From: Dave Burt <dave@...>
Date: 2005-07-15T16:45:52+09:00
Subject: Re: Capturing window display of another program?

"David Brady" <ruby_talk@shinybit.com> asked:
> Is it possible to take a screenshot of another window in Ruby?  (On Win32)
>
> I'd like to write a script to scrape the output of a graphics test program 
> (which I do not have source for) at regular intervals, and run tests 
> against them.  E.g., grab the display area & check to see if it's 
> generating a gradient fill (good), or a black display (bad) by testing 
> some of the pixels inside the display area.
>
> What about sending clicks, drags and keypresses to that window?  At that 
> point, it would be a poor man's WinRunner, hrm....
>

You can use Ruby to interface AutoIt's COM component to make this a lot 
easier than using straight Windows API calls:

http://www.autoitscript.com/autoit3/
http://www.autoitscript.com/autoit3/docs/functions.htm

AutoIt is freeware and can do all these things pretty easily, including 
sending clicks and keys to a window, except for taking a screenshot AFAIK, 
but PixelGetColor() and PixelSearch() can be used to search for a color in a 
rectangle or get the color of a pixel, so maybe that's even better for your 
purposes.

Cheers,
Dave