Add AsyncWidgetWrapper and WidgetWrapper

src/ui.rs

@@ -32,6 +32,13 @@ use self::widgets::BoxedWidget;
 /// Time to spend batch processing events before redrawing the screen.
 const EVENT_PROCESSING_TIME: Duration = Duration::from_millis(1000 / 15); // 15 fps
 
+/// Error for anything that can go wrong while rendering.
+#[derive(Debug, thiserror::Error)]
+pub enum UiError {
+    #[error("{0}")]
+    Io(#[from] io::Error),
+}
+
 pub enum UiEvent {
     GraphemeWidthsChanged,
     LogChanged,
@@ -51,8 +58,6 @@ enum Mode {
     Log,
 }
 
-// TODO Add Error for anything that can go wrong while rendering
-
 pub struct Ui {
     event_tx: UnboundedSender<UiEvent>,
 

src/ui/widgets.rs

@@ -19,7 +19,9 @@ pub mod rules;
 pub mod text;
 
 use async_trait::async_trait;
-use toss::{Frame, Size, WidthDb};
+use toss::{AsyncWidget, Frame, Size, WidthDb};
+
+use super::UiError;
 
 // TODO Add Error type and return Result-s (at least in Widget::render)
 
@@ -42,3 +44,66 @@ impl<W: 'static + Widget + Send + Sync> From<W> for BoxedWidget {
         Box::new(widget)
     }
 }
+
+/// Wrapper that implements [`Widget`] for an [`AsyncWidget`].
+pub struct AsyncWidgetWrapper<I> {
+    inner: I,
+}
+
+impl<I> AsyncWidgetWrapper<I> {
+    pub fn new(inner: I) -> Self {
+        Self { inner }
+    }
+}
+
+#[async_trait]
+impl<I> Widget for AsyncWidgetWrapper<I>
+where
+    I: AsyncWidget<UiError> + Send + Sync,
+{
+    async fn size(
+        &self,
+        widthdb: &mut WidthDb,
+        max_width: Option<u16>,
+        max_height: Option<u16>,
+    ) -> Size {
+        self.inner
+            .size(widthdb, max_width, max_height)
+            .await
+            .unwrap()
+    }
+
+    async fn render(self: Box<Self>, frame: &mut Frame) {
+        self.inner.draw(frame).await.unwrap();
+    }
+}
+
+/// Wrapper that implements [`AsyncWidget`] for a [`Widget`].
+pub struct WidgetWrapper {
+    inner: BoxedWidget,
+}
+
+impl WidgetWrapper {
+    pub fn new<W: Into<BoxedWidget>>(inner: W) -> Self {
+        Self {
+            inner: inner.into(),
+        }
+    }
+}
+
+#[async_trait]
+impl<E> AsyncWidget<E> for WidgetWrapper {
+    async fn size(
+        &self,
+        widthdb: &mut WidthDb,
+        max_width: Option<u16>,
+        max_height: Option<u16>,
+    ) -> Result<Size, E> {
+        Ok(self.inner.size(widthdb, max_width, max_height).await)
+    }
+
+    async fn draw(self, frame: &mut Frame) -> Result<(), E> {
+        self.inner.render(frame).await;
+        Ok(())
+    }
+}