When using CommonUI, the FaceButton-Bottom is already reserved by the system to simulate a Mouse Left Click. It's quite annoying, so I dug into the code and "fixed" the issue.

---

Custom FCommonAnalogCursor

The FCommonAnalogCursor is an InputAction pre-processor. When an input action is consumed by this pre-processor, the EnhancedInput Subsystem won't receive this input action.

I discovered that this function in FCommonAnalogCursor is intercepting our original InputAction. So, we just need to override it to prevent FCommonAnalogCursor from handling the InputAction of FaceButton-Bottom.

bool FCommonAnalogCursor::IsRelevantInput(const FKeyEvent& KeyEvent) const
{
	return IsUsingGamepad() && FAnalogCursor::IsRelevantInput(KeyEvent) && (IsGameViewportInFocusPathWithoutCapture() || (KeyEvent.GetKey() == EKeys::Virtual_Accept && CanReleaseMouseCapture()));
}

Here is my solution:

• Create those classes:

  

• like so:

  (UCommonUIActionRouterBase not need to manually call, the SubSystem will handle it, Subsystem)

  #pragma once
  
  #include "CoreMinimal.h"
  #include "Input/CommonUIActionRouterBase.h"
  #include "AuraUIActionRouterBase.generated.h"
  UCLASS()
  class AURA_API UAuraUIActionRouterBase : public UCommonUIActionRouterBase
  {
      GENERATED_BODY()
  
  protected:
      virtual TSharedRef<FCommonAnalogCursor> MakeAnalogCursor() const override;
  
  };
  
  #include "AuraUIActionRouterBase.h"
  
  #include "AuraAnalogCursor.h"
  #include "Input/CommonAnalogCursor.h"
  
  TSharedRef<FCommonAnalogCursor> UAuraUIActionRouterBase::MakeAnalogCursor() const
  {
      return FCommonAnalogCursor::CreateAnalogCursor<FAuraAnalogCursor>(*this);
  }

  #pragma once
  #include "Input/CommonAnalogCursor.h"
  
  class FAuraAnalogCursor final : public FCommonAnalogCursor
  {
      
  public:
      explicit FAuraAnalogCursor(const UCommonUIActionRouterBase& InActionRouter)
          : FCommonAnalogCursor(InActionRouter)
      {
      }
  
  protected:
      virtual bool IsRelevantInput(const FKeyEvent& KeyEvent) const override;
  
      
  };

• Only when the Active Input Mode is Menu Mode, should it simulate the Mouse Left Click.

Other Problem

At this moment, the FaceButton-Bottom doesn't simulate a Left Mouse Click in "Game Input Mode". However, if the FaceButton-Bottom doesn't handle your custom event properly, try opening the console and typing showdebug EnhancedInput. It's possible that some other Input-Action is overriding it, so you may need to adjust the Mapping priority. Or there could be another issue to consider. Please refer to Priority.

Doc

文档还告诉我们，光标的可见性，是否居中，都可以重写这个类来自定义自己要的行为。