Code cleanup part 2: Huge ass refactor edition

src/session_notification.rs

@@ -0,0 +1,31 @@
+use windows::{
+    core::{Interface},
+    Win32::{
+        Media::Audio::{
+            IAudioSessionControl, IAudioSessionControl2,
+            IAudioSessionNotification, IAudioSessionNotification_Impl,
+        },
+    },
+};
+
+#[windows::core::implement(IAudioSessionNotification)]
+pub(crate) struct SessionNotification {
+    pub(crate) callback: Box<dyn Fn(IAudioSessionControl2)>
+}
+
+impl IAudioSessionNotification_Impl for SessionNotification {
+    fn OnSessionCreated(
+        self: &SessionNotification,
+        newsession: &core::option::Option<IAudioSessionControl>,
+    ) -> windows::core::Result<()> {
+        let ses: IAudioSessionControl2 = newsession.as_ref().unwrap().cast().unwrap();
+        (self.callback)(ses);
+        Ok(())
+    }
+}
+
+impl Drop for SessionNotification {
+    fn drop(&mut self) {
+        println!("SN drop");
+    }
+}