Addressed multiple minor CR comments.

Signed-off-by: Danilo Aimini <82231674+AMZN-daimini@users.noreply.github.com>

Code/Framework/AzToolsFramework/AzToolsFramework/FocusMode/FocusModeNotificationBus.h

@@ -13,12 +13,16 @@
 
 namespace AzToolsFramework
 {
+    //! Used to notify when the editor focus changes.
     class FocusModeNotifications
         : public AZ::EBusTraits
     {
-    public:
-        virtual ~FocusModeNotifications() = default;
+    protected:
+        ~FocusModeNotifications() = default;
 
+    public:
+        //! Triggered when the editor focus is changed to a different entity.
+        //! @param entityId The entity the focus has been moved to.
         virtual void OnEditorFocusChanged(AZ::EntityId entityId) = 0;
     };
 

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabFocusHandler.cpp

@@ -79,7 +79,7 @@ namespace AzToolsFramework::Prefab
             return AZ::Failure(AZStd::string("Prefab Focus Handler: invalid instance to focus on."));
         }
 
-        if (&m_focusedInstance->get() != &focusedInstance->get())
+        if (!m_focusedInstance.has_value() || &m_focusedInstance->get() != &focusedInstance->get())
         {
             m_focusedInstance = focusedInstance;
             m_focusedTemplateId = focusedInstance->get().GetTemplateId();
@@ -90,8 +90,7 @@ namespace AzToolsFramework::Prefab
             AzToolsFramework::SelectEntity(containerEntityId);
 
             // Focus on the descendants of the container entity
-            FocusModeInterface* focusModeInterface = AZ::Interface<FocusModeInterface>::Get();
-            if (focusModeInterface)
+            if (FocusModeInterface* focusModeInterface = AZ::Interface<FocusModeInterface>::Get())
             {
                 focusModeInterface->SetFocusRoot(containerEntityId);
             }
@@ -104,17 +103,17 @@ namespace AzToolsFramework::Prefab
         return AZ::Success();
     }
     
-    TemplateId PrefabFocusHandler::GetFocusedPrefabTemplateId()
+    TemplateId PrefabFocusHandler::GetFocusedPrefabTemplateId() const
     {
         return m_focusedTemplateId;
     }
 
-    InstanceOptionalReference PrefabFocusHandler::GetFocusedPrefabInstance()
+    InstanceOptionalReference PrefabFocusHandler::GetFocusedPrefabInstance() const
     {
         return m_focusedInstance;
     }
 
-    bool PrefabFocusHandler::IsOwningPrefabBeingFocused(AZ::EntityId entityId)
+    bool PrefabFocusHandler::IsOwningPrefabBeingFocused(AZ::EntityId entityId) const
     {
         if (!m_focusedInstance.has_value())
         {
@@ -132,12 +131,12 @@ namespace AzToolsFramework::Prefab
         return instance.has_value() && (&instance->get() == &m_focusedInstance->get());
     }
 
-    const AZ::IO::Path& PrefabFocusHandler::GetPrefabFocusPath()
+    const AZ::IO::Path& PrefabFocusHandler::GetPrefabFocusPath() const
     {
         return m_instanceFocusPath;
     }
 
-    const int PrefabFocusHandler::GetPrefabFocusPathLength()
+    const int PrefabFocusHandler::GetPrefabFocusPathLength() const
     {
         return aznumeric_cast<int>(m_instanceFocusVector.size());
     }

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabFocusHandler.h

@@ -30,16 +30,16 @@ namespace AzToolsFramework::Prefab
         PrefabFocusHandler();
         ~PrefabFocusHandler();
 
-        // PrefabFocusInterface override ...
+        // PrefabFocusInterface overrides ...
         PrefabFocusOperationResult FocusOnOwningPrefab(AZ::EntityId entityId) override;
         PrefabFocusOperationResult FocusOnPathIndex(int index) override;
-        TemplateId GetFocusedPrefabTemplateId() override;
-        InstanceOptionalReference GetFocusedPrefabInstance() override;
-        bool IsOwningPrefabBeingFocused(AZ::EntityId entityId) override;
-        const AZ::IO::Path& GetPrefabFocusPath() override;
-        const int GetPrefabFocusPathLength() override;
+        TemplateId GetFocusedPrefabTemplateId() const override;
+        InstanceOptionalReference GetFocusedPrefabInstance() const override;
+        bool IsOwningPrefabBeingFocused(AZ::EntityId entityId) const override;
+        const AZ::IO::Path& GetPrefabFocusPath() const override;
+        const int GetPrefabFocusPathLength() const override;
 
-        // EditorEntityContextNotificationBus...
+        // EditorEntityContextNotificationBus overrides ...
         void OnEntityStreamLoadSuccess() override;
 
     private:

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabFocusInterface.h

@@ -33,22 +33,22 @@ namespace AzToolsFramework::Prefab
         virtual PrefabFocusOperationResult FocusOnPathIndex(int index) = 0;
 
         //! Returns the template id of the instance the prefab system is focusing on.
-        virtual TemplateId GetFocusedPrefabTemplateId() = 0;
+        virtual TemplateId GetFocusedPrefabTemplateId() const = 0;
 
         //! Returns a reference to the instance the prefab system is focusing on.
-        virtual InstanceOptionalReference GetFocusedPrefabInstance() = 0;
+        virtual InstanceOptionalReference GetFocusedPrefabInstance() const = 0;
 
         //! Returns whether the entity belongs to the instance that is being focused on, or one of its descendants.
         //! @param entityId The entityId of the queried entity.
         //! @return true if the entity belongs to the focused instance or one of its descendants, false otherwise.
-        virtual bool IsOwningPrefabBeingFocused(AZ::EntityId entityId) = 0;
+        virtual bool IsOwningPrefabBeingFocused(AZ::EntityId entityId) const = 0;
 
         //! Returns the path from the root instance to the currently focused instance.
         //! @return A path composed from the names of the container entities for the instance path.
-        virtual const AZ::IO::Path& GetPrefabFocusPath() = 0;
+        virtual const AZ::IO::Path& GetPrefabFocusPath() const = 0;
 
         //! Returns the size of the path to the currently focused instance.
-        virtual const int GetPrefabFocusPathLength() = 0;
+        virtual const int GetPrefabFocusPathLength() const = 0;
     };
 
 } // namespace AzToolsFramework::Prefab

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabFocusNotificationBus.h

@@ -9,14 +9,19 @@
 #pragma once
 
 #include <AzCore/EBus/EBus.h>
+#include <AzFramework/Entity/EntityContext.h>
 
 namespace AzToolsFramework::Prefab
 {
-    class PrefabFocusNotifications : public AZ::EBusTraits
+    //! Used to notify when the editor focus changes.
+    class PrefabFocusNotifications
+        : public AZ::EBusTraits
     {
-    public:
-        virtual ~PrefabFocusNotifications() = default;
+    protected:
+        ~PrefabFocusNotifications() = default;
 
+    public:
+        //! Triggered when the editor focus is changed to a different prefab.
         virtual void OnPrefabFocusChanged() = 0;
     };
 

Code/Framework/AzToolsFramework/AzToolsFramework/UI/Prefab/PrefabViewportFocusPathHandler.cpp

@@ -49,9 +49,7 @@ namespace AzToolsFramework::Prefab
         connect(m_backButton, &QToolButton::clicked, this,
             [&]()
             {
-                int length = m_prefabFocusInterface->GetPrefabFocusPathLength();
-
-                if (length > 1)
+                if (int length = m_prefabFocusInterface->GetPrefabFocusPathLength(); length > 1)
                 {
                     m_prefabFocusInterface->FocusOnPathIndex(length - 2);
                 }

Code/Framework/AzToolsFramework/AzToolsFramework/UI/Prefab/PrefabViewportFocusPathHandler.h

@@ -29,7 +29,7 @@ namespace AzToolsFramework::Prefab
 
         void Initialize(AzQtComponents::BreadCrumbs* breadcrumbsWidget, QToolButton* backButton);
 
-        // PrefabFocusNotificationBus...
+        // PrefabFocusNotificationBus overrides ...
         void OnPrefabFocusChanged() override;
 
     private: