no first load of config?

src/conf/bind.rs

@@ -1,5 +1,71 @@
 use crate::*;
 
+pub trait HasBinds {
+    fn binds_keys (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Bind<TuiEvent, Arc<str>>>>>;
+    fn binds_axis (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Axis<TuiEvent>>>>;
+    /// Clear the keys and axis bindings collections.
+    fn binds_clear (&self) {
+        *self.binds_keys().write() = Default::default();
+        *self.binds_axis().write() = Default::default();
+    }
+    /// Find a matching key binding.
+    fn binds_find (&self, id: impl AsRef<str>) -> Option<Arc<Bind<TuiEvent, Arc<str>>>> {
+        self.binds_keys().read().get(id.as_ref()).cloned()
+    }
+    /// Iterate over key bindings.
+    fn binds_for_each <T> (
+        &self, mut cb: impl FnMut(&Arc<str>, &Bind<TuiEvent, Arc<str>>)->T
+    ) {
+        for (k, v) in self.binds_keys().read().iter() {
+            cb(k, v);
+        }
+    }
+    /// Define a top-level key binding.
+    ///
+    /// ```
+    /// # use ::{std::sync::Arc, tek::*};
+    /// let config: Config = Default::default();
+    /// config.binds_def_keys(stringify!(Confirm (@enter confirm))).unwrap();
+    /// ```
+    fn binds_def_keys (&self, expr: impl Language) -> Usually<()> {
+        self.binds_keys().write().insert(
+            expr.head()?.ok_or("bind: missing name")?.into(),
+            Bind::new(expr.tail()?.unwrap_or(""))?.into()
+        );
+        Ok(())
+    }
+    /// Define an top-level axis binding (keypair).
+    ///
+    /// ```
+    /// # use ::{std::sync::Arc, tek::*};
+    /// let config: Config = Default::default();
+    /// config.binds_def_axis(stringify!(Y @up @down)).unwrap();
+    /// ```
+    fn binds_def_axis (&self, expr: impl Language) -> Usually<()> {
+        self.binds_axis().write().insert(
+            expr.head()?.ok_or("axis: missing name")?.into(),
+            Axis::eval(expr.tail()?.unwrap_or(""))?.into()
+        );
+        Ok(())
+    }
+}
+impl HasBinds for App {
+    fn binds_keys (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Bind<TuiEvent, Arc<str>>>>> {
+        &self.watch.config.keys
+    }
+    fn binds_axis (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Axis<TuiEvent>>>> {
+        &self.watch.config.axis
+    }
+}
+impl HasBinds for Config {
+    fn binds_keys (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Bind<TuiEvent, Arc<str>>>>> {
+        &self.keys
+    }
+    fn binds_axis (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Axis<TuiEvent>>>> {
+        &self.axis
+    }
+}
+
 /// A map of input events (e.g. [TuiEvent]) to [Binding]s.
 ///
 /// ```

src/conf/mode.rs

@@ -1,5 +1,94 @@
 use crate::*;
 
+/// Has a stack of currently active interaction modes.
+pub trait HasModeStack {
+    /// Stack of active modes.
+    fn mode_stack (&self) -> &RwLock<Vec<Arc<str>>>;
+
+    fn mode_stack_push (&self, mode: impl AsRef<str>) {
+        self.mode_stack().write().push(mode.as_ref().into())
+    }
+}
+impl HasModeStack for App {
+    fn mode_stack (&self) -> &RwLock<Vec<Arc<str>>> {
+        &self.stack
+    }
+}
+
+/// Collection of UI modes.
+///
+/// ```
+/// # use tek::*;
+///
+/// // Empty mode registry:
+/// let state: Config = Default::default();
+/// assert_eq!(state.modes_count(), 0);
+/// assert!(state.modes_get("Foo").is_none());
+///
+/// // Add a mode:
+/// let _ = state.modes_add(&"Foo (name Foo) (info Bar)").unwrap();
+/// assert_eq!(state.modes_count(), 1);
+/// assert!(state.modes_get("Foo").is_some());
+/// ```
+pub trait HasModes {
+    fn modes (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Mode>>>;
+
+    /// Register a mode.
+    ///
+    /// ```
+    /// # use ::{std::sync::Arc, tek::*};
+    /// let config: Config = Default::default();
+    ///
+    /// config.modes_add(stringify!(Menu
+    ///   (name Menu) (info Mode selector.) (axis Y Index) (bind Confirm)
+    ///   (view (bg (g 30) (bar/s 7 Logo (full/xy Dialog))))
+    /// )).unwrap();
+    ///
+    /// let _: Arc<Mode> = config.modes_get("Menu").unwrap();
+    /// ```
+    fn modes_add <'a> (&self, expr: impl Language) -> UsuallyRef<'a, ()> {
+        let name = expr.head()?.ok_or("mode: missing name")?;
+        let body = expr.tail()?.ok_or("mode: missing body")?;
+        let mut mode = Mode::default();
+        body.each(&mut mode, |c, s|c.add(s))?;
+        self.modes().write().insert(name.into(), Arc::new(mode));
+        Ok(())
+    }
+    /// Get a mode by name.
+    fn modes_get (&self, name: impl AsRef<str>) -> Option<Arc<Mode>> {
+        self.modes().read().get(name.as_ref()).cloned()
+    }
+    /// Run something for each mode.
+    fn modes_for_each <T> (&self, mut ator: impl FnMut(&str, &Mode)->T) {
+        for (k, v) in self.modes().read().iter() {
+            let _ = ator(k.as_ref(), v.as_ref());
+        }
+    }
+    /// Count modes.
+    fn modes_count (&self) -> usize {
+        self.modes().read().len()
+    }
+    /// Clear modes.
+    fn modes_clear (&self) {
+        *self.modes().write() = Default::default();
+    }
+}
+impl HasModes for App {
+    fn modes (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Mode>>> {
+        &self.watch.config.modes
+    }
+}
+impl HasModes for Config {
+    fn modes (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Mode>>> {
+        &self.modes
+    }
+}
+impl HasModes for Mode {
+    fn modes (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Mode>>> {
+        &self.modes
+    }
+}
+
 impl_as_mut!(Mode: |self: Mode| self);
 
 /// Group of view and keys definitions.

src/conf/view.rs

@@ -1,5 +1,38 @@
 use crate::*;
 
+pub trait HasViews {
+    fn views (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<View<Tui, App>>>>;
+    /// Load custom view definition.
+    fn views_add <'a> (&self, expr: impl Language) -> UsuallyRef<'a, ()> {
+        self.views().write().insert(
+            expr.head()?.ok_or("view: missing name")?.into(),
+            View::new(expr.tail()?.ok_or("view: missing body")?)?.into()
+        );
+        Ok(())
+    }
+    fn views_clear (&self) {
+        *self.views().write() = Default::default();
+    }
+    fn views_get (&self, name: impl AsRef<str>) -> Option<Arc<View<Tui, App>>> {
+        self.views().read().get(name.as_ref()).cloned()
+    }
+    fn views_for_each <T> (&self, cb: impl Fn(&Arc<str>, &Arc<View<Tui, App>>)->T) -> () {
+        for (k, v) in self.views().read().iter() {
+            cb(k, v);
+        }
+    }
+}
+impl HasViews for App {
+    fn views (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<View<Tui, App>>>> {
+        &self.watch.config.views
+    }
+}
+impl HasViews for Config {
+    fn views (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<View<Tui, App>>>> {
+        &self.views
+    }
+}
+
 impl_debug!(<S: Screen, T> View<S, T>: |self, w| { write!(w, "View({})", self.source) });
 impl_display!(<S: Screen, T> View<S, T>: |self, w| { write!(w, "View({})", self.source)  });
 impl_default!(ClockView: {
@@ -25,24 +58,6 @@ pub struct View<S: Screen, T> {
     pub render: Arc<Box<dyn Fn(&T, &mut S)->Drawn<S::Unit> + Send + Sync>>
 }
 
-/// The [Draw] implementation for [App] handles the loaded view,
-/// which is defined in terms of [dizzle] DSL.
-///
-/// If there is an error, the error is displayed. FIXME: overlay it
-/// Then, every top-level form of the DSL description is rendered.
-impl Draw<Tui> for App {
-    fn draw (&self, to: &mut Tui) -> Drawn<u16> {
-        #[cfg(feature = "prof2")] profiling::scope!("App::draw");
-        self.perf.cycle(&mut |_|{
-            draw_error(to, self.error.as_ref())?;
-            draw_mode_stack(to, &self)?;
-            view_debug(&self.perf, &self.size).draw(to)?;
-            #[cfg(feature = "prof2")] profiling::finish_frame!();
-            Ok(Some(to.area().into()))
-        })
-    }
-}
-
 pub fn draw_error (to: &mut Tui, error: &RwLock<Option<Arc<str>>>) -> Usually<()> {
     if let Some(e) = error.read().as_ref() {
         e.as_ref().align_c().draw(to)?;
@@ -50,22 +65,23 @@ pub fn draw_error (to: &mut Tui, error: &RwLock<Option<Arc<str>>>) -> Usually<()
     Ok(())
 }
 
-pub fn view_debug (perf: &PerfModel, size: &Sizer) -> impl Draw<Tui> {
+pub fn view_debug (
+    stack: &Vec<Arc<str>>,
+    perf: &PerfModel,
+    size: &Sizer,
+) -> impl Draw<Tui> {
     Split::Above.bar(0,
         Split::West.bar(16,
             format!("{}/{} {} ",
                 perf.used.load(Relaxed),
                 perf.window.load(Relaxed),
                 perf.clock.raw() / 10000000).align_e(),
-            format!("{}x{} ",
+            format!("{:03}x{:03} ",
                 size.0.load(Relaxed),
                 size.1.load(Relaxed)).align_w(),
         ).align_se(),
-        ()
+        //()
-        //Split::East.bar(16,
+        format!("{:?}", stack).align_sw(),
-            //format!("{}", self.modes.read()[0]),
-            //format!("{}", self.modes.read()[0])
-        //).align_sw()
     )
 }
 
@@ -95,6 +111,9 @@ pub fn draw_status_bar (to: &mut Tui, state: &App) -> Drawn<u16> {
 pub fn draw_mode_stack (to: &mut Tui, state: &App) -> Usually<()> {
     for name in state.mode_stack().read().iter() {
         let mut error = false;
+        //if state.watch.config.modes_count() > 0 {
+            //panic!("{name:?} {:?}", state.watch.config.modes);
+        //}
         if let Some(mode) = state.modes_get(name).as_ref().map(Arc::clone) {
             for (index, view) in mode.view.iter().enumerate() {
                 match (view.render)(state, to) {

src/tek.rs

@@ -112,7 +112,7 @@ pub struct App {
     /// Performance counter
     pub perf:    PerfModel,
     /// Available view modes and input bindings
-    pub config:  Arc<Watch>,
+    pub watch:   Arc<Watch>,
     /// Currently active modes
     pub stack:   Arc<RwLock<Vec<Arc<str>>>>,
     /// Undo history
@@ -152,7 +152,7 @@ impl App {
     pub fn new (
         exit:    Option<Exit>,
         project: Project,
-        config:  impl Into<Option<Arc<Watch>>>,
+        watch:   impl Into<Option<Arc<Watch>>>,
         mode:    impl AsRef<str>
     ) -> Self {
         App {
@@ -161,57 +161,93 @@ impl App {
             color:  ItemTheme::random(),
             dialog: Dialog::welcome(),
             stack:  Arc::new(RwLock::new(vec![mode.as_ref().into()])),
-            config: config.into().unwrap_or_default(),
+            watch:  watch.into().unwrap_or_default(),
             project,
             ..Default::default()
         }
     }
 }
 
-fn tek_jack_process (state: &mut App, client: &Client, scope: &ProcessScope) -> Control {
+/// Configuration watcher and manager.
-    let t0 = state.perf.get_t0();
+///
-    state.clock().update_from_scope(scope).unwrap();
+/// ```
-    let midi_in = state.project.midi_input_collect(scope);
+/// let config = tek::Watch::new(None);
-    if let Some(editor) = &state.editor() {
+/// ```
-        let mut pitch: Option<u7> = None;
+#[derive(Default, Debug)]
-        for port in midi_in.iter() {
+pub struct Watch {
-            for event in port.iter() {
+    /// XDG base directories of running user.
-                if let (_, Ok(LiveEvent::Midi {message: MidiMessage::NoteOn {key, ..}, ..}))
+    pub dirs: BaseDirectories,
-                    = event
+    /// Watcher
-                {
+    pub watch: RwLock<Option<PollWatcher>>,
-                    pitch = Some(key.clone());
+    /// App configuration
-                }
+    pub config: Config,
-            }
-        }
-        if let Some(pitch) = pitch {
-            editor.set_note_pos(pitch.as_int() as usize);
-        }
-    }
-    let result = state.project.tracks_jack_process(client, scope);
-    state.perf.update_from_jack_scope(t0, scope);
-    result
 }
 
-fn tek_jack_event (state: &mut App, event: JackEvent) {
+impl Watch {
-    use JackEvent::*;
+    /// Default configuration directory.
-    match event {
+    const DIR: &'static str = "tek";
-        SampleRate(sr) => { state.clock().timebase.sr.set(sr as f64); },
+    /// Default configuration subdirectory.
-        PortRegistration(_id, true) => {
+    const SUB: &'static str = "v0";
-            //let port = self.jack().port_by_id(id);
+    /// Default configuration file name.
-            //println!("\rport add: {id} {port:?}");
+    const EDN: &'static str = "tek.edn";
-            //println!("\rport add: {id}");
+    /// Create a new watched app configuration
+    /// from a set of XDG base directories,
+    pub fn new (dirs: Option<BaseDirectories>) -> Self {
+        Self {
+            dirs: dirs.unwrap_or_else(||BaseDirectories::with_profile(Self::DIR, Self::SUB)),
+            ..Default::default()
+        }
+    }
+    /// Create, initialize, and watch a new configuration.
+    pub fn run_watched <T: 'static> (
+        callback: impl FnOnce(Arc<Self>)->T,
+        dirs: impl Into<Option<BaseDirectories>>,
+    ) -> Usually<T> {
+        let watch = Arc::new(Self::new(dirs.into()));
+        Self::watch(watch.clone(), None)?;
+        let result = callback(watch);
+        Ok(result)
+    }
+    /// Watch a config's file for changes.
+    pub fn watch (config: Arc<Self>, poll: Option<Duration>) -> Usually<()> {
+        let poll = poll.unwrap_or(Duration::from_millis(250));
+        let opts = NotifyConfig::default().with_poll_interval(poll);
+        let mut watcher = ::notify_debouncer_full::notify::poll::PollWatcher::new({
+            let config = config.clone();
+            move|result|{
+                match result {
+                    Ok(_events) => if let Err(e) = config_init(config.as_ref()) {
+                        config.error_set(Some(format!("{e:?}").into()));
+                        panic!("{e:?}");
+                    } else {
+                        //println!("config updated");
                     },
-        PortRegistration(_id, false) => {
+                    Err(errors) => {
-            /*println!("\rport del: {id}")*/
+                        panic!("{errors:?}");
-        },
+                    }
-        PortsConnected(_a, _b, true) => { /*println!("\rport conn: {a} {b}")*/ },
+                }
-        PortsConnected(_a, _b, false) => { /*println!("\rport disc: {a} {b}")*/ },
+            }
-        ClientRegistration(_id, true) => {},
+        }, opts)?;
-        ClientRegistration(_id, false) => {},
+        if let Some(path) = config.get_file() {
-        ThreadInit => {},
+            //println!("watching: {path:?}");
-        XRun => {},
+            watcher.watch(&path, RecursiveMode::NonRecursive)?;
-        GraphReorder => {},
+            *config.as_ref().watch.try_write().unwrap() = Some(watcher);
-        _ => { panic!("{event:?}"); }
+            Ok(())
+        } else {
+            Err(format!("no config path").into())
+        }
+    }
+    /// Find the config file.
+    fn find_file (&self) -> Option<PathBuf> {
+        self.dirs.find_config_file(Self::EDN)
+    }
+    /// Place config file in default location.
+    fn place_file (&self) -> Result<PathBuf, std::io::Error> {
+        self.dirs.place_config_file(Self::EDN)
+    }
+    /// Get path to config file.
+    fn get_file (&self) -> Option<PathBuf> {
+        self.dirs.get_config_file(Self::EDN)
     }
 }
 
@@ -266,6 +302,53 @@ pub struct Project {
     #[cfg(feature = "scene")] pub scenes_scroll: usize,
 }
 
+fn tek_jack_process (state: &mut App, client: &Client, scope: &ProcessScope) -> Control {
+    let t0 = state.perf.get_t0();
+    state.clock().update_from_scope(scope).unwrap();
+    let midi_in = state.project.midi_input_collect(scope);
+    if let Some(editor) = &state.editor() {
+        let mut pitch: Option<u7> = None;
+        for port in midi_in.iter() {
+            for event in port.iter() {
+                if let (_, Ok(LiveEvent::Midi {message: MidiMessage::NoteOn {key, ..}, ..}))
+                    = event
+                {
+                    pitch = Some(key.clone());
+                }
+            }
+        }
+        if let Some(pitch) = pitch {
+            editor.set_note_pos(pitch.as_int() as usize);
+        }
+    }
+    let result = state.project.tracks_jack_process(client, scope);
+    state.perf.update_from_jack_scope(t0, scope);
+    result
+}
+
+fn tek_jack_event (state: &mut App, event: JackEvent) {
+    use JackEvent::*;
+    match event {
+        SampleRate(sr) => { state.clock().timebase.sr.set(sr as f64); },
+        PortRegistration(_id, true) => {
+            //let port = self.jack().port_by_id(id);
+            //println!("\rport add: {id} {port:?}");
+            //println!("\rport add: {id}");
+        },
+        PortRegistration(_id, false) => {
+            /*println!("\rport del: {id}")*/
+        },
+        PortsConnected(_a, _b, true) => { /*println!("\rport conn: {a} {b}")*/ },
+        PortsConnected(_a, _b, false) => { /*println!("\rport disc: {a} {b}")*/ },
+        ClientRegistration(_id, true) => {},
+        ClientRegistration(_id, false) => {},
+        ThreadInit => {},
+        XRun => {},
+        GraphReorder => {},
+        _ => { panic!("{event:?}"); }
+    }
+}
+
 impl Project {
     pub fn new (jack: &Jack<'static>) -> Self {
         Self {
@@ -600,7 +683,6 @@ impl Scene {
     }
 }
 
-pub type SceneWith<'a, T> = (usize, &'a Scene, usize, usize, T);
 impl ScenesView for App {
     fn w_mid (&self) -> u16 {
         (self.size.w() as u16).saturating_sub(self.w_side())
@@ -612,6 +694,7 @@ impl ScenesView for App {
         (self.size.h() as u16).saturating_sub(20)
     }
 }
+
 impl HasScenes for App {
     fn scenes_scroll (&self) -> usize {
         self.project.scenes_scroll()
@@ -1108,353 +1191,6 @@ pub fn scan (dir: &PathBuf) -> Usually<(Vec<OsString>, Vec<OsString>)> {
     Ok((subdirs, files))
 }
 
-/// Default configuration contents.
-const CONFIG_DEFAULT: &'static str = include_str!("tek.edn");
-
-pub fn config_init <C: AsRef<Watch> + AsRef<Config>> (config: C) -> Usually<C> {
-    // Write initial contents of configuration:
-    let watcher: &Watch = config.as_ref();
-    if watcher.find_file().is_none() {
-        std::fs::write(watcher.place_file()?, CONFIG_DEFAULT)?;
-    }
-    // Load config from file:
-    Ok(if let Some(path) = watcher.find_file() {
-        config_reload(config, std::fs::read_to_string(&path)?)?
-    } else {
-        return Err(format!("config_init: not found").into())
-    })
-}
-
-/// Reload configuration from source.
-pub fn config_reload <C: AsRef<Config>, L: Language> (state: C, src: L) -> Usually<C> {
-    state.as_ref().config_clear();
-    src.each(state, |c, s|config_add(c, s.trim()))
-}
-
-/// Load configuration item.
-fn config_add <C: AsRef<Config>, L: Language> (state: C, src: L) -> Usually<C> {
-    if let Some(expr) = src.expr()? {
-        match expr.head()? {
-            Some("mode") => state.as_ref().modes_add(expr.tail()),
-            Some("view") => state.as_ref().views_add(expr.tail()),
-            Some("bind") => state.as_ref().binds_def_keys(expr.tail()),
-            Some("axis") => state.as_ref().binds_def_axis(expr.tail()),
-            _ => return Err(format!("config_add: unexpected: {src:?}").into())
-        }?;
-        Ok(state)
-    } else {
-        Err(format!("Config::add_one: tried to add empty item").into())
-    }
-}
-
-/// Contains timestamped mode, view, and bind definitions.
-///
-/// ```
-/// # use ::{std::sync::Arc, tek::*};
-///
-/// // Default empty config:
-/// let config: Config = Default::default();
-///
-/// // Define a binding:
-/// config.binds_def_keys(stringify!(Confirm (@enter confirm))).unwrap();
-///
-/// // Define an axis:
-/// config.binds_def_axis(stringify!(Y @up @down)).unwrap();
-/// ```
-#[derive(Default, Debug)]
-pub struct Config {
-    /// Error caught during (re)loading
-    pub error: RwLock<Option<Arc<str>>>,
-    /// Timestamp
-    pub stamp: AtomicU64,
-    /// Active collection of interaction modes.
-    pub modes: Arc<RwLock<BTreeMap<Arc<str>, Arc<Mode>>>>,
-    /// Active collection of view definitions.
-    pub views: Arc<RwLock<BTreeMap<Arc<str>, Arc<View<Tui, App>>>>>,
-    /// Active collection of key bindings.
-    pub keys: Arc<RwLock<BTreeMap<Arc<str>, Arc<Bind<TuiEvent, Arc<str>>>>>>,
-    /// Active collection of axis bindings.
-    pub axis: Arc<RwLock<BTreeMap<Arc<str>, Arc<Axis<TuiEvent>>>>>,
-}
-
-impl Config {
-    /// Create a new timestamped config state.
-    pub fn new () -> Self {
-        Self { stamp: quanta::Clock::new().raw().into(), ..Default::default() }
-    }
-}
-
-/// Configuration watcher and manager.
-///
-/// ```
-/// let config = tek::Watch::new(None);
-/// ```
-#[derive(Default, Debug)]
-pub struct Watch {
-    /// XDG base directories of running user.
-    pub dirs: BaseDirectories,
-    /// Watcher
-    pub watch: RwLock<Option<PollWatcher>>,
-    /// Actual configuration
-    pub config: Config,
-}
-
-impl Watch {
-    /// Default configuration directory.
-    const DIR: &'static str = "tek";
-    /// Default configuration subdirectory.
-    const SUB: &'static str = "v0";
-    /// Default configuration file name.
-    const EDN: &'static str = "tek.edn";
-    /// Create a new watched app configuration
-    /// from a set of XDG base directories,
-    pub fn new (dirs: Option<BaseDirectories>) -> Self {
-        Self {
-            dirs: dirs.unwrap_or_else(||BaseDirectories::with_profile(Self::DIR, Self::SUB)),
-            ..Default::default()
-        }
-    }
-    /// Create, initialize, and watch a new configuration.
-    pub fn run_watched <T: 'static> (
-        callback: impl FnOnce(Arc<Self>)->T,
-        dirs: impl Into<Option<BaseDirectories>>,
-    ) -> Usually<T> {
-        let watch = Arc::new(Self::new(dirs.into()));
-        Self::watch(watch.clone(), None)?;
-        let result = callback(watch);
-        Ok(result)
-    }
-    /// Watch a config's file for changes.
-    pub fn watch (config: Arc<Self>, poll: Option<Duration>) -> Usually<()> {
-        let poll = poll.unwrap_or(Duration::from_millis(250));
-        let opts = NotifyConfig::default().with_poll_interval(poll);
-        let mut watcher = ::notify_debouncer_full::notify::poll::PollWatcher::new({
-            let config = config.clone();
-            move|result|{
-                match result {
-                    Ok(_events) => if let Err(e) = config_init(config.as_ref()) {
-                        config.error_set(Some(format!("{e:?}").into()));
-                        panic!("{e:?}");
-                    } else {
-                        //println!("config updated");
-                    },
-                    Err(errors) => {
-                        panic!("{errors:?}");
-                    }
-                }
-            }
-        }, opts)?;
-        if let Some(path) = config.get_file() {
-            //println!("watching: {path:?}");
-            watcher.watch(&path, RecursiveMode::NonRecursive)?;
-            *config.as_ref().watch.try_write().unwrap() = Some(watcher);
-            Ok(())
-        } else {
-            Err(format!("no config path").into())
-        }
-    }
-    /// Find the config file.
-    fn find_file (&self) -> Option<PathBuf> {
-        self.dirs.find_config_file(Self::EDN)
-    }
-    /// Place config file in default location.
-    fn place_file (&self) -> Result<PathBuf, std::io::Error> {
-        self.dirs.place_config_file(Self::EDN)
-    }
-    /// Get path to config file.
-    fn get_file (&self) -> Option<PathBuf> {
-        self.dirs.get_config_file(Self::EDN)
-    }
-}
-
-/// Has a stack of currently active interaction modes.
-pub trait HasModeStack {
-    /// Stack of active modes.
-    fn mode_stack (&self) -> &RwLock<Vec<Arc<str>>>;
-
-    fn mode_stack_push (&self, mode: impl AsRef<str>) {
-        self.mode_stack().write().push(mode.as_ref().into())
-    }
-}
-impl HasModeStack for App {
-    fn mode_stack (&self) -> &RwLock<Vec<Arc<str>>> {
-        &self.stack
-    }
-}
-
-/// Collection of UI modes.
-///
-/// ```
-/// # use tek::*;
-///
-/// // Empty mode registry:
-/// let state: Config = Default::default();
-/// assert_eq!(state.modes_count(), 0);
-/// assert!(state.modes_get("Foo").is_none());
-///
-/// // Add a mode:
-/// let _ = state.modes_add(&"Foo (name Foo) (info Bar)").unwrap();
-/// assert_eq!(state.modes_count(), 1);
-/// assert!(state.modes_get("Foo").is_some());
-/// ```
-pub trait HasModes {
-    fn modes (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Mode>>>;
-
-    /// Register a mode.
-    ///
-    /// ```
-    /// # use ::{std::sync::Arc, tek::*};
-    /// let config: Config = Default::default();
-    ///
-    /// config.modes_add(stringify!(Menu
-    ///   (name Menu) (info Mode selector.) (axis Y Index) (bind Confirm)
-    ///   (view (bg (g 30) (bar/s 7 Logo (full/xy Dialog))))
-    /// )).unwrap();
-    ///
-    /// let _: Arc<Mode> = config.modes_get("Menu").unwrap();
-    /// ```
-    fn modes_add <'a> (&self, expr: impl Language) -> UsuallyRef<'a, ()> {
-        let name = expr.head()?.ok_or("mode: missing name")?;
-        let body = expr.tail()?.ok_or("mode: missing body")?;
-        let mut mode = Mode::default();
-        body.each(&mut mode, |c, s|c.add(s))?;
-        self.modes().write().insert(name.into(), Arc::new(mode));
-        Ok(())
-    }
-    /// Get a mode by name.
-    fn modes_get (&self, name: impl AsRef<str>) -> Option<Arc<Mode>> {
-        self.modes().read().get(name.as_ref()).cloned()
-    }
-    /// Run something for each mode.
-    fn modes_for_each <T> (&self, mut ator: impl FnMut(&str, &Mode)->T) {
-        for (k, v) in self.modes().read().iter() {
-            let _ = ator(k.as_ref(), v.as_ref());
-        }
-    }
-    /// Count modes.
-    fn modes_count (&self) -> usize {
-        self.modes().read().len()
-    }
-    /// Clear modes.
-    fn modes_clear (&self) {
-        *self.modes().write() = Default::default();
-    }
-}
-impl HasModes for App {
-    fn modes (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Mode>>> {
-        &self.config.config.modes
-    }
-}
-impl HasModes for Config {
-    fn modes (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Mode>>> {
-        &self.modes
-    }
-}
-impl HasModes for Mode {
-    fn modes (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Mode>>> {
-        &self.modes
-    }
-}
-
-pub trait HasViews {
-    fn views (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<View<Tui, App>>>>;
-    /// Load custom view definition.
-    fn views_add <'a> (&self, expr: impl Language) -> UsuallyRef<'a, ()> {
-        self.views().write().insert(
-            expr.head()?.ok_or("view: missing name")?.into(),
-            View::new(expr.tail()?.ok_or("view: missing body")?)?.into()
-        );
-        Ok(())
-    }
-    fn views_clear (&self) {
-        *self.views().write() = Default::default();
-    }
-    fn views_get (&self, name: impl AsRef<str>) -> Option<Arc<View<Tui, App>>> {
-        self.views().read().get(name.as_ref()).cloned()
-    }
-    fn views_for_each <T> (&self, cb: impl Fn(&Arc<str>, &Arc<View<Tui, App>>)->T) -> () {
-        for (k, v) in self.views().read().iter() {
-            cb(k, v);
-        }
-    }
-}
-impl HasViews for App {
-    fn views (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<View<Tui, App>>>> {
-        &self.config.config.views
-    }
-}
-impl HasViews for Config {
-    fn views (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<View<Tui, App>>>> {
-        &self.views
-    }
-}
-
-pub trait HasBinds {
-    fn binds_keys (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Bind<TuiEvent, Arc<str>>>>>;
-    fn binds_axis (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Axis<TuiEvent>>>>;
-    /// Clear the keys and axis bindings collections.
-    fn binds_clear (&self) {
-        *self.binds_keys().write() = Default::default();
-        *self.binds_axis().write() = Default::default();
-    }
-    /// Find a matching key binding.
-    fn binds_find (&self, id: impl AsRef<str>) -> Option<Arc<Bind<TuiEvent, Arc<str>>>> {
-        self.binds_keys().read().get(id.as_ref()).cloned()
-    }
-    /// Iterate over key bindings.
-    fn binds_for_each <T> (
-        &self, mut cb: impl FnMut(&Arc<str>, &Bind<TuiEvent, Arc<str>>)->T
-    ) {
-        for (k, v) in self.binds_keys().read().iter() {
-            cb(k, v);
-        }
-    }
-    /// Define a top-level key binding.
-    ///
-    /// ```
-    /// # use ::{std::sync::Arc, tek::*};
-    /// let config: Config = Default::default();
-    /// config.binds_def_keys(stringify!(Confirm (@enter confirm))).unwrap();
-    /// ```
-    fn binds_def_keys (&self, expr: impl Language) -> Usually<()> {
-        self.binds_keys().write().insert(
-            expr.head()?.ok_or("bind: missing name")?.into(),
-            Bind::new(expr.tail()?.unwrap_or(""))?.into()
-        );
-        Ok(())
-    }
-    /// Define an top-level axis binding (keypair).
-    ///
-    /// ```
-    /// # use ::{std::sync::Arc, tek::*};
-    /// let config: Config = Default::default();
-    /// config.binds_def_axis(stringify!(Y @up @down)).unwrap();
-    /// ```
-    fn binds_def_axis (&self, expr: impl Language) -> Usually<()> {
-        self.binds_axis().write().insert(
-            expr.head()?.ok_or("axis: missing name")?.into(),
-            Axis::eval(expr.tail()?.unwrap_or(""))?.into()
-        );
-        Ok(())
-    }
-}
-impl HasBinds for App {
-    fn binds_keys (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Bind<TuiEvent, Arc<str>>>>> {
-        &self.config.config.keys
-    }
-    fn binds_axis (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Axis<TuiEvent>>>> {
-        &self.config.config.axis
-    }
-}
-impl HasBinds for Config {
-    fn binds_keys (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Bind<TuiEvent, Arc<str>>>>> {
-        &self.keys
-    }
-    fn binds_axis (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Axis<TuiEvent>>>> {
-        &self.axis
-    }
-}
-
 pub trait DispatchBind<C: Clone>: HasBinds + HasModeStack + HasModes + Namespace<C> {
     fn dispatch_bind (&mut self, input: &TuiEvent) -> Usually<()> {
         if let Some(bindings) = self.dispatch_bind_match(input) {
@@ -1471,7 +1207,7 @@ pub trait DispatchBind<C: Clone>: HasBinds + HasModeStack + HasModes + Namespace
     ///   (bind Confirm (@enter confirm))
     ///   (mode Test (axis Y Index) (bind (@escape Cancel) Confirm))
     /// )).unwrap();
-    /// println!("Modes: {:#?}", app.config.config.modes);
+    /// println!("Modes: {:#?}", app.watch.config.modes);
     ///
     /// // No mode is active:
     /// assert!(app.dispatch_bind_match(&"@left".into()).is_none());
@@ -1620,7 +1356,7 @@ pub use self::conf::*; mod conf {
     }
     impl HasConfig for App {
         fn config (&self) -> &Config {
-            &self.config.config
+            &self.watch.config
         }
     }
     impl HasConfig for Watch {
@@ -1633,6 +1369,82 @@ pub use self::conf::*; mod conf {
             self
         }
     }
+
+    /// Default configuration contents.
+    const CONFIG_DEFAULT: &'static str = include_str!("tek.edn");
+
+    pub fn config_init <C: AsRef<Watch> + AsRef<Config>> (config: C) -> Usually<C> {
+        // Write initial contents of configuration:
+        let watcher: &Watch = config.as_ref();
+        if watcher.find_file().is_none() {
+            std::fs::write(watcher.place_file()?, CONFIG_DEFAULT)?;
+        }
+        // Load config from file:
+        Ok(if let Some(path) = watcher.find_file() {
+            config_reload(config, std::fs::read_to_string(&path)?)?
+        } else {
+            return Err(format!("config_init: not found").into())
+        })
+    }
+
+    /// Reload configuration from source.
+    pub fn config_reload <C: AsRef<Config>, L: Language> (state: C, src: L) -> Usually<C> {
+        state.as_ref().config_clear();
+        src.each(state, |c, s|config_add(c, s.trim()))
+    }
+
+    /// Load configuration item.
+    fn config_add <C: AsRef<Config>, L: Language> (state: C, src: L) -> Usually<C> {
+        if let Some(expr) = src.expr()? {
+            match expr.head()? {
+                Some("mode") => state.as_ref().modes_add(expr.tail()),
+                Some("view") => state.as_ref().views_add(expr.tail()),
+                Some("bind") => state.as_ref().binds_def_keys(expr.tail()),
+                Some("axis") => state.as_ref().binds_def_axis(expr.tail()),
+                _ => return Err(format!("config_add: unexpected: {src:?}").into())
+            }?;
+            Ok(state)
+        } else {
+            Err(format!("Config::add_one: tried to add empty item").into())
+        }
+    }
+
+    /// Contains timestamped mode, view, and bind definitions.
+    ///
+    /// ```
+    /// # use ::{std::sync::Arc, tek::*};
+    ///
+    /// // Default empty config:
+    /// let config: Config = Default::default();
+    ///
+    /// // Define a binding:
+    /// config.binds_def_keys(stringify!(Confirm (@enter confirm))).unwrap();
+    ///
+    /// // Define an axis:
+    /// config.binds_def_axis(stringify!(Y @up @down)).unwrap();
+    /// ```
+    #[derive(Default, Debug)]
+    pub struct Config {
+        /// Error caught during (re)loading
+        pub error: RwLock<Option<Arc<str>>>,
+        /// Timestamp
+        pub stamp: AtomicU64,
+        /// Active collection of interaction modes.
+        pub modes: Arc<RwLock<BTreeMap<Arc<str>, Arc<Mode>>>>,
+        /// Active collection of view definitions.
+        pub views: Arc<RwLock<BTreeMap<Arc<str>, Arc<View<Tui, App>>>>>,
+        /// Active collection of key bindings.
+        pub keys: Arc<RwLock<BTreeMap<Arc<str>, Arc<Bind<TuiEvent, Arc<str>>>>>>,
+        /// Active collection of axis bindings.
+        pub axis: Arc<RwLock<BTreeMap<Arc<str>, Arc<Axis<TuiEvent>>>>>,
+    }
+
+    impl Config {
+        /// Create a new timestamped config state.
+        pub fn new () -> Self {
+            Self { stamp: quanta::Clock::new().raw().into(), ..Default::default() }
+        }
+    }
 }
 
 pub use self::gear::*; mod gear {
@@ -1731,18 +1543,18 @@ pub use self::gear::*; mod gear {
     }
 
     impl Action {
-        fn run (&self, config: Arc<Watch>, _trace: bool) -> Usually<()> {
+        fn run (&self, watch: Arc<Watch>, _trace: bool) -> Usually<()> {
             use Action::*;
             match self {
                 Version   => show_version(),
-                Config    => config.config_print(),
+                Config    => watch.config_print(),
                 Resume    => todo!("resume session"),
                 List      => todo!("list sessions"),
                 New(sesh) => Exit::run(|exit|Tui::run_main(
                     exit.clone(),
                     {
                         #[allow(unused_mut)]
-                        let mut app = App::new(Some(exit), sesh.init()?, config, "Menu");
+                        let mut app = App::new(Some(exit), sesh.init()?, watch, "Menu");
                         app.dialog = Dialog::welcome();
                         #[cfg(feature = "prof2")] {
                             if trace {
@@ -1931,7 +1743,7 @@ impl_has!(Sizer:                 |self: Project| self.size);
 impl_has!(Vec<MidiInput>:        |self: Project| self.midi_ins);
 impl_has!(Vec<MidiOutput>:       |self: Project| self.midi_outs);
 
-impl_as_ref!(Config:             |self: App|self.config.config.as_ref());
+impl_as_ref!(Config:             |self: App|self.watch.config.as_ref());
 impl_as_mut!(Option<MidiEditor>: |self: App|self.project.as_mut());
 impl_as_mut!(Option<Project>:    |self: App|todo!());
 impl_as_ref!(Option<MidiEditor>: |self: App|self.project.as_ref());
@@ -1965,3 +1777,21 @@ tui_keys!(self: App, input {
     #[cfg(feature = "prof2")] profiling::scope!("App::tui_keys!");
     self.dispatch_bind(input)
 });
+
+/// The [Draw] implementation for [App] handles the loaded view,
+/// which is defined in terms of [dizzle] DSL.
+///
+/// If there is an error, the error is displayed. FIXME: overlay it
+/// Then, every top-level form of the DSL description is rendered.
+impl Draw<Tui> for App {
+    fn draw (&self, to: &mut Tui) -> Drawn<u16> {
+        #[cfg(feature = "prof2")] profiling::scope!("App::draw");
+        self.perf.cycle(&mut |_|{
+            draw_error(to, self.error.as_ref())?;
+            draw_mode_stack(to, &self)?;
+            view_debug(&*self.stack.read(), &self.perf, &self.size).draw(to)?;
+            #[cfg(feature = "prof2")] profiling::finish_frame!();
+            Ok(Some(to.area().into()))
+        })
+    }
+}