Re: GtkLayout: correct use or kludge?

[greg <gregor waltz villanova edu>]

Havoc Pennington wrote:
> 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.

tell me about it :P i *did* actually have it sort of working before
using gdkwindows to hold and move the objects instead of a single
bin_window; REALLY messy though...


> > 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.

well, i think i have it now. it works pretty well. it's sooo much better
than what i was doing before at least :)

i want to get rid of as many usizes as possible, make it into a widget,
and get rid of the hard coded parameters, but you can see a small proof
of concept example here:

www.epix.net/~motorbt/test.zip


i basically used my second idea with multiple layouts, but i used a
table to hold the scrollbars and layouts.

and to think this project has been on hold for nearly a year because of
this. i should have had this idea SOONER! i always do things the "HARD
way"(TM) before doing it the "Right Way"(TM) ;o

thanks
-- 

-greg

http://neenjatech.org

Passionate hatred can give meaning and purpose to an empty life.
                -- Eric Hoffer