learn how workspaces + proc macros work & restructure everything

src/widget/position/sized.rs

@@ -0,0 +1,34 @@
+use crate::prelude::*;
+
+pub struct Sized {
+    pub inner: WidgetRef,
+    pub x: Option<Len>,
+    pub y: Option<Len>,
+}
+
+impl Sized {
+    fn apply_to_outer(&self, ctx: &mut SizeCtx) {
+        if let Some(x) = self.x {
+            ctx.outer.x.select_len(x.apply_rest());
+        }
+        if let Some(y) = self.y {
+            ctx.outer.y.select_len(y.apply_rest());
+        }
+    }
+}
+
+impl Widget for Sized {
+    fn draw(&mut self, painter: &mut Painter) {
+        painter.widget(&self.inner);
+    }
+
+    fn desired_width(&mut self, ctx: &mut SizeCtx) -> Len {
+        self.apply_to_outer(ctx);
+        self.x.unwrap_or_else(|| ctx.width(&self.inner))
+    }
+
+    fn desired_height(&mut self, ctx: &mut SizeCtx) -> Len {
+        self.apply_to_outer(ctx);
+        self.y.unwrap_or_else(|| ctx.height(&self.inner))
+    }
+}