From: "Marvin Gülker" <sutniuq@...>
Date: 2009-12-29T18:35:14+09:00
Subject: Re: au3 0.1.1 released

Edward Middleton wrote:
> Marvin Gülker wrote:
>> So, if you could help me out with #pack and #unpack, especially with 
>> structs in structs (I would look for an example from the WinAPI, if you 
>> want) I would start working on that again.
>>   
> 
> I haven't used Win32API, I just connected directly from dl.  Examples of
> the functions/structs you were having problems with would help.
> 
> Edward

OK - SendInput() is the main function to simulate keyboard and mouse 
input: http://msdn.microsoft.com/en-us/library/ms646310%28VS.85%29.aspx 
(from there you can also get to the descriptions of INPUT and 
KEYBDINPUT)
It takes the size of a C array containing INPUT structs, a C array 
containing INPUT structs and the size of an INPUT structure.
The INPUT struct itself wants a description wheather it is a keyboard or 
a mouse struct, and depending on that it chooses the MOUSEINPUT oder 
KEYBDINPUT struct from its second, an union, parameter.
I tried with keyboard simulation first, so I have to build up the 
KEYBDINPUT struct: That takes a virtual key code describing the key to 
simulate - unless you want to simulate unicode characters -, than an 
unicode character as a WORD if you want to simulate a unicode char. Next 
parameter is the input simulation type, e.g. unicode, followed by a time 
stamp and a pointer to extra message info.

That isn't as complicated as it sounds, but there are some problems I 
cannot get around. First, how to obtain the size of the INPUT structure? 
There's no sizeof keyword in Ruby... Second, how to transform a unicode 
char (Windows usually uses UTF-16LE I've found out when working on au3) 
into a WORD? As far as I know, this is an integer value, but a unicode 
char like ä consists of more than one byte? Third, as said, how to pack 
a struct into a struct, in this example: How to pack the KEYBDINPUT into 
the INPUT struct? And last but not least, how to build up a C array in 
Ruby?

That said, my quite incomplete code looks like this:
------------------------------------
SendInput = Win32::API.new("SendInput", 'IPI', 'I', "user32")
INPUT_KEYBOARD = 1 #We're using keyboard simulation
KEYEVENTF_UNICODE = 0x0004 #We want to simulate unicode chars

#INPUT struct: LP
#KEYBDINPUT struct: IILLP

keybdinput = [0, "a".encode("UTF16-LE").pack('I'), KEYEVENTF_UNICODE, 0, 
nil].pack('IILLP')
input = [INPUT_KEYBOARD, keybdinput].pack('LP')
#Yes, I know that the following line produces more than one error.
SendInput.call(1, [input], ??) #How to obtain the size of an INPUT?
-------------------------------------

Marvin
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