android: add {Active,}EventLoopExtAndroid::android_app

This type comes from the user and stored for the entire lifetime, so
no need to hide it from them after they've passed it to winit.

Fixes #3818.

src/changelog/unreleased.md

@@ -43,6 +43,7 @@ changelog entry.
 ### Added
 
 - On Web, implement `Error` for `platform::web::CustomCursorError`.
+- On Android, add `{Active,}EventLoopExtAndroid::android_app()` to access the app used to create the loop.
 
 ### Fixed
 

src/platform/android.rs

@@ -76,12 +76,22 @@ use crate::window::{Window, WindowAttributes};
 use self::activity::{AndroidApp, ConfigurationRef, Rect};
 
 /// Additional methods on [`EventLoop`] that are specific to Android.
-pub trait EventLoopExtAndroid {}
+pub trait EventLoopExtAndroid {
+    /// Get the [`AndroidApp`] which was used to create this event loop.
+    fn android_app(&self) -> &AndroidApp;
+}
 
-impl<T> EventLoopExtAndroid for EventLoop<T> {}
+impl<T> EventLoopExtAndroid for EventLoop<T> {
+    fn android_app(&self) -> &AndroidApp {
+        &self.event_loop.android_app
+    }
+}
 
 /// Additional methods on [`ActiveEventLoop`] that are specific to Android.
-pub trait ActiveEventLoopExtAndroid {}
+pub trait ActiveEventLoopExtAndroid {
+    /// Get the [`AndroidApp`] which was used to create this event loop.
+    fn android_app(&self) -> &AndroidApp;
+}
 
 /// Additional methods on [`Window`] that are specific to Android.
 pub trait WindowExtAndroid {
@@ -100,17 +110,21 @@ impl WindowExtAndroid for Window {
     }
 }
 
-impl ActiveEventLoopExtAndroid for ActiveEventLoop {}
+impl ActiveEventLoopExtAndroid for ActiveEventLoop {
+    fn android_app(&self) -> &AndroidApp {
+        &self.p.app
+    }
+}
 
 /// Additional methods on [`WindowAttributes`] that are specific to Android.
 pub trait WindowAttributesExtAndroid {}
 
 impl WindowAttributesExtAndroid for WindowAttributes {}
 
 pub trait EventLoopBuilderExtAndroid {
-    /// Associates the `AndroidApp` that was passed to `android_main()` with the event loop
+    /// Associates the [`AndroidApp`] that was passed to `android_main()` with the event loop
     ///
-    /// This must be called on Android since the `AndroidApp` is not global state.
+    /// This must be called on Android since the [`AndroidApp`] is not global state.
     fn with_android_app(&mut self, app: AndroidApp) -> &mut Self;
 
     /// Calling this will mark the volume keys to be manually handled by the application
@@ -147,7 +161,7 @@ impl<T> EventLoopBuilderExtAndroid for EventLoopBuilder<T> {
 /// depending on the `android_activity` crate, and instead consume the API that
 /// is re-exported by Winit.
 ///
-/// For compatibility applications should then import the `AndroidApp` type for
+/// For compatibility applications should then import the [`AndroidApp`] type for
 /// their `android_main(app: AndroidApp)` function like:
 /// ```rust
 /// #[cfg(target_os = "android")]

src/platform_impl/android/mod.rs

@@ -132,7 +132,7 @@ impl RedrawRequester {
 pub struct KeyEventExtra {}
 
 pub struct EventLoop<T: 'static> {
-    android_app: AndroidApp,
+    pub(crate) android_app: AndroidApp,
     window_target: event_loop::ActiveEventLoop,
     redraw_flag: SharedFlag,
     user_events_sender: mpsc::Sender<T>,
@@ -646,7 +646,7 @@ impl<T> EventLoopProxy<T> {
 }
 
 pub struct ActiveEventLoop {
-    app: AndroidApp,
+    pub(crate) app: AndroidApp,
     control_flow: Cell<ControlFlow>,
     exit: Cell<bool>,
     redraw_requester: RedrawRequester,