Hide AppRunner

/ · May 16, 2023 · May 16, 2023 · May 16, 2023 · May 16, 2023 · May 16, 2023
commit e289c70d4252e9bd152aff2a199325edfa0f69b1
diff --git a/crates/eframe/src/web/app_runner.rs b/crates/eframe/src/web/app_runner.rs
@@ -12,7 +12,6 @@ pub struct AppRunner {
     pub(crate) input: super::WebInput,
     app: Box<dyn epi::App>,
     pub(crate) needs_repaint: std::sync::Arc<NeedRepaint>,
-    pub(crate) is_destroyed: std::sync::Arc<super::IsDestroyed>,
     last_save_time: f64,
     screen_reader: super::screen_reader::ScreenReader,
     pub(crate) text_cursor_pos: Option<egui::Pos2>,
@@ -105,7 +104,6 @@ impl AppRunner {
             input: Default::default(),
             app,
             needs_repaint,
-            is_destroyed: Default::default(),
             last_save_time: now_sec(),
             screen_reader: Default::default(),
             text_cursor_pos: None,
@@ -154,32 +152,26 @@ impl AppRunner {
         self.painter.canvas_id()
     }
 
-    pub fn warm_up(&mut self) -> Result<(), JsValue> {
+    pub fn warm_up(&mut self) {
         if self.app.warm_up_enabled() {
             let saved_memory: egui::Memory = self.egui_ctx.memory(|m| m.clone());
             self.egui_ctx
                 .memory_mut(|m| m.set_everything_is_visible(true));
-            self.logic()?;
+            self.logic();
             self.egui_ctx.memory_mut(|m| *m = saved_memory); // We don't want to remember that windows were huge.
             self.egui_ctx.clear_animations();
         }
-        Ok(())
     }
 
-    pub fn destroy(&mut self) {
-        if self.is_destroyed.fetch() {
-            log::warn!("App was destroyed already");
-        } else {
-            log::debug!("Destroying");
-            self.painter.destroy();
-            self.is_destroyed.set_true();
-        }
+    pub fn destroy(mut self) {
+        log::debug!("Destroying AppRunner");
+        self.painter.destroy();
     }
 
     /// Returns how long to wait until the next repaint.
     ///
     /// Call [`Self::paint`] later to paint
-    pub fn logic(&mut self) -> Result<(std::time::Duration, Vec<egui::ClippedPrimitive>), JsValue> {
+    pub fn logic(&mut self) -> (std::time::Duration, Vec<egui::ClippedPrimitive>) {
         let frame_start = now_sec();
 
         super::resize_canvas_to_screen_size(self.canvas_id(), self.app.max_size_points());
@@ -206,7 +198,8 @@ impl AppRunner {
         }
 
         self.frame.info.cpu_usage = Some((now_sec() - frame_start) as f32);
-        Ok((repaint_after, clipped_primitives))
+
+        (repaint_after, clipped_primitives)
     }
 
     /// Paint the results of the last call to [`Self::logic`].

diff --git a/crates/eframe/src/web/app_runner_ref.rs b/crates/eframe/src/web/app_runner_ref.rs
@@ -2,36 +2,71 @@ use std::{cell::RefCell, rc::Rc};
 
 use wasm_bindgen::prelude::*;
 
-use crate::App;
+use crate::{epi, App};
 
-use super::{AppRunner, PanicHandler};
+use super::{events, AppRunner, PanicHandler};
 
 /// This is how we access the [`AppRunner`].
+///
 /// This is cheap to clone.
 #[derive(Clone)]
 pub struct AppRunnerRef {
-    /// If we ever panic during running, this mutex is poisoned.
-    /// So before we use it, we need to check `panic_handler`.
-    runner: Rc<RefCell<AppRunner>>,
-
     /// Have we ever panicked?
     panic_handler: PanicHandler,
 
+    /// If we ever panic during running, this RefCell is poisoned.
+    /// So before we use it, we need to check [`Self::panic_handler`].
+    runner: Rc<RefCell<Option<AppRunner>>>,
+
     /// In case of a panic, unsubscribe these.
     /// They have to be in a separate `Rc` so that we don't need to pass them to
     /// the panic handler, since they aren't `Send`.
     events_to_unsubscribe: Rc<RefCell<Vec<EventToUnsubscribe>>>,
 }
 
 impl AppRunnerRef {
-    pub fn new(panic_handler: PanicHandler, runner: AppRunner) -> Self {
+    pub fn new(panic_handler: PanicHandler) -> Self {
+        #[cfg(not(web_sys_unstable_apis))]
+        log::warn!(
+            "eframe compiled without RUSTFLAGS='--cfg=web_sys_unstable_apis'. Copying text won't work."
+        );
+
         Self {
             panic_handler,
-            runner: Rc::new(RefCell::new(runner)),
+            runner: Rc::new(RefCell::new(None)),
             events_to_unsubscribe: Rc::new(RefCell::new(Default::default())),
         }
     }
 
+    pub async fn initialize(
+        &self,
+        canvas_id: &str,
+        web_options: crate::WebOptions,
+        app_creator: epi::AppCreator,
+    ) -> Result<(), JsValue> {
+        self.destroy();
+
+        let follow_system_theme = web_options.follow_system_theme;
+
+        let mut runner = AppRunner::new(canvas_id, web_options, app_creator).await?;
+        runner.warm_up();
+        self.runner.replace(Some(runner));
+
+        // Install events:
+        {
+            events::install_canvas_events(self)?;
+            events::install_document_events(self)?;
+            events::install_window_events(self)?;
+            super::text_agent::install_text_agent(self)?;
+            if follow_system_theme {
+                events::install_color_scheme_change_event(self)?;
+            }
+            events::paint_and_schedule(self)?;
+        }
+
+        Ok(())
+    }
+
     fn unsubscribe_from_all_events(&self) {
         let events_to_unsubscribe: Vec<_> =
             std::mem::take(&mut *self.events_to_unsubscribe.borrow_mut());
@@ -48,7 +83,8 @@ impl AppRunnerRef {
 
     pub fn destroy(&self) {
         self.unsubscribe_from_all_events();
-        if let Some(mut runner) = self.try_lock() {
+
+        if let Some(runner) = self.runner.replace(None) {
             runner.destroy();
         }
     }
@@ -63,11 +99,8 @@ impl AppRunnerRef {
             None
         } else {
             let lock = self.runner.try_borrow_mut().ok()?;
-            if lock.is_destroyed.fetch() {
-                None
-            } else {
-                Some(lock)
-            }
+            std::cell::RefMut::filter_map(lock, |lock| -> Option<&mut AppRunner> { lock.as_mut() })
+                .ok()
         }
     }
 

diff --git a/crates/eframe/src/web/events.rs b/crates/eframe/src/web/events.rs
@@ -7,7 +7,7 @@ pub fn paint_and_schedule(runner_ref: &AppRunnerRef) -> Result<(), JsValue> {
     fn paint_if_needed(runner: &mut AppRunner) -> Result<(), JsValue> {
         if runner.needs_repaint.when_to_repaint() <= now_sec() {
             runner.needs_repaint.clear();
-            let (repaint_after, clipped_primitives) = runner.logic()?;
+            let (repaint_after, clipped_primitives) = runner.logic();
             runner.paint(&clipped_primitives)?;
             runner
                 .needs_repaint

diff --git a/crates/eframe/src/web/mod.rs b/crates/eframe/src/web/mod.rs
@@ -13,7 +13,7 @@ pub mod storage;
 mod text_agent;
 mod web_logger;
 
-pub use app_runner::AppRunner;
+pub(crate) use app_runner::AppRunner;
 pub use app_runner_ref::AppRunnerRef;
 pub use panic_handler::{PanicHandler, PanicSummary};
 pub use web_logger::WebLogger;
@@ -87,28 +87,10 @@ pub async fn start_web(
     web_options: crate::WebOptions,
     app_creator: epi::AppCreator,
 ) -> Result<AppRunnerRef, JsValue> {
-    #[cfg(not(web_sys_unstable_apis))]
-    log::warn!(
-        "eframe compiled without RUSTFLAGS='--cfg=web_sys_unstable_apis'. Copying text won't work."
-    );
-    let follow_system_theme = web_options.follow_system_theme;
-
-    let mut runner = AppRunner::new(canvas_id, web_options, app_creator).await?;
-    runner.warm_up()?;
-    let runner_ref = AppRunnerRef::new(panic_handler, runner);
-
-    // Install events:
-    {
-        events::install_canvas_events(&runner_ref)?;
-        events::install_document_events(&runner_ref)?;
-        events::install_window_events(&runner_ref)?;
-        text_agent::install_text_agent(&runner_ref)?;
-        if follow_system_theme {
-            events::install_color_scheme_change_event(&runner_ref)?;
-        }
-        events::paint_and_schedule(&runner_ref)?;
-    }
-
+    let runner_ref = AppRunnerRef::new(panic_handler);
+    runner_ref
+        .initialize(canvas_id, web_options, app_creator)
+        .await?;
     Ok(runner_ref)
 }
 

diff --git a/crates/eframe/src/web/panic_handler.rs b/crates/eframe/src/web/panic_handler.rs
@@ -6,6 +6,8 @@ use wasm_bindgen::prelude::*;
 /// Detects panics, logs them using `console.error`, and stores the panics message and callstack.
 ///
 /// This lets you query `PanicHandler` for the panic message (if any) so you can show it in the HTML.
+///
+/// Chep to clone (ref-counted).
 #[derive(Clone)]
 pub struct PanicHandler(Arc<Mutex<PanicHandlerInner>>);