/* Adept MobileRobots Robotics Interface for Applications (ARIA) Copyright (C) 2004, 2005 ActivMedia Robotics LLC Copyright (C) 2006, 2007, 2008, 2009, 2010 MobileRobots Inc. Copyright (C) 2011, 2012, 2013 Adept Technology This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA If you wish to redistribute ARIA under different terms, contact Adept MobileRobots for information about a commercial version of ARIA at robots@mobilerobots.com or Adept MobileRobots, 10 Columbia Drive, Amherst, NH 03031; +1-603-881-7960 */ #include #include "Aria.h" /** @example functorExample.cpp Illustrates the use of functors * * @sa @ref functors in the ARIA overview */ /* This is a class that has some callback methods. Functors which refer to these callbacks will be passed to the DriverClass. */ class CallbackContainer { public: void callback1(); void callback2(int i); bool callback3(const char *str); }; void CallbackContainer::callback1() { printf("CallbackContainer::callback1 called.\n"); } void CallbackContainer::callback2(int i) { printf("CallbackContainer::callback2 called with argument of '%d'\n", i); } bool CallbackContainer::callback3(const char *str) { printf("CallbackContainer::callback3 called with argument of '%s'.\n", str); return(true); } /* * Functors can also invoke global functions. */ void globalCallback() { printf("globalCallback() called.\n"); } /* This is a "driver" class. It takes three functors of different types and will invoke the three functors. This is a typical use of functors: to pass information or event notifications between loosely coupled objects. */ class DriverClass { public: void invokeFunctors(); void setCallback1(ArFunctor *func) {myFunc1=func;} void setCallback2(ArFunctor1 *func) {myFunc2=func;} void setCallback3(ArRetFunctor1 *func) {myFunc3=func;} protected: ArFunctor *myFunc1; ArFunctor1 *myFunc2; ArRetFunctor1 *myFunc3; }; void DriverClass::invokeFunctors() { bool ret; printf("Invoking functor1... "); myFunc1->invoke(); printf("Invoking functor2... "); myFunc2->invoke(23); /* For functors with return values, use invorkeR() instead of invoke() to get the return value. The invoke() function can also be used to invoke the functor, but the return value is lost. (And is a possible source of memory leaks if you were supposed to free a pointer returned.) */ printf("Invoking functor3... "); ret=myFunc3->invokeR("This is a string argument"); if (ret) printf("\t-> functor3 returned 'true'\n"); else printf("\t-> functor3 returned 'false'\n"); } int main() { CallbackContainer cb; DriverClass driver; ArFunctorC functor1(cb, &CallbackContainer::callback1); ArFunctor1C functor2(cb, &CallbackContainer::callback2); ArRetFunctor1C functor3(cb, &CallbackContainer::callback3); driver.setCallback1(&functor1); driver.setCallback2(&functor2); driver.setCallback3(&functor3); driver.invokeFunctors(); /* You can make functors that target global functions too. */ ArGlobalFunctor globalFunctor(&globalCallback); printf("Invoking globalFunctor... "); globalFunctor.invoke(); /* You can also include the values of arguments in an ArFunctor object, if you * want to use the same value in every invocation of the functor. */ ArFunctor1C functor4(cb, &CallbackContainer::callback2, 42); printf("Invoking functor with constant argument... "); functor4.invoke(); /* Functors can be downcast to parent interface classes, as long as their invocation * does not require arguments. */ ArFunctor* baseFunctor = &functor4; printf("Invoking downcast functor... "); baseFunctor->invoke(); return(0); }