Re: Maemomm

[Robert Pearce <rob bdt-home demon co uk>]

On Mon, 25 Jun 2007, Murray Cumming <murrayc murrayc com> wrote :
> >  Gdk::Pixmap *pixmap;
> >   Gdk::GC *gc;
> >
> > Declare in constructor.  It does not show error. but when i am going to
> > use the functions in the .cc files it shows error like:
> > Line 37 here:
> > gc = get_style()->get_fg_gc(get_state());
> >     win.draw_pixmap(gc ,
> >             pixmap,
> >             event->area.x, event->area.y,
> >             event->area.x, event->area.y,
> >             event->area.width, event->area.height);
>
> You probably mean win->draw_pixmap. The RefPtr smartpointer needs
> similar syntax to a pointer. That would explain your second error,
> though not your first.
>
> > ScribbleDrawingArea.cc:37: error: cannot convert `Glib::RefPtr<Gdk::GC>'
> > to `Gdk::GC*' in assignment
What happens if you just change the declaration of gc to
   Glib::RefPtr<Gdk::GC> gc;
?

As I understand it, a RefPtr can't be assigned to a normal C++ pointer, 
because it loses the reference counting. However, a RefPtr will be 
_cast_ to a C++ pointer automatically and invisibly, because the user of 
the C++ pointer won't be doing anything with the reference count.

Not that I'm an expert on this, but that's the impression I get.
--
Rob Pearce                       http://www.bdt-home.demon.co.uk

The contents of this | Windows NT crashed.
message are purely   | I am the Blue Screen of Death.
my opinion. Don't    | No one hears your screams.
believe a word.      |