add android NDK event loop (#1556)

* add android NDK event loop

* add Android build documentation & cargo-apk to CI

Co-authored-by: David Craven <david@craven.ch>

src/platform/android.rs

@@ -1,32 +1,39 @@
 #![cfg(any(target_os = "android"))]
 
-use crate::{EventLoop, Window, WindowBuilder};
-use std::os::raw::c_void;
+use crate::{
+    event_loop::{EventLoop, EventLoopWindowTarget},
+    window::{Window, WindowBuilder},
+};
+use ndk::configuration::Configuration;
+use ndk_glue::Rect;
 
 /// Additional methods on `EventLoop` that are specific to Android.
-pub trait EventLoopExtAndroid {
-    /// Makes it possible for glutin to register a callback when a suspend event happens on Android
-    fn set_suspend_callback(&self, cb: Option<Box<dyn Fn(bool) -> ()>>);
-}
+pub trait EventLoopExtAndroid {}
 
-impl EventLoopExtAndroid for EventLoop {
-    fn set_suspend_callback(&self, cb: Option<Box<dyn Fn(bool) -> ()>>) {
-        self.event_loop.set_suspend_callback(cb);
-    }
-}
+impl<T> EventLoopExtAndroid for EventLoop<T> {}
+
+/// Additional methods on `EventLoopWindowTarget` that are specific to Android.
+pub trait EventLoopWindowTargetExtAndroid {}
 
 /// Additional methods on `Window` that are specific to Android.
 pub trait WindowExtAndroid {
-    fn native_window(&self) -> *const c_void;
+    fn content_rect(&self) -> Rect;
+
+    fn config(&self) -> Configuration;
 }
 
 impl WindowExtAndroid for Window {
-    #[inline]
-    fn native_window(&self) -> *const c_void {
-        self.window.native_window()
+    fn content_rect(&self) -> Rect {
+        self.window.content_rect()
+    }
+
+    fn config(&self) -> Configuration {
+        self.window.config()
     }
 }
 
+impl<T> EventLoopWindowTargetExtAndroid for EventLoopWindowTarget<T> {}
+
 /// Additional methods on `WindowBuilder` that are specific to Android.
 pub trait WindowBuilderExtAndroid {}