wip: big flat pt.2: extract engine crate

src/engine.rs

@@ -1,49 +1,5 @@
 use crate::*;
 
-/// Platform backend.
-pub trait Engine: Send + Sync + Sized {
-    /// Input event type
-    type Input: Input<Self>;
-    /// Result of handling input
-    type Handled;
-    /// Render target
-    type Output: Output<Self>;
-    /// Unit of length
-    type Unit: Coordinate;
-    /// Rectangle without offset
-    type Size: Size<Self::Unit> + From<[Self::Unit;2]> + Debug + Copy;
-    /// Rectangle with offset
-    type Area: Area<Self::Unit> + From<[Self::Unit;4]> + Debug + Copy;
-    /// Prepare before run
-    fn setup (&mut self) -> Usually<()> { Ok(()) }
-    /// True if done
-    fn exited (&self) -> bool;
-    /// Clean up after run
-    fn teardown (&mut self) -> Usually<()> { Ok(()) }
-}
-
-/// A UI component that can render itself as a [Render], and [Handle] input.
-pub trait Component<E: Engine>: Render<E> + Handle<E> {}
-
-/// Everything that implements [Render] and [Handle] is a [Component].
-impl<E: Engine, C: Render<E> + Handle<E>> Component<E> for C {}
-
-/// A component that can exit.
-pub trait Exit: Send {
-    fn exited (&self) -> bool;
-    fn exit (&mut self);
-    fn boxed (self) -> Box<dyn Exit> where Self: Sized + 'static {
-        Box::new(self)
-    }
-}
-
-/// Marker trait for [Component]s that can [Exit].
-pub trait ExitableComponent<E>: Exit + Component<E> where E: Engine {
-    /// Perform type erasure for collecting heterogeneous components.
-    fn boxed (self) -> Box<dyn ExitableComponent<E>> where Self: Sized + 'static {
-        Box::new(self)
-    }
-}
-
-/// All [Components]s that implement [Exit] implement [ExitableComponent].
-impl<E: Engine, C: Component<E> + Exit> ExitableComponent<E> for C {}
+mod content; pub use self::content::*;
+mod render;  pub use self::render::*;
+mod handle;  pub use self::handle::*;