wip: compiles and runs (not enabled yet)

engine/src/output.rs

@@ -1,7 +1,5 @@
 use crate::*;
 use std::marker::PhantomData;
-//use std::sync::{Arc, Mutex, RwLock};
-
 /// Rendering target
 pub trait Output<E: Engine> {
     /// Current output area
@@ -10,31 +8,37 @@ pub trait Output<E: Engine> {
     fn area_mut (&mut self) -> &mut E::Area;
     /// Render widget in area
     fn place (&mut self, area: E::Area, content: &impl Render<E>);
-
     #[inline] fn x (&self) -> E::Unit { self.area().x() }
     #[inline] fn y (&self) -> E::Unit { self.area().y() }
     #[inline] fn w (&self) -> E::Unit { self.area().w() }
     #[inline] fn h (&self) -> E::Unit { self.area().h() }
     #[inline] fn wh (&self) -> E::Size { self.area().wh().into() }
 }
+pub struct Thunk<E: Engine, T: Content<E>, F: Fn()->T + Send + Sync>(F, PhantomData<E>);
+impl<E: Engine, T: Content<E>, F: Fn()->T + Send + Sync> Thunk<E, T, F> {
+    pub fn new (thunk: F) -> Self { Self(thunk, Default::default()) }
+}
+impl<E: Engine, T: Content<E>, F: Fn()->T + Send + Sync> Content<E> for Thunk<E, T, F> {
+    fn content (&self) -> impl Content<E> { (self.0)() }
+}
 pub trait Render<E: Engine>: Send + Sync {
-    fn layout (&self, area: E::Area) -> E::Area { area }
-    fn render (&self, output: &mut E::Output) {}
+    fn layout (&self, area: E::Area) -> E::Area;
+    fn render (&self, output: &mut E::Output);
+}
+pub trait Content<E: Engine>: Send + Sync + Sized {
+    fn content (&self) -> impl Render<E> { () }
+    fn layout (&self, area: E::Area) -> E::Area { self.content().layout(area) }
+    fn render (&self, output: &mut E::Output) { self.content().render(output) }
 }
 impl<E: Engine, C: Content<E>> Render<E> for C {
     fn layout (&self, area: E::Area) -> E::Area { Content::layout(self, area) }
     fn render (&self, output: &mut E::Output) { Content::render(self, output) }
 }
 impl<E: Engine> Content<E> for Box<dyn Render<E>> {
-    fn content (&self) -> impl Content<E> { self }
+    fn content (&self) -> impl Render<E> { self }
 }
 impl<E: Engine> Content<E> for &dyn Render<E> {
-    fn content (&self) -> impl Content<E> { self }
-}
-pub trait Content<E: Engine>: Send + Sync + Sized {
-    fn content (&self) -> impl Content<E> { () }
-    fn layout (&self, area: E::Area) -> E::Area { area }
-    fn render (&self, output: &mut E::Output) {}
+    fn content (&self) -> impl Render<E> { self }
 }
 /// The platonic ideal unit of [Content]: total emptiness at dead center.
 impl<E: Engine> Content<E> for () {
@@ -46,7 +50,7 @@ impl<E: Engine> Content<E> for () {
 }
 
 impl<E: Engine, T: Content<E>> Content<E> for &T {
-    fn content (&self) -> impl Content<E> {
+    fn content (&self) -> impl Render<E> {
         (*self).content()
     }
     fn layout (&self, area: E::Area) -> E::Area {
@@ -58,9 +62,8 @@ impl<E: Engine, T: Content<E>> Content<E> for &T {
 }
 
 impl<E: Engine, T: Content<E>> Content<E> for Option<T> {
-    fn content (&self) -> impl Content<E> {
+    fn content (&self) -> impl Render<E> {
         self.as_ref()
-            .map(|content|content.content())
     }
     fn layout (&self, area: E::Area) -> E::Area {
         self.as_ref()
@@ -73,18 +76,6 @@ impl<E: Engine, T: Content<E>> Content<E> for Option<T> {
     }
 }
 
-pub struct Thunk<E: Engine, T: Content<E>, F: Fn()->T + Send + Sync>(F, PhantomData<E>);
-
-impl<E: Engine, T: Content<E>, F: Fn()->T + Send + Sync> Thunk<E, T, F> {
-    pub fn new (thunk: F) -> Self {
-        Self(thunk, Default::default())
-    }
-}
-impl<E: Engine, T: Content<E>, F: Fn()->T + Send + Sync> Content<E> for Thunk<E, T, F> {
-    fn content (&self) -> impl Content<E> {
-        (self.0)()
-    }
-}
 
 #[macro_export] macro_rules! render {
     (($self:ident:$Struct:ty) => $content:expr) => {