Merge pull request #164 from hecrj/feature/custom-runtime

Custom futures executor with `iced_futures`

7 files changed, 121 insertions, 42 deletions

diff --git a/src/application.rs b/src/application.rs
index b940cc17..3a526f1b 100644
--- a/src/application.rs
+++ b/src/application.rs
@@ -1,4 +1,4 @@
-use crate::{window, Command, Element, Settings, Subscription};
+use crate::{window, Command, Element, Executor, Settings, Subscription};
 
 /// An interactive cross-platform application.
 ///
@@ -19,7 +19,7 @@ use crate::{window, Command, Element, Settings, Subscription};
 /// before](index.html#overview). We just need to fill in the gaps:
 ///
 /// ```no_run
-/// use iced::{button, Application, Button, Column, Command, Element, Settings, Text};
+/// use iced::{button, executor, Application, Button, Column, Command, Element, Settings, Text};
 ///
 /// pub fn main() {
 ///     Counter::run(Settings::default())
@@ -39,6 +39,7 @@ use crate::{window, Command, Element, Settings, Subscription};
 /// }
 ///
 /// impl Application for Counter {
+///     type Executor = executor::Null;
 ///     type Message = Message;
 ///
 ///     fn new() -> (Self, Command<Message>) {
@@ -80,6 +81,14 @@ use crate::{window, Command, Element, Settings, Subscription};
 /// }
 /// ```
 pub trait Application: Sized {
+    /// The [`Executor`] that will run commands and subscriptions.
+    ///
+    /// The [`executor::Default`] can be a good starting point!
+    ///
+    /// [`Executor`]: trait.Executor.html
+    /// [`executor::Default`]: executor/struct.Default.html
+    type Executor: Executor;
+
     /// The type of __messages__ your [`Application`] will produce.
     ///
     /// [`Application`]: trait.Application.html
@@ -185,6 +194,7 @@ where
     A: Application,
 {
     type Renderer = iced_wgpu::Renderer;
+    type Executor = A::Executor;
     type Message = A::Message;
 
     fn new() -> (Self, Command<A::Message>) {
diff --git a/src/element.rs b/src/element.rs
new file mode 100644
index 00000000..e5356fb6
--- /dev/null
+++ b/src/element.rs
@@ -0,0 +1,9 @@
+/// A generic widget.
+///
+/// This is an alias of an `iced_native` element with a default `Renderer`.
+#[cfg(not(target_arch = "wasm32"))]
+pub type Element<'a, Message> =
+    iced_winit::Element<'a, Message, iced_wgpu::Renderer>;
+
+#[cfg(target_arch = "wasm32")]
+pub use iced_web::Element;
diff --git a/src/executor.rs b/src/executor.rs
new file mode 100644
index 00000000..cbbd8283
--- /dev/null
+++ b/src/executor.rs
@@ -0,0 +1,54 @@
+//! Choose your preferred executor to power your application.
+pub use crate::common::{executor::Null, Executor};
+
+pub use platform::Default;
+
+#[cfg(not(target_arch = "wasm32"))]
+mod platform {
+    use iced_winit::{executor::ThreadPool, futures, Executor};
+
+    /// A default cross-platform executor.
+    ///
+    /// - On native platforms, it will use a `iced_futures::executor::ThreadPool`.
+    /// - On the Web, it will use `iced_futures::executor::WasmBindgen`.
+    #[derive(Debug)]
+    pub struct Default(ThreadPool);
+
+    impl Executor for Default {
+        fn new() -> Result<Self, futures::io::Error> {
+            Ok(Default(ThreadPool::new()?))
+        }
+
+        fn spawn(
+            &self,
+            future: impl futures::Future<Output = ()> + Send + 'static,
+        ) {
+            self.0.spawn(future);
+        }
+    }
+}
+
+#[cfg(target_arch = "wasm32")]
+mod platform {
+    use iced_web::{executor::WasmBindgen, futures, Executor};
+
+    /// A default cross-platform executor.
+    ///
+    /// - On native platforms, it will use a `iced_futures::executor::ThreadPool`.
+    /// - On the Web, it will use `iced_futures::executor::WasmBindgen`.
+    #[derive(Debug)]
+    pub struct Default(WasmBindgen);
+
+    impl Executor for Default {
+        fn new() -> Result<Self, futures::io::Error> {
+            Ok(Default(WasmBindgen::new()?))
+        }
+
+        fn spawn(
+            &self,
+            future: impl futures::Future<Output = ()> + Send + 'static,
+        ) {
+            self.0.spawn(future);
+        }
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 759dea2f..1da3f549 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -180,18 +180,30 @@
 #![deny(unsafe_code)]
 #![deny(rust_2018_idioms)]
 mod application;
-#[cfg(target_arch = "wasm32")]
-#[path = "web.rs"]
-mod platform;
-#[cfg(not(target_arch = "wasm32"))]
-#[path = "native.rs"]
-mod platform;
+mod element;
 mod sandbox;
 
+pub mod executor;
 pub mod settings;
+pub mod widget;
 pub mod window;
 
+#[doc(no_inline)]
+pub use widget::*;
+
 pub use application::Application;
-pub use platform::*;
+pub use element::Element;
+pub use executor::Executor;
 pub use sandbox::Sandbox;
 pub use settings::Settings;
+
+#[cfg(not(target_arch = "wasm32"))]
+use iced_winit as common;
+
+#[cfg(target_arch = "wasm32")]
+use iced_web as common;
+
+pub use common::{
+    futures, Align, Background, Color, Command, Font, HorizontalAlignment,
+    Length, Space, Subscription, Vector, VerticalAlignment,
+};
diff --git a/src/sandbox.rs b/src/sandbox.rs
index dda4c3f5..2c0332ff 100644
--- a/src/sandbox.rs
+++ b/src/sandbox.rs
@@ -1,4 +1,4 @@
-use crate::{Application, Command, Element, Settings, Subscription};
+use crate::{executor, Application, Command, Element, Settings, Subscription};
 
 /// A sandboxed [`Application`].
 ///
@@ -133,6 +133,7 @@ impl<T> Application for T
 where
     T: Sandbox,
 {
+    type Executor = executor::Null;
     type Message = T::Message;
 
     fn new() -> (Self, Command<T::Message>) {
diff --git a/src/web.rs b/src/web.rs
deleted file mode 100644
index 31f1a6fc..00000000
--- a/src/web.rs
+++ /dev/null
@@ -1 +0,0 @@
-pub use iced_web::*;
diff --git a/src/native.rs b/src/widget.rs
index 35441a3e..7d3a1cef 100644
--- a/src/native.rs
+++ b/src/widget.rs
@@ -1,27 +1,23 @@
-pub use iced_winit::{
-    Align, Background, Color, Command, Font, HorizontalAlignment, Length,
-    Space, Subscription, Vector, VerticalAlignment,
-};
-
-pub mod widget {
-    //! Display information and interactive controls in your application.
-    //!
-    //! # Re-exports
-    //! For convenience, the contents of this module are available at the root
-    //! module. Therefore, you can directly type:
-    //!
-    //! ```
-    //! use iced::{button, Button};
-    //! ```
-    //!
-    //! # Stateful widgets
-    //! Some widgets need to keep track of __local state__.
-    //!
-    //! These widgets have their own module with a `State` type. For instance, a
-    //! [`TextInput`] has some [`text_input::State`].
-    //!
-    //! [`TextInput`]: text_input/struct.TextInput.html
-    //! [`text_input::State`]: text_input/struct.State.html
+//! Display information and interactive controls in your application.
+//!
+//! # Re-exports
+//! For convenience, the contents of this module are available at the root
+//! module. Therefore, you can directly type:
+//!
+//! ```
+//! use iced::{button, Button};
+//! ```
+//!
+//! # Stateful widgets
+//! Some widgets need to keep track of __local state__.
+//!
+//! These widgets have their own module with a `State` type. For instance, a
+//! [`TextInput`] has some [`text_input::State`].
+//!
+//! [`TextInput`]: text_input/struct.TextInput.html
+//! [`text_input::State`]: text_input/struct.State.html
+#[cfg(not(target_arch = "wasm32"))]
+mod platform {
     pub use iced_wgpu::widget::*;
 
     pub mod image {
@@ -56,11 +52,9 @@ pub mod widget {
         iced_winit::Row<'a, Message, iced_wgpu::Renderer>;
 }
 
-#[doc(no_inline)]
-pub use widget::*;
+#[cfg(target_arch = "wasm32")]
+mod platform {
+    pub use iced_web::widget::*;
+}
 
-/// A generic widget.
-///
-/// This is an alias of an `iced_native` element with a default `Renderer`.
-pub type Element<'a, Message> =
-    iced_winit::Element<'a, Message, iced_wgpu::Renderer>;
+pub use platform::*;