Decouple iced from coffee

src/node.rs

@@ -0,0 +1,60 @@
+use stretch::node;
+
+use crate::{Number, Size, Style};
+
+/// The visual requirements of a [`Widget`] and its children.
+///
+/// When there have been changes and the [`Layout`] needs to be recomputed, the
+/// runtime obtains a [`Node`] by calling [`Widget::node`].
+///
+/// [`Style`]: struct.Style.html
+/// [`Widget`]: trait.Widget.html
+/// [`Node`]: struct.Node.html
+/// [`Widget::node`]: trait.Widget.html#tymethod.node
+/// [`Layout`]: struct.Layout.html
+#[derive(Debug)]
+pub struct Node(pub(crate) node::Node);
+
+impl Node {
+    /// Creates a new [`Node`] with the given [`Style`].
+    ///
+    /// [`Node`]: struct.Node.html
+    /// [`Style`]: struct.Style.html
+    pub fn new(style: Style) -> Node {
+        Self::with_children(style, Vec::new())
+    }
+
+    /// Creates a new [`Node`] with the given [`Style`] and children.
+    ///
+    /// [`Node`]: struct.Node.html
+    /// [`Style`]: struct.Style.html
+    pub(crate) fn with_children(style: Style, children: Vec<Node>) -> Node {
+        Node(node::Node::new(
+            style.0,
+            children.iter().map(|c| &c.0).collect(),
+        ))
+    }
+
+    /// Creates a new [`Node`] with the given [`Style`] and a measure function.
+    ///
+    /// This type of node cannot have any children.
+    ///
+    /// You should use this when your [`Widget`] can adapt its contents to the
+    /// size of its container. The measure function will receive the container
+    /// size as a parameter and must compute the size of the [`Node`] inside
+    /// the given bounds (if the `Number` for a dimension is `Undefined` it
+    /// means that it has no boundary).
+    ///
+    /// [`Node`]: struct.Node.html
+    /// [`Style`]: struct.Style.html
+    /// [`Widget`]: trait.Widget.html
+    pub fn with_measure<F>(style: Style, measure: F) -> Node
+    where
+        F: 'static + Fn(Size<Number>) -> Size<f32>,
+    {
+        Node(node::Node::new_leaf(
+            style.0,
+            Box::new(move |size| Ok(measure(size))),
+        ))
+    }
+}