Replace shouldCreateHID with supportedHIDUsages

Author: jechter

Assets/Tests/InputSystem/Plugins/HIDTests.cs

@@ -79,7 +79,7 @@ public void Devices_CanCreateGenericHID()
 
     [Test]
     [Category("Devices")]
-    public void Devices_DevicesNotAllowedByShouldCreateHIDAreSkipped()
+    public void Devices_DevicesNotAllowedBySupportedHIDUsagesAreSkipped()
     {
         var hidDescriptor = new HID.HIDDeviceDescriptor
         {
@@ -107,10 +107,9 @@ public void Devices_DevicesNotAllowedByShouldCreateHIDAreSkipped()
         Assert.That(InputSystem.devices, Has.Count.EqualTo(0));
         Assert.That(InputSystem.GetDeviceById(deviceId), Is.Null);
 
-        HIDSupport.shouldCreateHID += descriptor =>
-            descriptor.usagePage == (HID.UsagePage) 5678 && descriptor.usage == 1234
-            ? true
-            : (bool?)null;
+        HIDSupport.supportedHIDUsages = new ReadOnlyArray<HIDSupport.HIDPageUsage>(
+            new[] {new HIDSupport.HIDPageUsage((HID.UsagePage) 5678, 1234)}
+        );
 
         runtime.ReportNewInputDevice(descriptionJson, deviceId);
         InputSystem.Update();

Packages/com.unity.inputsystem/InputSystem/Plugins/HID/HID.cs

@@ -91,10 +91,7 @@ internal static string OnFindLayoutForDevice(int deviceId, ref InputDeviceDescri
             // Read HID descriptor.
             var hidDeviceDescriptor = ReadHIDDeviceDescriptor(deviceId, ref description, runtime);
 
-            // Check callbacks to see whether we should actually create a device for this specific HID.
-            // If no callback says yes or one says no, we ignore the device.
-            if (HIDSupport.s_ShouldCreateHID.All(f => f(hidDeviceDescriptor) != true) ||
-                HIDSupport.s_ShouldCreateHID.Any(f => f(hidDeviceDescriptor) == false))
+            if (!HIDSupport.supportedHIDUsages.Contains(new HIDSupport.HIDPageUsage(hidDeviceDescriptor.usagePage, hidDeviceDescriptor.usage)))
                 return null;
 
             // Determine if there's any usable elements on the device.

Packages/com.unity.inputsystem/InputSystem/Plugins/HID/HIDSupport.cs

@@ -28,29 +28,27 @@ namespace UnityEngine.InputSystem.HID
     /// </remarks>
     public static class HIDSupport
     {
-        public static event ShouldCreateHIDCallback shouldCreateHID
+        public struct HIDPageUsage
         {
-            add => s_ShouldCreateHID.Append(value);
-            remove => s_ShouldCreateHID.Remove(value);
-        }
+            public HID.UsagePage page;
+            public int usage;
 
-        internal static InlinedArray<ShouldCreateHIDCallback> s_ShouldCreateHID;
+            public HIDPageUsage(HID.UsagePage page, int usage)
+            {
+                this.page = page;
+                this.usage = usage;
+            }
 
-        private static bool? DefaultShouldCreateHIDCallback(HID.HIDDeviceDescriptor descriptor)
-        {
-            if (descriptor.usagePage == HID.UsagePage.GenericDesktop)
+            public HIDPageUsage(HID.GenericDesktop usage)
             {
-                switch (descriptor.usage)
-                {
-                    case (int)HID.GenericDesktop.Joystick:
-                    case (int)HID.GenericDesktop.Gamepad:
-                    case (int)HID.GenericDesktop.MultiAxisController:
-                        return true;
-                }
+                this.page = HID.UsagePage.GenericDesktop;
+                this.usage = (int)usage;
             }
-            return null;
         }
 
+
+        public static ReadOnlyArray<HIDPageUsage> supportedHIDUsages { get; set; }
+
         /// <summary>
         /// Add support for generic HIDs to InputSystem.
         /// </summary>
@@ -61,7 +59,12 @@ public static event ShouldCreateHIDCallback shouldCreateHID
 #endif
         static void Initialize()
         {
-            s_ShouldCreateHID.Append(DefaultShouldCreateHIDCallback);
+            supportedHIDUsages = new ReadOnlyArray<HIDPageUsage>(new[]
+            {
+                new HIDPageUsage(HID.GenericDesktop.Joystick),
+                new HIDPageUsage(HID.GenericDesktop.Gamepad),
+                new HIDPageUsage(HID.GenericDesktop.MultiAxisController),
+            });
 
             InputSystem.RegisterLayout<HID>();
             InputSystem.onFindLayoutForDevice += HID.OnFindLayoutForDevice;