1 files changed, 75 insertions, 0 deletions
diff --git a/daemons/brightnessd.c b/daemons/brightnessd.c
new file mode 100644
index 0000000..333dbf4
--- /dev/null
+++ b/daemons/brightnessd.c
@@ -0,0 +1,75 @@
+// brightnessd — display brightness daemon for bar
+//
+// Uses IOKit to listen for display brightness changes and posts
+// a Darwin notification.
+//
+// Compile:
+//   cc -o bar-brightnessd daemons/brightnessd.c \
+//       -framework IOKit -framework CoreFoundation
+
+#include <IOKit/IOKitLib.h>
+#include <IOKit/graphics/IOGraphicsLib.h>
+#include <notify.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+static volatile int keep_running = 1;
+static IONotificationPortRef notifyPort = NULL;
+
+static void handle_signal(int sig) {
+	(void)sig;
+	keep_running = 0;
+}
+
+static void brightness_changed(void *refcon, io_iterator_t iterator) {
+	(void)refcon;
+	// Drain the iterator
+	io_object_t obj;
+	while ((obj = IOIteratorNext(iterator))) {
+		IOObjectRelease(obj);
+	}
+	notify_post("bar.touch.<block-name>");
+}
+
+int main(void) {
+	signal(SIGINT, handle_signal);
+	signal(SIGTERM, handle_signal);
+
+	notifyPort = IONotificationPortCreate(kIOMasterPortDefault);
+	CFRunLoopSourceRef source = IONotificationPortGetRunLoopSource(notifyPort);
+	CFRunLoopAddSource(CFRunLoopGetCurrent(), source, kCFRunLoopDefaultMode);
+
+	// Watch for brightness-related display changes
+	CFMutableDictionaryRef matching = IOServiceMatching("AppleBacklightDisplay");
+	if (!matching) {
+		// Fallback: try Intel backlight
+		matching = IOServiceMatching("AppleIntelPanel");
+	}
+	if (!matching) {
+		matching = IOServiceMatching("IODisplay");
+	}
+
+	if (matching) {
+		io_iterator_t iter;
+		IOServiceAddMatchingNotification(
+			notifyPort, kIOFirstMatchNotification, matching,
+			brightness_changed, NULL, &iter);
+		brightness_changed(NULL, iter); // drain initial
+
+		// Also watch for termination to catch display disconnect
+		IOServiceAddMatchingNotification(
+			notifyPort, kIOTerminatedNotification, matching,
+			brightness_changed, NULL, &iter);
+	}
+
+	while (keep_running) {
+		pause();
+	}
+
+	if (notifyPort) {
+		IONotificationPortDestroy(notifyPort);
+	}
+	return 0;
+}