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

3 files changed, 91 insertions, 8 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);
 }
 
diff --git a/pulse.cc b/pulse.cc
index e42db12..b765d64 100644
--- a/pulse.cc
+++ b/pulse.cc
@@ -10,6 +10,7 @@
 // C++
 #include <string>
 #include <algorithm>
+#include <stdexcept>
 
 // External
 #include <pulse/pulseaudio.h>
@@ -155,6 +156,13 @@ Card* PulseClient::GetCard(const string& name) {
   return nullptr;
 }
 
+Card* PulseClient::GetCard(const Device& device) {
+  for (Card& card : cards_) {
+    if (device.card_idx_ == card.index_) return &card;
+  }
+  return nullptr;
+}
+
 Device* PulseClient::get_device(vector<Device>& devices, const uint32_t& index) {
   for (Device& device : devices) {
     if (device.index_ == index) return &device;
@@ -172,6 +180,48 @@ Device* PulseClient::get_device(vector<Device>& devices, const string& name) {
   return nullptr;
 }
 
+Device* PulseClient::GetDevice(const uint32_t& index, enum DeviceType type) {
+  switch (type) {
+    case DEVTYPE_SINK:
+      return GetSink(index);
+    case DEVTYPE_SOURCE:
+      return GetSource(index);
+    case DEVTYPE_SINK_INPUT:
+      return GetSinkInput(index);
+    case DEVTYPE_SOURCE_OUTPUT:
+      return GetSourceOutput(index);
+  }
+  throw std::runtime_error("Impossible DeviceType encountered in GetDevice");
+}
+
+Device* PulseClient::GetDevice(const string& name, enum DeviceType type) {
+  switch (type) {
+    case DEVTYPE_SINK:
+      return GetSink(name);
+    case DEVTYPE_SOURCE:
+      return GetSource(name);
+    case DEVTYPE_SINK_INPUT:
+      return GetSinkInput(name);
+    case DEVTYPE_SOURCE_OUTPUT:
+      return GetSourceOutput(name);
+  }
+  throw std::runtime_error("Impossible DeviceType encountered in GetDevice");
+}
+
+const vector<Device>& PulseClient::GetDevices(enum DeviceType type) const {
+  switch (type) {
+    case DEVTYPE_SINK:
+      return GetSinks();
+    case DEVTYPE_SOURCE:
+      return GetSources();
+    case DEVTYPE_SINK_INPUT:
+      return GetSinkInputs();
+    case DEVTYPE_SOURCE_OUTPUT:
+      return GetSourceOutputs();
+  }
+  throw std::runtime_error("Impossible DeviceType encountered in GetDevices");
+}
+
 Device* PulseClient::GetSink(const uint32_t& index) {
   return get_device(sinks_, index);
 }
@@ -495,7 +545,8 @@ Device::Device(const pa_sink_info* info) :
     index_(info->index),
     name_(info->name ? info->name : ""),
     desc_(info->description),
-    mute_(info->mute) {
+    mute_(info->mute),
+    card_idx_(info->card) {
   update_volume(info->volume);
   memcpy(&channels_, &info->channel_map, sizeof(pa_channel_map));
   balance_ = pa_cvolume_get_balance(&volume_, &channels_) * 100.0;
@@ -510,7 +561,8 @@ Device::Device(const pa_source_info* info) :
     index_(info->index),
     name_(info->name ? info->name : ""),
     desc_(info->description),
-    mute_(info->mute) {
+    mute_(info->mute),
+    card_idx_(info->card) {
   update_volume(info->volume);
   memcpy(&channels_, &info->channel_map, sizeof(pa_channel_map));
   balance_ = pa_cvolume_get_balance(&volume_, &channels_) * 100.0;
@@ -524,7 +576,8 @@ Device::Device(const pa_sink_input_info* info) :
     type_(DEVTYPE_SINK_INPUT),
     index_(info->index),
     name_(info->name ? info->name : ""),
-    mute_(info->mute) {
+    mute_(info->mute),
+    card_idx_(-1) {
   update_volume(info->volume);
   memcpy(&channels_, &info->channel_map, sizeof(pa_channel_map));
   balance_ = pa_cvolume_get_balance(&volume_, &channels_) * 100.0;
@@ -543,7 +596,8 @@ Device::Device(const pa_source_output_info* info) :
     type_(DEVTYPE_SOURCE_OUTPUT),
     index_(info->index),
     name_(info->name ? info->name : ""),
-    mute_(info->mute) {
+    mute_(info->mute),
+    card_idx_(-1) {
   update_volume(info->volume);
   volume_percent_ = volume_as_percent(&volume_);
   balance_ = pa_cvolume_get_balance(&volume_, &channels_) * 100.0;
diff --git a/pulse.h b/pulse.h
index 9bb0733..2c010b2 100644
--- a/pulse.h
+++ b/pulse.h
@@ -68,6 +68,7 @@ class Device {
   pa_channel_map channels_;
   int mute_;
   int balance_;
+  uint32_t card_idx_;
   Operations ops_;
 };
 
@@ -96,6 +97,17 @@ class Card {
 struct ServerInfo {
   string sink;
   string source;
+
+  const string GetDefault(enum DeviceType type) {
+    switch (type) {
+    case DEVTYPE_SINK:
+      return sink;
+    case DEVTYPE_SOURCE:
+      return source;
+    default:
+      return "";
+    }
+  }
 };
 
 template<typename T>
@@ -127,6 +139,11 @@ class PulseClient {
   // devices and cards are cleared before the new data is stored.
   void Populate();
 
+  // Get a device by index or name and type, or all devices by type.
+  Device* GetDevice(const uint32_t& index, enum DeviceType type);
+  Device* GetDevice(const string& name, enum DeviceType type);
+  const vector<Device>& GetDevices(enum DeviceType type) const;
+
   // Get a sink by index or name, or all sinks.
   Device* GetSink(const uint32_t& index);
   Device* GetSink(const string& name);
@@ -147,9 +164,11 @@ class PulseClient {
   Device* GetSourceOutput(const string& name);
   const vector<Device>& GetSourceOutputs() const { return source_outputs_; }
 
-  // Get a card by index or name, or all cards.
+  // Get a card by index or name, all cards, or get the card which
+  // a sink is attached to.
   Card* GetCard(const uint32_t& index);
   Card* GetCard(const string& name);
+  Card* GetCard(const Device& device);
   const vector<Card>& GetCards() const { return cards_; }
 
   // Get or set the volume of a device.