fix Size, begin fixing View

src/draw.rs

@@ -1,5 +1,17 @@
 use crate::{*, lang::*, color::*, space::*};
 
+/// Emit a [Draw]able.
+///
+/// Speculative. How to avoid conflicts with [Draw] proper?
+pub trait View<T: Screen> {
+    fn view (&self) -> impl Draw<T>;
+}
+impl<T: Screen, V: View<T>> Draw<T> for &V {
+    fn draw (self, to: &mut T) -> Usually<XYWH<T::Unit>> {
+        self.view().draw(to)
+    }
+}
+
 /// Drawable that supports dynamic dispatch.
 ///
 /// Drawables are composable, e.g. the [when] and [either] conditionals
@@ -8,6 +20,10 @@ use crate::{*, lang::*, color::*, space::*};
 /// Drawables are consumable, i.e. the [Draw::draw] method receives an
 /// owned `self` and does not return it, consuming the drawable.
 ///
+/// To draw a thing multiple times, instead of explicitly constructing it
+/// every time, implement the [View] trait instead, which will construct
+/// a [Draw]able.
+/// 
 /// ```
 /// use tengri::draw::*;
 /// struct TestScreen(bool);
@@ -26,13 +42,12 @@ use crate::{*, lang::*, color::*, space::*};
 pub trait Draw<T: Screen> {
     fn draw (self, to: &mut T) -> Usually<XYWH<T::Unit>>;
 }
-
+/// Empty draw
 impl<T: Screen> Draw<T> for () {
     fn draw (self, __: &mut T) -> Usually<XYWH<T::Unit>> {
         Ok(Default::default())
     }
 }
-
 impl<T: Screen, D: Draw<T>> Draw<T> for Option<D> {
     fn draw (self, to: &mut T) -> Usually<XYWH<T::Unit>> {
         Ok(self.map(|draw|draw.draw(to)).transpose()?.unwrap_or_default())
@@ -111,14 +126,3 @@ pub trait Screen: Space<Self::Unit> + Send + Sync + Sized {
         unimplemented!()
     }
 }
-
-/// Emit a [Draw]able.
-pub trait View<T: Screen> {
-    fn view (&self) -> impl Draw<T>;
-}
-
-impl<T: Screen, V: View<T>> Draw<T> for &V {
-    fn draw (self, to: &mut T) -> Usually<XYWH<T::Unit>> {
-        self.view().draw(to)
-    }
-}

src/space.rs

@@ -491,3 +491,24 @@ pub fn iter_west <
 > (_items: V, _cb: F) -> impl Draw<T> {
     thunk(move|_to: &mut T|{ todo!() })
 }
+
+#[derive(Default, Debug)]
+pub struct Size(AtomicUsize, AtomicUsize);
+impl X<u16> for Size {
+    fn x (&self) -> u16 { 0 }
+    fn w (&self) -> u16 { self.0.load(Relaxed) as u16 }
+}
+impl Y<u16> for Size {
+    fn y (&self) -> u16 { 0 }
+    fn h (&self) -> u16 { self.1.load(Relaxed) as u16 }
+}
+impl Size {
+    pub const fn of <T: Screen> (&self, of: impl Draw<T>) -> impl Draw<T> {
+        thunk(move|to: &mut T|{
+            let area = of.draw(to)?;
+            self.0.store(area.w().into(), Relaxed);
+            self.1.store(area.h().into(), Relaxed);
+            Ok(area)
+        })
+    }
+}

src/text.rs

@@ -17,11 +17,6 @@ pub(crate) use ::unicode_width::*;
             self.as_str().draw(to)
         }
     }
-    impl Draw<Tui> for std::sync::Arc<str> {
-        fn draw (self, to: &mut Tui) -> Usually<XYWH<u16>> {
-            self.as_ref().draw(to)
-        }
-    }
     impl Draw<Tui> for &std::sync::Arc<str> {
         fn draw (self, to: &mut Tui) -> Usually<XYWH<u16>> {
             self.as_ref().draw(to)