Fix up some examples (#3614)

crates/eframe/src/native/epi_integration.rs

@@ -229,22 +229,14 @@ impl EpiIntegration {
 
     pub fn on_window_event(
         &mut self,
-        app: &mut dyn epi::App,
         event: &winit::event::WindowEvent<'_>,
         egui_winit: &mut egui_winit::State,
-        viewport_id: ViewportId,
     ) -> EventResponse {
         crate::profile_function!(egui_winit::short_window_event_description(event));
 
         use winit::event::{ElementState, MouseButton, WindowEvent};
 
         match event {
-            WindowEvent::CloseRequested => {
-                if viewport_id == ViewportId::ROOT {
-                    self.close = app.on_close_event();
-                    log::debug!("App::on_close_event returned {}", self.close);
-                }
-            }
             WindowEvent::Destroyed => {
                 log::debug!("Received WindowEvent::Destroyed");
                 self.close = true;
@@ -281,23 +273,32 @@ impl EpiIntegration {
     ) -> egui::FullOutput {
         raw_input.time = Some(self.beginning.elapsed().as_secs_f64());
 
+        let close_requested = raw_input.viewport().close_requested();
+
         let full_output = self.egui_ctx.run(raw_input, |egui_ctx| {
             if let Some(viewport_ui_cb) = viewport_ui_cb {
                 // Child viewport
                 crate::profile_scope!("viewport_callback");
                 viewport_ui_cb(egui_ctx);
             } else {
-                // Root viewport
-                if egui_ctx.input(|i| i.viewport().close_requested()) {
-                    self.close = app.on_close_event();
-                    log::debug!("App::on_close_event returned {}", self.close);
-                }
-
                 crate::profile_scope!("App::update");
                 app.update(egui_ctx, &mut self.frame);
             }
         });
 
+        let is_root_viewport = viewport_ui_cb.is_none();
+        if is_root_viewport && close_requested {
+            let canceled = full_output.viewport_output[&ViewportId::ROOT]
+                .commands
+                .contains(&egui::ViewportCommand::CancelClose);
+            if canceled {
+                log::debug!("Closing of root viewport canceled with ViewportCommand::CancelClose");
+            } else {
+                log::debug!("Closing root viewport (ViewportCommand::CancelClose was not sent)");
+                self.close = true;
+            }
+        }
+
         self.pending_full_output.append(full_output);
         std::mem::take(&mut self.pending_full_output)
     }

crates/eframe/src/native/glow_integration.rs

@@ -568,6 +568,7 @@ impl GlowWinitRunning {
         } = &mut *glutin;
 
         let viewport = viewports.get_mut(&viewport_id).unwrap();
+        viewport.info.events.clear(); // they should have been processed
         let window = viewport.window.as_ref().unwrap();
         let gl_surface = viewport.gl_surface.as_ref().unwrap();
         let egui_winit = viewport.egui_winit.as_mut().unwrap();
@@ -748,12 +749,9 @@ impl GlowWinitRunning {
         };
         if let Some(viewport_id) = viewport_id {
             if let Some(viewport) = glutin.viewports.get_mut(&viewport_id) {
-                event_response = self.integration.on_window_event(
-                    self.app.as_mut(),
-                    event,
-                    viewport.egui_winit.as_mut().unwrap(),
-                    viewport.ids.this,
-                );
+                event_response = self
+                    .integration
+                    .on_window_event(event, viewport.egui_winit.as_mut().unwrap());
             }
         }
 
@@ -1340,6 +1338,7 @@ fn render_immediate_viewport(
     let Some(viewport) = viewports.get_mut(&ids.this) else {
         return;
     };
+    viewport.info.events.clear(); // they should have been processed
 
     let Some(winit_state) = &mut viewport.egui_winit else {
         return;

crates/eframe/src/native/wgpu_integration.rs

@@ -565,6 +565,8 @@ impl WgpuWinitRunning {
             return EventResult::Wait;
         };
 
+        viewport.info.events.clear(); // they should have been processed
+
         let Viewport {
             window: Some(window),
             egui_winit: Some(egui_winit),
@@ -657,8 +659,8 @@ impl WgpuWinitRunning {
 
         let Self {
             integration,
-            app,
             shared,
+            ..
         } = self;
         let mut shared = shared.borrow_mut();
 
@@ -742,9 +744,10 @@ impl WgpuWinitRunning {
         let event_response = viewport_id
             .and_then(|viewport_id| {
                 shared.viewports.get_mut(&viewport_id).and_then(|viewport| {
-                    viewport.egui_winit.as_mut().map(|egui_winit| {
-                        integration.on_window_event(app.as_mut(), event, egui_winit, viewport_id)
-                    })
+                    viewport
+                        .egui_winit
+                        .as_mut()
+                        .map(|egui_winit| integration.on_window_event(event, egui_winit))
                 })
             })
             .unwrap_or_default();
@@ -923,6 +926,7 @@ fn render_immediate_viewport(
     let Some(viewport) = viewports.get_mut(&ids.this) else {
         return;
     };
+    viewport.info.events.clear(); // they should have been processed
     let Some(winit_state) = &mut viewport.egui_winit else {
         return;
     };