SendMessage/PostMessage in Lua

That will sound extremely amateur but how do I SendMessage/PostMessage in Lua? :D I tried to google it but found nothing relevant...

Such a question from you ? ! gemisigo, gemisigo

Declare Function SendMessage Lib "USER32" Alias "SendMessageA" ( _
ByVal hWnd As Long, ByVal Msg As Long, _
wParam As Any, lParam As Any) As Long

any is string or long
require[[alien]]
local SendMessage= alien.User32.SendMessageA
SendMessage:types{ret ='long', abi = 'stdcall','long','long','string','string'}

or make it working with
plugin.call

Yep, I'm familiar with SendMessage and that was my first idea, too, but I was quite sure there must be a more straightforward approach to send a message in Lua. Unfortunately I haven't found any. Most programming languages (at least those capable sending/posting messages) do not need such preparations. But it seems that Lua does. Not that I have problems with that, I just thought it would be nice to be able to do it simpler. I should have thought that because Lua is not windows-only. But you know, dope dies dast :) hiccup :D

By the way, thanks for your help, Leo :)

Next question :)

I have:
local GetWindowThreadProcessId = alien.User32.GetWindowThreadProcessId
GetWindowThreadProcessId:types{ret = 'long', abi = 'stdcall', 'long', 'pointer'}

The 'long' is input, it's a handle to the window, the 'pointer' is a pointer to the variable that receives the identifier.

My problem is that it is a pointer and it should point to an integer/long. Lua is dinamically typed. How do I make something to point to an integer typed variable? How do I create a pointer at all??

I can create a userdata typed variable
local pointhere = alien.buffer(4)

and do a call to

local tid = GetWindowThreadProcessId(hwnd_mywindow, pointhere)

The value in 'tid' is okay (it contains the threadid) but the value in 'pointhere' is unusable. It should store the processid, but I cannot cast it to an int/long. Alien has something (alien.toint or alien.tolong) that should do it but it fails with a very funny error message:
lua: test.lua:32: bad argument #1 to 'toint' (userdata expected, got userdata).

Any idea?

EDIT: Okay, just to show that I'm smart and capable of improving myself, I'll answer my own question :D
Oh, yes, did I mention that I'm humble, too? :D

So, if anyone else is interested, the method is the following:

local pointhere = alien.buffer(4)
-- this creates a 4-byte buffer

local tid = GetWindowThreadProcessId(hwnd_mywindow, pointhere)
-- this fills tid and our 4-byte buffer

local long_at_pointhere = pointhere:get(1, 'long')
-- this tells that I want x bytes forming a 'long' value and starting at the first byte of the
-- 'pointhere' buffer to be in 'long_at_pointhere' variable and let its type be 'long'

I hope this helps those who meet the same difficulties I did. I there are any, of course.



Edited 1 time(s). Last edit at 01/29/2010 03:00AM by gemisigo.