Delivered-To: lablgtk at yquem.inria.fr
Date: Wed, 30 Jan 2008 16:11:11 +0900 (JST)
Message-Id: <20080130.161111.48533977.garrigue at math.nagoya-u.ac.jp>
To: gmalecha at rice.edu
Subject: Re: [Lablgtk] GnomeCanvas Enumerate Items
From: Jacques Garrigue <garrigue at math.nagoya-u.ac.jp>
In-Reply-To: <47A01A5D.8030706 at rice.edu>
References: <20080105.170933.98869039.garrigue at math.nagoya-u.ac.jp>
	<47A01A5D.8030706@rice.edu>
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From: Gregory Malecha <gmalecha at rice.edu>
> I was able to get most of this working using wrap_item. There are a few 
> cases that it apparently doesn't handle though. Mainly group, text, 
> rich_text, etc, the ones that aren't GnoCanvas.items. Here's the code 
> that I have:
> 
> type annotated_item =
>     Group of GnomeCanvas.group_p GnoCanvas.item (* I'd like this to be 
> GnoCanvas.group *)
[...]
>   else if GnomeCanvas.Types.is_a item GnomeCanvas.Types.group then
>     let gp = GnoCanvas.wrap_item item GnomeCanvas.Types.group in
>     Group gp
[..]
> Does anyone know of a way to get a GnoCanvas.group rather than a 
> GnomeCanvas.group_p GnoCanvas.item when performing the cast?

Since you have already checked that it has the right type, you can use
Gobject.unsafe_cast.

   new GnomeCanvas.group (Gobject.unsafe_cast item)

Looks safe enough to me.

Jacques
---------------------------------------------------------------------------
Jacques Garrigue      Nagoya University     garrigue at math.nagoya-u.ac.jp
		   <A HREF=http://www.math.nagoya-u.ac.jp/~garrigue/>JG</A>

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