diff --git a/src/audio.rs b/src/audio.rs
index bf5a6da00..da5a72a28 100644
--- a/src/audio.rs
+++ b/src/audio.rs
@@ -15,6 +15,7 @@ use std::mem;
 use std::ptr;
 use std::rc::Rc;
 use std::u8;
+use std::f64;
 
 
 
@@ -46,6 +47,7 @@ pub enum AlsaEvent {
 }
 
 
+// TODO: Audio struct? Separate more cleanly
 // TODO: implement free/destructor
 pub struct AlsaCard {
     _cannot_construct: (),
@@ -54,7 +56,8 @@ pub struct AlsaCard {
     pub selem_id: SelemId,
     pub watch_ids: Vec<u32>,
     pub last_action_timestamp: RefCell<i64>,
-    pub handlers: RefCell<Vec<Box<Fn(&AlsaCard, AudioSignal, AudioUser)>>>,
+    pub handlers: RefCell<Vec<Box<Fn(AudioSignal, AudioUser)>>>,
+    pub scroll_step: RefCell<u32>,
 }
 
 
@@ -77,6 +80,7 @@ impl AlsaCard {
                     .get_id();
         let vec_pollfd = PollDescriptors::get(&mixer)?;
 
+        // TODO: rework, should probably be a Box?
         let acard = Rc::new(RefCell::new(AlsaCard {
                                              _cannot_construct: (),
                                              card: card,
@@ -86,19 +90,27 @@ impl AlsaCard {
                                              last_action_timestamp:
                                                  RefCell::new(0),
                                              handlers: RefCell::new(vec![]),
+                                             scroll_step: RefCell::new(3),
                                          }));
 
         /* TODO: callback is registered here, which must be unregistered
          * when the mixer is destroyed!!
          * poll descriptors must be unwatched too */
-        let watch_ids = watch_poll_descriptors(vec_pollfd,
-                                               acard.clone().as_ptr());
+        let watch_ids = watch_poll_descriptors(vec_pollfd, acard.as_ptr());
         acard.borrow_mut().watch_ids = watch_ids;
 
         return Ok(acard.clone());
     }
 
 
+    pub fn switch_card(old_card: Rc<RefCell<AlsaCard>>,
+                       card_name: Option<String>,
+                       elem_name: Option<String>)
+                       -> Result<Rc<RefCell<AlsaCard>>> {
+
+    }
+
+
     pub fn selem(&self) -> Selem {
         return get_selems(&self.mixer)
                    .nth(self.selem_id.get_index() as usize)
@@ -123,6 +135,34 @@ impl AlsaCard {
     }
 
 
+    pub fn increase_vol(&self, user: AudioUser) -> Result<()> {
+        {
+            let mut rc = self.last_action_timestamp.borrow_mut();
+            *rc = glib::get_monotonic_time();
+        }
+        let old_vol = self.vol()?;
+        let new_vol = f64::ceil(old_vol + (*self.scroll_step.borrow() as f64));
+
+        debug!("Increase vol by {:?} to {:?}", (new_vol - old_vol), new_vol);
+
+        return self.set_vol(new_vol, user);
+    }
+
+
+    pub fn decrease_vol(&self, user: AudioUser) -> Result<()> {
+        {
+            let mut rc = self.last_action_timestamp.borrow_mut();
+            *rc = glib::get_monotonic_time();
+        }
+        let old_vol = self.vol()?;
+        let new_vol = old_vol - (*self.scroll_step.borrow() as f64);
+
+        debug!("Decrease vol by {:?} to {:?}", (new_vol - old_vol), new_vol);
+
+        return self.set_vol(new_vol, user);
+    }
+
+
     pub fn has_mute(&self) -> bool {
         return has_mute(&self.selem());
     }
@@ -176,23 +216,36 @@ impl AlsaCard {
                signal,
                user);
         let handlers = self.handlers.borrow();
-        let x: &Vec<Box<Fn(&AlsaCard, AudioSignal, AudioUser)>> = &*handlers;
-        for handler in x {
+        let handlers_ref: &Vec<Box<Fn(AudioSignal, AudioUser)>> =
+            handlers.as_ref();
+        for handler in handlers_ref {
             let unboxed = handler.as_ref();
-            unboxed(&self, signal, user);
+            unboxed(signal, user);
         }
     }
 
 
-    pub fn connect_handler(&self,
-                           cb: Box<Fn(&AlsaCard, AudioSignal, AudioUser)>) {
+    pub fn connect_handler(&self, cb: Box<Fn(AudioSignal, AudioUser)>) {
         self.handlers.borrow_mut().push(cb);
     }
 }
 
 
 impl Drop for AlsaCard {
-    fn drop (&mut self) {
+    // call Box::new(x), transmute the Box into a raw pointer, and then
+    // std::mem::forget
+    //
+    // if you unregister the callback, you should keep a raw pointer to the
+    // box
+    //
+    // For instance, `register` could return a raw pointer to the
+    // Box + a std::marker::PhantomData with the appropriate
+    // lifetime (if applicable)
+    //
+    // The struct could implement Drop, which unregisters the
+    // 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);
         unwatch_poll_descriptors(&self.watch_ids);
     }
diff --git a/src/ui_entry.rs b/src/ui_entry.rs
index ae8963060..a1df1c13a 100644
--- a/src/ui_entry.rs
+++ b/src/ui_entry.rs
@@ -10,7 +10,7 @@ use ui_tray_icon::*;
 pub fn init(appstate: Rc<AppS>) {
     {
         let apps = appstate.clone();
-        appstate.acard.borrow().connect_handler(Box::new(move |a, s, u| {
+        appstate.acard.borrow().connect_handler(Box::new(move |s, u| {
             match (s, u) {
                 (AudioSignal::AudioValuesChanged,
                  AudioUser::AudioUserUnknown) => {
diff --git a/src/ui_tray_icon.rs b/src/ui_tray_icon.rs
index 5ada55f04..271b6fe54 100644
--- a/src/ui_tray_icon.rs
+++ b/src/ui_tray_icon.rs
@@ -1,16 +1,33 @@
 use app_state::*;
+use gdk;
+use gdk_sys;
+use glib;
+use glib_sys;
+use std::mem;
 use gtk::prelude::*;
 use std::rc::Rc;
+use std::cell::RefCell;
+use libc;
+use audio::AudioUser::*;
+use errors::*;
 
 
 
 pub fn init_tray_icon(appstate: Rc<AppS>) {
+    {
+        let apps = appstate.clone();
+        let tray_icon = &appstate.gui.status_icon;
+        tray_icon.connect_activate(move |_| on_tray_icon_activate(&apps));
+        tray_icon.set_visible(true);
+    }
+    {
+        let tray_icon = &appstate.clone().gui.status_icon;
+        tray_icon.connect_scroll_event(move |_, e| {
+            on_tray_icon_scroll_event(&appstate.clone(), &e)
+        });
+        tray_icon.set_visible(true);
+    }
 
-    let tray_icon = &appstate.clone().gui.status_icon;
-    tray_icon.connect_activate(move |_| {
-                                   on_tray_icon_activate(&appstate.clone())
-                               });
-    tray_icon.set_visible(true);
 }
 
 
@@ -23,3 +40,24 @@ fn on_tray_icon_activate(appstate: &AppS) {
         popup_window.show_now();
     }
 }
+
+
+fn on_tray_icon_scroll_event(appstate: &AppS,
+                             event: &gdk::EventScroll)
+                             -> bool {
+
+    let scroll_dir = event.as_ref().direction;
+    match scroll_dir {
+        gdk_sys::GdkScrollDirection::Up => {
+            try_wr!(appstate.acard.borrow().increase_vol(AudioUserTrayIcon),
+                    false);
+        }
+        gdk_sys::GdkScrollDirection::Down => {
+            try_wr!(appstate.acard.borrow().decrease_vol(AudioUserTrayIcon),
+                    false);
+        }
+        _ => (),
+    }
+
+    return false;
+}