FunctionPointer.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy
00005  * of this software and associated documentation files (the "Software"), to deal
00006  * in the Software without restriction, including without limitation the rights
00007  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008  * copies of the Software, and to permit persons to whom the Software is
00009  * furnished to do so, subject to the following conditions:
00010  *
00011  * The above copyright notice and this permission notice shall be included in
00012  * all copies or substantial portions of the Software.
00013  *
00014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
00020  * SOFTWARE.
00021  */
00022 #ifndef MBED_FUNCTIONPOINTER_H
00023 #define MBED_FUNCTIONPOINTER_H
00024 
00025 #include <string.h>
00026 
00027 namespace mbed {
00028 
00029 /** A class for storing and calling a pointer to a static or member void function
00030  */
00031 class FunctionPointer {
00032 public:
00033 
00034     /** Create a FunctionPointer, attaching a static function
00035      *
00036      *  @param function The void static function to attach (default is none)
00037      */
00038     FunctionPointer(void (*function)(void) = 0);
00039 
00040     /** Create a FunctionPointer, attaching 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     FunctionPointer(T *object, void (T::*member)(void)) {
00047         attach(object, member);
00048     }
00049 
00050     /** Attach a static function
00051      *
00052      *  @param function The void static function to attach (default is none)
00053      */
00054     void attach(void (*function)(void) = 0);
00055 
00056     /** Attach a member function
00057      *
00058      *  @param object The object pointer to invoke the member function on (i.e. the this pointer)
00059      *  @param function The address of the void member function to attach
00060      */
00061     template<typename T>
00062     void attach(T *object, void (T::*member)(void)) {
00063         _object = static_cast<void*>(object);
00064         memcpy(_member, (char*)&member, sizeof(member));
00065         _membercaller = &FunctionPointer::membercaller<T>;
00066         _function = 0;
00067     }
00068 
00069     /** Call the attached static or member function
00070      */
00071     void call();
00072 
00073 private:
00074     template<typename T>
00075     static void membercaller(void *object, char *member) {
00076         T* o = static_cast<T*>(object);
00077         void (T::*m)(void);
00078         memcpy((char*)&m, member, sizeof(m));
00079         (o->*m)();
00080     }
00081 
00082     void (*_function)(void);                // static function pointer - 0 if none attached
00083     void *_object;                            // object this pointer - 0 if none attached
00084     char _member[16];                        // raw member function pointer storage - converted back by registered _membercaller
00085     void (*_membercaller)(void*, char*);    // registered membercaller function to convert back and call _member on _object
00086 };
00087 
00088 } // namespace mbed
00089 
00090 #endif
00091