Created attachment 118965 [details] [review]
[PATCH] Make GladePlaceholder able to be placed in a GtkScrolledWindow.

 gladeui/glade-marshallers.list |    1 +
 gladeui/glade-placeholder.c    |   11 +++++++++++
 gladeui/glade-placeholder.h    |    4 ++++
 3 files changed, 16 insertions(+), 0 deletions(-)

Ping? Ok to commit this patch?

I dont feel the warning warrants adding scrolling capabilities to
placeholders.

Maybe if we want to avoid the warning we could just make the 
adaptor->add()/adaptor->replace_child() implementations
for scrolled window use scrolled_window_add_with_viewport() in the
case of non-scrollable children instead ?

Note, that would mask the problem in glade and leave the problem
in the resulting application.

The real plan I've had in mind for this was to put it off
until we get a proper logging api in glade, in which case
we could save logs from gtk+ and put it in a widget complaint 
domain.

The option of actually handling an added viewport in the
project is also complex, the core wont allow for
recording commands in recursive ways (which means no
adding viewports in backend ->add() implementations).

I think we should think twice for now about removing the
error message.

This is fixed on master.