From df6fc46950e15bb30a92368f34dc2005393b0e5b Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 27 Sep 2019 22:24:07 +0300
Subject: [PATCH] Refactor signal connection handling in EventDispatcher

Connect the signals to functions on the Slot object to make them easier
to disconnect.
---
 source/io/eventdispatcher.cpp | 48 ++++++++++++++++++++---------------
 source/io/eventdispatcher.h   | 28 ++++++++++----------
 2 files changed, 40 insertions(+), 36 deletions(-)

diff --git a/source/io/eventdispatcher.cpp b/source/io/eventdispatcher.cpp
index cf37c1e..47aafa5 100644
--- a/source/io/eventdispatcher.cpp
+++ b/source/io/eventdispatcher.cpp
@@ -4,23 +4,19 @@
 #include "eventobject.h"
 #include "poll.h"
 
+using namespace std;
+
 namespace Msp {
 namespace IO {
 
-EventDispatcher::EventDispatcher()
-{ }
-
-EventDispatcher::~EventDispatcher()
-{ }
-
 void EventDispatcher::add(EventObject &obj)
 {
-	SlotMap::iterator i = objects.find(&obj);
+	Slot slot(*this, obj);
+	set<Slot>::iterator i = objects.find(slot);
 	if(i==objects.end())
 	{
-		i = objects.insert(SlotMap::value_type(&obj, Slot(&obj))).first;
-		i->second.evch_conn = obj.signal_events_changed.connect(sigc::bind(sigc::mem_fun(this, &EventDispatcher::object_events_changed), &obj));
-		i->second.del_conn = obj.signal_deleted.connect(sigc::bind(sigc::mem_fun(this, &EventDispatcher::object_deleted), &obj));
+		i = objects.insert(slot).first;
+		i->connect_signals();
 
 		if(obj.get_events())
 			poller.set_object(obj, obj.get_events());
@@ -29,11 +25,9 @@ void EventDispatcher::add(EventObject &obj)
 
 void EventDispatcher::remove(EventObject &obj)
 {
-	SlotMap::iterator i = objects.find(&obj);
+	set<Slot>::iterator i = objects.find(Slot(*this, obj));
 	if(i!=objects.end())
 	{
-		i->second.evch_conn.disconnect();
-		i->second.del_conn.disconnect();
 		objects.erase(i);
 
 		poller.set_object(obj, P_NONE);
@@ -67,21 +61,33 @@ void EventDispatcher::tick(const Time::Timer &timer)
 		tick();
 }
 
-void EventDispatcher::object_events_changed(PollEvent ev, EventObject *obj)
+void EventDispatcher::dispatch()
 {
-	poller.set_object(*obj, ev);
+	const Poller::SlotList &result = poller.get_result();
+	for(Poller::SlotList::const_iterator i=result.begin(); i!=result.end(); ++i)
+		i->object->event(i->events);
 }
 
-void EventDispatcher::object_deleted(EventObject *obj)
+
+EventDispatcher::Slot::Slot(EventDispatcher &d, EventObject &o):
+	disp(d),
+	obj(o)
+{ }
+
+void EventDispatcher::Slot::connect_signals() const
 {
-	remove(*obj);
+	obj.signal_events_changed.connect(sigc::mem_fun(this, &Slot::events_changed));
+	obj.signal_deleted.connect(sigc::mem_fun(this, &Slot::deleted));
 }
 
-void EventDispatcher::dispatch()
+void EventDispatcher::Slot::events_changed(PollEvent ev) const
 {
-	const Poller::SlotList &result = poller.get_result();
-	for(Poller::SlotList::const_iterator i=result.begin(); i!=result.end(); ++i)
-		i->object->event(i->events);
+	disp.poller.set_object(obj, ev);
+}
+
+void EventDispatcher::Slot::deleted() const
+{
+	disp.remove(obj);
 }
 
 } // namespace IO
diff --git a/source/io/eventdispatcher.h b/source/io/eventdispatcher.h
index b542d67..f95f477 100644
--- a/source/io/eventdispatcher.h
+++ b/source/io/eventdispatcher.h
@@ -1,7 +1,7 @@
 #ifndef MSP_IO_EVENTDISPATCHER_H_
 #define MSP_IO_EVENTDISPATCHER_H_
 
-#include <sigc++/connection.h>
+#include <set>
 #include <sigc++/trackable.h>
 #include <msp/time/timedelta.h>
 #include <msp/time/timer.h>
@@ -14,27 +14,27 @@ namespace IO {
 Put your I/O objects inside one of these to get signaled when something happens
 on some of them.
 */
-class EventDispatcher: public sigc::trackable
+class EventDispatcher
 {
 private:
-	struct Slot
+	struct Slot: public sigc::trackable
 	{
-		EventObject *obj;
-		sigc::connection evch_conn;
-		sigc::connection del_conn;
+		EventDispatcher &disp;
+		EventObject &obj;
 
-		Slot(EventObject *o): obj(o) { }
-	};
+		Slot(EventDispatcher &, EventObject &);
+
+		void connect_signals() const;
+		void events_changed(PollEvent) const;
+		void deleted() const;
 
-	typedef std::map<EventObject *, Slot> SlotMap;
+		bool operator<(const Slot &o) const { return &obj<&o.obj; }
+	};
 
 	Poller poller;
-	SlotMap objects;
+	std::set<Slot> objects;
 
 public:
-	EventDispatcher();
-	~EventDispatcher();
-
 	void add(EventObject &);
 	void remove(EventObject &);
 
@@ -51,8 +51,6 @@ public:
 	void tick(const Time::Timer &);
 
 private:
-	void object_events_changed(PollEvent, EventObject *);
-	void object_deleted(EventObject *);
 	void dispatch();
 };
 
-- 
2.43.0