Add Widget and Node

showbits-common/src/widget.rs

@@ -0,0 +1,23 @@
+use taffy::{AvailableSpace, Size};
+
+use crate::{Node, View};
+
+pub trait Widget {
+    #[allow(unused_variables)]
+    fn size(&mut self, known: Size<Option<f32>>, available: Size<AvailableSpace>) -> Size<f32> {
+        Size::ZERO
+    }
+
+    fn draw_below(&mut self, view: &mut View<'_>) -> anyhow::Result<()>;
+    fn draw_above(&mut self, view: &mut View<'_>) -> anyhow::Result<()>;
+}
+
+pub trait WidgetExt {
+    fn node(self) -> Node;
+}
+
+impl<W: Widget + 'static> WidgetExt for W {
+    fn node(self) -> Node {
+        Node::empty().widget(self)
+    }
+}