Re: Recording widget motion

[David Nečas (Yeti) <yeti physics muni cz>]

On Thu, Sep 07, 2006 at 09:42:16AM -0400, Samuel Cormier-Iijima wrote:
> I thought g_timeout_add
> would cause timing to be off (it would unsynchronize over time), but
> using a GTimer fixed it.

Yes, g_timeout_add() is just a best-effort timer, no
real-time.  But many apps do not need to run the callbacks
in precise intervals, they only need to know precisely when
the callback is actually called -- and this can be done with
a GTimer as you did.

> The problem I'm currently having is this: I'd
> like to know when the user is "holding" the slider, that is, has the
> mouse button pressed on the slider itself, not in the "trough", so
> that the user can record "over" his previous recording. This is kinda
> hard to explain, and I'm not sure if it's a good idea from a UI point
> of view...

I think I understand, but I'm afraid Gtk+ provides no public
interface for that.  Especially the extreme no-motion case
is hardly detectable, that is when user just presses the
slider but does not move it at all to set a fixed value over
a time interval.  IMO it's not a bad UI idea, except that
the value the slider `wants' at given moment (from previous
recording) becomes invisible once you press it.  So it's
hard not to cause a jump when you release it.  But it can be
visualized somehow.

In similar situations one can fork the Gtk+ widget and add
the required functionality, although in this case the fork
would have to include at least GtkRange, GtkScale, GtkHScale
and/or GtkVScale.

Yeti


--
Anonyms eat their boogers.