Making unsized Spacers similar to unsized Paths

composable-views/src/layout/spacing.rs

@@ -1,20 +1,18 @@
-use std::cell::OnceCell;
+use std::cell::Cell;
 
 use crate::{Bounds, Output, Size, View};
 
-pub struct Spacer(pub(crate) OnceCell<Size>);
+pub struct Spacer(Cell<Size>);
 
 impl Spacer {
     #[inline(always)]
     pub fn fill() -> Self {
-        Spacer(OnceCell::new()) // a flexible spacer has no size (yet)
+        Spacer(Cell::new(Size::new(f32::INFINITY, f32::INFINITY))) // a flexible spacer has no size (yet)
     }
 
     #[inline(always)]
     pub fn fixed(width: f32, height: f32) -> Self {
-        let spacer = Self::fill();
-        spacer.0.set(Size::new(width, height)).ok();
-        spacer
+        Spacer(Cell::new(Size::new(width, height)))
     }
 
     #[inline(always)]
@@ -37,19 +35,22 @@ impl Spacer {
 impl View for Spacer {
     #[inline]
     fn size(&self) -> Size {
-        self.0.get().cloned().unwrap_or_default()
+        match self.0.get() {
+            size if size.is_finite() => size,
+            _ => Size::zero(),
+        }
     }
 
     #[inline(always)]
     fn draw(&self, bounds: Bounds, onto: &mut impl Output) {}
 
     #[inline(always)]
     fn needs_layout(&self) -> bool {
-        self.0.get().is_none()
+        self.0.get().is_finite()
     }
 
     #[inline]
     fn update_layout(&self, size: Size, _bounds: Bounds) {
-        self.0.set(size).ok();
+        self.0.set(size);
     }
 }

composable-views/src/text/font.rs

@@ -60,11 +60,13 @@ impl<'a> Font<'a> {
     }
 
     /// Horizontal face ascender.
+    #[inline]
     pub fn ascender(&self) -> f32 {
         self.face.ascender() as f32
     }
 
     /// Horizontal face descender,
+    #[inline]
     pub fn descender(&self) -> f32 {
         self.face.descender() as f32
     }