Refactor PA to handle interior mutability / ref counting itself

applets/cosmic-applet-audio/src/pa.rs

@@ -1,11 +1,19 @@
 use futures::{channel::oneshot, future::poll_fn, task::Poll};
 use libpulse_binding::{
     callbacks::ListResult,
-    context::{introspect::SinkInfo, Context},
+    context::{
+        introspect::{Introspector, SinkInfo},
+        subscribe::{Facility, InterestMaskSet, Operation},
+        Context, FlagSet, State,
+    },
+    error::PAErr,
     volume::ChannelVolumes,
 };
 use libpulse_glib_binding::Mainloop;
-use std::rc::Rc;
+use std::{
+    cell::{Ref, RefCell},
+    rc::Rc,
+};
 
 pub struct DeviceInfo {
     pub name: Option<String>,
@@ -18,22 +26,66 @@ pub struct ServerInfo {
     pub default_source_name: Option<String>,
 }
 
-pub struct PA {
+struct PAInner {
     main_loop: Mainloop,
-    pub context: Context,
+    pub context: RefCell<Context>,
 }
 
+#[derive(Clone)]
+pub struct PA(Rc<PAInner>);
+
 impl PA {
     pub fn new() -> Option<Self> {
         let main_loop = Mainloop::new(None)?;
         let context = Context::new(&main_loop, "com.system76.cosmic.applets.audio")?;
-        Some(Self { main_loop, context })
+        Some(Self(Rc::new(PAInner {
+            main_loop,
+            context: RefCell::new(context),
+        })))
+    }
+
+    pub fn set_state_callback<F: Fn(&Self, State) + 'static>(&self, cb: F) {
+        let pa = self.clone(); // TODO: weak ref?
+        self.0
+            .context
+            .borrow_mut()
+            .set_state_callback(Some(Box::new(move || {
+                let state = pa.0.context.borrow().get_state();
+                cb(&pa, state);
+            })));
+    }
+
+    // TODO: builder pattern?
+    pub fn set_subscribe_callback<F: FnMut(Option<Facility>, Option<Operation>, u32) + 'static>(
+        &self,
+        cb: F,
+    ) {
+        self.0
+            .context
+            .borrow_mut()
+            .set_subscribe_callback(Some(Box::new(cb)));
+    }
+
+    pub fn subscribe(&self, mask: InterestMaskSet) {
+        // XXX cb; operation; async
+        self.0.context.borrow_mut().subscribe(mask, |_| {});
+    }
+
+    pub fn connect(&self) -> Result<(), PAErr> {
+        self.0
+            .context
+            .borrow_mut()
+            .connect(None, FlagSet::empty(), None)
+    }
+
+    fn introspect(&self) -> Introspector {
+        self.0.context.borrow().introspect()
     }
 
     pub async fn get_server_info(&self) -> ServerInfo {
         let (sender, receiver) = oneshot::channel();
         let mut sender = Some(sender);
-        self.context.introspect().get_server_info(move |info| {
+        self.introspect().get_server_info(move |info| {
             sender.take().unwrap().send(ServerInfo {
                 default_sink_name: info.default_sink_name.clone().map(|x| x.into_owned()),
                 default_source_name: info.default_source_name.clone().map(|x| x.into_owned()),
@@ -46,8 +98,7 @@ impl PA {
         let (sender, receiver) = oneshot::channel();
         let mut sender = Some(sender);
         let mut items = Some(Vec::new());
-        self.context
-            .introspect()
+        self.introspect()
             .get_sink_info_list(move |result| match result {
                 ListResult::Item(item) => items.as_mut().unwrap().push(DeviceInfo {
                     name: item.name.clone().map(|x| x.into_owned()),
@@ -74,8 +125,7 @@ impl PA {
         let (sender, receiver) = oneshot::channel();
         let mut sender = Some(sender);
         let mut sink = None;
-        self.context
-            .introspect()
+        self.introspect()
             .get_sink_info_by_name(&name, move |result| match result {
                 ListResult::Item(item) => {
                     sink = Some(DeviceInfo {
@@ -97,7 +147,7 @@ impl PA {
     /*
     // XXX async wait and handle error
     pub fn set_default_sink(&mut self, name: &str) {
-        self.context.set_default_sink(name, |_| {});
+        self.0.context.set_default_sink(name, |_| {});
     }
     */
 
@@ -105,8 +155,7 @@ impl PA {
         let (sender, receiver) = oneshot::channel();
         let mut sender = Some(sender);
         let mut items = Some(Vec::new());
-        self.context
-            .introspect()
+        self.introspect()
             .get_source_info_list(move |result| match result {
                 ListResult::Item(item) => items.as_mut().unwrap().push(DeviceInfo {
                     name: item.name.clone().map(|x| x.into_owned()),
@@ -133,8 +182,7 @@ impl PA {
         let (sender, receiver) = oneshot::channel();
         let mut sender = Some(sender);
         let mut source = None;
-        self.context
-            .introspect()
+        self.introspect()
             .get_source_info_by_name(&name, move |result| match result {
                 ListResult::Item(item) => {
                     source = Some(DeviceInfo {