From a1d62dd085ac70fc90a05095220156897bdd8f82 Mon Sep 17 00:00:00 2001
From: Tommaso Negri <me@tommasongr.com>
Date: Tue, 11 Aug 2026 17:50:39 +0200
Subject: refactor daemons + mpd + documentation

---
 daemons/volumed.c | 157 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 157 insertions(+)
 create mode 100644 daemons/volumed.c

(limited to 'daemons/volumed.c')

diff --git a/daemons/volumed.c b/daemons/volumed.c
new file mode 100644
index 0000000..ca6afa8
--- /dev/null
+++ b/daemons/volumed.c
@@ -0,0 +1,157 @@
+// volumed — volume daemon for bar
+//
+// Uses CoreAudio to listen for system volume/mute changes instead of
+// a CGEvent tap, so no Accessibility permission is required.
+//
+// When the volume changes, it posts a Darwin notification that tells
+// bar to refresh the "volume" block.
+//
+// Compile:
+//   cc -o bar-volumed daemons/volumed.c -framework CoreAudio
+
+#include <CoreAudio/CoreAudio.h>
+#include <notify.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+static volatile int keep_running = 1;
+
+static void handle_signal(int sig) {
+	(void)sig;
+	keep_running = 0;
+}
+
+// ── Volume change callback ───────────────────────────────────────────
+
+static OSStatus volume_changed(
+	AudioObjectID object,
+	UInt32 num_addresses,
+	const AudioObjectPropertyAddress addresses[],
+	void *context
+) {
+	(void)object; (void)num_addresses; (void)addresses; (void)context;
+	notify_post("bar.touch.<block-name>");
+	return noErr;
+}
+
+// ── Device change callback ───────────────────────────────────────────
+// Re-registers the volume listener when the output device changes
+// (e.g. headphones plugged in).
+
+static AudioDeviceID current_device = kAudioObjectUnknown;
+static void register_volume_listener(AudioDeviceID device);
+
+static OSStatus device_changed(
+	AudioObjectID object,
+	UInt32 num_addresses,
+	const AudioObjectPropertyAddress addresses[],
+	void *context
+) {
+	(void)object; (void)num_addresses; (void)addresses; (void)context;
+
+	AudioObjectPropertyAddress addr = {
+		kAudioHardwarePropertyDefaultOutputDevice,
+		kAudioObjectPropertyScopeGlobal,
+		kAudioObjectPropertyElementMain
+	};
+	AudioDeviceID new_device = kAudioObjectUnknown;
+	UInt32 size = sizeof(new_device);
+	AudioObjectGetPropertyData(
+		kAudioObjectSystemObject, &addr, 0, NULL, &size, &new_device);
+
+	if (new_device != current_device && new_device != kAudioObjectUnknown) {
+		register_volume_listener(new_device);
+	}
+	return noErr;
+}
+
+// ── Register listener on a device ────────────────────────────────────
+
+static void register_volume_listener(AudioDeviceID device) {
+	// Remove old listener if any
+	if (current_device != kAudioObjectUnknown) {
+		AudioObjectPropertyAddress old_addr = {
+			kAudioDevicePropertyVolumeScalar,
+			kAudioDevicePropertyScopeOutput,
+			1  // channel 1
+		};
+		AudioObjectRemovePropertyListener(
+			current_device, &old_addr, volume_changed, NULL);
+	}
+
+	current_device = device;
+
+	// Get the preferred stereo channel (usually 1)
+	UInt32 channel = 1;
+	AudioObjectPropertyAddress chan = {
+		kAudioDevicePropertyPreferredChannelsForStereo,
+		kAudioDevicePropertyScopeOutput,
+		kAudioObjectPropertyElementMain
+	};
+	UInt32 channels[2] = {0, 0};
+	UInt32 size = sizeof(channels);
+	if (AudioObjectGetPropertyData(device, &chan, 0, NULL, &size, &channels) == noErr) {
+		channel = channels[0];
+	}
+
+	// Listen for volume changes on the main output channel
+	AudioObjectPropertyAddress vol_addr = {
+		kAudioDevicePropertyVolumeScalar,
+		kAudioDevicePropertyScopeOutput,
+		channel
+	};
+	AudioObjectAddPropertyListener(device, &vol_addr, volume_changed, NULL);
+
+	// Also listen for mute changes
+	AudioObjectPropertyAddress mute_addr = {
+		kAudioDevicePropertyMute,
+		kAudioDevicePropertyScopeOutput,
+		kAudioObjectPropertyElementMain
+	};
+	AudioObjectAddPropertyListener(device, &mute_addr, volume_changed, NULL);
+}
+
+// ── Main ─────────────────────────────────────────────────────────────
+
+int main(void) {
+	signal(SIGINT, handle_signal);
+	signal(SIGTERM, handle_signal);
+
+	// Listen for output device changes
+	AudioObjectPropertyAddress dev_addr = {
+		kAudioHardwarePropertyDefaultOutputDevice,
+		kAudioObjectPropertyScopeGlobal,
+		kAudioObjectPropertyElementMain
+	};
+	AudioObjectAddPropertyListener(
+		kAudioObjectSystemObject, &dev_addr, device_changed, NULL);
+
+	// Register on the current device
+	UInt32 size = sizeof(current_device);
+	AudioObjectGetPropertyData(
+		kAudioObjectSystemObject, &dev_addr, 0, NULL, &size, &current_device);
+
+	if (current_device != kAudioObjectUnknown) {
+		register_volume_listener(current_device);
+	}
+
+	// Run until SIGINT/SIGTERM
+	while (keep_running) {
+		pause();
+	}
+
+	// Cleanup
+	if (current_device != kAudioObjectUnknown) {
+		AudioObjectPropertyAddress vol_addr = {
+			kAudioDevicePropertyVolumeScalar,
+			kAudioDevicePropertyScopeOutput,
+			1  // channel 1
+		};
+		AudioObjectRemovePropertyListener(
+			current_device, &vol_addr, volume_changed, NULL);
+	}
+
+	return 0;
+}
-- 
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