From: Tom Felker <tcfelker@...>
Date: 2003-07-01T13:35:38+09:00
Subject: Re: Drag and Drop in Windows with Explorer

On Mon, 2003-06-30 at 19:53, Harry Ohlsen wrote:
> Hi Tom,
> 
> Sorry, I don't have an answer to your question. I had a quick play with this some time back and didn't get anywhere.
> 
> If you get the code to work under Windows, can you post the final version to the mailing list?
> 
> Cheers,
> 
> Harry O.

Sure, I'll post any working code I get, but I'm a bit discouraged by my
further research:

<http://www.escribe.com/software/foxusers/m4610.html>

According to this, on Windows, Fox does DND in it's own way, not
Window's way, because OLE is too weird to be cross-platform. 
Unfortunately, Windows developers, and certainly Microsoft, won't jump
to change their DND to work with Fox.

<http://www.escribe.com/software/foxusers/m4066.html>
<http://msdn.microsoft.com/library/default.asp?url=/library/en-us/shellcc/platform/shell/programmersguide/legacyinformation/shelllib.asp>

However, while most of Windows uses OLE or COM or some other hip TLA,
there's also a special API for file dropping, and this person hacked up
a way to do this in C++.  This can be done in plain Ruby and FXRuby,
given the ability:

 - To call Windows functions (Yes)
 - To access a given FXWindow's handle (Maybe)
 - To intercept the WM_DROPFILES message and extract wParam (Maybe)
 - To work with pointers to pre-allocated buffers.  (Yes)

I might be able to hack this up tomorrow, if FXRuby and Fox let me get
low enough access.  I know it's possible in C++, but I can only hope
FXRuby exports enough to intercept messages and get handles.

If I were a Fox hacker, I'd say they should use this simpler API to
emulate Fox's DND, by sending synthetic messages and making it look like
"text/uri-list".

-- 
Tom Felker <tcfelker@mtco.com>