Add Widget and Node

showbits-common/src/node.rs

@@ -0,0 +1,30 @@
+use taffy::{NodeId, Style, TaffyResult, TaffyTree};
+
+use crate::Widget;
+
+pub struct Node {
+    layout: Style,
+    children: Vec<NodeId>,
+    widget: Option<Box<dyn Widget>>,
+}
+
+impl Node {
+    pub fn empty() -> Self {
+        Self {
+            layout: Style::default(),
+            children: vec![],
+            widget: None,
+        }
+    }
+
+    pub fn widget<W: Widget + 'static>(mut self, widget: W) -> Self {
+        self.widget = Some(Box::new(widget));
+        self
+    }
+
+    pub fn register(self, tree: &mut TaffyTree<Box<dyn Widget>>) -> TaffyResult<NodeId> {
+        let id = tree.new_with_children(self.layout, &self.children)?;
+        tree.set_node_context(id, self.widget)?;
+        Ok(id)
+    }
+}