EwFunctionPointer.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #ifndef EWFUNCTIONPOINTER_H
00017 #define EWFUNCTIONPOINTER_H
00018 
00019 #include <string.h>
00020 #include <stdint.h>
00021 #include "EwWindow.h"
00022 
00023 
00024 
00025 
00026 /** A class for storing and calling a pointer to a static or member void function
00027  */
00028 class EwFunctionPointer {
00029 public:
00030 
00031     /** Create a FunctionPointer, attaching a static function
00032      *
00033      *  @param function The void static function to attach (default is none)
00034      */
00035     EwFunctionPointer(void (*function)(EwWindow* w) = 0);
00036 
00037     /** Create a FunctionPointer, attaching a member function
00038      *
00039      *  @param object The object pointer to invoke the member function on (i.e. the this pointer)
00040      *  @param function The address of the void member function to attach
00041      */
00042     template<typename T>
00043     EwFunctionPointer(T *object, void (T::*member)(EwWindow* w)) {
00044         attach(object, member);
00045     }
00046 
00047     /** Attach a static function
00048      *
00049      *  @param function The void static function to attach (default is none)
00050      */
00051     void attach(void (*function)(EwWindow* w) = 0);
00052 
00053     /** Attach a member function
00054      *
00055      *  @param object The object pointer to invoke the member function on (i.e. the this pointer)
00056      *  @param function The address of the void member function to attach
00057      */
00058     template<typename T>
00059     void attach(T *object, void (T::*member)(EwWindow* w)) {
00060         _object = static_cast<void*>(object);
00061         memcpy(_member, (char*)&member, sizeof(member));
00062         _membercaller = &EwFunctionPointer::membercaller<T>;
00063         _function = 0;
00064     }
00065 
00066     /** Call the attached static or member function
00067      */
00068     void call(EwWindow* w);
00069 
00070 
00071 
00072 
00073 private:
00074     template<typename T>
00075     static void membercaller(void *object, char *member, EwWindow* w) {
00076         T* o = static_cast<T*>(object);
00077         void (T::*m)(EwWindow* w);
00078         memcpy((char*)&m, member, sizeof(m));
00079         (o->*m)(w);
00080     }
00081 
00082     void (*_function)(EwWindow* w);                // 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*, EwWindow* w);    // registered membercaller function to convert back and call _member on _object
00086 };
00087 
00088 
00089 
00090 #endif