From 7c65ba96bb499e980499e7c71917d6fb82a78385 Mon Sep 17 00:00:00 2001
From: Matt Hunzinger <matthunz2@gmail.com>
Date: Sat, 7 Dec 2024 12:07:32 -0500
Subject: [PATCH] feat: add support for reactive Bevy desktop apps

---
 Cargo.lock          |  1 +
 Cargo.toml          |  3 ++-
 examples/counter.rs |  2 ++
 src/ecs/mod.rs      | 24 +++++++++++++++++++++++-
 4 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index ec88645..5834d45 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -78,6 +78,7 @@ dependencies = [
  "bevy_time",
  "bevy_ui",
  "bevy_utils",
+ "bevy_winit",
  "crossbeam-queue",
  "futures",
  "hashbrown 0.15.2",
diff --git a/Cargo.toml b/Cargo.toml
index e4eb953..a02118e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,7 +8,7 @@ repository = "https://github.com/actuate-rs/actuate"
 
 [features]
 animation = ["ecs", "dep:bevy_math", "dep:bevy_time", "dep:tokio"]
-ecs = ["dep:bevy_app", "dep:bevy_ecs", "dep:bevy_hierarchy", "dep:bevy_utils"]
+ecs = ["std", "dep:bevy_app", "dep:bevy_ecs", "dep:bevy_hierarchy", "dep:bevy_utils", "dep:bevy_winit"]
 executor = ["std", "dep:tokio"]
 material = ["ecs", "picking", "dep:bevy_color", "dep:bevy_text", "dep:bevy_ui"]
 picking = ["dep:bevy_picking"]
@@ -37,6 +37,7 @@ bevy_text = { version = "0.15.0", optional = true }
 bevy_time = { version = "0.15.0", optional = true }
 bevy_ui = { version = "0.15.0", optional = true }
 bevy_utils = { version = "0.15.0", optional = true }
+bevy_winit = { version = "0.15.0", optional = true }
 crossbeam-queue = { version = "0.3.11", default-features = false, features = ["alloc"] }
 futures = "0.3.31"
 hashbrown = "0.15.2"
diff --git a/examples/counter.rs b/examples/counter.rs
index 7500786..4dc4966 100644
--- a/examples/counter.rs
+++ b/examples/counter.rs
@@ -2,6 +2,7 @@
 
 use actuate::prelude::*;
 use bevy::prelude::*;
+use bevy_winit::WinitSettings;
 
 // Counter composable.
 #[derive(Data)]
@@ -44,6 +45,7 @@ fn setup(mut commands: Commands) {
 fn main() {
     App::new()
         .add_plugins((DefaultPlugins, ActuatePlugin))
+        .insert_resource(WinitSettings::desktop_app())
         .add_systems(Startup, setup)
         .run();
 }
diff --git a/src/ecs/mod.rs b/src/ecs/mod.rs
index d7a4877..3266995 100644
--- a/src/ecs/mod.rs
+++ b/src/ecs/mod.rs
@@ -13,6 +13,7 @@ use bevy_ecs::{
     world::{CommandQueue, World},
 };
 use bevy_utils::HashMap;
+use bevy_winit::{EventLoopProxy, EventLoopProxyWrapper, WakeUp};
 use core::fmt;
 use slotmap::{DefaultKey, SlotMap};
 use std::{
@@ -20,6 +21,8 @@ use std::{
     collections::BTreeSet,
     mem, ptr,
     rc::Rc,
+    sync::Arc,
+    task::{Context, Wake, Waker},
 };
 
 #[cfg(feature = "picking")]
@@ -186,6 +189,16 @@ impl<C: Compose> Compose for CompositionContent<C> {
     }
 }
 
+struct RuntimeWaker {
+    proxy: EventLoopProxy<WakeUp>,
+}
+
+impl Wake for RuntimeWaker {
+    fn wake(self: Arc<Self>) {
+        self.proxy.send_event(WakeUp).unwrap();
+    }
+}
+
 fn compose(world: &mut World) {
     RUNTIME_CONTEXT.with(|runtime_cx| {
         let mut cell = runtime_cx.borrow_mut();
@@ -217,11 +230,20 @@ fn compose(world: &mut World) {
     rt.commands.borrow_mut().apply(world);
     drop(rt);
 
+    let proxy = (*world
+        .get_resource::<EventLoopProxyWrapper<WakeUp>>()
+        .unwrap())
+    .clone();
     let rt = &mut *world.non_send_resource_mut::<Runtime>();
     let mut composers = rt.composers.borrow_mut();
     for rt_composer in composers.values_mut() {
+        let waker = Waker::from(Arc::new(RuntimeWaker {
+            proxy: proxy.clone(),
+        }));
+        let mut cx = Context::from_waker(&waker);
+
         // TODO handle composition error.
-        let _ = rt_composer.composer.try_compose();
+        let _ = rt_composer.composer.poll_compose(&mut cx);
     }
 }