Update

src/alsa_pn.rs

@@ -10,7 +10,7 @@ use libc::c_int;
 use libc::c_uint;
 use libc::pollfd;
 use libc::size_t;
-use std::cell::RefCell;
+use std::cell::Cell;
 use std::iter::Map;
 use std::mem;
 use std::ptr;
@@ -30,9 +30,9 @@ pub enum AlsaEvent {
 pub struct AlsaCard {
     _cannot_construct: (),
     pub card: Card,
-    pub mixer: Rc<Mixer>,
+    pub mixer: Mixer,
     pub selem_id: SelemId,
-    pub watch_ids: RefCell<Vec<u32>>,
+    pub watch_ids: Cell<Vec<u32>>,
     pub cb: Rc<Fn(AlsaEvent)>,
 }
 
@@ -48,8 +48,10 @@ impl AlsaCard {
                 None => get_default_alsa_card(),
             }
         };
-        let mixer = Rc::new(get_mixer(&card)?);
-        let mixer2 = mixer.clone();
+        let mixer = get_mixer(&card)?;
+
+        let vec_pollfd = PollDescriptors::get(&mixer)?;
+
         let selem_id =
             get_selem_by_name(&mixer,
                               elem_name.unwrap_or(String::from("Master")))
@@ -61,17 +63,16 @@ impl AlsaCard {
                                  card: card,
                                  mixer: mixer,
                                  selem_id: selem_id,
-                                 watch_ids: RefCell::new(vec![]),
+                                 watch_ids: Cell::new(vec![]),
                                  cb: cb,
                              });
 
-        let vec_pollfd = PollDescriptors::get(mixer2.as_ref())?;
         /* TODO: callback is registered here, which must be unregistered
          * when the card is destroyed!!
          * poll descriptors must be unwatched too */
         let watch_ids = AlsaCard::watch_poll_descriptors(vec_pollfd,
                                                          acard.as_ref());
-        *acard.watch_ids.borrow_mut() = watch_ids;
+        acard.watch_ids.set(watch_ids);
 
         return Ok(acard);
     }
@@ -167,6 +168,7 @@ impl AlsaCard {
 }
 
 
+// TODO: test that this is actually triggered when switching cards
 impl Drop for AlsaCard {
     // call Box::new(x), transmute the Box into a raw pointer, and then
     // std::mem::forget
@@ -182,15 +184,12 @@ impl Drop for AlsaCard {
     // callback and frees the Box, by simply transmuting the
     // raw pointer to a Box<T>
     fn drop(&mut self) {
-        debug!("Destructing watch_ids: {:?}", self.watch_ids);
-        AlsaCard::unwatch_poll_descriptors(&self.watch_ids.borrow());
+        debug!("Destructing watch_ids: {:?}", self.watch_ids.get_mut());
+        AlsaCard::unwatch_poll_descriptors(&self.watch_ids.get_mut());
     }
 }
 
 
-
-
-
 extern "C" fn watch_cb(chan: *mut glib_sys::GIOChannel,
                        cond: glib_sys::GIOCondition,
                        data: glib_sys::gpointer)

src/audio.rs

@@ -1,5 +1,6 @@
 use errors::*;
 use glib;
+use std::cell::Cell;
 use std::cell::RefCell;
 use std::rc::Rc;
 use std::f64;
@@ -32,7 +33,7 @@ pub struct Audio {
     pub acard: RefCell<Box<AlsaCard>>,
     pub last_action_timestamp: RefCell<i64>,
     pub handlers: Rc<RefCell<Vec<Box<Fn(AudioSignal, AudioUser)>>>>,
-    pub scroll_step: RefCell<u32>,
+    pub scroll_step: Cell<u32>,
 }
 
 
@@ -57,7 +58,7 @@ impl Audio {
             acard: RefCell::new(AlsaCard::new(card_name, elem_name, cb)?),
             last_action_timestamp: last_action_timestamp.clone(),
             handlers: handlers.clone(),
-            scroll_step: RefCell::new(5),
+            scroll_step: Cell::new(5),
         };
 
         return Ok(audio);
@@ -68,12 +69,12 @@ impl Audio {
                         card_name: Option<String>,
                         elem_name: Option<String>)
                         -> Result<()> {
+        debug!("Switching cards");
+        let cb = self.acard.borrow().cb.clone();
         let mut ac = self.acard.borrow_mut();
-        let cb = self.acard
-            .borrow()
-            .cb
-            .clone();
-        *ac = AlsaCard::new(card_name, elem_name, cb)?;
+        *ac = AlsaCard::new(card_name,
+                            elem_name,
+                            cb)?;
 
         return Ok(());
     }
@@ -102,7 +103,7 @@ impl Audio {
             *rc = glib::get_monotonic_time();
         }
         let old_vol = self.vol()?;
-        let new_vol = f64::ceil(old_vol + (*self.scroll_step.borrow() as f64));
+        let new_vol = f64::ceil(old_vol + (self.scroll_step.get() as f64));
 
         debug!("Increase vol by {:?} to {:?}", (new_vol - old_vol), new_vol);
 
@@ -116,7 +117,7 @@ impl Audio {
             *rc = glib::get_monotonic_time();
         }
         let old_vol = self.vol()?;
-        let new_vol = old_vol - (*self.scroll_step.borrow() as f64);
+        let new_vol = old_vol - (self.scroll_step.get() as f64);
 
         debug!("Decrease vol by {:?} to {:?}", (new_vol - old_vol), new_vol);
 

src/main.rs

@@ -43,14 +43,14 @@ use app_state::*;
 fn main() {
     gtk::init().unwrap();
 
-    let apps = Rc::new(AppS::new());
-
     flexi_logger::LogOptions::new()
        .log_to_file(false)
        // ... your configuration options go here ...
        .init(Some("pnmixer=debug".to_string()))
        .unwrap_or_else(|e| panic!("Logger initialization failed with {}", e));
 
+    let apps = Rc::new(AppS::new());
+
     ui_entry::init(apps);
 
     gtk::main();