local _ipairs = ipairs
function ipairs(t)local mt = getmetatable(t) if mt and mt.__ipairs thenreturn mt.__ipairs(t)endreturn _ipairs(t)
endlocal _pairs = pairs
function pairs(t)local mt = getmetatable(t)if mt and mt.__pairs thenreturn mt.__pairs(t)endreturn _pairs(t)
end

require "stdext"local debug = debug
local string = string
local print = printlocal util = {}function util.trace(prefix)prefix = prefix .. " "return function(...)print(prefix .. string.format(...))end
endfunction util.callee()return debug.getinfo(2, "f").func
endfunction util.getupvalues(func)local u = {}local i = 0while true doi = i + 1local key, value = debug.getupvalue(func, i)if key thenu[key] = valueelsebreakendendreturn u
endreturn util

local util = require "util"
local class = require "class"local trace = util.trace("[EventDispatcher]")
local assert = assert
local next = next
local pairs = pairslocal ANONYMOUS = {}
local hashlist = {}local EventDispatcher = class("EventDispatcher")function EventDispatcher:ctor()self._listeners = {}
endfunction EventDispatcher:addEventListener(event, listener, owner, priority)assert(event)assert(listener)local list = self._listeners[event]if not list thenlist = hashlist.new()self._listeners[event] = listendlist:insert(owner or ANONYMOUS, listener, priority)
endfunction EventDispatcher:removeEventListener(event, listener, owner)assert(event)assert(listener)local list = self._listeners[event]if list thenlist:remove(owner or ANONYMOUS, listener)if list:empty() thenself._listeners[event] = nilendend
endfunction EventDispatcher:dispatchEvent(event, ...)assert(event, "event type is nil")if self:hasEventListener(event) thenfor _, owner, listener in pairs(self._listeners[event]) doif owner == ANONYMOUS thenlistener(self, ...)elselistener(owner, self, ...)endendend
endfunction EventDispatcher:hasEventListener(event)return self._listeners[event] ~= nil
end-------------------------------------------------------------------------------
-- hashlist
--
-------------------------------------------------------------------------------
local tostring = tostring
hashlist.__index = hashlistlocal function makeindex(owner, handler)return tostring(owner) .. "|" .. tostring(handler)
endfunction hashlist.new()local self = setmetatable({}, hashlist)self.header = {}self.header.next = self.headerself.header.prev = self.headerself.entries = {}return self
endlocal function itor(header, current)local entry = current.nextif entry ~= header thenreturn entry, entry.key, entry.valueend
endfunction hashlist:__pairs()return itor, self.header, self.header
endfunction hashlist:insert(key, value, priority)local idx = makeindex(key, value)if self.entries[idx] then return endlocal entry = {key = key, value = value, priority = priority}local header, current = self.headerif not priority thencurrent = header.prevelsecurrent = headerlocal next = current.nextwhile next ~= header doif not next.priority or priority <= next.priority thenbreakelsecurrent = nextnext = current.nextendendendentry.next = current.nextentry.prev = currentcurrent.next.prev = entrycurrent.next = entryself.entries[idx] = entry
endfunction hashlist:empty()return next(self.entries) == nil
endfunction hashlist:remove(key, value)local idx = makeindex(key, value)local entry = self.entries[idx]if entry thenentry.prev.next = entry.nextentry.next.prev = entry.prevself.entries[idx] = nilend
endreturn EventDispatcher

local class = require "class"
local EventDispatcher = require "EventDispatcher"local A = class("A", EventDispatcher)function A:ctor()self:addEventListener("test", self.testHandler, self)
endfunction A:testHandler()print("test in testHandler")
endlocal a = A.new()a:addEventListener("test", function()a:removeEventListener("test", util.callee())print("test outside")
end)a:addEventListener("test", function()print("test priority")
end, nil, 0)

a:dispatchEvent("test", "a", "b")

a:dispatchEvent("test", "a", "b")