Re: Decorating scales

["Matthias Clasen" <matthias clasen gmail com>]

On Tue, Jan 6, 2009 at 5:06 PM, Stefan Kost <ensonic hora-obscura de> wrote:
>
> I would like that a lot. One thing slightly related is that I wonder if the
> GtkAdjustment* could be hinted to the theme engines. E.g. for a Panorma function
> the adjustment would be -100 ... 100 or 1.0 ... 1.0. Right now most themes draw
> a filled bar from the left and not from where zero is (the middle for panorama).

Theme engines can and do poke at the widget and get the adjustment,
even if that is not really a nice thing to do.

The general idea of drawing scales filled in to the thumb is somewhat
problematic, since there are plenty of uses for scales where that is
not appropriate (like the balance slider I mentioned initially, or
your panorama example).

We do have style properties allowing to control different drawing of
the lower/upper half of the trough (GtkRange::trough-side-details),
but we are missing some way for applications to indicate if it is
appropriate for a scale to be treated this way, short of
gtk_rc_parse_string().