add centeral actionset syncing

Signed-off-by: Schmarni <marnistromer@gmail.com>

crates/bevy_openxr/src/openxr/action_set_syncing.rs

@@ -0,0 +1,37 @@
+use crate::{init::OxrPreUpdateSet, resources::OxrSession};
+use bevy::prelude::*;
+use bevy_xr::session::{session_running, status_changed_to};
+
+impl Plugin for OxrActionSyncingPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_event::<OxrAttachActionSet>();
+        app.add_systems(
+            PreUpdate,
+            sync_sets
+                .run_if(session_running)
+                .in_set(OxrPreUpdateSet::SyncActions),
+        );
+    }
+}
+
+fn sync_sets(session: Res<OxrSession>, mut events: EventReader<OxrSyncActionSet>) {
+    let sets = events
+        .read()
+        .map(|v| &v.0)
+        .map(|s| openxr::ActionSet::from(s))
+        .collect::<Vec<_>>();
+
+    if sets.is_empty() {
+        return;
+    }
+
+    if let Err(err) = session.sync_actions(sets) {
+        warn!("error while syncing actionsets: {}", err.to_string());
+    }
+}
+
+#[derive(Event, Clone)]
+/// Send this event for every ActionSet you want to attach to the [`OxrSession`] once the Session Status changed to Ready. all requests will
+pub struct OxrSyncActionSet(pub openxr::ActionSet);
+
+pub struct OxrActionSyncingPlugin;