From: Leandro Lucarella <llucarella@integratech.com.ar>
Date: Wed, 21 Mar 2007 21:31:43 +0000 (+0000)
Subject: Add mem_cb functor to use an arbitrary memeber function as an event handler.
X-Git-Tag: 0.3~6
X-Git-Url: https://git.llucax.com/software/eventxx.git/commitdiff_plain/c584f2e4d45ee21a00dae09f4be54144eafef7ac?ds=inline

Add mem_cb functor to use an arbitrary memeber function as an event handler.
---

diff --git a/eventxx b/eventxx
index 6287659..94ee113 100644
--- a/eventxx
+++ b/eventxx
@@ -180,6 +180,12 @@
  * callbacks.
  */
 
+/** @example wrapped-functor-way.cpp
+ *
+ * This is a simple example illustrating the usage with an arbitrary member
+ * function as an event handler callbacks.
+ */
+
 /** @example mixed-way.cpp
  *
  * This is a simple example illustrating the usage with a mix of C-like callbacks
@@ -373,6 +379,9 @@ struct time: ::timeval
  * function objects (see eventxx::event, eventxx::timer and eventxx::signal
  * templates). The former are just typedef'ed specialization of the later.
  *
+ * A member function wrapper functor (eventxx::mem_cb) is also included,
+ * so you can use any member function (method) as an event handler.
+ *
  * All events derive from a plain class (not template) eventxx::basic_event, one
  * of the main utilities of it (besides containing common code ;) is to be used
  * in STL containers.
@@ -689,6 +698,38 @@ typedef eventxx::timer< ccallback_type > ctimer;
 /// Shortcut to C-style signal handler.
 typedef eventxx::signal< ccallback_type > csignal;
 
+/**
+ * Helper functor to use an arbitrary member function as an event handler.
+ *
+ * With this wrapper, you can use any object method, which accepts the right
+ * parameters (int, short) and returns void, as an event handler. This way you
+ * don't have to overload the operator() which can be confusing depending on the
+ * context.
+ *
+ * You can see an usage example in the Examples Section.
+ */
+template < typename O, typename M >
+struct mem_cb
+{
+	/**
+	 * Member function callback constructor.
+	 *
+	 * It expects to receive a class as the first parameter (O), and a
+	 * member function (of that class O) as the second parameter.
+	 *
+	 * When this instance is called with fd and ev as function arguments,
+	 * object.method(fd, ev) will be called.
+	 *
+	 * @param object Object to be used.
+	 * @param method Method to be called.
+	 */
+	mem_cb(O& object, M method) throw():
+		_object(object), _method(method) {}
+	void operator() (int fd, short ev) { (_object.*_method)(fd, ev); }
+	protected:
+		O& _object;
+		M _method;
+}; // struct mem_cb
 
 //@}
 
@@ -957,8 +998,7 @@ struct dispatcher
 
 }; // struct dispatcher
 
-
-} // namespace event
+} // namespace eventxx
 
 #endif // _EVENTXX_HPP_
 
diff --git a/test/Makefile b/test/Makefile
index 4beddbf..477a591 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -6,7 +6,7 @@ CXXFLAGS=-I.. -g -Wall
 LDFLAGS=-levent
 
 targets=bench test-eof test-time test-weof trivial c-way functor-way \
-	prio-test mixed-way
+	wrapped-functor-way prio-test mixed-way
 
 all: $(targets)
 
diff --git a/test/wrapped-functor-way.cpp b/test/wrapped-functor-way.cpp
new file mode 100644
index 0000000..9664b8a
--- /dev/null
+++ b/test/wrapped-functor-way.cpp
@@ -0,0 +1,36 @@
+#include <eventxx>
+#include <iostream>
+#include <csignal>
+
+using eventxx::dispatcher;
+
+struct handler
+{
+	dispatcher& d;
+	int i;
+	handler(dispatcher& d): d(d), i(0) {}
+	void handle_event(int signum, short event)
+	{
+		std::cout << ++i << " interrupts, ";
+		if (i < 5) std::cout << "keep going...\n";
+		else
+		{
+			std::cout << "done!\n";
+			d.exit();
+		}
+	}
+};
+
+typedef eventxx::mem_cb< handler, void (handler::*)(int, short) > cb_type;
+
+int main()
+{
+	dispatcher d;
+	handler h(d);
+	cb_type cb(h, &handler::handle_event);
+	eventxx::signal< cb_type > e(SIGINT, cb);
+	d.add(e);
+	d.dispatch();
+	return 0;
+}
+