Re: the latest cellrenderer scoop

[Bjarne Steinsbø <bosteins broadpark no>]

muppet wrote:

> i just put Gtk2::CellRenderer::Base 0.04 on my website,
> http://asofyet.org/muppet/software/gtk2-perl/Gtk2-CellRenderer-Base- 
> 0.04.tar.gz
>
> this version simplifies things rather a lot.  The  
> Gtk2::CellRenderer::Base class no longer actually exists.  You do a  
> normal Glib::Object::Subclass of Gtk2::CellRenderer or any of its  
> derivatives, and then call __PACKAGE__->_install_overrides;  this  
> installs into the GObjectClass structure the perl marshallers which  
> look for the on_get_size, on_render, on_activate, and 
> on_start_editing  subs.
>
> you can call the parent from within your child subs by doing 
> parent_foo  instead of on_foo, like this:
>
>   sub on_get_size {  shift->parent_get_size (@_)  }
>
> that uses caller() to find the calling context, so it can find the  
> parent of that package.  (this hack is necessary because GObjects  
> always show up as the bottom of the hierarchy.)
>
>
> my only complaint about this version is the new syntax is ugly:
>
>   use Glib::Object::Subclass ......;
>   __PACKAGE__->_install_overrides;
>
> it would be possible to create another pragma-like module to wrap 
> that  up for us, a la Glib::Object::Subclass, but i hesitate to do 
> this  because it most likely would entail duplicating Subclass.pm.
>
> on the plus side, this is all self-contained -- everything is  
> implemented in Base.xs, and could easily be dropped into  
> Gtk2/xs/GtkCellRenderer.xs without any problems.
>
>
> whatchoo think?

muppet,

I'm not sure why, but I've got some problems here.  "example.pl" dumps 
core on me.  It happens whenever I click on the drop-down list to start 
editing it.  Is it supposed to do this?  I noticed it was slightly 
changed from 0.03, so I have assumed that it was re-written for the new 
stuff in 0.04?

I never got around to trying out version 0.03 before 0.04.  Also, 
comparing the patches released with version 0.03 to the changes in 0.04, 
I thought (and still do) that the Glib-patch was no longer necessary.  
So I patched up the Gtk2 library and installed it.  The patches seem 
innocent enough that I didn't bother with setting up a parallel 
installation for testing.

"example.pl" dumped core.

Next step was to install the Glib patch as well.  I could have been 
wrong about it's importance.  No difference, still a core dump.

I then went back to version 0.03, and this one didn't core dump.  So 
it's something introduced in 0.04.

"fancy.pl" does not *not* throw a segmentation violation.

That's where I am so far.  I might continue digging, but that's probably 
a waste of time until you can give me a hint at which direction you want 
me to go.

I'm sorry I don't have my environment/installation set up to do proper 
C-level debugging.  I actually think I haven't started up "gdb" in 
years, I was rather surprised at myself that I still remembered how to 
get a back-trace from a core.  So rather basic information, I'm afraid.  
This is from 0.04 *after* installing the glib-patch:

(gdb) bt
#0  0x4083fec8 in gtk2perl_cell_renderer_start_editing ()
  from 
/usr/lib/perl5/site_perl/5.8.0/i686-linux/auto/Gtk2/CellRenderer/Base/Base.so
#1  0x40526746 in gtk_cell_renderer_start_editing () from 
/usr/lib/libgtk-x11-2.0.so.0
#2  0x4069a308 in gtk_tree_view_column_cell_process_action () from 
/usr/lib/libgtk-x11-2.0.so.0
#3  0x406982bf in _gtk_tree_view_column_cell_event () from 
/usr/lib/libgtk-x11-2.0.so.0
#4  0x40681dd5 in gtk_tree_view_button_press () from 
/usr/lib/libgtk-x11-2.0.so.0
#5  0x405b411f in _gtk_marshal_BOOLEAN__BOXED () from 
/usr/lib/libgtk-x11-2.0.so.0
#6  0x40245477 in g_type_class_meta_marshal () from 
/usr/lib/libgobject-2.0.so.0
#7  0x40244e18 in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#8  0x40256e79 in signal_emit_unlocked_R () from 
/usr/lib/libgobject-2.0.so.0
#9  0x40256111 in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#10 0x40256634 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
#11 0x406a6580 in gtk_widget_event_internal () from 
/usr/lib/libgtk-x11-2.0.so.0
#12 0x405b3506 in gtk_propagate_event () from /usr/lib/libgtk-x11-2.0.so.0
#13 0x405b25e6 in gtk_main_do_event () from /usr/lib/libgtk-x11-2.0.so.0
#14 0x4077fd73 in gdk_event_dispatch () from /usr/lib/libgdk-x11-2.0.so.0
#15 0x402974d0 in g_main_dispatch () from /usr/lib/libglib-2.0.so.0
#16 0x40295912 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#17 0x40297988 in g_main_context_iterate () from /usr/lib/libglib-2.0.so.0
#18 0x40295ee2 in g_main_loop_run () from /usr/lib/libglib-2.0.so.0
#19 0x405b205f in gtk_main () from /usr/lib/libgtk-x11-2.0.so.0
#20 0x4033bb6e in XS_Gtk2_main () from 
/usr/lib/perl5/site_perl/5.8.0/i686-linux/auto/Gtk2/Gtk2.so
#21 0x080c041e in Perl_pp_entersub ()
#22 0x080ba489 in Perl_runops_standard ()
#23 0x08062674 in S_run_body ()
#24 0x0806243d in perl_run ()
#25 0x0805effc in main ()
#26 0x400c4be7 in __libc_start_main () from /lib/libc.so.6

Bjarne