Toggle button LED on mute & speakers

pa.c

@@ -18,7 +18,7 @@ static void xpa_on_sink_input_info(pa_context *ctx,
 	struct sink_input_watch *w = sink_inputs_get(info->name);
 	if (w) {
 		sink_input_watch_add_index(w, info->index);
-		sink_input_watch_update(w, info->volume.values[0], info->mute != 0);
+		sink_input_watch_update(w, info->sink, info->volume.values[0], info->mute != 0);
 	}
 }
 

pa_sink_input_watch_list.c

@@ -35,7 +35,8 @@ void sink_input_watch_remove_index(struct sink_input_watch *w, uint32_t pa_index
 	}
 }
 
-void sink_input_watch_update(struct sink_input_watch *w, pa_volume_t volume, bool mute) {
+void sink_input_watch_update(struct sink_input_watch *w, uint32_t sink_index, pa_volume_t volume, bool mute) {
+	w->sink = sink_index;
 	w->volume = volume;
 	w->mute = mute;
 	if (w->volume_changed) {
@@ -49,6 +50,7 @@ struct sink_input_watch *sink_inputs_add_sink(const char* sink_name) {
 			sizeof(struct sink_input_watch) * sink_inputs.len);
 	struct sink_input_watch *item = &sink_inputs.items[sink_inputs.len - 1];
 	item->name = strdup(sink_name);
+	item->sink = -1;
 	item->volume = PA_VOLUME_MUTED;
 	item->mute = true;
 	item->indices.len = 0;

pa_sink_input_watch_list.h

@@ -3,6 +3,7 @@
 
 struct sink_input_watch {
 	const char *name;
+	uint32_t sink;
 	pa_volume_t volume;
 	bool mute;
 	struct indices_list {
@@ -15,7 +16,7 @@ struct sink_input_watch {
 
 void sink_input_watch_add_index(struct sink_input_watch *w, uint32_t pa_index);
 void sink_input_watch_remove_index(struct sink_input_watch *w, uint32_t pa_index);
-void sink_input_watch_update(struct sink_input_watch *w, pa_volume_t volume, bool mute);
+void sink_input_watch_update(struct sink_input_watch *w, uint32_t sink_index, pa_volume_t volume, bool mute);
 struct sink_input_watch *sink_inputs_add_sink(const char* sink_name);
 struct sink_input_watch *sink_inputs_get(const char *sink_name);
 void sink_inputs_remove_index(uint32_t pa_index);

panelcontrol.c

@@ -37,6 +37,8 @@ gboolean on_alsa_readable(GIOChannel *source, GIOCondition condition, gpointer d
 	return TRUE;
 }
 
+static int port;
+
 snd_seq_t *alsa(int source) {
 	// connect to ALSA seq
 	snd_seq_t *seq;
@@ -45,7 +47,7 @@ snd_seq_t *alsa(int source) {
 		exit(1);
 	}
 	snd_seq_set_client_name(seq, CLIENT_NAME);
-	int port = snd_seq_create_simple_port(seq, CLIENT_NAME,
+	port = snd_seq_create_simple_port(seq, CLIENT_NAME,
 			SND_SEQ_PORT_CAP_WRITE|SND_SEQ_PORT_CAP_SUBS_WRITE
 			|SND_SEQ_PORT_CAP_READ|SND_SEQ_PORT_CAP_SUBS_READ,
 			SND_SEQ_PORT_TYPE_APPLICATION);
@@ -104,6 +106,25 @@ snd_seq_t *alsa(int source) {
 //static const struct encoder_map_entry encoder_map[] = {
 //	{.encoder = ENC1, .sink_input = NULL, .action = &change_volume},
 //};
+void midi_button_led(snd_seq_t *seq, enum button button, enum button_led_state state) {
+	snd_seq_event_t ev;
+	snd_seq_ev_clear(&ev);
+	snd_seq_ev_set_source(&ev, port);
+	snd_seq_ev_set_subs(&ev);
+	snd_seq_ev_set_direct(&ev);
+	snd_seq_ev_set_noteon(&ev, 0, button, state);
+	snd_seq_event_output_direct(seq, &ev);
+}
+
+void show_mute_and_speakers(struct sink_input_watch *w) {
+	snd_seq_t *seq = w->userdata;
+	midi_button_led(seq, TOP1, w->mute ? BUTTON_LED_ON : BUTTON_LED_OFF);
+
+	uint32_t speakers = 3;
+	uint32_t headphones = 4;
+
+	midi_button_led(seq, BOTTOM1, w->sink == speakers ? BUTTON_LED_ON : BUTTON_LED_OFF);
+}
 
 int main(int argc, char *argv[]) {
 	if (argc != 2) {
@@ -112,10 +133,13 @@ int main(int argc, char *argv[]) {
 	}
 	int source = atoi(argv[1]);
 
+	snd_seq_t *seq = alsa(source);
+
 	struct sink_input_watch *mpd = sink_inputs_add_sink("mpd pulse");
+	mpd->userdata = seq;
+	mpd->volume_changed = show_mute_and_speakers;
 
 	pa();
-	snd_seq_t *seq = alsa(source);
 
 	// create PA watch object for sink name "mpd pulse"
 	// with a callback function on change (info, sinks)
@@ -127,7 +151,7 @@ int main(int argc, char *argv[]) {
 	// on change from MIDI side, the callback is executed and passed the
 	// MIDI action as well as the mapping struct with the PA watch reference
 
-	GMainLoop *main_loop = g_main_loop_new (NULL, FALSE);
+	GMainLoop *main_loop = g_main_loop_new(NULL, FALSE);
 	g_main_loop_run(main_loop);
 	g_main_loop_unref(main_loop);
 	return 0;

panelcontrol.h

@@ -24,6 +24,11 @@ enum button {
 	LAYERB = 85,
 };
 
+enum button_led_state {
+	BUTTON_LED_ON = 127,
+	BUTTON_LED_OFF = 0,
+};
+
 enum encoder {
 	ENC1 = 16,
 	ENC2 = 17,