0.1.0-2-beta.1.fix.3

crates/engines/engine-v1-sdl/src/lib.rs

@@ -1,5 +1,5 @@
 // file: crates/engines/engine-v1-sdl/src/lib.rs
-// version: 3
+// version: 4
 
 #![warn(missing_docs)]
 #![deny(unreachable_pub)]
@@ -12,3 +12,5 @@ mod unit_tests;
 
 /// Re-export of the minimal SDL3 runtime used by Desktop POC runners.
 pub use self::runtime::SdlRuntime;
+/// Re-export of the platform-native Back request bridge.
+pub use self::runtime::request_platform_back;

crates/engines/engine-v1-sdl/src/runtime.rs

@@ -1,5 +1,5 @@
 // file: crates/engines/engine-v1-sdl/src/runtime.rs
-// version: 11
+// version: 12
 
 /// Minimal SDL3 runtime used by Desktop and Android POC runners.
 pub struct SdlRuntime {
@@ -9,6 +9,17 @@ pub struct SdlRuntime {
     frame_duration: std::time::Duration,
 }
 
+static PLATFORM_BACK_REQUESTED: std::sync::atomic::AtomicBool = std::sync::atomic::AtomicBool::new(false);
+
+/// Requests the active SDL runtime to evaluate a platform-native Back action.
+///
+/// Platform adapters use this signal when the host operating system does not expose Back
+/// as a normal SDL keyboard event.
+pub fn request_platform_back() {
+    PLATFORM_BACK_REQUESTED.store(true, std::sync::atomic::Ordering::Release);
+    return;
+}
+
 impl SdlRuntime {
     /// Creates a minimal SDL3 runtime configuration.
     #[must_use]
@@ -21,10 +32,6 @@ impl SdlRuntime {
     where
         G: engine_v1_common::EngineGame,
     {
-        #[cfg(target_os = "android")]
-        {
-            let _ = sdl3::hint::set(sdl3::hint::names::ANDROID_TRAP_BACK_BUTTON, "1");
-        }
         let sdl = match sdl3::init() {
             std::result::Result::Ok(value) => value,
             std::result::Result::Err(error) => return std::result::Result::Err(error.to_string()),
@@ -47,6 +54,12 @@ impl SdlRuntime {
         let mut pointer = engine_v1_common::PointerState::inactive();
         tracing::info!(title = %self.title, width = self.width, height = self.height, "SDL3 runtime started");
         'running: loop {
+            if take_platform_back_request() {
+                tracing::info!(source = "platform_back", "SDL3 platform Back requested");
+                if quit_requested(game, engine_v1_common::QuitSource::PlatformBack) {
+                    break 'running;
+                }
+            }
             let mut input = engine_v1_common::InputState::none().with_pointer(pointer);
             for event in events.poll_iter() {
                 match event {
@@ -166,6 +179,10 @@ fn render_scene(canvas: &mut sdl3::render::WindowCanvas, scene: engine_v1_common
 
 const SWIPE_DIRECTION_THRESHOLD: f32 = 0.04;
 
+fn take_platform_back_request() -> bool {
+    return PLATFORM_BACK_REQUESTED.swap(false, std::sync::atomic::Ordering::AcqRel);
+}
+
 fn quit_requested<G>(game: &mut G, source: engine_v1_common::QuitSource) -> bool
 where
     G: engine_v1_common::EngineGame,

crates/engines/engine-v1-sdl/unit_tests/swipe.rs

@@ -1,5 +1,5 @@
 // file: crates/engines/engine-v1-sdl/unit_tests/swipe.rs
-// version: 3
+// version: 4
 
 fn pointer(x: f32, y: f32) -> engine_v1_common::PointerState {
     return engine_v1_common::PointerState::normalized(true, x, y);
@@ -48,3 +48,10 @@ fn runtime_respects_game_quit_decision() {
     assert!(!super::quit_requested(&mut game, engine_v1_common::QuitSource::PlatformBack));
     assert_eq!(game.requests, 1);
 }
+
+#[test]
+fn platform_back_bridge_is_consumed_once() {
+    super::request_platform_back();
+    assert!(super::take_platform_back_request());
+    assert!(!super::take_platform_back_request());
+}