diff --git a/crates/tek/src/layout/measure.rs b/crates/tek/src/layout/measure.rs
index af163125..27429cb6 100644
--- a/crates/tek/src/layout/measure.rs
+++ b/crates/tek/src/layout/measure.rs
@@ -4,20 +4,14 @@ pub trait HasSize<E: Engine> {
     fn size (&self) -> &Measure<E>;
 }
 
-#[macro_export] macro_rules! implementor {
-    ($name:ident => $Trait:ident) => {
-        #[macro_export] macro_rules! $name {
-            (|$self:ident:$Struct:ident$(<$($L:lifetime),*$($T:ident$(:$U:path)?),*>)?|$cb:expr) => {
-                impl $(<$($L),*$($T $(: $U)?),*>)? $Trait for $Struct $(<$($L),*$($T),*>)? {
-                    fn clock (&$self) -> &ClockModel { $cb }
-                }
-            }
+#[macro_export] macro_rules! has_size {
+    (<$E:ty>|$self:ident:$Struct:ident$(<$($L:lifetime),*$($T:ident$(:$U:path)?),*>)?|$cb:expr) => {
+        impl $(<$($L),*$($T $(: $U)?),*>)? HasSize<$E> for $Struct $(<$($L),*$($T),*>)? {
+            fn size (&$self) -> &Measure<$E> { $cb } // TODO provide trait body
         }
     }
 }
 
-implementor!(has_size => HasSize);
-
 impl<E: Engine> LayoutDebug<E> for E {}
 
 pub trait LayoutDebug<E: Engine> {
diff --git a/crates/tek/src/tui/phrase_editor.rs b/crates/tek/src/tui/phrase_editor.rs
index c2793400..fc579483 100644
--- a/crates/tek/src/tui/phrase_editor.rs
+++ b/crates/tek/src/tui/phrase_editor.rs
@@ -100,7 +100,7 @@ impl Command<PhraseEditorModel> for PhraseCommand {
 /// Contains state for viewing and editing a phrase
 pub struct PhraseEditorModel {
     /// Renders the phrase
-    pub mode:   Box<dyn PhraseViewMode>,
+    pub mode: Box<dyn PhraseViewMode>,
 }
 
 impl Default for PhraseEditorModel {
@@ -111,12 +111,12 @@ impl Default for PhraseEditorModel {
 
 render!(|self: PhraseEditorModel|self.mode);
 
-pub trait PhraseViewMode: Render<Tui> + MIDIRange + MIDIPoint + Debug + Send + Sync {
+pub trait PhraseViewMode: Render<Tui> + HasSize<Tui> + MIDIRange + MIDIPoint + Debug + Send + Sync {
     fn buffer_size (&self, phrase: &Phrase) -> (usize, usize);
-    fn redraw      (&mut self);
-    fn phrase      (&self) -> &Option<Arc<RwLock<Phrase>>>;
-    fn phrase_mut  (&mut self) -> &mut Option<Arc<RwLock<Phrase>>>;
-    fn set_phrase  (&mut self, phrase: Option<&Arc<RwLock<Phrase>>>) {
+    fn redraw (&mut self);
+    fn phrase (&self) -> &Option<Arc<RwLock<Phrase>>>;
+    fn phrase_mut (&mut self) -> &mut Option<Arc<RwLock<Phrase>>>;
+    fn set_phrase (&mut self, phrase: Option<&Arc<RwLock<Phrase>>>) {
         *self.phrase_mut() = phrase.map(|p|p.clone());
         self.redraw();
     }
@@ -124,7 +124,7 @@ pub trait PhraseViewMode: Render<Tui> + MIDIRange + MIDIPoint + Debug + Send + S
 
 impl MIDIViewport<Tui> for PhraseEditorModel {}
 
-has_size!(|self:PhraseEditorModel|&self.size);
+has_size!(<Tui>|self:PhraseEditorModel|self.mode.size());
 
 impl MIDIRange for PhraseEditorModel {
     fn time_zoom (&self) -> usize { self.mode.time_zoom() }
@@ -150,16 +150,16 @@ impl PhraseViewMode for PhraseEditorModel {
     fn buffer_size (&self, phrase: &Phrase) -> (usize, usize) {
         self.mode.buffer_size(phrase)
     }
-    fn redraw      (&mut self) {
+    fn redraw (&mut self) {
         self.mode.redraw()
     }
-    fn phrase      (&self) -> &Option<Arc<RwLock<Phrase>>> {
+    fn phrase (&self) -> &Option<Arc<RwLock<Phrase>>> {
         self.mode.phrase()
     }
-    fn phrase_mut  (&mut self) -> &mut Option<Arc<RwLock<Phrase>>> {
+    fn phrase_mut (&mut self) -> &mut Option<Arc<RwLock<Phrase>>> {
         self.mode.phrase_mut()
     }
-    fn set_phrase  (&mut self, phrase: Option<&Arc<RwLock<Phrase>>>) {
+    fn set_phrase (&mut self, phrase: Option<&Arc<RwLock<Phrase>>>) {
         self.mode.set_phrase(phrase)
     }
 }
diff --git a/crates/tek/src/tui/piano_horizontal.rs b/crates/tek/src/tui/piano_horizontal.rs
index ca559a2e..5cabba28 100644
--- a/crates/tek/src/tui/piano_horizontal.rs
+++ b/crates/tek/src/tui/piano_horizontal.rs
@@ -241,6 +241,8 @@ impl PianoHorizontal {
     }
 }
 
+has_size!(<Tui>|self:PianoHorizontal|&self.size);
+
 impl MIDIRange for PianoHorizontal {
     fn time_zoom (&self) -> usize { self.range.time_zoom() }
     fn set_time_zoom (&self, x: usize) { self.range.set_time_zoom(x); }