Convert to using IReadOnlyBindableVariable

Author: keveleigh

org.mixedrealitytoolkit.input/Controllers/HandModel.cs

@@ -94,13 +94,13 @@ protected virtual void Start()
                 }
             }
 
-            MRTKInputFocusManager.OnXrSessionFocus.AddListener(OnXrSessionFocus);
+            MRTKInputFocusManager.XrSessionHasFocus.SubscribeAndUpdate(OnXrSessionFocus);
         }
 
         /// <summary>
         /// See <see cref="MonoBehaviour"/>.
         /// </summary>
-        private void OnDestroy() => MRTKInputFocusManager.OnXrSessionFocus.RemoveListener(OnXrSessionFocus);
+        private void OnDestroy() => MRTKInputFocusManager.XrSessionHasFocus.Unsubscribe(OnXrSessionFocus);
 
         /// <summary>
         /// Sent to all GameObjects when the player gets or loses focus.

org.mixedrealitytoolkit.input/Subsystems/Hands/HandsProvider.cs

@@ -61,7 +61,7 @@ public override bool TryGetEntireHand(XRNode handNode, out IReadOnlyList<HandJoi
         {
             Debug.Assert(handNode == XRNode.LeftHand || handNode == XRNode.RightHand, "Non-hand XRNode used in TryGetEntireHand query.");
 
-            if (!MRTKInputFocusManager.HasFocus)
+            if (!MRTKInputFocusManager.XrSessionHasFocus.Value)
             {
                 jointPoses = Array.Empty<HandJointPose>();
                 return false;
@@ -75,7 +75,7 @@ public override bool TryGetJoint(TrackedHandJoint joint, XRNode handNode, out Ha
         {
             Debug.Assert(handNode == XRNode.LeftHand || handNode == XRNode.RightHand, "Non-hand XRNode used in TryGetJoint query.");
 
-            if (!MRTKInputFocusManager.HasFocus)
+            if (!MRTKInputFocusManager.XrSessionHasFocus.Value)
             {
                 jointPose = default;
                 return false;

org.mixedrealitytoolkit.input/Utilities/MRTKInputFocusManager.cs

@@ -2,8 +2,8 @@
 // Licensed under the BSD 3-Clause
 
 using System.Collections.Generic;
+using Unity.XR.CoreUtils.Bindings.Variables;
 using UnityEngine;
-using UnityEngine.Events;
 using UnityEngine.InputSystem;
 
 namespace MixedReality.Toolkit.Input
@@ -17,20 +17,11 @@ public sealed class MRTKInputFocusManager : MonoBehaviour
         private InputActionReference[] inputActionReferences;
 
         /// <summary>
-        /// Provides an event based on the current XrSession becoming focused or not.
-        /// </summary>
-        public static UnityEvent<bool> OnXrSessionFocus { get; } = new UnityEvent<bool>();
-
-        /// <summary>
-        /// Whether the current XrSession has focus or not.
+        /// Whether the current XrSession has focus or not, stored as a bindable variable that can be subscribed to for value changes.
         /// </summary>
         /// <remarks>Always <see langword="true"/> in the editor.</remarks>
-        public static bool HasFocus => Application.isEditor ||
-#if SNAPDRAGON_SPACES_PRESENT
-            lastSessionState == 5;
-#else
-            Application.isFocused;
-#endif
+        public static IReadOnlyBindableVariable<bool> XrSessionHasFocus => xrSessionHasFocus;
+        private static readonly BindableVariable<bool> xrSessionHasFocus = new(Application.isEditor);
 
         /// <summary>
         /// We want to ensure we're focused for input, as some runtimes continue reporting "tracked" while pose updates are paused.
@@ -40,7 +31,7 @@ public sealed class MRTKInputFocusManager : MonoBehaviour
         /// </summary>
         private void OnFocusChange(bool focus)
         {
-            OnXrSessionFocus?.Invoke(focus);
+            xrSessionHasFocus.Value = focus;
 
             foreach (InputActionReference reference in inputActionReferences)
             {