This makes sure nodes are ready before finding the default node, avoiding audio
glitch in wrong device if profile was also changed while changing the default
node (can happen with Gnome Sound Settings).
Since nodes are destroyed and recreated again when a device profile changes, the
only way to make sure device nodes are ready is to check the profile classes
structure, which tell us how many total nodes the device has, and then check
that those nodes exist for that device. A rescan is triggered whenever devices,
nodes or ports changed.
This patch also improves the logic when finding default nodes, allowing virtual
sources to be set as default sources.
Fixes#85 and #130
Previously a default source had to be Audio/Source and a default sink
had to be Audio/Sink. This did not account for:
- monitor sources (Audio/Sink)
- duplex nodes (Audio/Duplex)
- virtual sources (Audio/Source/Virtual)
With this change the restriction is now on the number of input/output
ports, so any Audio/* node with output ports is a valid target to select
as a default source, while any Audio/* node with input ports is a valid
target for a default sink.
Fixes#60
