[gtkmm] Gtk::Container::remove and a question

[Robin <robin bourianes free fr>]

Hi,

I have noticed something odd (IMO) in the remove method of Gtk::Container.

When a managed widget is removed from a Gtk::Container, the remove
method adds a reference to it, and the result is that the widget is not
deleted. The programmer have to call my_widget->unreference () after the
remove call to delete it.

I thought that the fact to set a widget "Gtk managed" means that it
would be deleted by gtk when necessary. There is a comment in the remove
method explaining that the reference is here to prevent deleting the
widget in case the widget will be added to another Gtk::Container.

IMO, when a widget is set managed, this reference shouldn't be added
because if the programmer wants to remove the widget and then add it to
another container, _he_ has to put calls to reference () and unreference
() around the operation.
When I used the remove method, due to the fact i had set my widget
managed, I was expecting the widget to be deleted.


/* pseudo code */
Gtk::Widget* widget = new Gtk::Widget ();

widget->set_manage ();

.....

widget->reference ();
container1->remove (*widget);
container2->add (*widget);
widget->unreference ();

...
/* pseudo code */

My other question is more a c++ related question but I can't figure it 
out ...

In fact, the example of custom container found in the gtkmm tutorial 
(http://www.gtkmm.org/docs/gtkmm-2.4/docs/tutorial/html/ch21.html#id2749211) 
doesn't compile on my box.
It fails with this :

/usr/include/gtkmm-2.4/gtkmm/widget.h: In member function « virtual void
   MyContainer::set_child_widgets(Gtk::Widget&, Gtk::Widget&) »:
/usr/include/gtkmm-2.4/gtkmm/widget.h:2434: error: `void
   Gtk::Widget::set_parent(Gtk::Widget&)' is protected
mycontainer.cc:20: error: within this context
...
(other messages like above with Gtk::Widget::unparent)

I have the same problem in a custom container I'm writting for a project 
of mine but I don't understand the reason as the custom container is a 
Gtk::Widget ...

I'm runinng a Debian unstable with gcc -v :

Lecture des spécification à partir de 
/usr/lib/gcc-lib/i486-linux/3.3.5/specs
Configuré avec: ../src/configure -v 
--enable-languages=c,c++,java,f77,pascal,objc,ada,treelang --prefix=/usr 
--mandir=/usr/share/man --infodir=/usr/share/info 
--with-gxx-include-dir=/usr/include/c++/3.3 --enable-shared 
--with-system-zlib --enable-nls --without-included-gettext 
--enable-__cxa_atexit --enable-clocale=gnu --enable-debug 
--enable-java-gc=boehm --enable-java-awt=xlib --enable-objc-gc i486-linux
Modèle de thread: posix
version gcc 3.3.5 (Debian 1:3.3.5-1)

Is this a compiler bug or did I missed something ?

Thank you :)

PS : Sorry if my message is not correctly wrapped but I have trouble 
with my email client :p