1 files changed, 83 insertions, 0 deletions
diff --git a/util/events.lua b/util/events.lua
new file mode 100644
index 00000000..412acccd
--- /dev/null
+++ b/util/events.lua
@@ -0,0 +1,83 @@
+-- Prosody IM
+-- Copyright (C) 2008-2010 Matthew Wild
+-- Copyright (C) 2008-2010 Waqas Hussain
+-- 
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+
+
+local pairs = pairs;
+local t_insert = table.insert;
+local t_sort = table.sort;
+local setmetatable = setmetatable;
+local next = next;
+
+module "events"
+
+function new()
+	local handlers = {};
+	local event_map = {};
+	local function _rebuild_index(handlers, event)
+		local _handlers = event_map[event];
+		if not _handlers or next(_handlers) == nil then return; end
+		local index = {};
+		for handler in pairs(_handlers) do
+			t_insert(index, handler);
+		end
+		t_sort(index, function(a, b) return _handlers[a] > _handlers[b]; end);
+		handlers[event] = index;
+		return index;
+	end;
+	setmetatable(handlers, { __index = _rebuild_index });
+	local function add_handler(event, handler, priority)
+		local map = event_map[event];
+		if map then
+			map[handler] = priority or 0;
+		else
+			map = {[handler] = priority or 0};
+			event_map[event] = map;
+		end
+		handlers[event] = nil;
+	end;
+	local function remove_handler(event, handler)
+		local map = event_map[event];
+		if map then
+			map[handler] = nil;
+			handlers[event] = nil;
+			if next(map) == nil then
+				event_map[event] = nil;
+			end
+		end
+	end;
+	local function add_handlers(handlers)
+		for event, handler in pairs(handlers) do
+			add_handler(event, handler);
+		end
+	end;
+	local function remove_handlers(handlers)
+		for event, handler in pairs(handlers) do
+			remove_handler(event, handler);
+		end
+	end;
+	local function fire_event(event, ...)
+		local h = handlers[event];
+		if h then
+			for i=1,#h do
+				local ret = h[i](...);
+				if ret ~= nil then return ret; end
+			end
+		end
+	end;
+	return {
+		add_handler = add_handler;
+		remove_handler = remove_handler;
+		add_handlers = add_handlers;
+		remove_handlers = remove_handlers;
+		fire_event = fire_event;
+		_handlers = handlers;
+		_event_map = event_map;
+	};
+end
+
+return _M;