FunctionPointer.h

00001 /* mbed Microcontroller Library - FunctionPointer
00002  * Copyright (c) 2007-2009 ARM Limited. All rights reserved.
00003  */ 
00004  
00005 #ifndef MBED_FUNCTIONPOINTER_H
00006 #define MBED_FUNCTIONPOINTER_H
00007 
00008 #include <string.h>
00009 
00010 namespace mbed { 
00011 
00012 /** A class for storing and calling a pointer to a static or member void function
00013  */
00014 class FunctionPointer {
00015 
00016 public:
00017 
00018     /** Create a FunctionPointer, attaching a static function
00019      * 
00020      *  @param function The void static function to attach (default is none)
00021      */
00022     FunctionPointer(void (*function)(void) = 0);
00023 
00024     /** Create a FunctionPointer, attaching a member function
00025      * 
00026      *  @param object The object pointer to invoke the member function on (i.e. the this pointer)
00027      *  @param function The address of the void member function to attach 
00028      */
00029     template<typename T>    
00030     FunctionPointer(T *object, void (T::*member)(void)) {
00031         attach(object, member);
00032     }
00033 
00034     /** Attach a static function
00035      * 
00036      *  @param function The void static function to attach (default is none)
00037      */
00038     void attach(void (*function)(void) = 0);
00039     
00040     /** Attach a member function
00041      * 
00042      *  @param object The object pointer to invoke the member function on (i.e. the this pointer)
00043      *  @param function The address of the void member function to attach 
00044      */
00045     template<typename T>
00046     void attach(T *object, void (T::*member)(void)) {
00047         _object = static_cast<void*>(object);
00048         memcpy(_member, (char*)&member, sizeof(member));
00049         _membercaller = &FunctionPointer::membercaller<T>;
00050         _function = 0;
00051     }
00052 
00053     /** Call the attached static or member function
00054      */        
00055     void call();
00056         
00057 private:
00058 
00059     template<typename T>
00060     static void membercaller(void *object, char *member) {    
00061         T* o = static_cast<T*>(object);
00062         void (T::*m)(void);
00063         memcpy((char*)&m, member, sizeof(m));
00064         (o->*m)();
00065     }
00066     
00067     /** Static function pointer - 0 if none attached
00068      */
00069     void (*_function)(void);
00070     
00071     /** Object this pointer - 0 if none attached
00072      */
00073     void *_object;
00074     
00075     /** Raw member function pointer storage - converted back by registered _membercaller
00076      */
00077     char _member[16];
00078     
00079     /** Registered membercaller function to convert back and call _member on _object
00080      */
00081     void (*_membercaller)(void*, char*);
00082     
00083 };
00084 
00085 } // namespace mbed
00086 
00087 #endif