mistakes were fixed and sins were committed

src/core/rect.rs

@@ -36,6 +36,14 @@ impl Widget for Rect {
             inner_radius: self.inner_radius,
         });
     }
+
+    fn desired_width(&mut self, _: &mut SizeCtx) -> Len {
+        Len::rest(1)
+    }
+
+    fn desired_height(&mut self, _: &mut SizeCtx) -> Len {
+        Len::rest(1)
+    }
 }
 
 pub fn rect(color: UiColor) -> Rect {