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--[[ $Id: CallbackHandler-1.0.lua 60548 2008-02-07 11:04:06Z nevcairiel $ ]]
local MAJOR, MINOR = "CallbackHandler-1.0", 3
local CallbackHandler = LibStub:NewLibrary(MAJOR, MINOR)
if not CallbackHandler then return end -- No upgrade needed
local meta = {__index = function(tbl, key) tbl[key] = {} return tbl[key] end}
local type = type
local pcall = pcall
local pairs = pairs
local assert = assert
local concat = table.concat
local loadstring = loadstring
local next = next
local select = select
local type = type
local xpcall = xpcall
local function errorhandler(err)
return geterrorhandler()(err)
end
local function CreateDispatcher(argCount)
local code = [[
local next, xpcall, eh = ...
local method, ARGS
local function call() method(ARGS) end
local function dispatch(handlers, ...)
local index
index, method = next(handlers)
if not method then return end
local OLD_ARGS = ARGS
ARGS = ...
repeat
xpcall(call, eh)
index, method = next(handlers, index)
until not method
ARGS = OLD_ARGS
end
return dispatch
]]
local ARGS, OLD_ARGS = {}, {}
for i = 1, argCount do ARGS[i], OLD_ARGS[i] = "arg"..i, "old_arg"..i end
code = code:gsub("OLD_ARGS", concat(OLD_ARGS, ", ")):gsub("ARGS", concat(ARGS, ", "))
return assert(loadstring(code, "safecall Dispatcher["..argCount.."]"))(next, xpcall, errorhandler)
end
local Dispatchers = setmetatable({}, {__index=function(self, argCount)
local dispatcher = CreateDispatcher(argCount)
rawset(self, argCount, dispatcher)
return dispatcher
end})
--------------------------------------------------------------------------
-- CallbackHandler:New
--
-- target - target object to embed public APIs in
-- RegisterName - name of the callback registration API, default "RegisterCallback"
-- UnregisterName - name of the callback unregistration API, default "UnregisterCallback"
-- UnregisterAllName - name of the API to unregister all callbacks, default "UnregisterAllCallbacks". false == don't publish this API.
function CallbackHandler:New(target, RegisterName, UnregisterName, UnregisterAllName, OnUsed, OnUnused)
-- TODO: Remove this after beta has gone out
assert(not OnUsed and not OnUnused, "ACE-80: OnUsed/OnUnused are deprecated. Callbacks are now done to registry.OnUsed and registry.OnUnused")
RegisterName = RegisterName or "RegisterCallback"
UnregisterName = UnregisterName or "UnregisterCallback"
if UnregisterAllName==nil then -- false is used to indicate "don't want this method"
UnregisterAllName = "UnregisterAllCallbacks"
end
-- we declare all objects and exported APIs inside this closure to quickly gain access
-- to e.g. function names, the "target" parameter, etc
-- Create the registry object
local events = setmetatable({}, meta)
local registry = { recurse=0, events=events }
-- registry:Fire() - fires the given event/message into the registry
function registry:Fire(eventname, ...)
if not rawget(events, eventname) or not next(events[eventname]) then return end
local oldrecurse = registry.recurse
registry.recurse = oldrecurse + 1
Dispatchers[select('#', ...) + 1](events[eventname], eventname, ...)
registry.recurse = oldrecurse
if registry.insertQueue and oldrecurse==0 then
-- Something in one of our callbacks wanted to register more callbacks; they got queued
for eventname,callbacks in pairs(registry.insertQueue) do
local first = not rawget(events, eventname) or not next(events[eventname]) -- test for empty before. not test for one member after. that one member may have been overwritten.
for self,func in pairs(callbacks) do
events[eventname][self] = func
-- fire OnUsed callback?
if first and registry.OnUsed then
registry.OnUsed(registry, target, eventname)
first = nil
end
end
end
registry.insertQueue = nil
end
end
-- Registration of a callback, handles:
-- self["method"], leads to self["method"](self, ...)
-- self with function ref, leads to functionref(...)
-- "addonId" (instead of self) with function ref, leads to functionref(...)
-- all with an optional arg, which, if present, gets passed as first argument (after self if present)
target[RegisterName] = function(self, eventname, method, ... --[[actually just a single arg]])
if type(eventname) ~= "string" then
error("Usage: "..RegisterName.."(eventname, method[, arg]): 'eventname' - string expected.", 2)
end
method = method or eventname
local first = not rawget(events, eventname) or not next(events[eventname]) -- test for empty before. not test for one member after. that one member may have been overwritten.
if type(method) ~= "string" and type(method) ~= "function" then
error("Usage: "..RegisterName.."(\"eventname\", \"methodname\"): 'methodname' - string or function expected.", 2)
end
local regfunc
if type(method) == "string" then
-- self["method"] calling style
if type(self) ~= "table" then
error("Usage: "..RegisterName.."(\"eventname\", \"methodname\"): self was not a table?", 2)
elseif self==target then
error("Usage: "..RegisterName.."(\"eventname\", \"methodname\"): do not use Library:"..RegisterName.."(), use your own 'self'", 2)
elseif type(self[method]) ~= "function" then
error("Usage: "..RegisterName.."(\"eventname\", \"methodname\"): 'methodname' - method '"..tostring(method).."' not found on self.", 2)
end
if select("#",...)>=1 then -- this is not the same as testing for arg==nil!
local arg=select(1,...)
regfunc = function(...) self[method](self,arg,...) end
else
regfunc = function(...) self[method](self,...) end
end
else
-- function ref with self=object or self="addonId"
if type(self)~="table" and type(self)~="string" then
error("Usage: "..RegisterName.."(self or \"addonId\", eventname, method): 'self or addonId': table or string expected.", 2)
end
if select("#",...)>=1 then -- this is not the same as testing for arg==nil!
local arg=select(1,...)
regfunc = function(...) method(arg,...) end
else
regfunc = method
end
end
if events[eventname][self] or registry.recurse<1 then
-- if registry.recurse<1 then
-- we're overwriting an existing entry, or not currently recursing. just set it.
events[eventname][self] = regfunc
-- fire OnUsed callback?
if registry.OnUsed and first then
registry.OnUsed(registry, target, eventname)
end
else
-- we're currently processing a callback in this registry, so delay the registration of this new entry!
-- yes, we're a bit wasteful on garbage, but this is a fringe case, so we're picking low implementation overhead over garbage efficiency
registry.insertQueue = registry.insertQueue or setmetatable({},meta)
registry.insertQueue[eventname][self] = regfunc
end
end
-- Unregister a callback
target[UnregisterName] = function(self, eventname)
if not self or self==target then
error("Usage: "..UnregisterName.."(eventname): bad 'self'", 2)
end
if type(eventname) ~= "string" then
error("Usage: "..UnregisterName.."(eventname): 'eventname' - string expected.", 2)
end
if rawget(events, eventname) and events[eventname][self] then
events[eventname][self] = nil
-- Fire OnUnused callback?
if registry.OnUnused and not next(events[eventname]) then
registry.OnUnused(registry, target, eventname)
end
end
if registry.insertQueue and rawget(registry.insertQueue, eventname) and registry.insertQueue[eventname][self] then
registry.insertQueue[eventname][self] = nil
end
end
-- OPTIONAL: Unregister all callbacks for given selfs/addonIds
if UnregisterAllName then
target[UnregisterAllName] = function(...)
if select("#",...)<1 then
error("Usage: "..UnregisterAllName.."([whatFor]): missing 'self' or \"addonId\" to unregister events for.", 2)
end
if select("#",...)==1 and ...==target then
error("Usage: "..UnregisterAllName.."([whatFor]): supply a meaningful 'self' or \"addonId\"", 2)
end
for i=1,select("#",...) do
local self = select(i,...)
if registry.insertQueue then
for eventname, callbacks in pairs(registry.insertQueue) do
if callbacks[self] then
callbacks[self] = nil
end
end
end
for eventname, callbacks in pairs(events) do
if callbacks[self] then
callbacks[self] = nil
-- Fire OnUnused callback?
if registry.OnUnused and not next(callbacks) then
registry.OnUnused(registry, target, eventname)
end
end
end
end
end
end
return registry
end
-- CallbackHandler purposefully does NOT do explicit embedding. Nor does it
-- try to upgrade old implicit embeds since the system is selfcontained and
-- relies on closures to work.
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