Re: Trouble with create_cairo_context

[Jonathon Jongsma <jonathon quotidian org>]

Mark Tilford wrote:
> On Sun, Sep 28, 2008 at 7:43 PM, Jonathon Jongsma
> <jonathon quotidian org> wrote:
> > Mark Tilford wrote:
> > > On Sat, Sep 27, 2008 at 1:55 PM, Mark Tilford <ralphmerridew gmail com>
> > > wrote:
> > > > Anybody ever figure out what caused this problem?  I can't get the
> > > > clock example to work:
> > > >
> > > > ~/src/gtk/clock$ g++ `pkg-config --cflags --libs gtkmm-2.4`
> > > > `pkg-config --cflags --libs cairomm-1.0` -g clock.cc main.cc
> > > > ~/src/gtk/clock$ ./a.out
> > > > ./a.out: symbol lookup error: ./a.out: undefined symbol:
> > > > _ZN3Gdk8Drawable20create_cairo_contextEv
> > > I found a workaround:
> > > Instead of
> > > m_cairo_context = widget.get_window()->create_cairo_context();
> > > Use
> > > m_cairo_context = Cairo::RefPtr<Cairo::Context>(new
> > > Cairo::Context(gdk_cairo_create(widget.get_window()->gobj())));
> > >
> > > In case anybody else runs into the same problem.
> > > _______________________________________________
> > > gtkmm-list mailing list
> > > gtkmm-list gnome org
> > > http://mail.gnome.org/mailman/listinfo/gtkmm-list
> > You're probably trying to link against a too-old version of gtkmm (?)  I
> > believe the gdk_cairo_create() function was added in GTK+ 2.6, but it wasn't
> > wrapped until the next release of gtkmm (due to the fact that cairomm wasn't
> > yet stable in time for gtkmm-2.6)
> >
> > * I might not have the version numbers exactly correct, but I know for sure
> > that there was a 1-version gap between when cairo support was added to GTK+
> > and when it was added to gtkmm.
> >
> > --
> > jonner
>
>
> Exactly which version do I have / which file do I need to upgrade?
> (gtkmm numbering has me completely confused.)
>
> ii  libgtkmm-2.4-1c2a           1:2.12.5-2                  C++
> wrappers for GTK+ 2.4 (shared libraries)
> ii  libgtkmm-2.4-dev            1:2.12.5-2                  C++
> wrappers for GTK+ 2.4 (development files)
> ii  libgtkmm-2.4-doc            1:2.12.5-2                  C++
> wrappers for GTK+ 2.4 (documentation)
> ii  libcairomm-1.0-1            1.4.2-1                     C++
> wrappers for Cairo (shared libraries)
> ii  libcairomm-1.0-dev          1.4.2-1                     C++
> wrappers for Cairo (development files)
> ii  libcairomm-1.0-doc          1.4.2-1                     C++
> wrappers for Cairo (documentation)

Those versions should all be plenty new.  I just double-checked and 
create_cairo_context() was added in gtkmm 2.10 and you have 2.12 (you 
can be more sure about what version you're linking against by running 
`pkg-config --modversion gtkmm-2.4`)

btw, the second pkg-config invocation (the one for cairomm-1.0) is not 
necessary since gtkmm will pull that in automatically.

Also, I just noticed that this error is not occurring at link time, but 
instead at runtime.  that seems very strange... maybe your environment 
is broken and you need to set LD_LIBRARY_PATH or something?

(also, I'm copying this message back to gtkmm-list.  you're more likely 
to get good advice if you keep it on-list so other people can chime in)
--
jonner