Subject: Re: [linux-audio-dev] back to the API
From: David Olofson (audiality_AT_swipnet.se)
Date: ma loka 25 1999 - 18:00:14 EDT
On Mon, 25 Oct 1999, Paul Barton-Davis wrote:
> >Well, I believe plug-in code should be as simple as possible, so I
> >don't see why alternative ways of changing parameters makes sense...
>
> the alternatives allow the event source to not have to know the
> current value of the object being changed. this allows more
> flexibility in possible representations to the user, and also avoids
> an attempt to cache values when it can be avoided.
>
> having a button that says "XXX has changed by +0.5" is a much better
> design than a UI that is *forced* to know the current value of XXX in
> order to send the event. OTOH, when a button selects a known value,
> having to know the old value is also pretty silly.
>
> Of course, if it wants to display the value of XXX, it has to know it,
> but its easy to imagine UI elements that don't need to work like
> this. why force them to ?
Ok... It adds complexity to the event system definition (plugins
*have to* support both) and automation code (position tracking), but
it might not be that bad. And there is complexity involved with
keeping track of the current value of a parameter as well.
OTOH, sending inc/dec events to plugins is kind of like moving a
part of the UI into the plugin, IMO. It might be a little speed
optimization when used, and even simplify things in those cases. But
how often do you use inc/dec buttons without any indicator? I can't
remember seeing *any* plugin GUI that has such a function, and from
the user POV, I don't think I want to see any - how would you know
what you're doing?
* Sliders know their position anyway - trying to work around
that only results in position/parameter sync bugs.
* Inc/dec buttons affect some kind of display. (Well, I've
seen other similar things that don't work like that, and
that's usually a very annoying experience. "Where the h*ll
am I!?")
* "Mode select" style buttons (radio) send fixed values. No
inc/dec events here.
I'm probably missing something, 'cause actually I can't see much point
in supporting inc/dec and similar things at plugin level at all...
//David
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