Guard bevy_winit plugins, methods and systems thar rely on `WindowP…

…lugin`

crates/bevy_winit/src/lib.rs

@@ -17,7 +17,7 @@ extern crate alloc;
 use bevy_derive::Deref;
 use bevy_reflect::prelude::ReflectDefault;
 use bevy_reflect::Reflect;
-use bevy_window::{RawHandleWrapperHolder, WindowEvent};
+use bevy_window::{RawHandleWrapperHolder, WindowEvent, WindowPlugin};
 use core::marker::PhantomData;
 use winit::{event_loop::EventLoop, window::WindowId};
 
@@ -129,8 +129,12 @@ impl<T: Event> Plugin for WinitPlugin<T> {
             .init_resource::<WinitSettings>()
             .insert_resource(DisplayHandleWrapper(event_loop.owned_display_handle()))
             .add_event::<RawWinitWindowEvent>()
-            .set_runner(|app| winit_runner(app, event_loop))
-            .add_systems(
+            .set_runner(|app| winit_runner(app, event_loop));
+
+        app.add_plugins(cursor::CursorPlugin);
+
+        if app.is_plugin_added::<WindowPlugin>() {
+            app.add_systems(
                 Last,
                 (
                     // `exit_on_all_closed` only checks if windows exist but doesn't access data,
@@ -141,9 +145,8 @@ impl<T: Event> Plugin for WinitPlugin<T> {
                 )
                     .chain(),
             );
-
-        app.add_plugins(AccessKitPlugin);
-        app.add_plugins(cursor::CursorPlugin);
+            app.add_plugins(AccessKitPlugin);
+        }
     }
 }
 

crates/bevy_winit/src/state.rs

@@ -18,7 +18,7 @@ use bevy_input::{
 };
 #[cfg(any(not(target_arch = "wasm32"), feature = "custom_cursor"))]
 use bevy_log::error;
-use bevy_log::{trace, warn};
+use bevy_log::{once, trace, warn};
 #[cfg(feature = "custom_cursor")]
 use bevy_math::URect;
 use bevy_math::{ivec2, DVec2, Vec2};
@@ -41,7 +41,7 @@ use winit::{
 
 use bevy_window::{
     AppLifecycle, CursorEntered, CursorLeft, CursorMoved, FileDragAndDrop, Ime, RequestRedraw,
-    Window, WindowBackendScaleFactorChanged, WindowCloseRequested, WindowDestroyed,
+    Window, WindowBackendScaleFactorChanged, WindowCloseRequested, WindowCreated, WindowDestroyed,
     WindowEvent as BevyWindowEvent, WindowFocused, WindowMoved, WindowOccluded, WindowResized,
     WindowScaleFactorChanged, WindowThemeChanged,
 };
@@ -493,8 +493,14 @@ impl<T: Event> ApplicationHandler<T> for WinitAppRunnerState<T> {
             SystemState::<CreateWindowParams<Added<Window>>>::from_world(self.world_mut());
         create_monitors(event_loop, create_monitor.get_mut(self.world_mut()));
         create_monitor.apply(self.world_mut());
-        create_windows(event_loop, create_window.get_mut(self.world_mut()));
-        create_window.apply(self.world_mut());
+        if self
+            .world_mut()
+            .get_resource::<Events<WindowCreated>>()
+            .is_some()
+        {
+            create_windows(event_loop, create_window.get_mut(self.world_mut()));
+            create_window.apply(self.world_mut());
+        }
 
         // TODO: This is a workaround for https://github.com/bevyengine/bevy/issues/17488
         //       while preserving the iOS fix in https://github.com/bevyengine/bevy/pull/11245
@@ -862,9 +868,13 @@ impl<T: Event> WinitAppRunnerState<T> {
         }
 
         if !buffered_events.is_empty() {
-            world
-                .resource_mut::<Events<BevyWindowEvent>>()
-                .send_batch(buffered_events);
+            if let Some(mut events) = world.get_resource_mut::<Events<BevyWindowEvent>>() {
+                events.send_batch(buffered_events);
+            } else {
+                once!(warn!(
+                    "Lost windows events because `Events<WindowEvents>` is not available."
+                ));
+            }
         }
     }