1 files changed, 77 insertions, 0 deletions
diff --git a/src/carbon.c b/src/carbon.c
new file mode 100644
index 0000000..dcfc2d8
--- /dev/null
+++ b/src/carbon.c
@@ -0,0 +1,77 @@
+#include "carbon.h"
+
+#define internal static
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated"
+internal inline char *
+find_process_name_for_psn(ProcessSerialNumber *psn)
+{
+    CFStringRef process_name_ref;
+    if (CopyProcessName(psn, &process_name_ref) == noErr) {
+        char *process_name = copy_cfstring(process_name_ref);
+        for (char *s = process_name; *s; ++s) *s = tolower(*s);
+        CFRelease(process_name_ref);
+        return process_name;
+    }
+    return NULL;
+}
+
+inline char *
+find_process_name_for_pid(pid_t pid)
+{
+    ProcessSerialNumber psn;
+    GetProcessForPID(pid, &psn);
+    return find_process_name_for_psn(&psn);
+}
+
+internal inline char *
+find_active_process_name(void)
+{
+    ProcessSerialNumber psn;
+    GetFrontProcess(&psn);
+    return find_process_name_for_psn(&psn);
+}
+#pragma clang diagnostic pop
+
+internal OSStatus
+carbon_event_handler(EventHandlerCallRef ref, EventRef event, void *context)
+{
+    struct carbon_event *carbon = (struct carbon_event *) context;
+
+    ProcessSerialNumber psn;
+    if (GetEventParameter(event,
+                          kEventParamProcessID,
+                          typeProcessSerialNumber,
+                          NULL,
+                          sizeof(psn),
+                          NULL,
+                          &psn) != noErr) {
+        return -1;
+    }
+
+    if (carbon->process_name) {
+        free(carbon->process_name);
+        carbon->process_name = NULL;
+    }
+
+    carbon->process_name = find_process_name_for_psn(&psn);
+
+    return noErr;
+}
+
+bool carbon_event_init(struct carbon_event *carbon)
+{
+    carbon->target = GetApplicationEventTarget();
+    carbon->handler = NewEventHandlerUPP(carbon_event_handler);
+    carbon->type.eventClass = kEventClassApplication;
+    carbon->type.eventKind = kEventAppFrontSwitched;
+    carbon->process_name = find_active_process_name();
+
+    return InstallEventHandler(carbon->target,
+                               carbon->handler,
+                               1,
+                               &carbon->type,
+                               carbon,
+                               &carbon->handler_ref) == noErr;
+}