Default to std::sync::mpsc, introduce crossbeam feature (#775)

* create/update-signal fn use std channel, introduce `crossbeam feature`

* fmt

* apply requested changes

* simplify feature by rename, add changelog

* another rename

---------

Co-authored-by: Karol <[email protected]>

CHANGELOG.md

@@ -1,7 +1,7 @@
 # Changelog
 
 ## Unreleased
-
+- Use by default `std::sync::mpsc::channel` and place crossbeam behind the `crossbeam` feature [#775](https://github.com/lapce/floem/pull/775)
 
 ## [0.2.0] - 2024-11-13
 

Cargo.toml

@@ -58,7 +58,6 @@ tokio = { version = "1", features = ["sync", "rt"], optional = true }
 raw-window-handle = { workspace = true }
 unicode-segmentation = "1.10.0"
 peniko = { workspace = true }
-crossbeam-channel = "0.5.6"
 im-rc = "15.1.0"
 serde = { workspace = true, optional = true }
 lapce-xi-rope = { workspace = true, optional = true }
@@ -81,7 +80,7 @@ image = { workspace = true }
 im = { workspace = true }
 winit = { workspace = true }
 futures = { version = "0.3.30", optional = true }
-crossbeam = "0.8"
+crossbeam = { version = "0.8", optional = true }
 
 [target.'cfg(any(target_os = "windows", target_os = "macos"))'.dependencies]
 muda = { workspace = true }
@@ -147,3 +146,5 @@ tokio = ["dep:tokio"]
 rfd-async-std = ["dep:rfd", "rfd/async-std"]
 rfd-tokio = ["dep:rfd", "rfd/tokio"]
 futures = ["dep:futures"]
+
+crossbeam = [ "dep:crossbeam", "floem_renderer/crossbeam" ]

renderer/Cargo.toml

@@ -16,8 +16,11 @@ cosmic-text = { version = "0.12.1", features = ["shape-run-cache"] }
 
 winit = { workspace = true }
 wgpu = { workspace = true }
-crossbeam = { version = "0.8" }
+crossbeam = { version = "0.8", optional = true }
 futures = "0.3.26"
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 wasm-bindgen-futures = { version = "0.4" }
+
+[features]
+crossbeam = [ "dep:crossbeam" ]

renderer/src/gpu_resources.rs

@@ -10,7 +10,10 @@
 
 use std::{future::Future, sync::Arc};
 
-use crossbeam::channel::{self, Receiver};
+#[cfg(feature = "crossbeam")]
+use crossbeam::channel::{bounded as sync_channel, Receiver};
+#[cfg(not(feature = "crossbeam"))]
+use std::sync::mpsc::{sync_channel, Receiver};
 use wgpu::Backends;
 
 use winit::window::{Window, WindowId};
@@ -53,7 +56,8 @@ impl GpuResources {
         });
         // Channel passing to do async out-of-band within the winit event_loop since wasm can't
         // execute futures with a return value
-        let (tx, rx) = channel::bounded(1);
+        let (tx, rx) = sync_channel(1);
+
         spawn({
             async move {
                 let surface = match instance.create_surface(Arc::clone(&window)) {

src/app.rs

@@ -1,6 +1,10 @@
 use std::{cell::RefCell, rc::Rc};
 
-use crossbeam_channel::{Receiver, Sender};
+#[cfg(feature = "crossbeam")]
+use crossbeam::channel::{unbounded as channel, Receiver, Sender};
+#[cfg(not(feature = "crossbeam"))]
+use std::sync::mpsc::{channel, Receiver, Sender};
+
 use floem_reactive::WriteSignal;
 use parking_lot::Mutex;
 use raw_window_handle::HasDisplayHandle;
@@ -160,7 +164,8 @@ impl Application {
         crate::app_delegate::set_app_delegate();
 
         let event_loop_proxy = event_loop.create_proxy();
-        let (sender, receiver) = crossbeam_channel::unbounded();
+        let (sender, receiver) = channel();
+
         *EVENT_LOOP_PROXY.lock() = Some((event_loop_proxy.clone(), sender));
         unsafe {
             Clipboard::init(event_loop.display_handle().unwrap().as_raw());

src/context.rs

@@ -14,6 +14,11 @@ use std::time::{Duration, Instant};
 #[cfg(target_arch = "wasm32")]
 use web_time::{Duration, Instant};
 
+#[cfg(feature = "crossbeam")]
+use crossbeam::channel::Receiver;
+#[cfg(not(feature = "crossbeam"))]
+use std::sync::mpsc::Receiver;
+
 use taffy::prelude::NodeId;
 
 use crate::animate::{AnimStateKind, RepeatMode};
@@ -1210,7 +1215,7 @@ pub enum PaintState {
     /// The renderer is not yet initialized. This state is used to wait for the GPU resources to be acquired.
     PendingGpuResources {
         window: Arc<dyn Window>,
-        rx: crossbeam::channel::Receiver<Result<GpuResources, GpuResourceError>>,
+        rx: Receiver<Result<GpuResources, GpuResourceError>>,
         font_embolden: f32,
         /// This field holds an instance of `Renderer::Uninitialized` until the GPU resources are acquired,
         /// which will be returned in `PaintState::renderer` and `PaintState::renderer_mut`.
@@ -1227,7 +1232,7 @@ pub enum PaintState {
 impl PaintState {
     pub fn new(
         window: Arc<dyn Window>,
-        rx: crossbeam::channel::Receiver<Result<GpuResources, GpuResourceError>>,
+        rx: Receiver<Result<GpuResources, GpuResourceError>>,
         scale: f64,
         size: Size,
         font_embolden: f32,

src/ext_event.rs

@@ -12,11 +12,16 @@ use crate::{
     Application,
 };
 
-#[derive(Debug)]
+#[cfg(feature = "crossbeam")]
+use crossbeam::channel::Receiver;
+#[cfg(not(feature = "crossbeam"))]
+use std::sync::mpsc::Receiver;
+
 /// # SAFETY
 ///
 /// **DO NOT USE THIS** trigger except for when using with `create_ext_action` or when you guarantee that
 /// the signal is never used from a different thread than it was created on.
+#[derive(Debug)]
 pub struct ExtSendTrigger {
     signal: RwSignal<()>,
 }
@@ -123,7 +128,7 @@ pub fn create_ext_action<T: Send + 'static>(
 
 pub fn update_signal_from_channel<T: Send + 'static>(
     writer: WriteSignal<Option<T>>,
-    rx: crossbeam_channel::Receiver<T>,
+    rx: Receiver<T>,
 ) {
     let cx = Scope::new();
     let trigger = with_scope(cx, ExtSendTrigger::new);
@@ -158,9 +163,7 @@ pub fn update_signal_from_channel<T: Send + 'static>(
     });
 }
 
-pub fn create_signal_from_channel<T: Send + 'static>(
-    rx: crossbeam_channel::Receiver<T>,
-) -> ReadSignal<Option<T>> {
+pub fn create_signal_from_channel<T: Send + 'static>(rx: Receiver<T>) -> ReadSignal<Option<T>> {
     let cx = Scope::new();
     let trigger = with_scope(cx, ExtSendTrigger::new);