From 5d8091fc7fae22ab17f6a1892bb910616160d8cc Mon Sep 17 00:00:00 2001
From: Mads Marquart <mads@marquart.dk>
Date: Wed, 29 May 2024 11:51:53 +0200
Subject: [PATCH] Implement ApplicationHandler for `&mut A` and `Box<A>`
 (#3709)

---
 src/application.rs          | 114 ++++++++++++++++++++++++++++++++++++
 src/changelog/unreleased.md |   1 +
 2 files changed, 115 insertions(+)

diff --git a/src/application.rs b/src/application.rs
index 118ba6e528..977a7c79f2 100644
--- a/src/application.rs
+++ b/src/application.rs
@@ -223,3 +223,117 @@ pub trait ApplicationHandler<T: 'static = ()> {
         let _ = event_loop;
     }
 }
+
+impl<A: ?Sized + ApplicationHandler<T>, T: 'static> ApplicationHandler<T> for &mut A {
+    #[inline]
+    fn new_events(&mut self, event_loop: &ActiveEventLoop, cause: StartCause) {
+        (**self).new_events(event_loop, cause);
+    }
+
+    #[inline]
+    fn resumed(&mut self, event_loop: &ActiveEventLoop) {
+        (**self).resumed(event_loop);
+    }
+
+    #[inline]
+    fn user_event(&mut self, event_loop: &ActiveEventLoop, event: T) {
+        (**self).user_event(event_loop, event);
+    }
+
+    #[inline]
+    fn window_event(
+        &mut self,
+        event_loop: &ActiveEventLoop,
+        window_id: WindowId,
+        event: WindowEvent,
+    ) {
+        (**self).window_event(event_loop, window_id, event);
+    }
+
+    #[inline]
+    fn device_event(
+        &mut self,
+        event_loop: &ActiveEventLoop,
+        device_id: DeviceId,
+        event: DeviceEvent,
+    ) {
+        (**self).device_event(event_loop, device_id, event);
+    }
+
+    #[inline]
+    fn about_to_wait(&mut self, event_loop: &ActiveEventLoop) {
+        (**self).about_to_wait(event_loop);
+    }
+
+    #[inline]
+    fn suspended(&mut self, event_loop: &ActiveEventLoop) {
+        (**self).suspended(event_loop);
+    }
+
+    #[inline]
+    fn exiting(&mut self, event_loop: &ActiveEventLoop) {
+        (**self).exiting(event_loop);
+    }
+
+    #[inline]
+    fn memory_warning(&mut self, event_loop: &ActiveEventLoop) {
+        (**self).memory_warning(event_loop);
+    }
+}
+
+impl<A: ?Sized + ApplicationHandler<T>, T: 'static> ApplicationHandler<T> for Box<A> {
+    #[inline]
+    fn new_events(&mut self, event_loop: &ActiveEventLoop, cause: StartCause) {
+        (**self).new_events(event_loop, cause);
+    }
+
+    #[inline]
+    fn resumed(&mut self, event_loop: &ActiveEventLoop) {
+        (**self).resumed(event_loop);
+    }
+
+    #[inline]
+    fn user_event(&mut self, event_loop: &ActiveEventLoop, event: T) {
+        (**self).user_event(event_loop, event);
+    }
+
+    #[inline]
+    fn window_event(
+        &mut self,
+        event_loop: &ActiveEventLoop,
+        window_id: WindowId,
+        event: WindowEvent,
+    ) {
+        (**self).window_event(event_loop, window_id, event);
+    }
+
+    #[inline]
+    fn device_event(
+        &mut self,
+        event_loop: &ActiveEventLoop,
+        device_id: DeviceId,
+        event: DeviceEvent,
+    ) {
+        (**self).device_event(event_loop, device_id, event);
+    }
+
+    #[inline]
+    fn about_to_wait(&mut self, event_loop: &ActiveEventLoop) {
+        (**self).about_to_wait(event_loop);
+    }
+
+    #[inline]
+    fn suspended(&mut self, event_loop: &ActiveEventLoop) {
+        (**self).suspended(event_loop);
+    }
+
+    #[inline]
+    fn exiting(&mut self, event_loop: &ActiveEventLoop) {
+        (**self).exiting(event_loop);
+    }
+
+    #[inline]
+    fn memory_warning(&mut self, event_loop: &ActiveEventLoop) {
+        (**self).memory_warning(event_loop);
+    }
+}
diff --git a/src/changelog/unreleased.md b/src/changelog/unreleased.md
index 314d13ec4a..3e6cb6465c 100644
--- a/src/changelog/unreleased.md
+++ b/src/changelog/unreleased.md
@@ -44,6 +44,7 @@ changelog entry.
 ### Added
 
 - Reexport `raw-window-handle` versions 0.4 and 0.5 as `raw_window_handle_04` and `raw_window_handle_05`.
+- Implement `ApplicationHandler` for `&mut` references and heap allocations to something that implements `ApplicationHandler`.
 
 ### Removed