Add Either3 widget

src/widget.rs

@@ -1,6 +1,6 @@
 use async_trait::async_trait;
 
-use crate::widgets::{Background, Border, Either, Float, Layer, Padding};
+use crate::widgets::{Background, Border, Either, Either3, Float, Layer, Padding};
 use crate::{Frame, Size};
 
 // TODO Feature-gate these traits
@@ -45,6 +45,18 @@ pub trait WidgetExt: Sized {
         Either::Second(self)
     }
 
+    fn first3<W2, W3>(self) -> Either3<Self, W2, W3> {
+        Either3::First(self)
+    }
+
+    fn second3<W1, W3>(self) -> Either3<W1, Self, W3> {
+        Either3::Second(self)
+    }
+
+    fn third3<W1, W2>(self) -> Either3<W1, W2, Self> {
+        Either3::Third(self)
+    }
+
     fn float(self) -> Float<Self> {
         Float::new(self)
     }

src/widgets/either.rs

@@ -20,15 +20,15 @@ where
         max_height: Option<u16>,
     ) -> Result<Size, E> {
         match self {
-            Self::First(l) => l.size(frame, max_width, max_height),
-            Self::Second(r) => r.size(frame, max_width, max_height),
+            Self::First(w) => w.size(frame, max_width, max_height),
+            Self::Second(w) => w.size(frame, max_width, max_height),
         }
     }
 
     fn draw(self, frame: &mut Frame) -> Result<(), E> {
         match self {
-            Self::First(l) => l.draw(frame),
-            Self::Second(r) => r.draw(frame),
+            Self::First(w) => w.draw(frame),
+            Self::Second(w) => w.draw(frame),
         }
     }
 }
@@ -46,15 +46,79 @@ where
         max_height: Option<u16>,
     ) -> Result<Size, E> {
         match self {
-            Self::First(l) => l.size(frame, max_width, max_height).await,
-            Self::Second(r) => r.size(frame, max_width, max_height).await,
+            Self::First(w) => w.size(frame, max_width, max_height).await,
+            Self::Second(w) => w.size(frame, max_width, max_height).await,
         }
     }
 
     async fn draw(self, frame: &mut Frame) -> Result<(), E> {
         match self {
-            Self::First(l) => l.draw(frame).await,
-            Self::Second(r) => r.draw(frame).await,
+            Self::First(w) => w.draw(frame).await,
+            Self::Second(w) => w.draw(frame).await,
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+pub enum Either3<I1, I2, I3> {
+    First(I1),
+    Second(I2),
+    Third(I3),
+}
+
+impl<E, I1, I2, I3> Widget<E> for Either3<I1, I2, I3>
+where
+    I1: Widget<E>,
+    I2: Widget<E>,
+    I3: Widget<E>,
+{
+    fn size(
+        &self,
+        frame: &mut Frame,
+        max_width: Option<u16>,
+        max_height: Option<u16>,
+    ) -> Result<Size, E> {
+        match self {
+            Self::First(w) => w.size(frame, max_width, max_height),
+            Self::Second(w) => w.size(frame, max_width, max_height),
+            Self::Third(w) => w.size(frame, max_width, max_height),
+        }
+    }
+
+    fn draw(self, frame: &mut Frame) -> Result<(), E> {
+        match self {
+            Self::First(w) => w.draw(frame),
+            Self::Second(w) => w.draw(frame),
+            Self::Third(w) => w.draw(frame),
+        }
+    }
+}
+
+#[async_trait]
+impl<E, I1, I2, I3> AsyncWidget<E> for Either3<I1, I2, I3>
+where
+    I1: AsyncWidget<E> + Send + Sync,
+    I2: AsyncWidget<E> + Send + Sync,
+    I3: AsyncWidget<E> + Send + Sync,
+{
+    async fn size(
+        &self,
+        frame: &mut Frame,
+        max_width: Option<u16>,
+        max_height: Option<u16>,
+    ) -> Result<Size, E> {
+        match self {
+            Self::First(w) => w.size(frame, max_width, max_height).await,
+            Self::Second(w) => w.size(frame, max_width, max_height).await,
+            Self::Third(w) => w.size(frame, max_width, max_height).await,
+        }
+    }
+
+    async fn draw(self, frame: &mut Frame) -> Result<(), E> {
+        match self {
+            Self::First(w) => w.draw(frame).await,
+            Self::Second(w) => w.draw(frame).await,
+            Self::Third(w) => w.draw(frame).await,
         }
     }
 }