FIX: Fixed ISubmitHandler.OnSubmit event processing when operating in Manual Update mode (case ISXB-1141) (#2041)

* [Input System] Fix for event processing when operating in Manual Update mode (case ISXB-1141)
* [Input System] Added CHANGELOG.md entry for ISubmitHandler.OnSubmit fix (ISXB-1141)

Author: AlexTyrer

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -15,6 +15,7 @@ however, it has to be formatted properly to pass verification tests.
 - Reverted changes from 0ddd534d8 (ISXB-746) which introduced a regression [ISXB-1127](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-1127).
 - Fixed `ArgumentNullException: Value cannot be null.` during the migration of Project-wide Input Actions from `InputManager.asset` to `InputSystem_Actions.inputactions` asset which lead do the lost of the configuration [ISXB-1105](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-1105)
 - Fixed pointerId staying the same when simultaneously releasing and then pressing in the same frame on mobile using touch. [ISXB-1006](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-845)
+- Fixed ISubmitHandler.OnSubmit event processing when operating in Manual Update mode (ISXB-1141)
 
 ### Changed
 - Added back the InputManager to InputSystem project-wide asset migration code with performance improvement (ISX-2086)

Packages/com.unity.inputsystem/InputSystem/Actions/InputAction.cs

@@ -1186,6 +1186,16 @@ public unsafe bool IsInProgress()
             return false;
         }
 
+        private int ExpectedFrame()
+        {
+            // Used by the Was<XXX>ThisFrame() methods below.
+            // When processing events manually the event processing will happen one frame later.
+            //
+            int frameOffset = InputSystem.settings.updateMode == InputSettings.UpdateMode.ProcessEventsManually ? 1 : 0;
+            int expectedFrame = Time.frameCount - frameOffset;
+            return expectedFrame;
+        }
+
         /// <summary>
         /// Returns true if the action's value crossed the press threshold (see <see cref="InputSettings.defaultButtonPressPoint"/>)
         /// at any point in the frame.
@@ -1236,7 +1246,7 @@ public unsafe bool WasPressedThisFrame()
             {
                 var actionStatePtr = &state.actionStates[m_ActionIndexInState];
                 var currentUpdateStep = InputUpdate.s_UpdateStepCount;
-                return actionStatePtr->pressedInUpdate == currentUpdateStep && currentUpdateStep != default && actionStatePtr->frame == Time.frameCount;
+                return actionStatePtr->pressedInUpdate == currentUpdateStep && currentUpdateStep != default && actionStatePtr->frame == ExpectedFrame();
             }
 
             return false;
@@ -1285,7 +1295,7 @@ public unsafe bool WasReleasedThisFrame()
             {
                 var actionStatePtr = &state.actionStates[m_ActionIndexInState];
                 var currentUpdateStep = InputUpdate.s_UpdateStepCount;
-                return actionStatePtr->releasedInUpdate == currentUpdateStep && currentUpdateStep != default && actionStatePtr->frame == Time.frameCount;
+                return actionStatePtr->releasedInUpdate == currentUpdateStep && currentUpdateStep != default && actionStatePtr->frame == ExpectedFrame();
             }
 
             return false;
@@ -1344,7 +1354,7 @@ public unsafe bool WasPerformedThisFrame()
             {
                 var actionStatePtr = &state.actionStates[m_ActionIndexInState];
                 var currentUpdateStep = InputUpdate.s_UpdateStepCount;
-                return actionStatePtr->lastPerformedInUpdate == currentUpdateStep && currentUpdateStep != default && actionStatePtr->frame == Time.frameCount;
+                return actionStatePtr->lastPerformedInUpdate == currentUpdateStep && currentUpdateStep != default && actionStatePtr->frame == ExpectedFrame();
             }
 
             return false;
@@ -1417,7 +1427,7 @@ public unsafe bool WasCompletedThisFrame()
             {
                 var actionStatePtr = &state.actionStates[m_ActionIndexInState];
                 var currentUpdateStep = InputUpdate.s_UpdateStepCount;
-                return actionStatePtr->lastCompletedInUpdate == currentUpdateStep && currentUpdateStep != default && actionStatePtr->frame == Time.frameCount;
+                return actionStatePtr->lastCompletedInUpdate == currentUpdateStep && currentUpdateStep != default && actionStatePtr->frame == ExpectedFrame();
             }
 
             return false;