output: more big refactors

output/src/widget/widget_tryptich.rs

@@ -0,0 +1,31 @@
+#[allow(unused)] use crate::*;
+
+/// A three-column layout.
+pub struct Tryptich<A, B, C> {
+    pub top:    bool,
+    pub h:      u16,
+    pub left:   (u16, A),
+    pub middle: (u16, B),
+    pub right:  (u16, C),
+}
+
+impl Tryptich<(), (), ()> {
+    pub fn center (h: u16) -> Self {
+        Self { h, top: false, left: (0, ()), middle: (0, ()), right: (0, ()) }
+    }
+    pub fn top (h: u16) -> Self {
+        Self { h, top: true, left: (0, ()), middle: (0, ()), right: (0, ()) }
+    }
+}
+
+impl<A, B, C> Tryptich<A, B, C> {
+    pub fn left <D> (self, w: u16, content: D) -> Tryptich<D, B, C> {
+        Tryptich { left: (w, content), ..self }
+    }
+    pub fn middle <D> (self, w: u16, content: D) -> Tryptich<A, D, C> {
+        Tryptich { middle: (w, content), ..self }
+    }
+    pub fn right <D> (self, w: u16, content: D) -> Tryptich<A, B, D> {
+        Tryptich { right: (w, content), ..self }
+    }
+}