Re: How do you deal with event functions?

[Shmuel Zeigerman <shmuz@...>]

Jose Marin wrote:
> With Lua 5.1, is there some "proper" way of store
> references to user Lua functions, to be called later?
[...]
> I see 2 ways of do this:
>
> 1) provide a "SetOnKeyPressed" to Lua, and in the code
> it would be called like this:
>
>    SetOnKeyPressed(OnKeyPressed)
[...]
> 2)provide the same SetOnKeyPressed function, but the
> user would pass a string, like this:
>
> SetOnKeyPressed("OnKeyPressed")
[...]
> In Lua 5.1, what's the pro's and con's of these 2
> methods?
>
> Is there a better way of do this?

Don't know if it's better but here's a way that seem
to combine the pro's of the 2 above 2 ways.

-- start of Lua example
t_events = {
  KeyPressed  = OnKeyPressed,
  LeftClick   = OnLeftClick,
  DoubleClick = function (x,y) print (x,y) end,
  -- etc.
}

function OnEvent (event, ...)
  local f = t_events [event]
  if f then return f (...) end
end

SetEvent (OnEvent)
-- end of Lua example

C provides SetEvent function, and Lua registers only
*one* event handler. C calls that handler passing
event name (a string) and any number of parameters.

--
Shmuel