISABLED = false;

// Macro to define nested class.
// Functor must not hold a ref-ptr to its owner
// (would create a cycle of reference-counted pointers).
#define CLASS_TICK_FUNCTOR( CLASS, MEMBER )                             \
    class TickFunctor : public base::Timer::Functor                     \
    {                                                                   \
    public:                                                             \
        TickFunctor( CLASS& obj ) : MEMBER(obj) { }                     \
        void operator()( const Milliseconds millisecElapsed );          \
    private:                                                            \
        CLASS& MEMBER;                                                  \
    };                                                                  \
    friend class TickFunctor;

// Macro.
#define CLASS_TICK_FUNCTOR_BASIC                                        \
    class TickFunctor : public base::Timer::Functor                     \
    {                                                                   \
    public:                                                             \
        void operator()( const Milliseconds millisecElapsed );          \
    };                                                                  \
    friend class TickFunctor;

class Timer
{

private:
    enum eRegistered { CALLBACK_UNREGISTERED = 0,  // "REGISTERED" predefined on Windows
                       CALLBACK_REGISTERED   = 1 };

public:
    enum eDisablement { CAN_DISABLE, CANNOT_DISABLE };

    class Functor : public Shared
    {
    
    public:
                        Functor( void ) { }
        virtual         ~Functor() { }
        virtual void    operator()( const Milliseconds millisecElapsed ) = 0;
    };

private:
    class Callback : public Shared
    {
    
    friend class Timer;
    public:
                    Callback( const bool registered,
                              const SharedPtr<Functor> functor,
                              const Milliseconds millisecFreq,
                              const Timer::eDisablement canDisable = CAN_DISABLE );
                    Callback( const Callback& src );
                    ~Callback();
        void        CallIfTimeHasCome( const Milliseconds millisecElapsed );
        bool        IfRegistered( void ) const { return mRegistered; }
        bool        IfCanDisable( void ) const { return mCanDisable; }

    private:
        enum                { NEVER_CALLED = -1 };
        bool                mRegistered;        
        shptr<Functor>      mFunctor;           
        Milliseconds        mMillisecFreq;      
        Milliseconds        mMillisecCalled;    
        bool                mCanDisable;        
    public:
        
    };

private:
    Timer( void );  // singleton
    ~Timer();

public:
// Client interface:
    CLASS_METHOD Timer& GetInstance( void )
    {
        if ( UX( msInstance == NULL ) )
            msInstance = new Timer;
        return *msInstance;
    }
    void                Enable( bool enable );
    Milliseconds        GetElapsedTime( void ) { return mElapsedTime; }  // time since start of program
    void                Register( SharedPtr<Functor> functor, const Milliseconds millisecFreq, eDisablement canDisable = CAN_DISABLE );
    void                Unregister( SharedPtr<Functor> functor );

// For integration:
    void                Tick( const Milliseconds millisecElapsed );

private:
    typedef map<SafePtr<Functor>,Callback> Callbacks;

    Callbacks::iterator Find( SafePtr<Functor> functor );

private:
    CLASS_CONST uint    MIN_MILLISEC = 1;
    CLASS_CONST uint    MAX_MILLISEC = THOUSAND * 60 * 60;  // 1 hour
    CLASS_VAR Timer*    msInstance;
    bool                mEnabled;
    bool                mBusy;          
    Milliseconds        mElapsedTime;   
    Callbacks           mCallbacks;     
};

} // namespace base

#endif // BASE_TIMER_HH

Palomino Flight Simulator documents generated by doxygen 1.5.6 on Mon Dec 29 17:26:59 2008