midi: add pgup/pgdn; cleanup

crates/app/src/api.rs

@@ -117,8 +117,8 @@ defcom!([self, app: Tek]
         (Clock      [cmd: ClockCommand]    cmd.delegate(app, Self::Clock)?)
         (Editor     [cmd: MidiEditCommand] delegate_to_editor(app, cmd)?)
         (Pool       [cmd: PoolCommand]     delegate_to_pool(app, cmd)?)
-        (ToggleHelp [] cmd!({ app.modal = match app.modal { Some(Modal::Help) => None, _ => Some(Modal::Help) }}))
-        (ToggleMenu [] cmd!({ app.modal = match app.modal { Some(Modal::Menu) => None, _ => Some(Modal::Menu) }}))
+        (ToggleHelp []                     cmd!(app.toggle_modal(Some(Modal::Help))))
+        (ToggleMenu []                     cmd!(app.toggle_modal(Some(Modal::Menu))))
         (Color      [p: ItemTheme]         app.set_color(Some(p)).map(Self::Color))
         (Enqueue    [c: MaybeClip]         cmd_todo!("\n\rtodo: enqueue {c:?}"))
         (History    [d: isize]             cmd_todo!("\n\rtodo: history {d:?}"))
@@ -144,7 +144,7 @@ defcom!([self, app: Tek]
         (Stop       [index: usize]           cmd!(app.tracks[index].player.enqueue_next(None)))
         (Add        []                       Some(Self::Del(app.track_add_focus()?)))
         (SetColor   [i: usize, c: ItemTheme] Some(Self::SetColor(i, app.track_set_color(i, c))))
-        (ToggleRec  [] { app.track_toggle_record();  Some(Self::ToggleRec)  })
+        (ToggleRec  [] { app.track_toggle_record();  Some(Self::ToggleRec) })
         (ToggleMon  [] { app.track_toggle_monitor(); Some(Self::ToggleMon) }))
 
     (SceneCommand

crates/app/src/model.rs

@@ -182,6 +182,14 @@ impl Tek {
         }
     }
 
+    pub fn toggle_modal (&mut self, modal: Option<Modal>) {
+        self.modal = if self.modal == modal {
+            None
+        } else {
+            modal
+        }
+    }
+
     // Create new clip in pool when entering empty cell
     pub fn clip_auto_create (&mut self) {
         if let Some(ref pool) = self.pool