Re: Strange bug while subclassing Gtk2::Box

[muppet <scott asofyet org>]

On Oct 30, 2005, at 2:08 PM, Eduardo M KALINOWSKI wrote:

> Jaap Karssenberg wrote:
>
> > For zim I'm working on a Gtk2::Ex::PathBar class to implement a path
> > bar that looks like the one that is found in the gtk filechooser.

Rock.

> > Now
> > I have a strange bug. My implementation works perfectly fine on my  
> > own
> > system which runs archlinux.

What versions of gtk+ and Gtk2?

> > The problem is this: my widget is a subclass of Gtk2::Box which
> > implements size_request and size_allocate. Now on some systems it
> > justs works, on other systems it doesn't. When it doesn't the buttons
> > are allocated but they don't show up in the widget. But they are
> > there, they are clickable - they just don't show.
> >
> > The code below reproduces the problem. If you do see the buttons that
> > means you have one of the systems where it just works, if you see an
> > empty space try clicking it, you should see output from the buttons
> > being clicked in your terminal.
>
> I'm running Debian, libgtk2-perl version 1.081, gtk version 2.6.10  
> and I
> don't see the buttons, but indeed they're clickable. I'm using the
> default gtk theme.

With the stock gtk+ on FC3 (2.4.14), i see nothing, as you  
described.  Tried using console X and remote X, no difference.

However, with gtk+ 2.8.2 running out of a JHBuild sandbox on the very  
same machine, i see a series of buttons.

So it's not merely distro differences.

I instrumented your code with some calls to  
Glib::Object::signal_add_emission_hook() (from Glib 1.10x), ran the  
code in both sandboxes, and compared the output.  For some reason,  
the older gtk+ (which doesn't show the buttons) does not propagate  
expose events to the HBox's children, but gtk+ 2.8 does.

Making your MyBox derive from HBox and disabling your do_size_allocate 
() results in a working example on both versions.  You probably want  
to compare your do_size_allocate() with gtk_hbox_size_allocate() and  
see what you're doing differently.


--
"the ternary operator makes it a bit less ugly."
    -- kaffee