Re: GtkLayout: correct use or kludge?

[Havoc Pennington <hp redhat com>]

greg <gregor waltz villanova edu> writes: 
> the widget is basically a container in which the children get scrolled
> differently. one child gets scrolled in both directions, while others
> are only scrolled by one or none. so, the latter widgets are stationary
> in at least one direction. all of the children are visible at all times;
> they never scroll off the viewable area as would happen if they were
> scrolled normally.

Ouch, this is going to be a real pain in the ass to do smoothly. Well,
"no scrolling" is easy; just make the child a child of layout->window
not layout->bin_window - except the layout has no API for that, so
you'll need a custom container widget using layout code,
probably. Scrolling in one direction I don't know how you'll do.

> i was about to try one of two ideas, but before i start i was hoping to
> get some opinions.
>
> 1) use a gtklayout to hold everything. move the children on scroll
> events accordingly by setting their attribute (x,y) position. then use
> gdk_window_lower to put the fully scrollable child under everthing so it
> doesn't obscure other children when scrolled.
>
> 2) use a layout to hold multiple layouts. each child layout is given a
> viewable area (size) and attached to the appropriate scroll bars.
>
> i think 2 sounds better, but i'm not sure yet. any ideas?

Neither of those sounds really right... 

The idea of a layout is that child widgets are automatically scrolled
for you. So you may not want to use a layout, if you're doing this -
you'll have to scroll, then move the one-dimension children back in
one dimension, which will flicker and jump, and require a confusing
calculation of some kind.

Maybe have a look at the GtkLayout test in testgtk, that could be
helpful.

Havoc