Conditional availability of properties

[Arun Raghavan]

On Fri, 2011-09-16 at 21:57 +0200, Stefan Sauer wrote:
> On 09/13/11 04:49, Arun Raghavan wrote:
> > Hey folks,
> > I'm looking at adding the GstStreamVolume interface to pulsesrc since
> > PulseAudio 1.0 will support per-source-output volumes. However, there is
> > one potential problem here that I believe might raise objections.
> >
> > The interface (which is really just the "volume" and "mute" properties)
> > will only be available if pulsesrc is compiled against PulseAudio 1.0
> > since we want to be able to compile against older versions as well.
> >
> > IMO this isn't a huge problem if we document that users should be
> > checking to see if pulsesrc implements the interface before using it
> > (this is what I've seen users of pulsesink do as well).
> We have some options.
> 
> 1.) add the properties, if the installed pulseaudio is recent enough
> 2.) always add the properties and use GstPropertyProbe to signal their
> availability
> 3.) make it and interface and use GstImplementsInterface (which is on
> the to-kill list for 0.11)

I was thinking of doing (1) + (3) and then solve the problem for 0.11
however all the other instances of GstImplementsInterface are done.

Cheers,
Arun