Merge pull request #699 from JayceFayne/smol

Add `smol` async runtime support

10 files changed, 151 insertions, 11 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ee650337..70673f79 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,9 +6,54 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 ### Added
-- `"system_font"` feature gates reading system fonts. [#370]
+- Support for the [`smol`] async runtime. [#699]
+
+[#699]: https://github.com/hecrj/iced/pull/699
+[`smol`]: https://github.com/smol-rs/smol
+
+## [0.2.0] - 2020-11-26
+- __[`Canvas` interactivity][canvas]__ (#325)  
+  A trait-based approach to react to mouse and keyboard interactions in [the `Canvas` widget][#193].
+
+- __[`iced_graphics` subcrate][opengl]__ (#354)  
+  A backend-agnostic graphics subcrate that can be leveraged to build new renderers.
+
+- __[OpenGL renderer][opengl]__ (#354)  
+  An OpenGL renderer powered by [`iced_graphics`], [`glow`], and [`glutin`]. It is an alternative to the default [`wgpu`] renderer.
+
+- __[Overlay support][pick_list]__ (#444)  
+  Basic support for superpositioning interactive widgets on top of other widgets.
+
+- __[Faster event loop][view]__ (#597)  
+  The event loop now takes advantage of the data dependencies in [The Elm Architecture] and leverages the borrow checker to keep the widget tree alive between iterations, avoiding unnecessary rebuilds.
+
+- __[Event capturing][event]__ (#614)  
+  The runtime now can tell whether a widget has handled an event or not, easing [integration with existing applications].
+
+- __[`PickList` widget][pick_list]__ (#444)  
+  A drop-down selector widget built on top of the new overlay support.
+
+- __[`QRCode` widget][qr_code]__ (#622)  
+  A widget that displays a QR code, powered by [the `qrcode` crate].
+
+[canvas]: https://github.com/hecrj/iced/pull/325
+[opengl]: https://github.com/hecrj/iced/pull/354
+[`iced_graphics`]: https://github.com/hecrj/iced/pull/354
+[pane_grid]: https://github.com/hecrj/iced/pull/397
+[pick_list]: https://github.com/hecrj/iced/pull/444
+[error]: https://github.com/hecrj/iced/pull/514
+[view]: https://github.com/hecrj/iced/pull/597
+[event]: https://github.com/hecrj/iced/pull/614
+[color]: https://github.com/hecrj/iced/pull/200
+[qr_code]: https://github.com/hecrj/iced/pull/622
+[#193]: https://github.com/hecrj/iced/pull/193
+[`glutin`]: https://github.com/rust-windowing/glutin
+[`wgpu`]: https://github.com/gfx-rs/wgpu-rs
+[`glow`]: https://github.com/grovesNL/glow
+[the `qrcode` crate]: https://docs.rs/qrcode/0.12.0/qrcode/
+[integration with existing applications]: https://github.com/hecrj/iced/pull/183
+[The Elm Architecture]: https://guide.elm-lang.org/architecture/
 
-[#370]: https://github.com/hecrj/iced/pull/370
 
 ## [0.1.1] - 2020-04-15
 ### Added
@@ -114,7 +159,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - First release! :tada:
 
-[Unreleased]: https://github.com/hecrj/iced/compare/0.1.1...HEAD
+[Unreleased]: https://github.com/hecrj/iced/compare/0.2.0...HEAD
+[0.2.0]: https://github.com/hecrj/iced/compare/0.1.1...0.2.0
 [0.1.1]: https://github.com/hecrj/iced/compare/0.1.0...0.1.1
 [0.1.0]: https://github.com/hecrj/iced/compare/0.1.0-beta...0.1.0
 [0.1.0-beta]: https://github.com/hecrj/iced/compare/0.1.0-alpha...0.1.0-beta
diff --git a/Cargo.toml b/Cargo.toml
index 6221ae4b..75499df9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -41,6 +41,8 @@ tokio = ["iced_futures/tokio"]
 tokio_old = ["iced_futures/tokio_old"]
 # Enables `async-std` as the `executor::Default` on native platforms
 async-std = ["iced_futures/async-std"]
+# Enables `smol` as the `executor::Default` on native platforms
+smol = ["iced_futures/smol"]
 # Enables advanced color conversion via `palette`
 palette = ["iced_core/palette"]
 
diff --git a/examples/stopwatch/Cargo.toml b/examples/stopwatch/Cargo.toml
index 075aa111..9f935951 100644
--- a/examples/stopwatch/Cargo.toml
+++ b/examples/stopwatch/Cargo.toml
@@ -6,4 +6,4 @@ edition = "2018"
 publish = false
 
 [dependencies]
-iced = { path = "../..", features = ["tokio"] }
+iced = { path = "../..", features = ["smol"] }
diff --git a/futures/Cargo.toml b/futures/Cargo.toml
index 92b504a6..c266f705 100644
--- a/futures/Cargo.toml
+++ b/futures/Cargo.toml
@@ -36,6 +36,10 @@ version = "1.0"
 optional = true
 features = ["unstable"]
 
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies.smol]
+version = "1.2"
+optional = true
+
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 wasm-bindgen-futures = "0.4"
 
diff --git a/futures/src/executor.rs b/futures/src/executor.rs
index fa87216a..b35b5bc1 100644
--- a/futures/src/executor.rs
+++ b/futures/src/executor.rs
@@ -13,6 +13,9 @@ mod tokio_old;
 #[cfg(all(not(target_arch = "wasm32"), feature = "async-std"))]
 mod async_std;
 
+#[cfg(all(not(target_arch = "wasm32"), feature = "smol"))]
+mod smol;
+
 #[cfg(target_arch = "wasm32")]
 mod wasm_bindgen;
 
@@ -30,6 +33,9 @@ pub use self::tokio_old::TokioOld;
 #[cfg(all(not(target_arch = "wasm32"), feature = "async-std"))]
 pub use self::async_std::AsyncStd;
 
+#[cfg(all(not(target_arch = "wasm32"), feature = "smol"))]
+pub use self::smol::Smol;
+
 #[cfg(target_arch = "wasm32")]
 pub use wasm_bindgen::WasmBindgen;
 
diff --git a/futures/src/executor/smol.rs b/futures/src/executor/smol.rs
new file mode 100644
index 00000000..deafd43a
--- /dev/null
+++ b/futures/src/executor/smol.rs
@@ -0,0 +1,18 @@
+use crate::Executor;
+
+use futures::Future;
+
+/// A `smol` runtime.
+#[cfg_attr(docsrs, doc(cfg(feature = "smol")))]
+#[derive(Debug)]
+pub struct Smol;
+
+impl Executor for Smol {
+    fn new() -> Result<Self, futures::io::Error> {
+        Ok(Self)
+    }
+
+    fn spawn(&self, future: impl Future<Output = ()> + Send + 'static) {
+        smol::spawn(future).detach();
+    }
+}
diff --git a/futures/src/lib.rs b/futures/src/lib.rs
index c7c6fd3a..01cf5c89 100644
--- a/futures/src/lib.rs
+++ b/futures/src/lib.rs
@@ -17,10 +17,22 @@ pub mod executor;
 pub mod subscription;
 
 #[cfg(all(
-    any(feature = "tokio", feature = "tokio_old", feature = "async-std"),
+    any(
+        feature = "tokio",
+        feature = "tokio_old",
+        feature = "async-std",
+        feature = "smol"
+    ),
     not(target_arch = "wasm32")
 ))]
-#[cfg_attr(docsrs, doc(cfg(any(feature = "tokio", feature = "async-std"))))]
+#[cfg_attr(
+    docsrs,
+    doc(cfg(any(
+        feature = "tokio",
+        feature = "async-std",
+        feature = "smol"
+    )))
+)]
 pub mod time;
 
 pub use command::Command;
diff --git a/futures/src/time.rs b/futures/src/time.rs
index d015d2f0..c11942d2 100644
--- a/futures/src/time.rs
+++ b/futures/src/time.rs
@@ -13,6 +13,41 @@ pub fn every<H: std::hash::Hasher, E>(
 
 struct Every(std::time::Duration);
 
+#[cfg(all(
+    not(any(feature = "tokio_old", feature = "tokio", feature = "async-std")),
+    feature = "smol"
+))]
+impl<H, E> subscription::Recipe<H, E> for Every
+where
+    H: std::hash::Hasher,
+{
+    type Output = std::time::Instant;
+
+    fn hash(&self, state: &mut H) {
+        use std::hash::Hash;
+
+        std::any::TypeId::of::<Self>().hash(state);
+        self.0.hash(state);
+    }
+
+    fn stream(
+        self: Box<Self>,
+        _input: futures::stream::BoxStream<'static, E>,
+    ) -> futures::stream::BoxStream<'static, Self::Output> {
+        use futures::stream::StreamExt;
+        use std::time::Instant;
+
+        let duration = self.0;
+
+        futures::stream::unfold(Instant::now(), move |last_tick| async move {
+            let last_tick = smol::Timer::at(last_tick + duration).await;
+
+            Some((last_tick, last_tick))
+        })
+        .boxed()
+    }
+}
+
 #[cfg(feature = "async-std")]
 impl<H, E> subscription::Recipe<H, E> for Every
 where
@@ -41,7 +76,7 @@ where
 
 #[cfg(all(
     any(feature = "tokio", feature = "tokio_old"),
-    not(feature = "async-std")
+    not(any(feature = "async-std", feature = "smol"))
 ))]
 impl<H, E> subscription::Recipe<H, E> for Every
 where
diff --git a/src/executor.rs b/src/executor.rs
index 0333bc1d..9f3656b1 100644
--- a/src/executor.rs
+++ b/src/executor.rs
@@ -10,19 +10,30 @@ mod platform {
     #[cfg(feature = "tokio_old")]
     type Executor = executor::TokioOld;
 
-    #[cfg(all(not(feature = "tokio_old"), feature = "tokio"))]
+    #[cfg(all(feature = "tokio", not(feature = "tokio_old")))]
     type Executor = executor::Tokio;
 
     #[cfg(all(
+        feature = "async-std",
         not(any(feature = "tokio_old", feature = "tokio")),
-        feature = "async-std"
     ))]
     type Executor = executor::AsyncStd;
 
+    #[cfg(all(
+        feature = "smol",
+        not(any(
+            feature = "tokio_old",
+            feature = "tokio",
+            feature = "async-std"
+        )),
+    ))]
+    type Executor = executor::Smol;
+
     #[cfg(not(any(
         feature = "tokio_old",
         feature = "tokio",
-        feature = "async-std"
+        feature = "async-std",
+        feature = "smol",
     )))]
     type Executor = executor::ThreadPool;
 
diff --git a/src/lib.rs b/src/lib.rs
index 3578ea82..dedcac7a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -191,7 +191,12 @@ pub mod widget;
 pub mod window;
 
 #[cfg(all(
-    any(feature = "tokio", feature = "tokio_old", feature = "async-std"),
+    any(
+        feature = "tokio",
+        feature = "tokio_old",
+        feature = "async-std",
+        feature = "smol"
+    ),
     not(target_arch = "wasm32")
 ))]
 #[cfg_attr(
@@ -200,6 +205,7 @@ pub mod window;
         feature = "tokio",
         feature = "tokio_old",
         feature = "async-std"
+        feature = "smol"
     )))
 )]
 pub mod time;