From f75706abc49ba887b2ee5c9bc4c539928c54b901 Mon Sep 17 00:00:00 2001
From: Steve Streeting <steve@stevestreeting.com>
Date: Wed, 18 Nov 2020 15:47:50 +0000
Subject: [PATCH] Make MenuStack able to restore input modes, game pause state
 and mouse pointer on exit

---
 .../Private/StevesUI/MenuStack.cpp            | 41 +++++++++++++++++++
 .../Public/StevesHelperCommon.h               |  3 ++
 .../Public/StevesUI/MenuStack.h               |  4 ++
 3 files changed, 48 insertions(+)

diff --git a/Source/StevesUEHelpers/Private/StevesUI/MenuStack.cpp b/Source/StevesUEHelpers/Private/StevesUI/MenuStack.cpp
index adbc45e..b236fc2 100644
--- a/Source/StevesUEHelpers/Private/StevesUI/MenuStack.cpp
+++ b/Source/StevesUEHelpers/Private/StevesUI/MenuStack.cpp
@@ -20,6 +20,8 @@ void UMenuStack::NativeConstruct()
         LastInputMode = GS->GetLastInputModeUsed();
     }
 
+    SavePreviousInputMousePauseState();
+
     ApplyInputModeChange(InputModeSettingOnOpen);
     ApplyMousePointerVisibility(MousePointerVisibilityOnOpen);
     ApplyGamePauseChange(GamePauseSettingOnOpen);
@@ -35,6 +37,36 @@ void UMenuStack::NativeDestruct()
 
 }
 
+
+void UMenuStack::SavePreviousInputMousePauseState()
+{
+    auto PC = GetOwningPlayer();    
+    UGameViewportClient* GVC = GetWorld()->GetGameViewport();
+
+    if (GVC->IgnoreInput())
+    {
+        PreviousInputMode = EInputModeChange::UIOnly;
+    }
+    else
+    {
+        const auto CaptureMode = GVC->CaptureMouseOnClick();
+        // Game-only mode captures permanently, that seems to be the best way to detect
+        if (CaptureMode == EMouseCaptureMode::CapturePermanently ||
+            CaptureMode == EMouseCaptureMode::CapturePermanently_IncludingInitialMouseDown)
+        {
+            PreviousInputMode = EInputModeChange::GameOnly;
+        }
+        else
+        {
+            PreviousInputMode = EInputModeChange::GameAndUI;
+        }
+    }
+    PreviousMouseVisibility = PC->bShowMouseCursor ? EMousePointerVisibilityChange::Visible : EMousePointerVisibilityChange::Hidden;
+    PreviousPauseState = UGameplayStatics::IsGamePaused(GetWorld()) ? EGamePauseChange::Paused : EGamePauseChange::Unpaused;
+    
+    
+}
+
 void UMenuStack::ApplyInputModeChange(EInputModeChange Change) const
 {
     auto PC = GetOwningPlayer();    
@@ -51,6 +83,9 @@ void UMenuStack::ApplyInputModeChange(EInputModeChange Change) const
     case EInputModeChange::GameOnly:
         PC->SetInputMode(FInputModeGameOnly());
         break;
+    case EInputModeChange::Restore:
+        ApplyInputModeChange(PreviousInputMode);
+        break;
     }
 }
 
@@ -67,6 +102,9 @@ void UMenuStack::ApplyMousePointerVisibility(EMousePointerVisibilityChange Chang
     case EMousePointerVisibilityChange::Hidden:
         PC->bShowMouseCursor = false;
         break;
+    case EMousePointerVisibilityChange::Restore:
+        ApplyMousePointerVisibility(PreviousMouseVisibility);
+        break;
     }
 }
 
@@ -82,6 +120,9 @@ void UMenuStack::ApplyGamePauseChange(EGamePauseChange Change) const
     case EGamePauseChange::Unpaused:
         UGameplayStatics::SetGamePaused(GetWorld(), false);
         break;
+    case EGamePauseChange::Restore:
+        ApplyGamePauseChange(PreviousPauseState);
+        break;
     }    
     
 }
diff --git a/Source/StevesUEHelpers/Public/StevesHelperCommon.h b/Source/StevesUEHelpers/Public/StevesHelperCommon.h
index d3df577..bae210e 100644
--- a/Source/StevesUEHelpers/Public/StevesHelperCommon.h
+++ b/Source/StevesUEHelpers/Public/StevesHelperCommon.h
@@ -14,6 +14,7 @@ UENUM(BlueprintType)
 enum class EInputModeChange : uint8
 {
     DoNotChange UMETA(DisplayName="No Change"),
+    Restore UMETA(DisplayName="Restore To Previous"),
     UIOnly UMETA(DisplayName="UI Only"),
     GameAndUI UMETA(DisplayName="Game And UI"),
     GameOnly UMETA(DisplayName="Game Only")
@@ -23,6 +24,7 @@ UENUM(BlueprintType)
 enum class EMousePointerVisibilityChange : uint8
 {
     DoNotChange UMETA(DisplayName="No Change"),
+    Restore UMETA(DisplayName="Restore To Previous"),
     Visible UMETA(DisplayName="Pointer Visible"),
     Hidden UMETA(DisplayName="Pointer Hidden")
 };
@@ -31,6 +33,7 @@ UENUM(BlueprintType)
 enum class EGamePauseChange : uint8
 {
     DoNotChange UMETA(DisplayName="No Change"),
+    Restore UMETA(DisplayName="Restore To Previous"),
     Paused UMETA(DisplayName="Pause Game"),
     Unpaused UMETA(DisplayName="Unpause Game")
 };
diff --git a/Source/StevesUEHelpers/Public/StevesUI/MenuStack.h b/Source/StevesUEHelpers/Public/StevesUI/MenuStack.h
index 4c3accb..f1c826a 100644
--- a/Source/StevesUEHelpers/Public/StevesUI/MenuStack.h
+++ b/Source/StevesUEHelpers/Public/StevesUI/MenuStack.h
@@ -27,6 +27,9 @@ class STEVESUEHELPERS_API UMenuStack : public UFocusableInputInterceptorUserWidg
 
 protected:
     EInputMode LastInputMode;
+    EInputModeChange PreviousInputMode;
+    EMousePointerVisibilityChange PreviousMouseVisibility;
+    EGamePauseChange PreviousPauseState;
     
     TArray<UMenuBase*> Menus;
 
@@ -35,6 +38,7 @@ protected:
     virtual void NativeConstruct() override;
     virtual void NativeDestruct() override;
 
+    void SavePreviousInputMousePauseState();
     virtual void ApplyInputModeChange(EInputModeChange Change) const;
     virtual void ApplyMousePointerVisibility(EMousePointerVisibilityChange Change) const;
     virtual void ApplyGamePauseChange(EGamePauseChange Change) const;