allow RepaintSignal: ?Sync

eframe/CHANGELOG.md

@@ -13,6 +13,7 @@ NOTE: [`egui_web`](../egui_web/CHANGELOG.md), [`egui-winit`](../egui-winit/CHANG
 * Added `App::on_exit_event` ([#1038](https://github.com/emilk/egui/pull/1038))
 * Shift-scroll will now result in horizontal scrolling on all platforms ([#1136](https://github.com/emilk/egui/pull/1136)).
 * Log using the `tracing` crate. Log to stdout by adding `tracing_subscriber::fmt::init();` to your `main` ([#1192](https://github.com/emilk/egui/pull/1192)).
+* `backend::RepaintSignal` no longer requires `Sync`, but now requires new method `dyn_clone` ([#1187](https://github.com/emilk/egui/pull/1187)).
 
 
 ## 0.16.0 - 2021-12-29

egui-winit/CHANGELOG.md

@@ -10,6 +10,7 @@ All notable changes to the `egui-winit` integration will be noted in this file.
 * Shift-scroll will now result in horizontal scrolling on all platforms ([#1136](https://github.com/emilk/egui/pull/1136)).
 * Require knowledge about max texture side (e.g. `GL_MAX_TEXTURE_SIZE`)) ([#1154](https://github.com/emilk/egui/pull/1154)).
 * Fixed `enable_drag` for Windows. Now called only once just after left click ([#1108](https://github.com/emilk/egui/pull/1108)).
+* Updated `EpiIntegration::new` signature ([#1187](https://github.com/emilk/egui/pull/1187)).
 
 
 ## 0.16.0 - 2021-12-29

egui-winit/src/epi.rs

@@ -211,14 +211,17 @@ pub struct EpiIntegration {
 }
 
 impl EpiIntegration {
-    pub fn new(
+    pub fn new<S>(
         integration_name: &'static str,
         max_texture_side: usize,
         window: &winit::window::Window,
-        repaint_signal: std::sync::Arc<dyn epi::backend::RepaintSignal>,
+        repaint_signal: S,
         persistence: crate::epi::Persistence,
         app: Box<dyn epi::App>,
-    ) -> Self {
+    ) -> Self
+    where
+        S: epi::backend::RepaintSignal,
+    {
         let egui_ctx = egui::Context::default();
 
         *egui_ctx.memory() = persistence.load_memory().unwrap_or_default();

egui_glium/src/epi_backend.rs

@@ -4,13 +4,16 @@ use crate::*;
 
 struct RequestRepaintEvent;
 
-struct GliumRepaintSignal(
-    std::sync::Mutex<glutin::event_loop::EventLoopProxy<RequestRepaintEvent>>,
-);
+#[derive(Clone)]
+struct GliumRepaintSignal(glutin::event_loop::EventLoopProxy<RequestRepaintEvent>);
 
 impl epi::backend::RepaintSignal for GliumRepaintSignal {
     fn request_repaint(&self) {
-        self.0.lock().unwrap().send_event(RequestRepaintEvent).ok();
+        self.0.send_event(RequestRepaintEvent).ok();
+    }
+
+    fn dyn_clone(&self) -> Box<dyn epi::backend::RepaintSignal> {
+        Box::new(self.clone())
     }
 }
 
@@ -40,9 +43,7 @@ pub fn run(app: Box<dyn epi::App>, native_options: &epi::NativeOptions) -> ! {
     let event_loop = glutin::event_loop::EventLoop::with_user_event();
     let display = create_display(window_builder, &event_loop);
 
-    let repaint_signal = std::sync::Arc::new(GliumRepaintSignal(std::sync::Mutex::new(
-        event_loop.create_proxy(),
-    )));
+    let repaint_signal = GliumRepaintSignal(event_loop.create_proxy());
 
     let mut painter = crate::Painter::new(&display);
     let mut integration = egui_winit::epi::EpiIntegration::new(

egui_glow/src/epi_backend.rs

@@ -3,11 +3,16 @@ use egui_winit::winit;
 
 struct RequestRepaintEvent;
 
-struct GlowRepaintSignal(std::sync::Mutex<winit::event_loop::EventLoopProxy<RequestRepaintEvent>>);
+#[derive(Clone)]
+struct GlowRepaintSignal(winit::event_loop::EventLoopProxy<RequestRepaintEvent>);
 
 impl epi::backend::RepaintSignal for GlowRepaintSignal {
     fn request_repaint(&self) {
-        self.0.lock().unwrap().send_event(RequestRepaintEvent).ok();
+        self.0.send_event(RequestRepaintEvent).ok();
+    }
+
+    fn dyn_clone(&self) -> Box<dyn epi::backend::RepaintSignal> {
+        Box::new(self.clone())
     }
 }
 
@@ -55,9 +60,7 @@ pub fn run(app: Box<dyn epi::App>, native_options: &epi::NativeOptions) -> ! {
     let event_loop = winit::event_loop::EventLoop::with_user_event();
     let (gl_window, gl) = create_display(window_builder, &event_loop);
 
-    let repaint_signal = std::sync::Arc::new(GlowRepaintSignal(std::sync::Mutex::new(
-        event_loop.create_proxy(),
-    )));
+    let repaint_signal = GlowRepaintSignal(event_loop.create_proxy());
 
     let mut painter = crate::Painter::new(&gl, None, "")
         .unwrap_or_else(|error| panic!("some OpenGL error occurred {}\n", error));

egui_web/CHANGELOG.md

@@ -10,6 +10,7 @@ All notable changes to the `egui_web` integration will be noted in this file.
 * Shift-scroll will now result in horizontal scrolling ([#1136](https://github.com/emilk/egui/pull/1136)).
 * Updated `epi::IntegrationInfo::web_location_hash` on `hashchange` event ([#1140](https://github.com/emilk/egui/pull/1140)).
 * Panics will now be logged using `console.error`.
+* Updated `NeedRepaint` implementation ([#1187](https://github.com/emilk/egui/pull/1187)).
 
 
 ## 0.16.0 - 2021-12-29

egui_web/src/backend.rs

@@ -55,11 +55,12 @@ impl WebInput {
 
 use std::sync::atomic::Ordering::SeqCst;
 
-pub struct NeedRepaint(std::sync::atomic::AtomicBool);
+#[derive(Clone)]
+pub struct NeedRepaint(std::sync::Arc<std::sync::atomic::AtomicBool>);
 
 impl Default for NeedRepaint {
     fn default() -> Self {
-        Self(true.into())
+        Self(std::sync::Arc::new(true.into()))
     }
 }
 
@@ -77,6 +78,10 @@ impl epi::backend::RepaintSignal for NeedRepaint {
     fn request_repaint(&self) {
         self.0.store(true, SeqCst);
     }
+
+    fn dyn_clone(&self) -> Box<dyn epi::backend::RepaintSignal> {
+        Box::new(self.clone())
+    }
 }
 
 // ----------------------------------------------------------------------------
@@ -87,7 +92,7 @@ pub struct AppRunner {
     painter: Box<dyn Painter>,
     pub(crate) input: WebInput,
     app: Box<dyn epi::App>,
-    pub(crate) needs_repaint: std::sync::Arc<NeedRepaint>,
+    pub(crate) needs_repaint: NeedRepaint,
     storage: LocalStorage,
     last_save_time: f64,
     screen_reader: crate::screen_reader::ScreenReader,
@@ -102,7 +107,7 @@ impl AppRunner {
 
         let prefer_dark_mode = crate::prefer_dark_mode();
 
-        let needs_repaint: std::sync::Arc<NeedRepaint> = Default::default();
+        let needs_repaint = NeedRepaint::default();
 
         let frame = epi::Frame::new(epi::backend::FrameData {
             info: epi::IntegrationInfo {

epi/src/lib.rs

@@ -290,7 +290,10 @@ pub struct Frame(pub Arc<Mutex<backend::FrameData>>);
 impl Frame {
     /// Create a `Frame` - called by the integration.
     #[doc(hidden)]
-    pub fn new(frame_data: backend::FrameData) -> Self {
+    pub fn new<S>(frame_data: backend::FrameData<S>) -> Self
+    where
+        S: backend::RepaintSignal,
+    {
         Self(Arc::new(Mutex::new(frame_data)))
     }
 
@@ -448,23 +451,27 @@ pub mod backend {
     use super::*;
 
     /// How to signal the [`egui`] integration that a repaint is required.
-    pub trait RepaintSignal: Send + Sync {
+    pub trait RepaintSignal: Send + std::any::Any {
         /// This signals the [`egui`] integration that a repaint is required.
         ///
         /// Call this e.g. when a background process finishes in an async context and/or background thread.
         fn request_repaint(&self);
+
+        /// Method to dynamically clone self. Calling [`RepaintSignal::request_repaint`] on a clone should
+        /// be equivalent to a call on the original value. You may use [`Box::downcast`] to get a concrete type.
+        fn dyn_clone(&self) -> Box<dyn RepaintSignal>;
     }
 
     /// The data required by [`Frame`] each frame.
-    pub struct FrameData {
+    pub struct FrameData<S: ?Sized + RepaintSignal = dyn RepaintSignal> {
         /// Information about the integration.
         pub info: IntegrationInfo,
 
         /// Where the app can issue commands back to the integration.
         pub output: AppOutput,
 
-        /// If you need to request a repaint from another thread, clone this and send it to that other thread.
-        pub repaint_signal: std::sync::Arc<dyn RepaintSignal>,
+        /// If you need to request a repaint from another thread, [`RepaintSignal::dyn_clone`] this and send it to that other thread.
+        pub repaint_signal: S,
     }
 
     /// Action that can be taken by the user app.