don't crash on add track/scene

src/view/chain.rs

@@ -1,6 +1,4 @@
-use crate::core::*;
-use crate::model::*;
-use crate::view::{*, Direction};
+use crate::{core::*, model::*, view::*};
 
 pub struct ChainView<'a> {
     pub track:     Option<&'a Track>,
@@ -58,42 +56,3 @@ impl<'a> Render for ChainView<'a> {
         }
     }
 }
-
-type Renderables<'a> = &'a [JackDevice];
-
-impl<'a> Direction {
-    fn split_focus (&self, index: usize, items: Renderables<'a>, style: Style) -> SplitFocus<'a> {
-        SplitFocus(*self, index, items, style)
-    }
-}
-
-pub struct SplitFocus<'a>(pub Direction, pub usize, pub Renderables<'a>, pub Style);
-
-impl<'a> Render for SplitFocus<'a> {
-    fn render (&self, buf: &mut Buffer, area: Rect) -> Usually<Rect> {
-        let Rect { mut x, mut y, mut width, mut height } = area;
-        let mut results = vec![];
-        for item in self.2.iter() {
-            if width == 0 || height == 0 {
-                break
-            }
-            let result = item.render(buf, Rect { x, y, width, height })?;
-            results.push(result);
-            match self.0 {
-                Direction::Down => {
-                    y = y + result.height;
-                    height = height.saturating_sub(result.height);
-                },
-                Direction::Right => {
-                    x = x + result.width;
-                    width = width.saturating_sub(result.width);
-                },
-            }
-        }
-        results
-            .get(self.1)
-            .map(|focused|Lozenge(self.3).draw(buf, Rect { width, ..*focused }))
-            .transpose()?;
-        Ok(area)
-    }
-}