Re: Creating an aggregating GtkContainer

[Per Hermansson <hermansson per bredband net>]

Tristan Van Berkom wrote:
> On Wed, Nov 18, 2009 at 7:22 PM, Per Hermansson
> <hermansson per bredband net> wrote:
>   
> > Thanks, maybe I'm asking for the impossible :)
> > Say I use a scroll window for the different subcontainers to allow some
> > overflow.
> > Would it be possible to listen for signals on the containers and when the
> > widgets have gotten their size
> > allocated move them if the scrollbars became visible as a result of this.
> > The user will then probably experience some flicker as containers are
> > repainted and widgets moved.
> > Would this be reasonable/possible to implement?
> >
> >     
>
> First lets clarify, you are writing a container implementation, technically you
> allocate space for the children, usually according to the size they requested.
>
> So best not hook onto signals before properly implementing ->size_allocate()
> and ->size_request() for your composite widget (from there you should be
> able to manage all the main children - when reparenting a child this should
> be all automatic, maybe theres a need for gtk_container_check_resize() in
> some corner cases I couldnt say off hand).
>
> Somehow I doubt that you want to move widgets around based on size
> reallocation, I think that a well designed application layout should just stand
> alone and widgets jumping around will confuse the user more than anything
> else.
>
> At any rate, there are nice things you can do like making sure an important
> widget in the undetermined size window gets focus and is visible inside the
> scrolled window - or remembering scroll positions of various tabs when they
> get replaced or reloaded or such.
>   
I agree that this will surely be confusing to anyone watching widgets 
move around.
What I understand from the design makers is that having multiple 
containers that span different
parts of the application is a replacement for having a single scrollable 
container since scrollbars
are not user friendly.

Anyway, I'm gonna test your advice and see if I can approximate the 
widget's size to avoid
unnecessary flickering and widgets moving around. Other than that I 
don't think its possible
to do what I want with GTK+.

Thanks
Per