signal/slot

signals.lua

module('signals',package.seeall)

local oo = require "loop.base"

Signal = oo.class{
	name = '',
	slots = {}
}

function Signal:__init(name)
	local obj = oo.rawnew(self, {
		name = name,
		next_slot_id = 1,
		slots={},
	}
	)
	return obj
end

function Signal:connect(fun)
	assert( fun ~= nil, 'Signal:Connect - signal can not connect to nil' )
	local id = self.next_slot_id
	self.next_slot_id = self.next_slot_id + 1
	self.slots[id] = fun
	return id
end

function Signal:disconnect(id)
	self.slots[id] = nil
end

local function error_hook( err )
    local msg = string.format("%s\n%s",err,debug.traceback())
    --logger:warn( msg )
	print(msg)
end

function Signal:trigger()
	local f = function(...)
        local arg={... }
        print(string.format('signal: (%s) is triggered.',self.name))
		for _,fn in pairs(self.slots) do
            xpcall( function() fn(unpack(arg)) end,error_hook)
		end
	end
	return f
end

function Signal:dump()
	for _,v in pairs(self.slots) do
		print( prettytostring(debug.getinfo( v )) )
	end
end

signals = {}

function get(sigName)
	if signals[sigName] == nil then
		signals[sigName] = Signal(sigName)
	end
	return signals[sigName]
end