diff --git a/Cargo.lock b/Cargo.lock
index a1cde1cd..404aba1e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2546,6 +2546,15 @@ dependencies = [
  "tek_proc",
 ]
 
+[[package]]
+name = "tek_test"
+version = "0.1.0"
+dependencies = [
+ "tek_core",
+ "tek_mixer",
+ "tek_sequencer",
+]
+
 [[package]]
 name = "thiserror"
 version = "1.0.61"
diff --git a/Cargo.toml b/Cargo.toml
index 51f234d1..ecdaa97c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,4 +4,5 @@ members = [
   "crates/tek_core",
   "crates/tek_mixer",
   "crates/tek_sequencer",
+  "crates/tek_test",
 ]
diff --git a/crates/tek_core/src/audio.rs b/crates/tek_core/src/audio.rs
index f96090c8..a3d23759 100644
--- a/crates/tek_core/src/audio.rs
+++ b/crates/tek_core/src/audio.rs
@@ -18,7 +18,7 @@ pub trait Device<E: Engine>: Component<E> + Process {
 /// All things that implement the required traits can be treated as `Device`.
 impl<D, E: Engine> Device<E> for D where D: Component<E> + Process {}
 
-impl<E: Engine> Render<E> for Box<dyn Device<E>> {
+impl<'a, E: Engine> Render<E> for Box<dyn Device<E> + 'a> {
     fn render (&self, to: &mut E) -> Perhaps<E::Rendered> {
         (**self).render(to)
     }
diff --git a/crates/tek_core/src/engine.rs b/crates/tek_core/src/engine.rs
index 8c76bec5..ec13a12b 100644
--- a/crates/tek_core/src/engine.rs
+++ b/crates/tek_core/src/engine.rs
@@ -13,7 +13,7 @@ pub trait Engine: Sized {
 
     /// Unit of distance.
     type Unit: Number;
-    type Area: Area<Self::Unit> + From<[Self::Unit;4]>;
+    type Area: Area<Self::Unit> + From<[Self::Unit;4]> + Debug;
 
     type HandleInput;
     type Handled;
diff --git a/crates/tek_core/src/engine/collect.rs b/crates/tek_core/src/engine/collect.rs
index 4c95aee7..51054e85 100644
--- a/crates/tek_core/src/engine/collect.rs
+++ b/crates/tek_core/src/engine/collect.rs
@@ -53,7 +53,7 @@ impl<'a, E: Engine> Collect<'a, E> for Collection<'a, E> {
     }
 }
 
-pub struct Layers<'a, E: Engine>(pub &'a [&'a dyn Render<E>]);
+pub struct Layers<'a, E: Engine>(pub &'a [&'a dyn Layout<E>]);
 
 // this actually works, except for the type inference
 //pub struct Layers<'a, E: Engine + 'a, I: std::iter::IntoIterator<Item = &'a dyn Render<E>>>(
diff --git a/crates/tek_core/src/engine/component.rs b/crates/tek_core/src/engine/component.rs
index cbd99c42..f2e498b5 100644
--- a/crates/tek_core/src/engine/component.rs
+++ b/crates/tek_core/src/engine/component.rs
@@ -15,3 +15,97 @@ pub trait ExitableComponent<E>: Exit + Component<E> where E: Engine {
 }
 
 impl<E: Engine, C: Component<E> + Exit> ExitableComponent<E> for C {}
+
+pub trait Widget {
+    type Engine: Engine;
+    fn layout (&self, to: <<Self as Widget>::Engine as Engine>::Area) ->
+        Perhaps<<<Self as Widget>::Engine as Engine>::Area>;
+    fn render (&self, to: &mut Self::Engine) ->
+        Perhaps<<<Self as Widget>::Engine as Engine>::Area>;
+}
+impl<E: Engine> Widget for Box<dyn Widget<Engine = E>> {
+    type Engine = E;
+    fn layout (&self, to: E::Area) -> Perhaps<E::Area> {
+        (**self).layout(to)
+    }
+    fn render (&self, to: &mut E) -> Perhaps<E::Area> {
+        (**self).render(to)
+    }
+}
+impl<E: Engine> Widget for &dyn Widget<Engine = E> {
+    type Engine = E;
+    fn layout (&self, to: E::Area)  -> Perhaps<E::Area> {
+        (*self).layout(to)
+    }
+    fn render (&self, to: &mut E) -> Perhaps<E::Area> {
+        (*self).render(to)
+    }
+}
+impl<E: Engine> Widget for &mut dyn Widget<Engine = E> {
+    type Engine = E;
+    fn layout (&self, to: E::Area) -> Perhaps<E::Area> {
+        (**self).layout(to)
+    }
+    fn render (&self, to: &mut E) -> Perhaps<E::Area> {
+        (**self).render(to)
+    }
+}
+impl<E: Engine, W: Widget<Engine = E>> Widget for Arc<W> {
+    type Engine = E;
+    fn layout (&self, to: E::Area) -> Perhaps<E::Area> {
+        self.as_ref().layout(to)
+    }
+    fn render (&self, to: &mut E) -> Perhaps<E::Area> {
+        self.as_ref().render(to)
+    }
+}
+impl<E: Engine, W: Widget<Engine = E>> Widget for Mutex<W> {
+    type Engine = E;
+    fn layout (&self, to: E::Area) -> Perhaps<E::Area> {
+        self.lock().unwrap().layout(to)
+    }
+    fn render (&self, to: &mut E) -> Perhaps<E::Area> {
+        self.lock().unwrap().render(to)
+    }
+}
+impl<E: Engine, W: Widget<Engine = E>> Widget for RwLock<W> {
+    type Engine = E;
+    fn layout (&self, to: E::Area) -> Perhaps<E::Area> {
+        self.read().unwrap().layout(to)
+    }
+    fn render (&self, to: &mut E) -> Perhaps<E::Area> {
+        self.read().unwrap().render(to)
+    }
+}
+impl<E: Engine, W: Widget<Engine = E>> Widget for Option<W> {
+    type Engine = E;
+    fn layout (&self, to: E::Area) -> Perhaps<E::Area> {
+        Ok(self.as_ref().map(|widget|widget.layout(to)).transpose()?.flatten())
+    }
+    fn render (&self, to: &mut E) -> Perhaps<E::Area> {
+        Ok(self.as_ref().map(|widget|widget.render(to)).transpose()?.flatten())
+    }
+}
+
+pub trait Content {
+    type Engine: Engine;
+    fn content (&self) -> impl Widget<Engine = <Self as Content>::Engine>;
+}
+//impl<E> Content<E> for () where E: Engine {
+    //fn content (&self) -> impl Widget<E> {
+        //()
+    //}
+//}
+impl<W> Widget for W where W: Content {
+    type Engine = <Self as Content>::Engine;
+    fn layout (&self, to: <<Self as Content>::Engine as Engine>::Area) 
+        -> Perhaps<<<Self as Content>::Engine as Engine>::Area>
+    {
+        self.content().layout(to)
+    }
+    fn render (&self, to: &mut <Self as Content>::Engine)
+        -> Perhaps<<<Self as Content>::Engine as Engine>::Area>
+    {
+        self.content().render(to)
+    }
+}
diff --git a/crates/tek_core/src/engine/layout.rs b/crates/tek_core/src/engine/layout.rs
index d647db5d..5acf498a 100644
--- a/crates/tek_core/src/engine/layout.rs
+++ b/crates/tek_core/src/engine/layout.rs
@@ -14,11 +14,26 @@ pub fn center_box (area: [u16;4], w: u16, h: u16) -> [u16;4] {
 pub trait Layout<E: Engine>: Render<E> {
     fn layout (&self, area: E::Area) -> Perhaps<E::Area>;
 }
+impl<'a, E: Engine> Layout<E> for Box<dyn Layout<E> + 'a> {
+    fn layout (&self, area: E::Area) -> Perhaps<E::Area> {
+        (**self).layout(area)
+    }
+}
+impl<'a, E: Engine> Layout<E> for Box<dyn Component<E> + 'a> {
+    fn layout (&self, area: E::Area) -> Perhaps<E::Area> {
+        (**self).layout(area)
+    }
+}
 impl<E: Engine, T: Layout<E>> Layout<E> for &T {
     fn layout (&self, area: E::Area) -> Perhaps<E::Area> {
         (*self).layout(area)
     }
 }
+impl<E: Engine, T: Layout<E>> Layout<E> for &mut T {
+    fn layout (&self, area: E::Area) -> Perhaps<E::Area> {
+        (**self).layout(area)
+    }
+}
 impl<E: Engine, T: Layout<E>> Layout<E> for Option<T> {
     fn layout (&self, area: E::Area) -> Perhaps<E::Area> {
         match self {
@@ -127,6 +142,7 @@ impl<E: Engine, L: Layout<E>> Layout<E> for Offset<E::Unit, L> {
 
 impl<E: Engine, R: Render<E> + Layout<E>> Render<E> for Min<E::Unit, R> {
     fn render (&self, to: &mut E) -> Perhaps<E::Rendered> {
+        // 🡘  🡙 ←🡙→
         self.layout(to.area())?
             .map(|area|to.with_area(area.x(), area.y(), area.w(), area.h()))
             .map(|to|match self {
diff --git a/crates/tek_core/src/engine/render.rs b/crates/tek_core/src/engine/render.rs
index 4ad9aaff..29c330de 100644
--- a/crates/tek_core/src/engine/render.rs
+++ b/crates/tek_core/src/engine/render.rs
@@ -27,6 +27,16 @@ impl<'a, E: Engine> Render<E> for Box<dyn Render<E> + 'a> {
         (**self).render(to)
     }
 }
+impl<'a, E: Engine> Render<E> for Box<dyn Layout<E> + 'a> {
+    fn render (&self, to: &mut E) -> Perhaps<E::Rendered> {
+        (**self).render(to)
+    }
+}
+impl<'a, E: Engine> Render<E> for Box<dyn Component<E> + 'a> {
+    fn render (&self, to: &mut E) -> Perhaps<E::Rendered> {
+        (**self).render(to)
+    }
+}
 
 /// Immutable references can be rendered.
 impl<R, E: Engine> Render<E> for &R where R: Render<E> {
diff --git a/crates/tek_core/src/tui.rs b/crates/tek_core/src/tui.rs
index 28ad2ab8..55d2c084 100644
--- a/crates/tek_core/src/tui.rs
+++ b/crates/tek_core/src/tui.rs
@@ -79,7 +79,7 @@ impl Tui {
         let _input_thread = {
             let engine = engine.clone();
             let state  = state.clone();
-            let poll   = Duration::from_millis(100);
+            let poll   = Duration::from_millis(20);
             spawn(move || loop {
                 if ::crossterm::event::poll(poll).is_ok() {
                     let event = TuiEvent::Input(::crossterm::event::read().unwrap());
diff --git a/crates/tek_core/src/tui/tui_border.rs b/crates/tek_core/src/tui/tui_border.rs
index 78c97859..ce99c926 100644
--- a/crates/tek_core/src/tui/tui_border.rs
+++ b/crates/tek_core/src/tui/tui_border.rs
@@ -98,6 +98,11 @@ macro_rules! border {
             const SE: &'static str = $se;
             $($x)*
         }
+        impl Layout<Tui> for $T {
+            fn layout (&self, area: [u16;4]) -> Perhaps<[u16;4]> {
+                Ok(Some(area))
+            }
+        }
         impl Render<Tui> for $T {
             fn render (&self, to: &mut Tui) -> Perhaps<[u16;4]> {
                 self.draw(to)
diff --git a/crates/tek_core/src/tui/tui_colors.rs b/crates/tek_core/src/tui/tui_colors.rs
index 467b9d8d..cd3a2454 100644
--- a/crates/tek_core/src/tui/tui_colors.rs
+++ b/crates/tek_core/src/tui/tui_colors.rs
@@ -33,9 +33,14 @@ impl Render<Tui> for Styled<&str> {
 
 pub struct FillBg(pub Color);
 
+impl Layout<Tui> for FillBg {
+    fn layout (&self, area: [u16;4]) -> Perhaps<[u16;4]> {
+        Ok(Some(area))
+    }
+}
 impl Render<Tui> for FillBg {
     fn render (&self, to: &mut Tui) -> Perhaps<[u16;4]> {
-        to.fill_bg(to.area, self.0);
+        to.fill_bg(to.area(), self.0);
         Ok(Some(to.area))
     }
 }
diff --git a/crates/tek_core/src/tui/tui_layout.rs b/crates/tek_core/src/tui/tui_layout.rs
index ba11ee85..34069775 100644
--- a/crates/tek_core/src/tui/tui_layout.rs
+++ b/crates/tek_core/src/tui/tui_layout.rs
@@ -1,12 +1,29 @@
 use crate::*;
 
+impl<'a> Layout<Tui> for Layers<'a, Tui> {
+    fn layout (&self, area: [u16;4]) -> Perhaps<[u16;4]> {
+        let [x, y, ..] = area;
+        let mut w = 0;
+        let mut h = 0;
+        for layer in self.0.iter() {
+            if let Some(layer_area) = layer.layout(area)? {
+                w = w.max(layer_area.w());
+                h = h.max(layer_area.h());
+            }
+        }
+        Ok(Some([x, y, w, h]))
+    }
+}
 impl<'a> Render<Tui> for Layers<'a, Tui> {
     fn render (&self, to: &mut Tui) -> Perhaps<[u16;4]> {
-        let area = to.area();
-        for layer in self.0.iter() {
-            layer.render(to)?;
-        }
-        Ok(Some(area))
+        self.layout(to.area())?
+            .map(|area| {
+                for layer in self.0.iter() {
+                    layer.render(to.with_rect(area))?;
+                }
+                Ok(area)
+            })
+            .transpose()
     }
 }
 
@@ -20,18 +37,16 @@ impl<'a> Render<Tui> for Layered<'a, Tui> {
     }
 }
 
-impl<'a> Render<Tui> for Split<'a, Tui> {
-    fn render (&self, to: &mut Tui) -> Perhaps<[u16;4]> {
-        Ok(Some(self.render_areas(to)?.0))
-    }
-}
-
 impl<'a> Layout<Tui> for Split<'a, Tui> {
     fn layout (&self, area: [u16;4]) -> Perhaps<[u16;4]> {
         todo!()
     }
 }
-
+impl<'a> Render<Tui> for Split<'a, Tui> {
+    fn render (&self, to: &mut Tui) -> Perhaps<[u16;4]> {
+        Ok(Some(self.render_areas(to)?.0))
+    }
+}
 // TODO
 impl<'a> Split<'a, Tui> {
     pub fn render_areas (&self, to: &mut Tui) -> Usually<([u16;4], Vec<Option<[u16;4]>>)> {
@@ -73,7 +88,7 @@ impl<'a> Split<'a, Tui> {
     }
 }
 
-impl<L: Layout<Tui>> Layout<Tui> for Align<L> where Self: Render<Tui> {
+impl<T: Render<Tui> + Layout<Tui>> Layout<Tui> for Align<T> {
     fn layout (&self, outer_area: [u16;4]) -> Perhaps<[u16;4]> {
         Ok(match self {
             Self::Center(inner) => inner,
@@ -106,7 +121,7 @@ impl<L: Layout<Tui>> Layout<Tui> for Align<L> where Self: Render<Tui> {
     }
 }
 
-impl<R: Render<Tui> + Layout<Tui>> Render<Tui> for Align<R> {
+impl<T: Render<Tui> + Layout<Tui>> Render<Tui> for Align<T> {
     fn render (&self, to: &mut Tui) -> Perhaps<[u16;4]> {
         self.layout(to.area())?
             .map(|area|to.with_area(area.x(), area.y(), area.w(), area.h()))
diff --git a/crates/tek_test/src/main.rs b/crates/tek_test/src/main.rs
index cd210778..67cdc6af 100644
--- a/crates/tek_test/src/main.rs
+++ b/crates/tek_test/src/main.rs
@@ -1,23 +1,53 @@
 use tek_core::*;
+use tek_core::jack::*;
 
 pub fn main () -> Usually<()> {
     Tui::run(Arc::new(RwLock::new(Demo::new())))?;
     Ok(())
 }
 
-pub struct Demo {
+pub struct Demo<E: Engine> {
     index: usize,
-    items: Vec<Box<dyn Component<Tui>>>
+    items: Vec<Box<dyn Component<E>>>
 }
 
-impl Demo {
+impl Demo<Tui> {
     fn new () -> Self {
-        let items = vec![];
+        let mut items: Vec<Box<dyn Component<Tui>>> = vec![];
+        items.push(Box::new(tek_sequencer::TransportPlayPauseButton {
+            value:   Some(TransportState::Stopped),
+            focused: true
+        }));
+        items.push(Box::new(tek_sequencer::TransportPlayPauseButton {
+            value:   Some(TransportState::Rolling),
+            focused: false
+        }));
         Self { index: 0, items }
     }
+    fn content <'a> (&'a self) -> impl Layout<Tui> + 'a {
+        Align::Center(Layers(&[
+            &Outset::WH(2, 1, FillBg(Color::Rgb(0,128,128))),
+            &Layers(&[
+                &"---------",
+                &Align::Center("...")
+            ])
+        ]))
+    }
 }
 
-impl Handle<Tui> for Demo {
+impl Layout<Tui> for Demo<Tui> {
+    fn layout (&self, area: [u16;4]) -> Perhaps<[u16;4]> {
+        self.content().layout(area)
+    }
+}
+
+impl Render<Tui> for Demo<Tui> {
+    fn render (&self, to: &mut Tui) -> Perhaps<[u16;4]> {
+        self.content().render(to)
+    }
+}
+
+impl Handle<Tui> for Demo<Tui> {
     fn handle (&mut self, from: &Tui) -> Perhaps<bool> {
         match from.event() {
             key!(KeyCode::PageUp) => {
@@ -36,15 +66,3 @@ impl Handle<Tui> for Demo {
         }
     }
 }
-
-impl Layout<Tui> for Demo {
-    fn layout (&self, area: [u16;4]) -> Perhaps<[u16;4]> {
-        Align::Center(self.items[self.index]).layout(area)
-    }
-}
-
-impl Render<Tui> for Demo {
-    fn render (&self, to: &mut Tui) -> Perhaps<[u16;4]> {
-        Align::Center(self.items[self.index]).render(to)
-    }
-}