Oops forgot new files

Source/StevesUEHelpers/Private/StevesUI/MenuSystem.cpp

@@ -0,0 +1,75 @@
+#include "StevesUI/MenuSystem.h"
+#include "StevesUI/MenuStack.h"
+
+DEFINE_LOG_CATEGORY(LogMenuSystem)
+
+TWeakObjectPtr<UMenuStack> FMenuSystem::GetHighestFocusPriority()
+{
+    int Highest = -999;
+    TWeakObjectPtr<UMenuStack> Ret;
+    
+    for (auto && S : ActiveMenuStacks)
+    {
+        if (S.IsValid() && S->IsRequestingFocus() && S->FocusPriority > Highest)
+        {
+            Highest = S->FocusPriority;
+            Ret = S;
+        }
+    }
+        
+    return Ret;
+}
+
+void FMenuSystem::MenuStackOpened(UMenuStack* Stack)
+{
+    UE_LOG(LogMenuSystem, Display, TEXT("MenuStack %s opened"), *Stack->GetName());
+    // check to make sure we never dupe, shouldn't normally be a problem
+    // but let's just be safe, there will never be that many
+    bool bPresent = false;    
+    for (auto && S : ActiveMenuStacks)
+    {
+        if (S.Get() == Stack)
+        {
+            bPresent = true;
+            break;
+        }
+    }
+    if (!bPresent)
+        ActiveMenuStacks.Add(Stack);
+
+    if (Stack->IsRequestingFocus())
+    {
+        auto Highest = GetHighestFocusPriority();
+        if (!Highest.IsValid() || Highest->FocusPriority <= Stack->FocusPriority)
+        {
+            // give new stack the focus if it's equal or higher priority than anything else
+            UE_LOG(LogMenuSystem, Display, TEXT("Giving focus to MenuStack %s"), *Stack->GetName());
+            Stack->TakeFocusIfDesired();
+        }        
+    }
+}
+
+void FMenuSystem::MenuStackClosed(UMenuStack* Stack)
+{
+    UE_LOG(LogMenuSystem, Display, TEXT("MenuStack %s closed"), *Stack->GetName());
+    
+    for (int i = 0; i < ActiveMenuStacks.Num(); ++i)
+    {
+        if (ActiveMenuStacks[i].Get() == Stack)
+        {
+            ActiveMenuStacks.RemoveAt(i);
+            break;
+        }
+    }
+
+    // if the menu closing had focus, give it to the highest remaining stack
+    if (Stack->HasFocusedDescendants())
+    {
+        auto Highest = GetHighestFocusPriority();
+        if (Highest.IsValid())
+        {
+            UE_LOG(LogMenuSystem, Display, TEXT("Giving focus to MenuStack %s"), *Highest->GetName());
+            Highest->TakeFocusIfDesired();
+        }       
+    }
+}

Source/StevesUEHelpers/Public/StevesUI/MenuSystem.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "CoreMinimal.h"
+
+DECLARE_LOG_CATEGORY_EXTERN(LogMenuSystem, Log, All)
+
+class FMenuSystem
+{
+protected:
+    TArray<TWeakObjectPtr<class UMenuStack>> ActiveMenuStacks;
+
+    TWeakObjectPtr<UMenuStack> GetHighestFocusPriority();
+public:
+    void MenuStackOpened(UMenuStack* Stack);
+    void MenuStackClosed(UMenuStack* Stack);
+    
+};