Derive the card from the targetted device

Unless explicitly specified, target a card based on the selected device.
Note that not all devices will be tied to a card.

falconindy  » put differently, if i have multiple cards, what determines which
              card is used by pulse for a given app?
tanuk       » In theory, the logic can be anything (it depends on what
              policy-implementing modules are loaded). By default, routing is mostly
              handled by module-stream-restore, which chooses the sink based on the
              user's previous routing choices.
tanuk       » If the user hasn't done any routing choices, the fallback logic is to
              select the current "default sink".
tanuk       » I don't recommend trying to guess the routing policy.
falconindy  » i guess my understanding of pulse internals is lacking
falconindy  » but that's rather enlightening
falconindy  » is there any way to figure out the connection between a sink and a card?
tanuk       » Yes... (One moment, I'll look up things.)
falconindy  » ah. uint32_t card
falconindy  » appears to be in pa_sink_info
falconindy  » so that ties the sink to the index of a card?
tanuk       » Yep.
falconindy  » awesome, that's good enough for what i need to do
tanuk       » Not all sinks are part of a card, though, but those that are will have
              the card index set.
falconindy  » also good to know

1 files changed, 13 insertions, 3 deletions

diff --git a/ponymix.cc b/ponymix.cc
index 824daa6..874728f 100644
--- a/ponymix.cc
+++ b/ponymix.cc
@@ -146,7 +146,8 @@ static int ListCards(PulseClient& ponymix, int, char*[]) {
 }
 
 static int ListProfiles(PulseClient& ponymix, int, char*[]) {
-  // TODO: Is there any sense of a "default card" ?
+  if (opt_card == nullptr) errx(1, "error: no card selected");
+
   auto card = ponymix.GetCard(opt_card);
   if (card == nullptr) errx(1, "error: no match found for card: %s", opt_card);
 
@@ -500,15 +501,24 @@ int main(int argc, char* argv[]) {
   ponymix.Populate();
 
   // defaults
+  ServerInfo defaults = ponymix.GetDefaults();
   opt_action = "defaults";
   opt_devtype = DEVTYPE_SINK;
-  opt_device = ponymix.GetDefaults().sink.c_str();
-  opt_card = ponymix.GetCards()[0].Name().c_str();
+  opt_device = defaults.sink.c_str();
 
   if (!parse_options(argc, argv)) return 1;
   argc -= optind;
   argv += optind;
 
+  // cards are tricky... find the one that belongs to the chosen sink.
+  if (opt_card == nullptr) {
+    const Device* device = ponymix.GetDevice(opt_device, opt_devtype);
+    if (device) {
+      const Card* card = ponymix.GetCard(*device);
+      if (card) opt_card = card->Name().c_str();
+    }
+  }
+
   return CommandDispatch(ponymix, argc, argv);
 }