From 879a43fbc4a51a12cb40b8faaa76253832e57cda Mon Sep 17 00:00:00 2001
From: Emmanuel Lepage Vallee <elv1313@gmail.com>
Date: Sat, 5 Apr 2014 23:54:04 -0400
Subject: [PATCH] Add ability to track connections

One interesting use case for this is to only do expensive
operations if something is connected to the signal:

--   item:connect_signal("connection",function(_,name,count)
--     if name == "mouse::move" and count == 0 then
--       widget:connect_signal("mouse::move",conn)
--     end
--   end)
--   item:connect_signal("disconnection",function(_,name,count)
--     if count == 0 then
--       widget:connect_signal("mouse::move",conn)
--     end
--   end)
---
 object.lua | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/object.lua b/object.lua
index 6bb686c..a894821 100644
--- a/object.lua
+++ b/object.lua
@@ -11,12 +11,14 @@ local function setup_object(args)
     function data:connect_signal(name,func)
         signals[name] = signals[name] or {}
         table.insert(signals[name],func)
+        data:emit_signal("connection",name,#signals[name])
     end
     
     function data:disconnect_signal(name,func)
         for k,v in pairs(signals[name] or {}) do
             if v == func then
                 signals[name][k] = nil
+                data:emit_signal("disconnection",name,#signals[name])
             end
         end
     end