PangAttrShape destroy func firing unexepctedly

[Travis Griggs <travisgriggs gmail com>]

On Sep 7, 2010, at 6:23 PM, Travis Griggs wrote:

> What My Binding Ended up Looking Like (for now)
>
> With Behdad's and Tony's direction, I established a single shape  
> renderer for any Context I create a binding for in Smalltalk. When  
> I'm creating the attribute, I do it with the two rectangles, and  
> with a Block Closure. Block Closures are Smalltalk arbitrary  
> functions, that close over any current values needed for the  
> function. So I get both data and behavior all in one, a lot, or a  
> little. I keep a table on the Smalltalk side, which maps Smalltalk  
> blocks, to an arbitrary incrementing counter. The index, is what I  
> stuff in the data of the attribute. So when I get the callback, I  
> fetch the Smalltalk block associated with the particular attribute's  
> data key, execute the block with the mapped arguments. Works pretty  
> well.

Or maybe it doesn't work so well. It works well as long as I don't try  
to clean out said table.

If I do the following pseudo code:

attList = pango_attr_list_new();
attribute = pango_attr_shape_new_with_data( rect1, rect2, aNumber,  
null, aDestoryFunc );
pango_attr_list_insert( attList, attribute );
layout = pango_layout_new(context);
pango_layout_set_attributes( layout, attList );
pango_cairo_show_layout( cr, layout );

Something weird happens. aDestroyFunc happens sometime after I do the  
show_layout. Which is weird (and currently undesirable) to me. I've  
been grousing around the pango source, haven't seen where it's  
happening yet. I know that after the show, the attList still has a ref  
count of 2 (one from me creating it, and the other from the layout),  
so it's not destroying it there. I must be missing part of the memory  
management model here, any help much appreciated, trying to get this  
stuff figured out so I can give glowing reports when talking about  
binding to it next week at ESUG.

TIA

--
Travis Griggs
tgriggs cincom com
"The dissenter is every human being at those moments of his life when  
he resigns momentarily from the herd and thinks for himself." - 
Archibald MacLeish, poet and librarian