test
Dependents: BLE_PowerBank_HeyFaradey
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ble/FunctionPointerWithContext.h
- Committer:
- rgrover1
- Date:
- 2015-11-03
- Revision:
- 873:2e1a7bcf6590
- Parent:
- 862:d4be8c0b9ab3
- Child:
- 879:4de7fb4da6ca
File content as of revision 873:2e1a7bcf6590:
/* mbed Microcontroller Library * Copyright (c) 2006-2013 ARM Limited * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef MBED_FUNCTIONPOINTER_WITH_CONTEXT_H #define MBED_FUNCTIONPOINTER_WITH_CONTEXT_H #include <string.h> /** A class for storing and calling a pointer to a static or member void function * which takes a context. */ template <typename ContextType> class FunctionPointerWithContext { public: typedef FunctionPointerWithContext<ContextType> *pFunctionPointerWithContext_t; typedef void (*pvoidfcontext_t)(ContextType context); /** Create a FunctionPointerWithContext, attaching a static function * * @param function The void static function to attach (default is none) */ FunctionPointerWithContext(void (*function)(ContextType context) = NULL) : _function(NULL), _caller(NULL), _next(NULL) { attach(function); } /** Create a FunctionPointerWithContext, attaching a member function * * @param object The object pointer to invoke the member function on (i.e. the this pointer) * @param function The address of the void member function to attach */ template<typename T> FunctionPointerWithContext(T *object, void (T::*member)(ContextType context)) : _memberFunctionAndPointer(), _caller(NULL), _next(NULL) { attach(object, member); } /** Attach a static function * * @param function The void static function to attach (default is none) */ void attach(void (*function)(ContextType context) = NULL) { _function = function; _caller = functioncaller; } /** Attach a member function * * @param object The object pointer to invoke the member function on (i.e. the this pointer) * @param function The address of the void member function to attach */ template<typename T> void attach(T *object, void (T::*member)(ContextType context)) { _memberFunctionAndPointer._object = static_cast<void *>(object); memcpy(_memberFunctionAndPointer._memberFunction, (char*) &member, sizeof(member)); _caller = &FunctionPointerWithContext::membercaller<T>; } /** Call the attached static or member function; and if there are chained * FunctionPointers their callbacks are invoked as well. * @Note: all chained callbacks stack up; so hopefully there won't be too * many FunctionPointers in a chain. */ void call(ContextType context) { _caller(this, context); /* Propagate the call to next in the chain. */ if (_next) { _next->call(context); } } /** * Setup an external FunctionPointer as a next in the chain of related * callbacks. Invoking call() on the head FunctionPointer will invoke all * chained callbacks. * * Refer to 'CallChain' as an alternative. */ void chainAsNext(pFunctionPointerWithContext_t next) { _next = next; } pFunctionPointerWithContext_t getNext(void) const { return _next; } pvoidfcontext_t get_function() const { return (pvoidfcontext_t)_function; } private: template<typename T> static void membercaller(pFunctionPointerWithContext_t self, ContextType context) { if (self->_memberFunctionAndPointer._object) { T *o = static_cast<T *>(self->_memberFunctionAndPointer._object); void (T::*m)(ContextType); memcpy((char*) &m, self->_memberFunctionAndPointer._memberFunction, sizeof(m)); (o->*m)(context); } } static void functioncaller(pFunctionPointerWithContext_t self, ContextType context) { if (self->_function) { self->_function(context); } } struct MemberFunctionAndPtr { /* * forward declaration of a class and a member function to this class. * Because the compiler doesn't know anything about the forwarded member * function, it will always use the biggest size and the biggest alignment * that a member function can take for objects of type UndefinedMemberFunction. */ class UndefinedClass; typedef void (UndefinedClass::*UndefinedMemberFunction)(ContextType); void* _object; union { char _memberFunction[sizeof(UndefinedMemberFunction)]; UndefinedMemberFunction _alignment; }; }; union { pvoidfcontext_t _function; /**< static function pointer - NULL if none attached */ /** * object this pointer and pointer to member - * _memberFunctionAndPointer._object will be NULL if none attached */ MemberFunctionAndPtr _memberFunctionAndPointer; }; void (*_caller)(FunctionPointerWithContext*, ContextType); pFunctionPointerWithContext_t _next; /**< Optional link to make a chain out of functionPointers; this * allows chaining function pointers without requiring * external memory to manage the chain. Also refer to * 'CallChain' as an alternative. */ }; #endif // ifndef MBED_FUNCTIONPOINTER_WITH_CONTEXT_H