chore: avoid unsafe in examples

By using `OwnedDisplayHandle`, which uses reference-counting, instead of
`DisplayHandle<'static>` (where the user has to guarantee that the
Application doesn't outlive the event loop).

winit/Cargo.toml

@@ -76,9 +76,13 @@ winit-core.workspace = true
 
 [dev-dependencies]
 image = { workspace = true, features = ["png"] }
-softbuffer.workspace = true
 tracing = { workspace = true, features = ["log"] }
 tracing-subscriber = { workspace = true, features = ["env-filter"] }
+# Launching a window without drawing to it has unpredictable results varying from platform to
+# platform. We use the `softbuffer` crate in our examples because of its ease of use to avoid
+# confusion around this. `glutin` or `wgpu` could also be used to fill the window buffer, but they
+# are more complicated to set up.
+softbuffer.workspace = true
 
 [target.'cfg(target_os = "android")'.dependencies]
 winit-android.workspace = true

winit/examples/application.rs

@@ -15,7 +15,6 @@ use std::time::Instant;
 use std::{fmt, mem};
 
 use cursor_icon::CursorIcon;
-use rwh_06::{DisplayHandle, HasDisplayHandle};
 use softbuffer::{Context, Surface};
 use tracing::{error, info};
 #[cfg(web_platform)]
@@ -25,7 +24,7 @@ use winit::cursor::{Cursor, CustomCursor, CustomCursorSource};
 use winit::dpi::{LogicalSize, PhysicalPosition, PhysicalSize};
 use winit::error::RequestError;
 use winit::event::{DeviceEvent, DeviceId, MouseButton, MouseScrollDelta, WindowEvent};
-use winit::event_loop::{ActiveEventLoop, EventLoop};
+use winit::event_loop::{ActiveEventLoop, EventLoop, OwnedDisplayHandle};
 use winit::icon::{Icon, RgbaIcon};
 use winit::keyboard::{Key, ModifiersState};
 use winit::monitor::Fullscreen;
@@ -45,9 +44,6 @@ use winit_core::application::macos::ApplicationHandlerExtMacOS;
 #[path = "util/tracing.rs"]
 mod tracing_init;
 
-#[path = "util/fill.rs"]
-mod fill;
-
 /// The amount of points to around the window for drag resize direction calculations.
 const BORDER_SIZE: f64 = 20.;
 
@@ -94,20 +90,12 @@ struct Application {
     /// Drawing context.
     ///
     /// With OpenGL it could be EGLDisplay.
-    context: Option<Context<DisplayHandle<'static>>>,
+    context: Context<OwnedDisplayHandle>,
 }
 
 impl Application {
     fn new(event_loop: &EventLoop, receiver: Receiver<Action>, sender: Sender<Action>) -> Self {
-        // SAFETY: we drop the context right before the event loop is stopped, thus making it safe.
-        let context = Some(
-            Context::new(unsafe {
-                std::mem::transmute::<DisplayHandle<'_>, DisplayHandle<'static>>(
-                    event_loop.display_handle().unwrap(),
-                )
-            })
-            .unwrap(),
-        );
+        let context = Context::new(event_loop.owned_display_handle()).unwrap();
 
         // You'll have to choose an icon size at your own discretion. On X11, the desired size
         // varies by WM, and on Windows, you still have to account for screen scaling. Here
@@ -596,9 +584,7 @@ impl ApplicationHandlerExtMacOS for Application {
 /// State of the window.
 struct WindowState {
     /// Render surface.
-    ///
-    /// NOTE: This surface must be dropped before the `Window`.
-    surface: Surface<DisplayHandle<'static>, Arc<dyn Window>>,
+    surface: Surface<OwnedDisplayHandle, Arc<dyn Window>>,
     /// The actual winit Window.
     window: Arc<dyn Window>,
     /// The window theme we're drawing with.
@@ -639,9 +625,7 @@ impl WindowState {
     fn new(app: &Application, window: Box<dyn Window>) -> Result<Self, Box<dyn Error>> {
         let window: Arc<dyn Window> = Arc::from(window);
 
-        // SAFETY: the surface is dropped before the `window` which provided it with handle, thus
-        // it doesn't outlive it.
-        let surface = Surface::new(app.context.as_ref().unwrap(), Arc::clone(&window))?;
+        let surface = Surface::new(&app.context, Arc::clone(&window))?;
 
         let theme = window.theme().unwrap_or(Theme::Dark);
         info!("Theme: {theme:?}");
@@ -928,13 +912,17 @@ impl WindowState {
             return Ok(());
         }
 
-        if self.animated_fill_color {
-            fill::fill_window_with_animated_color(&*self.window, self.start_time);
-            return Ok(());
-        }
-
         let mut buffer = self.surface.buffer_mut()?;
 
+        if self.animated_fill_color {
+            // Fill the entire buffer with a single color.
+            let time = self.start_time.elapsed().as_secs_f32() * 1.5;
+            let blue = (time.sin() * 255.0) as u32;
+            let green = ((time.cos() * 255.0) as u32) << 8;
+            let red = ((1.0 - time.sin() * 255.0) as u32) << 16;
+            let color = red | green | blue;
+            buffer.fill(color);
+        } else {
             // Draw a different color inside the safe area
             let surface_size = self.window.surface_size();
             let insets = self.window.safe_area();
@@ -960,6 +948,7 @@ impl WindowState {
                     }
                 }
             }
+        }
 
         // Present the buffer
         self.window.pre_present_notify();

winit/examples/child_window.rs

@@ -3,11 +3,12 @@
 fn main() -> Result<(), impl std::error::Error> {
     use std::collections::HashMap;
 
+    use softbuffer::{Context, Surface};
     use tracing::info;
     use winit::application::ApplicationHandler;
     use winit::dpi::{LogicalPosition, LogicalSize, Position};
     use winit::event::{ElementState, KeyEvent, WindowEvent};
-    use winit::event_loop::{ActiveEventLoop, EventLoop};
+    use winit::event_loop::{ActiveEventLoop, EventLoop, OwnedDisplayHandle};
     use winit::raw_window_handle::HasRawWindowHandle;
     use winit::window::{Window, WindowAttributes, WindowId};
 
@@ -16,18 +17,20 @@ fn main() -> Result<(), impl std::error::Error> {
 
     #[derive(Debug)]
     struct WindowData {
-        window: Box<dyn Window>,
+        surface: Surface<OwnedDisplayHandle, Box<dyn Window>>,
         color: u32,
     }
 
     impl WindowData {
-        fn new(window: Box<dyn Window>, color: u32) -> Self {
-            Self { window, color }
+        fn new(context: &Context<OwnedDisplayHandle>, window: Box<dyn Window>, color: u32) -> Self {
+            let surface = Surface::new(context, window).unwrap();
+            Self { surface, color }
         }
     }
 
-    #[derive(Default, Debug)]
+    #[derive(Debug)]
     struct Application {
+        context: Context<OwnedDisplayHandle>,
         parent_window_id: Option<WindowId>,
         windows: HashMap<WindowId, WindowData>,
     }
@@ -42,7 +45,7 @@ fn main() -> Result<(), impl std::error::Error> {
             info!("Parent window id: {:?})", window.id());
             self.parent_window_id = Some(window.id());
 
-            self.windows.insert(window.id(), WindowData::new(window, 0xffbbbbbb));
+            self.windows.insert(window.id(), WindowData::new(&self.context, window, 0xffbbbbbb));
         }
 
         fn window_event(
@@ -73,18 +76,24 @@ fn main() -> Result<(), impl std::error::Error> {
                         0xff000000 + 3_u32.pow((child_index + 2).rem_euclid(16) as u32);
 
                     let parent_window = self.windows.get(&self.parent_window_id.unwrap()).unwrap();
-                    let child_window =
-                        spawn_child_window(parent_window.window.as_ref(), event_loop, child_index);
+                    let child_window = spawn_child_window(
+                        parent_window.surface.window().as_ref(),
+                        event_loop,
+                        child_index,
+                    );
                     let child_id = child_window.id();
                     info!("Child window created with id: {child_id:?}");
-                    self.windows.insert(child_id, WindowData::new(child_window, child_color));
+                    self.windows.insert(
+                        child_id,
+                        WindowData::new(&self.context, child_window, child_color),
+                    );
                 },
                 WindowEvent::RedrawRequested => {
-                    if let Some(window) = self.windows.get(&window_id) {
+                    if let Some(window) = self.windows.get_mut(&window_id) {
                         if window_id == self.parent_window_id.unwrap() {
-                            fill::fill_window(window.window.as_ref());
+                            fill::fill(&mut window.surface);
                         } else {
-                            fill::fill_window_with_color(window.window.as_ref(), window.color);
+                            fill::fill_with_color(&mut window.surface, window.color);
                         }
                     }
                 },
@@ -118,7 +127,8 @@ fn main() -> Result<(), impl std::error::Error> {
     }
 
     let event_loop = EventLoop::new().unwrap();
-    event_loop.run_app(Application::default())
+    let context = Context::new(event_loop.owned_display_handle()).unwrap();
+    event_loop.run_app(Application { context, parent_window_id: None, windows: HashMap::new() })
 }
 
 #[cfg(not(any(x11_platform, macos_platform, windows_platform)))]

winit/examples/control_flow.rs

@@ -4,12 +4,13 @@ use std::thread;
 #[cfg(not(web_platform))]
 use std::time;
 
+use softbuffer::{Context, Surface};
 use tracing::{info, warn};
 #[cfg(web_platform)]
 use web_time as time;
 use winit::application::ApplicationHandler;
 use winit::event::{ElementState, KeyEvent, StartCause, WindowEvent};
-use winit::event_loop::{ActiveEventLoop, ControlFlow, EventLoop};
+use winit::event_loop::{ActiveEventLoop, ControlFlow, EventLoop, OwnedDisplayHandle};
 use winit::keyboard::{Key, NamedKey};
 use winit::window::{Window, WindowAttributes, WindowId};
 
@@ -52,7 +53,7 @@ struct ControlFlowDemo {
     request_redraw: bool,
     wait_cancelled: bool,
     close_requested: bool,
-    window: Option<Box<dyn Window>>,
+    surface: Option<Surface<OwnedDisplayHandle, Box<dyn Window>>>,
 }
 
 impl ApplicationHandler for ControlFlowDemo {
@@ -69,7 +70,10 @@ impl ApplicationHandler for ControlFlowDemo {
         let window_attributes = WindowAttributes::default().with_title(
             "Press 1, 2, 3 to change control flow mode. Press R to toggle redraw requests.",
         );
-        self.window = Some(event_loop.create_window(window_attributes).unwrap());
+        let window = event_loop.create_window(window_attributes).unwrap();
+        let context = Context::new(event_loop.owned_display_handle()).unwrap();
+        let surface = Surface::new(&context, window).unwrap();
+        self.surface = Some(surface);
     }
 
     fn window_event(
@@ -112,9 +116,9 @@ impl ApplicationHandler for ControlFlowDemo {
                 _ => (),
             },
             WindowEvent::RedrawRequested => {
-                let window = self.window.as_ref().unwrap();
-                window.pre_present_notify();
-                fill::fill_window(window.as_ref());
+                let surface = self.surface.as_mut().unwrap();
+                surface.window().pre_present_notify();
+                fill::fill(surface);
             },
             _ => (),
         }
@@ -122,7 +126,7 @@ impl ApplicationHandler for ControlFlowDemo {
 
     fn about_to_wait(&mut self, event_loop: &dyn ActiveEventLoop) {
         if self.request_redraw && !self.wait_cancelled && !self.close_requested {
-            self.window.as_ref().unwrap().request_redraw();
+            self.surface.as_ref().unwrap().window().request_redraw();
         }
 
         match self.mode {

winit/examples/dnd.rs

@@ -1,9 +1,10 @@
 use std::error::Error;
 
+use softbuffer::{Context, Surface};
 use tracing::info;
 use winit::application::ApplicationHandler;
 use winit::event::WindowEvent;
-use winit::event_loop::{ActiveEventLoop, EventLoop};
+use winit::event_loop::{ActiveEventLoop, EventLoop, OwnedDisplayHandle};
 use winit::window::{Window, WindowAttributes, WindowId};
 
 #[path = "util/fill.rs"]
@@ -16,27 +17,24 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     let event_loop = EventLoop::new()?;
 
-    let app = Application::new();
+    let app = Application::default();
     Ok(event_loop.run_app(app)?)
 }
 
 /// Application state and event handling.
-#[derive(Debug)]
+#[derive(Default, Debug)]
 struct Application {
-    window: Option<Box<dyn Window>>,
-}
-
-impl Application {
-    fn new() -> Self {
-        Self { window: None }
-    }
+    surface: Option<Surface<OwnedDisplayHandle, Box<dyn Window>>>,
 }
 
 impl ApplicationHandler for Application {
     fn can_create_surfaces(&mut self, event_loop: &dyn ActiveEventLoop) {
         let window_attributes =
             WindowAttributes::default().with_title("Drag and drop files on me!");
-        self.window = Some(event_loop.create_window(window_attributes).unwrap());
+        let window = event_loop.create_window(window_attributes).unwrap();
+        let context = Context::new(event_loop.owned_display_handle()).unwrap();
+        let surface = Surface::new(&context, window).unwrap();
+        self.surface = Some(surface);
     }
 
     fn window_event(
@@ -53,9 +51,9 @@ impl ApplicationHandler for Application {
                 info!("{event:?}");
             },
             WindowEvent::RedrawRequested => {
-                let window = self.window.as_ref().unwrap();
-                window.pre_present_notify();
-                fill::fill_window(window.as_ref());
+                let surface = self.surface.as_mut().unwrap();
+                surface.window().pre_present_notify();
+                fill::fill(surface);
             },
             WindowEvent::CloseRequested => {
                 event_loop.exit();

winit/examples/ime.rs

@@ -9,10 +9,11 @@ use std::cmp;
 use std::error::Error;
 
 use dpi::{LogicalPosition, PhysicalSize};
+use softbuffer::{Context, Surface};
 use tracing::{error, info};
 use winit::application::ApplicationHandler;
 use winit::event::{Ime, WindowEvent};
-use winit::event_loop::{ActiveEventLoop, EventLoop};
+use winit::event_loop::{ActiveEventLoop, EventLoop, OwnedDisplayHandle};
 use winit::keyboard::{Key, ModifiersState, NamedKey};
 #[cfg(web_platform)]
 use winit::platform::web::WindowAttributesWeb;
@@ -30,7 +31,7 @@ const IME_CURSOR_SIZE: PhysicalSize<u32> = PhysicalSize::new(20, 20);
 
 #[derive(Debug)]
 struct App {
-    window: Option<Box<dyn Window>>,
+    surface: Option<Surface<OwnedDisplayHandle, Box<dyn Window>>>,
     input_state: TextInputState,
     modifiers: ModifiersState,
 }
@@ -73,14 +74,12 @@ impl ApplicationHandler for App {
         #[cfg(web_platform)]
         let window_attributes = WindowAttributes::default()
             .with_platform_attributes(Box::new(WindowAttributesWeb::default().with_append(true)));
-        self.window = match event_loop.create_window(window_attributes) {
-            Ok(window) => Some(window),
-            Err(err) => {
-                error!("error creating window: {err}");
-                event_loop.exit();
-                return;
-            },
-        };
+        let window = event_loop.create_window(window_attributes).expect("failed creating window");
+
+        let context =
+            Context::new(event_loop.owned_display_handle()).expect("failed creating context");
+        let surface = Surface::new(&context, window).expect("failed creating surface");
+        self.surface = Some(surface);
 
         // Allow IME out of the box.
         let enable_request = ImeEnableRequest::new(
@@ -101,11 +100,13 @@ impl ApplicationHandler for App {
         match event {
             WindowEvent::CloseRequested => {
                 info!("Close was requested; stopping");
-                self.window = None;
+                self.surface = None;
                 event_loop.exit();
             },
-            WindowEvent::SurfaceResized(_) => {
-                self.window.as_ref().expect("resize event without a window").request_redraw();
+            WindowEvent::SurfaceResized(surface_size) => {
+                let surface = self.surface.as_mut().expect("resize event without a surface");
+                fill::resize(surface, surface_size);
+                surface.window().request_redraw();
             },
             WindowEvent::RedrawRequested => {
                 // Redraw the application.
@@ -114,13 +115,13 @@ impl ApplicationHandler for App {
                 // this event rather than in AboutToWait, since rendering in here allows
                 // the program to gracefully handle redraws requested by the OS.
 
-                let window = self.window.as_ref().expect("redraw request without a window");
+                let surface = self.surface.as_mut().expect("redraw event without a surface");
 
                 // Notify that you're about to draw.
-                window.pre_present_notify();
+                surface.window().pre_present_notify();
 
                 // Draw.
-                fill::fill_window(window.as_ref());
+                fill::fill(surface);
 
                 // For contiguous redraw loop you can request a redraw from here.
                 // window.request_redraw();
@@ -214,14 +215,14 @@ impl App {
     }
 
     fn handle_ime_event(&mut self, event: Ime) {
-        let window = self.window.as_ref().expect("IME request without a window");
+        let surface = self.surface.as_ref().expect("IME request without a window");
         match event {
-            Ime::Enabled => info!("IME enabled for Window={:?}", window.id()),
+            Ime::Enabled => info!("IME enabled for Window={:?}", surface.window().id()),
             Ime::Preedit(text, caret_pos) => info!("Preedit: {text}, with caret at {caret_pos:?}"),
             Ime::Commit(text) => {
                 self.input_state.append_text(&text);
                 let request_data = self.get_ime_update();
-                window.request_ime_update(ImeRequest::Update(request_data)).unwrap();
+                surface.window().request_ime_update(ImeRequest::Update(request_data)).unwrap();
                 self.print_input_state();
             },
             Ime::DeleteSurrounding { before_bytes, after_bytes } => {
@@ -246,7 +247,7 @@ impl App {
                     error!("Buggy IME tried to delete with indices not on char boundary.");
                 }
             },
-            Ime::Disabled => info!("IME disabled for Window={:?}", window.id()),
+            Ime::Disabled => info!("IME disabled for Window={:?}", surface.window().id()),
         }
     }
 
@@ -312,7 +313,7 @@ impl App {
     }
 
     fn window(&self) -> &dyn Window {
-        self.window.as_ref().unwrap().as_ref()
+        self.surface.as_ref().unwrap().window().as_ref()
     }
 }
 
@@ -355,7 +356,7 @@ Use CTRL+h to cycle content hint permutations.
     );
 
     let app = App {
-        window: None,
+        surface: None,
         input_state: TextInputState {
             ime_enabled: true,
             contents: String::new(),

winit/examples/pump_events.rs

@@ -7,11 +7,12 @@ fn main() -> std::process::ExitCode {
     use std::thread::sleep;
     use std::time::Duration;
 
+    use softbuffer::{Context, Surface};
     use tracing::info;
     use winit::application::ApplicationHandler;
     use winit::event::WindowEvent;
     use winit::event_loop::pump_events::{EventLoopExtPumpEvents, PumpStatus};
-    use winit::event_loop::{ActiveEventLoop, EventLoop};
+    use winit::event_loop::{ActiveEventLoop, EventLoop, OwnedDisplayHandle};
     use winit::window::{Window, WindowAttributes, WindowId};
 
     #[path = "util/fill.rs"]
@@ -21,13 +22,16 @@ fn main() -> std::process::ExitCode {
 
     #[derive(Default, Debug)]
     struct PumpDemo {
-        window: Option<Box<dyn Window>>,
+        surface: Option<Surface<OwnedDisplayHandle, Box<dyn Window>>>,
     }
 
     impl ApplicationHandler for PumpDemo {
         fn can_create_surfaces(&mut self, event_loop: &dyn ActiveEventLoop) {
             let window_attributes = WindowAttributes::default().with_title("A fantastic window!");
-            self.window = Some(event_loop.create_window(window_attributes).unwrap());
+            let window = event_loop.create_window(window_attributes).unwrap();
+
+            let context = Context::new(event_loop.owned_display_handle()).unwrap();
+            self.surface = Some(Surface::new(&context, window).unwrap());
         }
 
         fn window_event(
@@ -38,16 +42,16 @@ fn main() -> std::process::ExitCode {
         ) {
             info!("{event:?}");
 
-            let window = match self.window.as_ref() {
-                Some(window) => window,
+            let surface = match self.surface.as_mut() {
+                Some(surface) => surface,
                 None => return,
             };
 
             match event {
                 WindowEvent::CloseRequested => event_loop.exit(),
                 WindowEvent::RedrawRequested => {
-                    fill::fill_window(window.as_ref());
-                    window.request_redraw();
+                    fill::fill(surface);
+                    surface.window().request_redraw();
                 },
                 _ => (),
             }

winit/examples/run_on_demand.rs

@@ -5,11 +5,12 @@
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     use std::time::Duration;
 
+    use softbuffer::{Context, Surface};
     use tracing::info;
     use winit::application::ApplicationHandler;
     use winit::event::WindowEvent;
     use winit::event_loop::run_on_demand::EventLoopExtRunOnDemand;
-    use winit::event_loop::{ActiveEventLoop, EventLoop};
+    use winit::event_loop::{ActiveEventLoop, EventLoop, OwnedDisplayHandle};
     use winit::window::{Window, WindowAttributes, WindowId};
 
     #[path = "util/fill.rs"]
@@ -17,27 +18,30 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     #[path = "util/tracing.rs"]
     mod tracing;
 
-    #[derive(Default, Debug)]
+    #[derive(Debug)]
     struct App {
+        context: Context<OwnedDisplayHandle>,
         idx: usize,
+        surface: Option<Surface<OwnedDisplayHandle, Box<dyn Window>>>,
         window_id: Option<WindowId>,
-        window: Option<Box<dyn Window>>,
     }
 
     impl ApplicationHandler for App {
         fn about_to_wait(&mut self, _event_loop: &dyn ActiveEventLoop) {
-            if let Some(window) = self.window.as_ref() {
-                window.request_redraw();
+            if let Some(surface) = self.surface.as_ref() {
+                surface.window().request_redraw();
             }
         }
 
         fn can_create_surfaces(&mut self, event_loop: &dyn ActiveEventLoop) {
             let window_attributes = WindowAttributes::default()
-                .with_title("Fantastic window number one!")
+                .with_title(format!("Fantastic window number {}!", self.idx))
                 .with_surface_size(winit::dpi::LogicalSize::new(128.0, 128.0));
             let window = event_loop.create_window(window_attributes).unwrap();
             self.window_id = Some(window.id());
-            self.window = Some(window);
+
+            let surface = Surface::new(&self.context, window).unwrap();
+            self.surface = Some(surface);
         }
 
         fn window_event(
@@ -53,19 +57,17 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
                 return;
             }
 
-            let window = match self.window.as_mut() {
-                Some(window) => window,
-                None => return,
+            let Some(surface) = self.surface.as_mut() else {
+                return;
             };
 
             match event {
                 WindowEvent::CloseRequested => {
                     info!("Window {} CloseRequested", self.idx);
-                    fill::cleanup_window(window.as_ref());
-                    self.window = None;
+                    self.surface = None;
                 },
                 WindowEvent::RedrawRequested => {
-                    fill::fill_window(window.as_ref());
+                    fill::fill(surface);
                 },
                 _ => (),
             }
@@ -76,7 +78,8 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     let mut event_loop = EventLoop::new().unwrap();
 
-    let mut app = App { idx: 1, ..Default::default() };
+    let context = Context::new(event_loop.owned_display_handle()).unwrap();
+    let mut app = App { context, idx: 1, surface: None, window_id: None };
     event_loop.run_app_on_demand(&mut app)?;
 
     info!("Finished first loop");

winit/examples/util/fill.rs

@@ -1,115 +1,43 @@
-//! Fill the window buffer with a solid color.
-//!
-//! Launching a window without drawing to it has unpredictable results varying from platform to
-//! platform. In order to have well-defined examples, this module provides an easy way to
-//! fill the window buffer with a solid color.
-//!
-//! The `softbuffer` crate is used, largely because of its ease of use. `glutin` or `wgpu` could
-//! also be used to fill the window buffer, but they are more complicated to use.
-
-use std::cell::RefCell;
-use std::collections::HashMap;
-use std::mem;
-use std::mem::ManuallyDrop;
 use std::num::NonZeroU32;
-#[cfg(not(web_platform))]
-use std::time::Instant;
 
-use softbuffer::{Context, Surface};
-#[cfg(web_platform)]
-use web_time::Instant;
-use winit::window::{Window, WindowId};
+use rwh_06::{HasDisplayHandle, HasWindowHandle};
+use softbuffer::Surface;
+use winit::window::Window;
 
-thread_local! {
-    // NOTE: You should never do things like that, create context and drop it before
-    // you drop the event loop. We do this for brevity to not blow up examples. We use
-    // ManuallyDrop to prevent destructors from running.
+/// Resize the surface.
+pub fn resize(
+    surface: &mut Surface<impl HasDisplayHandle, impl HasWindowHandle>,
+    surface_size: dpi::PhysicalSize<u32>,
+) {
+    // Handle zero-sized buffers.
     //
-    // A static, thread-local map of graphics contexts to open windows.
-    static GC: ManuallyDrop<RefCell<Option<GraphicsContext>>> = const { ManuallyDrop::new(RefCell::new(None)) };
-}
-
-/// The graphics context used to draw to a window.
-struct GraphicsContext {
-    /// The global softbuffer context.
-    context: RefCell<Context<&'static dyn Window>>,
-
-    /// The hash map of window IDs to surfaces.
-    surfaces: HashMap<WindowId, Surface<&'static dyn Window, &'static dyn Window>>,
-}
-
-impl GraphicsContext {
-    fn new(w: &dyn Window) -> Self {
-        Self {
-            context: RefCell::new(
-                Context::new(unsafe { mem::transmute::<&'_ dyn Window, &'static dyn Window>(w) })
-                    .expect("Failed to create a softbuffer context"),
-            ),
-            surfaces: HashMap::new(),
-        }
-    }
-
-    fn create_surface(
-        &mut self,
-        window: &dyn Window,
-    ) -> &mut Surface<&'static dyn Window, &'static dyn Window> {
-        self.surfaces.entry(window.id()).or_insert_with(|| {
-            Surface::new(&self.context.borrow(), unsafe {
-                mem::transmute::<&'_ dyn Window, &'static dyn Window>(window)
-            })
-            .expect("Failed to create a softbuffer surface")
-        })
-    }
-
-    fn destroy_surface(&mut self, window: &dyn Window) {
-        self.surfaces.remove(&window.id());
-    }
-}
-
-pub fn fill_window_with_color(window: &dyn Window, color: u32) {
-    GC.with(|gc| {
-        let size = window.surface_size();
+    // FIXME(madsmtm): This should be done by softbuffer internally in the future:
+    // https://github.com/rust-windowing/softbuffer/issues/238
     let (Some(width), Some(height)) =
-            (NonZeroU32::new(size.width), NonZeroU32::new(size.height))
+        (NonZeroU32::new(surface_size.width), NonZeroU32::new(surface_size.height))
     else {
         return;
     };
 
-        // Either get the last context used or create a new one.
-        let mut gc = gc.borrow_mut();
-        let surface = gc.get_or_insert_with(|| GraphicsContext::new(window)).create_surface(window);
-
-        // Fill a buffer with a solid color
-
     surface.resize(width, height).expect("Failed to resize the softbuffer surface");
+}
+
+/// Fill the window buffer with a solid color.
+pub fn fill_with_color(
+    surface: &mut Surface<impl HasDisplayHandle, impl HasWindowHandle + AsRef<dyn Window>>,
+    color: u32,
+) {
+    let surface_size = surface.window().as_ref().surface_size();
+    resize(surface, surface_size);
 
     let mut buffer = surface.buffer_mut().expect("Failed to get the softbuffer buffer");
     buffer.fill(color);
     buffer.present().expect("Failed to present the softbuffer buffer");
-    })
 }
 
 #[allow(dead_code)]
-pub fn fill_window(window: &dyn Window) {
-    fill_window_with_color(window, 0xff181818);
-}
-
-#[allow(dead_code)]
-pub fn fill_window_with_animated_color(window: &dyn Window, start: Instant) {
-    let time = start.elapsed().as_secs_f32() * 1.5;
-    let blue = (time.sin() * 255.0) as u32;
-    let green = ((time.cos() * 255.0) as u32) << 8;
-    let red = ((1.0 - time.sin() * 255.0) as u32) << 16;
-    let color = red | green | blue;
-    fill_window_with_color(window, color);
-}
-
-#[allow(dead_code)]
-pub fn cleanup_window(window: &dyn Window) {
-    GC.with(|gc| {
-        let mut gc = gc.borrow_mut();
-        if let Some(context) = gc.as_mut() {
-            context.destroy_surface(window);
-        }
-    });
+pub fn fill(
+    surface: &mut Surface<impl HasDisplayHandle, impl HasWindowHandle + AsRef<dyn Window>>,
+) {
+    fill_with_color(surface, 0xff181818);
 }

winit/examples/window.rs

@@ -2,10 +2,11 @@
 
 use std::error::Error;
 
-use tracing::{error, info};
+use softbuffer::{Context, Surface};
+use tracing::info;
 use winit::application::ApplicationHandler;
 use winit::event::WindowEvent;
-use winit::event_loop::{ActiveEventLoop, EventLoop};
+use winit::event_loop::{ActiveEventLoop, EventLoop, OwnedDisplayHandle};
 #[cfg(web_platform)]
 use winit::platform::web::WindowAttributesWeb;
 use winit::window::{Window, WindowAttributes, WindowId};
@@ -17,7 +18,7 @@ mod tracing;
 
 #[derive(Default, Debug)]
 struct App {
-    window: Option<Box<dyn Window>>,
+    surface: Option<Surface<OwnedDisplayHandle, Box<dyn Window>>>,
 }
 
 impl ApplicationHandler for App {
@@ -27,14 +28,12 @@ impl ApplicationHandler for App {
         #[cfg(web_platform)]
         let window_attributes = WindowAttributes::default()
             .with_platform_attributes(Box::new(WindowAttributesWeb::default().with_append(true)));
-        self.window = match event_loop.create_window(window_attributes) {
-            Ok(window) => Some(window),
-            Err(err) => {
-                error!("error creating window: {err}");
-                event_loop.exit();
-                return;
-            },
-        }
+        let window = event_loop.create_window(window_attributes).expect("failed creating window");
+
+        let context =
+            Context::new(event_loop.owned_display_handle()).expect("failed creating context");
+        let surface = Surface::new(&context, window).expect("failed creating surface");
+        self.surface = Some(surface);
     }
 
     fn window_event(&mut self, event_loop: &dyn ActiveEventLoop, _: WindowId, event: WindowEvent) {
@@ -44,8 +43,10 @@ impl ApplicationHandler for App {
                 info!("Close was requested; stopping");
                 event_loop.exit();
             },
-            WindowEvent::SurfaceResized(_) => {
-                self.window.as_ref().expect("resize event without a window").request_redraw();
+            WindowEvent::SurfaceResized(surface_size) => {
+                let surface = self.surface.as_mut().expect("resize event without a surface");
+                fill::resize(surface, surface_size);
+                surface.window().request_redraw();
             },
             WindowEvent::RedrawRequested => {
                 // Redraw the application.
@@ -54,13 +55,15 @@ impl ApplicationHandler for App {
                 // this event rather than in AboutToWait, since rendering in here allows
                 // the program to gracefully handle redraws requested by the OS.
 
-                let window = self.window.as_ref().expect("redraw request without a window");
+                let surface = self.surface.as_mut().expect("redraw event without a surface");
 
                 // Notify that you're about to draw.
-                window.pre_present_notify();
+                surface.window().pre_present_notify();
 
                 // Draw.
-                fill::fill_window(window.as_ref());
+                let mut buffer = surface.buffer_mut().expect("Failed to get the softbuffer buffer");
+                buffer.fill(0xff181818);
+                buffer.present().expect("Failed to present the softbuffer buffer");
 
                 // For contiguous redraw loop you can request a redraw from here.
                 // window.request_redraw();

winit/examples/x11_embed.rs

@@ -3,9 +3,10 @@ use std::error::Error;
 
 #[cfg(x11_platform)]
 fn main() -> Result<(), Box<dyn Error>> {
+    use softbuffer::{Context, Surface};
     use winit::application::ApplicationHandler;
     use winit::event::WindowEvent;
-    use winit::event_loop::{ActiveEventLoop, EventLoop};
+    use winit::event_loop::{ActiveEventLoop, EventLoop, OwnedDisplayHandle};
     use winit::platform::x11::WindowAttributesX11;
     use winit::window::{Window, WindowAttributes, WindowId};
 
@@ -17,7 +18,7 @@ fn main() -> Result<(), Box<dyn Error>> {
     #[derive(Debug)]
     pub struct XEmbedDemo {
         parent_window_id: u32,
-        window: Option<Box<dyn Window>>,
+        surface: Option<Surface<OwnedDisplayHandle, Box<dyn Window>>>,
     }
 
     impl ApplicationHandler for XEmbedDemo {
@@ -29,7 +30,10 @@ fn main() -> Result<(), Box<dyn Error>> {
                 WindowAttributesX11::default().with_embed_parent_window(self.parent_window_id);
             window_attributes = window_attributes.with_platform_attributes(Box::new(x11_attrs));
 
-            self.window = Some(event_loop.create_window(window_attributes).unwrap());
+            let window = event_loop.create_window(window_attributes).unwrap();
+            let context = Context::new(event_loop.owned_display_handle()).unwrap();
+            let surface = Surface::new(&context, window).unwrap();
+            self.surface = Some(surface);
         }
 
         fn window_event(
@@ -38,19 +42,19 @@ fn main() -> Result<(), Box<dyn Error>> {
             _window_id: WindowId,
             event: WindowEvent,
         ) {
-            let window = self.window.as_ref().unwrap();
             match event {
                 WindowEvent::CloseRequested => event_loop.exit(),
                 WindowEvent::RedrawRequested => {
-                    window.pre_present_notify();
-                    fill::fill_window(window.as_ref());
+                    let surface = self.surface.as_mut().unwrap();
+                    surface.window().pre_present_notify();
+                    fill::fill(surface);
                 },
                 _ => (),
             }
         }
 
         fn about_to_wait(&mut self, _event_loop: &dyn ActiveEventLoop) {
-            self.window.as_ref().unwrap().request_redraw();
+            self.surface.as_ref().unwrap().window().request_redraw();
         }
     }
 
@@ -63,7 +67,7 @@ fn main() -> Result<(), Box<dyn Error>> {
     tracing::init();
     let event_loop = EventLoop::new()?;
 
-    Ok(event_loop.run_app(XEmbedDemo { parent_window_id, window: None })?)
+    Ok(event_loop.run_app(XEmbedDemo { parent_window_id, surface: None })?)
 }
 
 #[cfg(not(x11_platform))]