Remove the PrefabEditManager. Introduce the FocusMode system on the Editor side, and a PrefabFocusHandler on the Prefab side to handle focus.

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

Code/Framework/AzToolsFramework/AzToolsFramework/Application/ToolsApplication.cpp

@@ -28,6 +28,7 @@
 #include <AzToolsFramework/ToolsComponents/TransformComponent.h>
 #include <AzToolsFramework/Entity/EditorEntityContextComponent.h>
 #include <AzToolsFramework/Entity/EditorEntityInfoBus.h>
+#include <AzToolsFramework/FocusMode/FocusModeSystemComponent.h>
 #include <AzToolsFramework/Slice/SliceMetadataEntityContextComponent.h>
 #include <AzToolsFramework/Prefab/PrefabSystemComponent.h>
 #include <AzToolsFramework/UI/Prefab/PrefabIntegrationManager.h>
@@ -248,6 +249,7 @@ namespace AzToolsFramework
         components.insert(components.end(), {
                 azrtti_typeid<EditorEntityContextComponent>(),
                 azrtti_typeid<Components::EditorEntityUiSystemComponent>(),
+                azrtti_typeid<FocusModeFramework::FocusModeSystemComponent>(),
                 azrtti_typeid<SliceMetadataEntityContextComponent>(),
                 azrtti_typeid<Prefab::PrefabSystemComponent>(),
                 azrtti_typeid<EditorEntityFixupComponent>(),

Code/Framework/AzToolsFramework/AzToolsFramework/AzToolsFrameworkModule.cpp

@@ -22,6 +22,7 @@
 #include <AzToolsFramework/Entity/EditorEntityModelComponent.h>
 #include <AzToolsFramework/Entity/EditorEntitySearchComponent.h>
 #include <AzToolsFramework/Entity/EditorEntitySortComponent.h>
+#include <AzToolsFramework/FocusMode/FocusModeSystemComponent.h>
 #include <AzToolsFramework/PropertyTreeEditor/PropertyTreeEditorComponent.h>
 #include <AzToolsFramework/Render/EditorIntersectorComponent.h>
 #include <AzToolsFramework/Slice/SliceDependencyBrowserComponent.h>
@@ -69,6 +70,7 @@ namespace AzToolsFramework
             Components::EditorSelectionAccentSystemComponent::CreateDescriptor(),
             EditorEntityContextComponent::CreateDescriptor(),
             EditorEntityFixupComponent::CreateDescriptor(),
+            FocusModeFramework::FocusModeSystemComponent::CreateDescriptor(),
             SliceMetadataEntityContextComponent::CreateDescriptor(),
             SliceRequestComponent::CreateDescriptor(),
             Prefab::PrefabSystemComponent::CreateDescriptor(),

Code/Framework/AzToolsFramework/AzToolsFramework/FocusMode/FocusModeInterface.h

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) Contributors to the Open 3D Engine Project. For complete copyright and license terms please see the LICENSE at the root of
+ * this distribution.
+ *
+ * SPDX-License-Identifier: Apache-2.0 OR MIT
+ *
+ */
+
+#pragma once
+
+#include <AzCore/Interface/Interface.h>
+#include <AzCore/Serialization/SerializeContext.h>
+
+
+namespace AzToolsFramework::FocusModeFramework
+{
+    /*!
+     * FocusModeInterface
+     * Interface to handle the Editor Focus Mode.
+     */
+    class FocusModeInterface
+    {
+    public:
+        AZ_RTTI(FocusModeInterface, "{437243B0-F86B-422F-B7B8-4A21CC000702}");
+
+        //! Sets the root entity the Editor should focus on.
+        //! The Editor will only allow the user to select entities belonging to the sub-tree that has root in the entityId provided.
+        //! @param entityId The entityId that will become the new focus root.
+        virtual void SetFocusRoot(AZ::EntityId entityId) = 0;
+
+        //! Returns the entity id of the root of the current Editor focus.
+        //! @return The id of the entity that is the root of the Editor focus.
+        virtual AZ::EntityId GetFocusRoot() = 0;
+
+        //! Returns whether the entity id provided is part of the focused sub-tree.
+        //! @return True if entityId belongs to the focused sub-tree, false otherwise.
+        virtual bool IsInFocusSubTree(AZ::EntityId entityId) = 0;
+    };
+
+} // namespace AzToolsFramework::FocusModeFrameworkclassPrefabEditPublicInterface

Code/Framework/AzToolsFramework/AzToolsFramework/FocusMode/FocusModeSystemComponent.cpp

@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) Contributors to the Open 3D Engine Project. For complete copyright and license terms please see the LICENSE at the root of
+ * this distribution.
+ *
+ * SPDX-License-Identifier: Apache-2.0 OR MIT
+ *
+ */
+
+#pragma once
+
+#include <AzCore/Component/TransformBus.h>
+
+#include <AzToolsFramework/FocusMode/FocusModeSystemComponent.h>
+
+namespace AzToolsFramework::FocusModeFramework
+{
+    FocusModeSystemComponent::~FocusModeSystemComponent()
+    {
+        AZ::Interface<FocusModeInterface>::Unregister(this);
+    }
+
+    void FocusModeSystemComponent::Init()
+    {
+        AZ::Interface<FocusModeInterface>::Register(this);
+    }
+
+    void FocusModeSystemComponent::Activate()
+    {
+    }
+
+    void FocusModeSystemComponent::Deactivate()
+    {
+    }
+
+    void FocusModeSystemComponent::Reflect(AZ::ReflectContext* /*context*/)
+    {
+    }
+
+    void FocusModeSystemComponent::GetProvidedServices(AZ::ComponentDescriptor::DependencyArrayType& provided)
+    {
+        provided.push_back(AZ_CRC_CE("EditorFocusMode"));
+    }
+
+    void FocusModeSystemComponent::GetRequiredServices([[maybe_unused]] AZ::ComponentDescriptor::DependencyArrayType& required)
+    {
+    }
+
+    void FocusModeSystemComponent::GetIncompatibleServices([[maybe_unused]] AZ::ComponentDescriptor::DependencyArrayType& incompatible)
+    {
+    }
+
+    void FocusModeSystemComponent::SetFocusRoot(AZ::EntityId entityId)
+    {
+        m_focusRoot = entityId;
+
+        // TODO - If m_focusRoot != AZ::EntityId(), register focus mode
+        //        Else, unregister focus mode
+    }
+
+    AZ::EntityId FocusModeSystemComponent::GetFocusRoot()
+    {
+        return m_focusRoot;
+    }
+
+    bool FocusModeSystemComponent::IsInFocusSubTree(AZ::EntityId entityId)
+    {
+        if (m_focusRoot == AZ::EntityId())
+        {
+            return true;
+        }
+
+        return IsInFocusSubTree_helper(entityId, m_focusRoot);
+    }
+
+    bool FocusModeSystemComponent::IsInFocusSubTree_helper(AZ::EntityId entityId, AZ::EntityId focusRootId)
+    {
+        if (entityId == AZ::EntityId())
+        {
+            return false;
+        }
+
+        if (entityId == focusRootId)
+        {
+            return true;
+        }
+
+        AZ::EntityId parentId;
+        AZ::TransformBus::EventResult(parentId, entityId, &AZ::TransformInterface::GetParentId);
+
+        return IsInFocusSubTree_helper(parentId, focusRootId);
+    }
+
+} // namespace AzToolsFramework::FocusModeFramework

Code/Framework/AzToolsFramework/AzToolsFramework/FocusMode/FocusModeSystemComponent.h

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) Contributors to the Open 3D Engine Project. For complete copyright and license terms please see the LICENSE at the root of
+ * this distribution.
+ *
+ * SPDX-License-Identifier: Apache-2.0 OR MIT
+ *
+ */
+
+#pragma once
+
+#include <AzCore/Component/Component.h>
+#include <AzCore/Memory/SystemAllocator.h>
+
+#include <AzToolsFramework/FocusMode/FocusModeInterface.h>
+
+namespace AzToolsFramework::FocusModeFramework
+{
+    class FocusModeSystemComponent final
+        : public AZ::Component
+        , private FocusModeInterface
+    {
+    public:
+        AZ_COMPONENT(FocusModeSystemComponent, "{6CE522FE-2057-4794-BD05-61E04BD8EA30}");
+
+        FocusModeSystemComponent() = default;
+        virtual ~FocusModeSystemComponent();
+
+        // AZ::Component...
+        void Init() override;
+        void Activate() override;
+        void Deactivate() override;
+
+        static void Reflect(AZ::ReflectContext* context);
+        static void GetProvidedServices(AZ::ComponentDescriptor::DependencyArrayType& provided);
+        static void GetRequiredServices(AZ::ComponentDescriptor::DependencyArrayType& required);
+        static void GetIncompatibleServices(AZ::ComponentDescriptor::DependencyArrayType& incompatible);
+
+        // FocusModeInterface...
+        void SetFocusRoot(AZ::EntityId entityId) override;
+        AZ::EntityId GetFocusRoot() override;
+        bool IsInFocusSubTree(AZ::EntityId entityId) override;
+
+    private:
+        static bool IsInFocusSubTree_helper(AZ::EntityId entityId, AZ::EntityId focusRootId);
+
+        AZ::EntityId m_focusRoot;
+    };
+
+} // namespace AzToolsFramework::FocusModeFramework

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

@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) Contributors to the Open 3D Engine Project.
+ * For complete copyright and license terms please see the LICENSE at the root of this distribution.
+ *
+ * SPDX-License-Identifier: Apache-2.0 OR MIT
+ *
+ */
+
+#include <AzToolsFramework/Prefab/PrefabFocusHandler.h>
+
+#include <AzToolsFramework/Entity/PrefabEditorEntityOwnershipInterface.h>
+#include <AzToolsFramework/Prefab/Instance/Instance.h>
+#include <AzToolsFramework/Prefab/Instance/InstanceEntityMapperInterface.h>
+
+namespace AzToolsFramework::Prefab
+{
+    FocusModeFramework::FocusModeInterface* PrefabFocusHandler::s_focusModeInterface = nullptr;
+    InstanceEntityMapperInterface* PrefabFocusHandler::s_instanceEntityMapperInterface = nullptr;
+    PrefabEditorEntityOwnershipInterface* PrefabFocusHandler::s_prefabEditorEntityOwnershipInterface = nullptr;
+
+    PrefabFocusHandler::~PrefabFocusHandler()
+    {
+        AZ::Interface<PrefabFocusInterface>::Unregister(this);
+    }
+
+    void PrefabFocusHandler::Initialize()
+    {
+        s_focusModeInterface = AZ::Interface<FocusModeFramework::FocusModeInterface>::Get();
+        AZ_Assert(
+            s_focusModeInterface,
+            "Prefab - PrefabFocusHandler - "
+            "Focus Mode Interface could not be found. "
+            "Check that it is being correctly initialized.");
+
+        s_instanceEntityMapperInterface = AZ::Interface<InstanceEntityMapperInterface>::Get();
+        AZ_Assert(
+            s_instanceEntityMapperInterface,
+            "Prefab - PrefabFocusHandler - "
+            "Instance Entity Mapper Interface could not be found. "
+            "Check that it is being correctly initialized.");
+
+        s_prefabEditorEntityOwnershipInterface = AZ::Interface<PrefabEditorEntityOwnershipInterface>::Get();
+        AZ_Assert(
+            s_prefabEditorEntityOwnershipInterface,
+            "Prefab - PrefabFocusHandler - "
+            "Prefab Editor Entity Ownership Interface could not be found. "
+            "Check that it is being correctly initialized.");
+
+        AZ::Interface<PrefabFocusInterface>::Register(this);
+    }
+
+    void PrefabFocusHandler::FocusOnOwningPrefab(AZ::EntityId entityId)
+    {
+        InstanceOptionalReference focusedInstance;
+
+        if (entityId == AZ::EntityId())
+        {
+            focusedInstance = s_prefabEditorEntityOwnershipInterface->GetRootPrefabInstance();
+        }
+        else
+        {
+            focusedInstance = s_instanceEntityMapperInterface->FindOwningInstance(entityId);
+        }
+
+        if (!focusedInstance.has_value())
+        {
+            // TODO - ERROR
+        }
+
+        m_focusedInstance = focusedInstance;
+        m_focusedTemplateId = focusedInstance->get().GetTemplateId();
+        s_focusModeInterface->SetFocusRoot(focusedInstance->get().GetContainerEntityId());
+    }
+    
+    TemplateId PrefabFocusHandler::GetFocusedPrefabTemplateId()
+    {
+        return m_focusedTemplateId;
+    }
+
+    InstanceOptionalReference PrefabFocusHandler::GetFocusedPrefabInstance()
+    {
+        return m_focusedInstance;
+    }
+
+    bool PrefabFocusHandler::IsOwningPrefabBeingFocused(AZ::EntityId entityId)
+    {
+        if (entityId == AZ::EntityId())
+        {
+            // TODO - Warn?
+            return false;
+        }
+
+        InstanceOptionalReference instance = s_instanceEntityMapperInterface->FindOwningInstance(entityId);
+
+        if (!instance.has_value())
+        {
+            // TODO - ERROR
+        }
+
+        return (&instance->get() == &m_focusedInstance->get());
+    }
+
+} // namespace AzToolsFramework::Prefab

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

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) Contributors to the Open 3D Engine Project. For complete copyright and license terms please see the LICENSE at the root of
+ * this distribution.
+ *
+ * SPDX-License-Identifier: Apache-2.0 OR MIT
+ *
+ */
+
+#pragma once
+
+#include <AzCore/Memory/SystemAllocator.h>
+
+#include <AzToolsFramework/FocusMode/FocusModeInterface.h>
+#include <AzToolsFramework/Prefab/PrefabFocusInterface.h>
+#include <AzToolsFramework/Prefab/Template/Template.h>
+
+namespace AzToolsFramework
+{
+    class PrefabEditorEntityOwnershipInterface;
+}
+
+namespace AzToolsFramework::FocusModeFramework
+{
+    class FocusModeInterface;
+}
+
+namespace AzToolsFramework::Prefab
+{
+    class InstanceEntityMapperInterface;
+
+    class PrefabFocusHandler final
+        : private PrefabFocusInterface
+    {
+    public:
+        AZ_CLASS_ALLOCATOR(PrefabFocusHandler, AZ::SystemAllocator, 0);
+
+        ~PrefabFocusHandler();
+
+        void Initialize();
+
+        // PrefabFocusInterface...
+        void FocusOnOwningPrefab(AZ::EntityId entityId) override;
+        TemplateId GetFocusedPrefabTemplateId() override;
+        InstanceOptionalReference GetFocusedPrefabInstance() override;
+        bool IsOwningPrefabBeingFocused(AZ::EntityId entityId) override;
+
+    private:
+        InstanceOptionalReference m_focusedInstance;
+        TemplateId m_focusedTemplateId;
+
+        static FocusModeFramework::FocusModeInterface* s_focusModeInterface;
+        static InstanceEntityMapperInterface* s_instanceEntityMapperInterface;
+        static PrefabEditorEntityOwnershipInterface* s_prefabEditorEntityOwnershipInterface;
+    };
+
+} // namespace AzToolsFramework::Prefab

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

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) Contributors to the Open 3D Engine Project. For complete copyright and license terms please see the LICENSE at the root of
+ * this distribution.
+ *
+ * SPDX-License-Identifier: Apache-2.0 OR MIT
+ *
+ */
+
+#pragma once
+
+#include <AzCore/Interface/Interface.h>
+#include <AzCore/Serialization/SerializeContext.h>
+
+#include <AzToolsFramework/Prefab/Instance/Instance.h>
+#include <AzToolsFramework/Prefab/Template/Template.h>
+
+namespace AzToolsFramework::Prefab
+{
+    /*!
+     * PrefabFocusInterface
+     */
+    class PrefabFocusInterface
+    {
+    public:
+        AZ_RTTI(PrefabFocusInterface, "{F3CFA37B-5FD8-436A-9C30-60EB54E350E1}");
+
+        // TODO - Add comment
+        virtual void FocusOnOwningPrefab(AZ::EntityId entityId) = 0;
+
+        // TODO - Add comment
+        virtual TemplateId GetFocusedPrefabTemplateId() = 0;
+
+        // TODO - Add comment
+        virtual InstanceOptionalReference GetFocusedPrefabInstance() = 0;
+
+        // TODO - Add comment
+        virtual bool IsOwningPrefabBeingFocused(AZ::EntityId entityId) = 0;
+    };
+
+} // namespace AzToolsFramework::Prefab

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabSystemComponent.cpp

@@ -34,6 +34,7 @@ namespace AzToolsFramework
             m_prefabLoader.RegisterPrefabLoaderInterface();
             m_instanceUpdateExecutor.RegisterInstanceUpdateExecutorInterface();
             m_instanceToTemplatePropagator.RegisterInstanceToTemplateInterface();
+            m_prefabFocusHandler.Initialize();
             m_prefabPublicHandler.RegisterPrefabPublicHandlerInterface();
             m_prefabPublicRequestHandler.Connect();
             AZ::SystemTickBus::Handler::BusConnect();

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabSystemComponent.h

@@ -21,6 +21,7 @@
 #include <AzToolsFramework/Prefab/Instance/InstanceToTemplatePropagator.h>
 #include <AzToolsFramework/Prefab/Instance/TemplateInstanceMapper.h>
 #include <AzToolsFramework/Prefab/Link/Link.h>
+#include <AzToolsFramework/Prefab/PrefabFocusHandler.h>
 #include <AzToolsFramework/Prefab/PrefabIdTypes.h>
 #include <AzToolsFramework/Prefab/PrefabLoader.h>
 #include <AzToolsFramework/Prefab/PrefabPublicHandler.h>
@@ -369,7 +370,7 @@ namespace AzToolsFramework
             // A counter for generating unique Link Ids.
             AZStd::atomic<LinkId> m_linkIdCounter = 0u;
 
-            // Used for finding the owning instance of an arbitrary entity
+            // Used for finding the owning instance of an arbitrary entity.
             InstanceEntityMapper m_instanceEntityMapper;
 
             // Used for finding the Instances owned by an arbitrary Template.
@@ -378,16 +379,19 @@ namespace AzToolsFramework
             // Used for loading/saving Prefab Template files.
             PrefabLoader m_prefabLoader;
 
-            // Handler the public Prefab API used by UI and scripting
+            // Handles the Prefab Focus API that determines what prefab is being edited.
+            PrefabFocusHandler m_prefabFocusHandler;
+
+            // Handles the public Prefab API used by UI and scripting.
             PrefabPublicHandler m_prefabPublicHandler;
 
             // Used for updating Instances of Prefab Template.
             InstanceUpdateExecutor m_instanceUpdateExecutor;
 
-            // Used for updating Templates when Instances are modified
+            // Used for updating Templates when Instances are modified.
             InstanceToTemplatePropagator m_instanceToTemplatePropagator;
 
-            // Handler of the public Prefab requests
+            // Handler of the public Prefab requests.
             PrefabPublicRequestHandler m_prefabPublicRequestHandler;
         };
     } // namespace Prefab

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

@@ -8,7 +8,6 @@
 
 #include <AzToolsFramework/UI/Prefab/LevelRootUiHandler.h>
 
-#include <AzToolsFramework/UI/Prefab/PrefabEditInterface.h>
 #include <AzToolsFramework/Prefab/PrefabPublicInterface.h>
 #include <AzToolsFramework/UI/Outliner/EntityOutlinerListModel.hxx>
 
@@ -24,14 +23,6 @@ namespace AzToolsFramework
 
     LevelRootUiHandler::LevelRootUiHandler()
     {
-        m_prefabEditInterface = AZ::Interface<Prefab::PrefabEditInterface>::Get();
-
-        if (m_prefabEditInterface == nullptr)
-        {
-            AZ_Assert(false, "LevelRootUiHandler - could not get PrefabEditInterface on LevelRootUiHandler construction.");
-            return;
-        }
-
         m_prefabPublicInterface = AZ::Interface<Prefab::PrefabPublicInterface>::Get();
 
         if (m_prefabPublicInterface == nullptr)

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

@@ -14,7 +14,6 @@ namespace AzToolsFramework
 {
     namespace Prefab
     {
-        class PrefabEditInterface;
         class PrefabPublicInterface;
     };
 
@@ -36,7 +35,6 @@ namespace AzToolsFramework
         void PaintItemBackground(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const override;
 
     private:
-        Prefab::PrefabEditInterface* m_prefabEditInterface = nullptr;
         Prefab::PrefabPublicInterface* m_prefabPublicInterface = nullptr;
 
         static constexpr int m_levelRootBorderThickness = 1;

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

@@ -1,43 +0,0 @@
-/*
- * Copyright (c) Contributors to the Open 3D Engine Project.
- * For complete copyright and license terms please see the LICENSE at the root of this distribution.
- *
- * SPDX-License-Identifier: Apache-2.0 OR MIT
- *
- */
-
-#pragma once
-
-#include <AzCore/Interface/Interface.h>
-#include <AzCore/Serialization/SerializeContext.h>
-
-namespace AzToolsFramework
-{
-    namespace Prefab
-    {
-        /*!
-         * PrefabEditInterface
-         * Interface to expose the API to Edit Prefabs in the Editor.
-         */
-        class PrefabEditInterface
-        {
-        public:
-            AZ_RTTI(PrefabEditInterface, "{DABB1D43-3760-420E-9F1E-5104F0AFF167}");
-
-            /**
-             * Sets the prefab for the instance owning the entity provided as the prefab being edited.
-             * @param entityId The entity whose owning prefab should be edited.
-             */
-            virtual void EditOwningPrefab(AZ::EntityId entityId) = 0;
-            
-            /**
-             * Queries the Edit Manager to know if the provided entity is part of the prefab currently being edited.
-             * @param entityId The entity whose prefab editing state we want to query.
-             * @return True if the prefab owning this entity is being edited, false otherwise.
-             */
-            virtual bool IsOwningPrefabBeingEdited(AZ::EntityId entityId) = 0;
-        };
-
-    } // namespace Prefab
-} // namespace AzToolsFramework
-

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

@@ -1,46 +0,0 @@
-/*
- * Copyright (c) Contributors to the Open 3D Engine Project.
- * For complete copyright and license terms please see the LICENSE at the root of this distribution.
- *
- * SPDX-License-Identifier: Apache-2.0 OR MIT
- *
- */
-
-#include <AzToolsFramework/UI/Prefab/PrefabEditManager.h>
-
-#include <AzCore/Serialization/SerializeContext.h>
-
-namespace AzToolsFramework
-{
-    namespace Prefab
-    {
-        PrefabEditManager::PrefabEditManager()
-        {
-            m_prefabPublicInterface = AZ::Interface<PrefabPublicInterface>::Get();
-
-            if (m_prefabPublicInterface == nullptr)
-            {
-                AZ_Assert(false, "Prefab - could not get PrefabPublicInterface on PrefabEditManager construction.");
-                return;
-            }
-
-            AZ::Interface<PrefabEditInterface>::Register(this);
-        }
-
-        PrefabEditManager::~PrefabEditManager()
-        {
-            AZ::Interface<PrefabEditInterface>::Unregister(this);
-        }
-
-        void PrefabEditManager::EditOwningPrefab(AZ::EntityId entityId)
-        {
-            m_instanceBeingEdited = m_prefabPublicInterface->GetInstanceContainerEntityId(entityId);
-        }
-
-        bool PrefabEditManager::IsOwningPrefabBeingEdited(AZ::EntityId entityId)
-        {
-            AZ::EntityId containerEntity = m_prefabPublicInterface->GetInstanceContainerEntityId(entityId);
-            return m_instanceBeingEdited == containerEntity;
-        }
-    }
-}

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

@@ -1,40 +0,0 @@
-/*
- * Copyright (c) Contributors to the Open 3D Engine Project.
- * For complete copyright and license terms please see the LICENSE at the root of this distribution.
- *
- * SPDX-License-Identifier: Apache-2.0 OR MIT
- *
- */
-
-#pragma once
-
-#include <AzCore/Component/EntityId.h>
-#include <AzCore/Memory/SystemAllocator.h>
-
-#include <AzToolsFramework/Prefab/PrefabPublicInterface.h>
-#include <AzToolsFramework/UI/Prefab/PrefabEditInterface.h>
-
-namespace AzToolsFramework
-{
-    namespace Prefab
-    {
-        class PrefabEditManager final
-            : private PrefabEditInterface
-        {
-        public:
-            AZ_CLASS_ALLOCATOR(PrefabEditManager, AZ::SystemAllocator, 0);
-
-            PrefabEditManager();
-            ~PrefabEditManager();
-
-        private:
-            // PrefabEditInterface...
-            void EditOwningPrefab(AZ::EntityId entityId) override;
-            bool IsOwningPrefabBeingEdited(AZ::EntityId entityId) override;
-
-            AZ::EntityId m_instanceBeingEdited;
-
-            PrefabPublicInterface* m_prefabPublicInterface;
-        };
-    }
-}

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

@@ -22,6 +22,7 @@
 #include <AzToolsFramework/AssetBrowser/AssetBrowserBus.h>
 #include <AzToolsFramework/AssetBrowser/AssetSelectionModel.h>
 #include <AzToolsFramework/AssetBrowser/Entries/SourceAssetBrowserEntry.h>
+#include <AzToolsFramework/Prefab/PrefabFocusInterface.h>
 #include <AzToolsFramework/Prefab/PrefabLoaderInterface.h>
 #include <AzToolsFramework/ToolsComponents/EditorLayerComponentBus.h>
 #include <AzToolsFramework/UI/EditorEntityUi/EditorEntityUiInterface.h>
@@ -57,9 +58,9 @@ namespace AzToolsFramework
     {
         
         EditorEntityUiInterface* PrefabIntegrationManager::s_editorEntityUiInterface = nullptr;
-        PrefabPublicInterface* PrefabIntegrationManager::s_prefabPublicInterface = nullptr;
-        PrefabEditInterface* PrefabIntegrationManager::s_prefabEditInterface = nullptr;
+        PrefabFocusInterface* PrefabIntegrationManager::s_prefabFocusInterface = nullptr;
         PrefabLoaderInterface* PrefabIntegrationManager::s_prefabLoaderInterface = nullptr;
+        PrefabPublicInterface* PrefabIntegrationManager::s_prefabPublicInterface = nullptr;
         PrefabSystemComponentInterface* PrefabIntegrationManager::s_prefabSystemComponentInterface = nullptr;
 
         const AZStd::string PrefabIntegrationManager::s_prefabFileExtension = ".prefab";
@@ -102,13 +103,6 @@ namespace AzToolsFramework
                 return;
             }
 
-            s_prefabEditInterface = AZ::Interface<PrefabEditInterface>::Get();
-            if (s_prefabEditInterface == nullptr)
-            {
-                AZ_Assert(false, "Prefab - could not get PrefabEditInterface on PrefabIntegrationManager construction.");
-                return;
-            }
-
             s_prefabLoaderInterface = AZ::Interface<PrefabLoaderInterface>::Get();
             if (s_prefabLoaderInterface == nullptr)
             {
@@ -123,6 +117,13 @@ namespace AzToolsFramework
                 return;
             }
 
+            s_prefabFocusInterface = AZ::Interface<PrefabFocusInterface>::Get();
+            if (s_prefabFocusInterface == nullptr)
+            {
+                AZ_Assert(false, "Prefab - could not get PrefabFocusInterface on PrefabIntegrationManager construction.");
+                return;
+            }
+
             EditorContextMenuBus::Handler::BusConnect();
             PrefabInstanceContainerNotificationBus::Handler::BusConnect();
             AZ::Interface<PrefabIntegrationInterface>::Register(this);
@@ -224,7 +225,7 @@ namespace AzToolsFramework
                         // Edit Prefab
                         if (prefabWipFeaturesEnabled)
                         {
-                            bool beingEdited = s_prefabEditInterface->IsOwningPrefabBeingEdited(selectedEntity);
+                            bool beingEdited = s_prefabFocusInterface->IsOwningPrefabBeingFocused(selectedEntity);
 
                             if (!beingEdited)
                             {
@@ -428,7 +429,7 @@ namespace AzToolsFramework
 
         void PrefabIntegrationManager::ContextMenu_EditPrefab(AZ::EntityId containerEntity)
         {
-            s_prefabEditInterface->EditOwningPrefab(containerEntity);
+            s_prefabFocusInterface->FocusOnOwningPrefab(containerEntity);
         }
 
         void PrefabIntegrationManager::ContextMenu_SavePrefab(AZ::EntityId containerEntity)

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

@@ -17,7 +17,7 @@
 #include <AzToolsFramework/Prefab/PrefabPublicInterface.h>
 #include <AzToolsFramework/Prefab/PrefabSystemComponentInterface.h>
 #include <AzToolsFramework/UI/Prefab/LevelRootUiHandler.h>
-#include <AzToolsFramework/UI/Prefab/PrefabEditManager.h>
+
 #include <AzToolsFramework/UI/Prefab/PrefabIntegrationBus.h>
 #include <AzToolsFramework/UI/Prefab/PrefabIntegrationInterface.h>
 #include <AzToolsFramework/UI/Prefab/PrefabUiHandler.h>
@@ -28,7 +28,7 @@ namespace AzToolsFramework
 {
     namespace Prefab
     {
-
+        class PrefabFocusInterface;
         class PrefabLoaderInterface;
 
         //! Structure for saving/retrieving user settings related to prefab workflows.
@@ -80,9 +80,6 @@ namespace AzToolsFramework
             void ExecuteSavePrefabDialog(TemplateId templateId, bool useSaveAllPrefabsPreference) override;
 
         private:
-            // Manages the Edit Mode UI for prefabs
-            PrefabEditManager m_prefabEditManager;
-
             // Used to handle the UI for the level root
             LevelRootUiHandler m_levelRootUiHandler;
 
@@ -135,13 +132,12 @@ namespace AzToolsFramework
             AZStd::unique_ptr<QDialog> ConstructSavePrefabDialog(TemplateId templateId, bool useSaveAllPrefabsPreference);
             void SavePrefabsInDialog(QDialog* unsavedPrefabsDialog);
 
-
             static const AZStd::string s_prefabFileExtension;
 
             static EditorEntityUiInterface* s_editorEntityUiInterface;
-            static PrefabPublicInterface* s_prefabPublicInterface;
-            static PrefabEditInterface* s_prefabEditInterface;
+            static PrefabFocusInterface* s_prefabFocusInterface;
             static PrefabLoaderInterface* s_prefabLoaderInterface;
+            static PrefabPublicInterface* s_prefabPublicInterface;
             static PrefabSystemComponentInterface* s_prefabSystemComponentInterface;
         };
     }

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

@@ -8,7 +8,7 @@
 
 #include <AzToolsFramework/UI/Prefab/PrefabUiHandler.h>
 
-#include <AzToolsFramework/UI/Prefab/PrefabEditInterface.h>
+#include <AzToolsFramework/Prefab/PrefabFocusInterface.h>
 #include <AzToolsFramework/Prefab/PrefabPublicInterface.h>
 #include <AzToolsFramework/UI/Outliner/EntityOutlinerListModel.hxx>
 
@@ -26,21 +26,19 @@ namespace AzToolsFramework
 
     PrefabUiHandler::PrefabUiHandler()
     {
-        m_prefabEditInterface = AZ::Interface<Prefab::PrefabEditInterface>::Get();
-
-        if (m_prefabEditInterface == nullptr)
-        {
-            AZ_Assert(false, "PrefabUiHandler - could not get PrefabEditInterface on PrefabUiHandler construction.");
-            return;
-        }
-
         m_prefabPublicInterface = AZ::Interface<Prefab::PrefabPublicInterface>::Get();
-
         if (m_prefabPublicInterface == nullptr)
         {
             AZ_Assert(false, "PrefabUiHandler - could not get PrefabPublicInterface on PrefabUiHandler construction.");
             return;
         }
+
+        m_prefabFocusInterface = AZ::Interface<Prefab::PrefabFocusInterface>::Get();
+        if (m_prefabFocusInterface == nullptr)
+        {
+            AZ_Assert(false, "PrefabUiHandler - could not get PrefabFocusInterface on PrefabUiHandler construction.");
+            return;
+        }
     }
 
     QString PrefabUiHandler::GenerateItemInfoString(AZ::EntityId entityId) const
@@ -83,7 +81,7 @@ namespace AzToolsFramework
 
     QIcon PrefabUiHandler::GenerateItemIcon(AZ::EntityId entityId) const
     {
-        if (m_prefabEditInterface->IsOwningPrefabBeingEdited(entityId))
+        if (m_prefabFocusInterface->IsOwningPrefabBeingFocused(entityId))
         {
             return QIcon(m_prefabEditIconPath);
         }
@@ -105,7 +103,7 @@ namespace AzToolsFramework
         const bool hasVisibleChildren = index.data(EntityOutlinerListModel::ExpandedRole).value<bool>() && index.model()->hasChildren(index);
 
         QColor backgroundColor = m_prefabCapsuleColor;
-        if (m_prefabEditInterface->IsOwningPrefabBeingEdited(entityId))
+        if (m_prefabFocusInterface->IsOwningPrefabBeingFocused(entityId))
         {
             backgroundColor = m_prefabCapsuleEditColor;
         }
@@ -191,7 +189,7 @@ namespace AzToolsFramework
         const bool isLastColumn = descendantIndex.column() == EntityOutlinerListModel::ColumnLockToggle;
 
         QColor borderColor = m_prefabCapsuleColor;
-        if (m_prefabEditInterface->IsOwningPrefabBeingEdited(entityId))
+        if (m_prefabFocusInterface->IsOwningPrefabBeingFocused(entityId))
         {
             borderColor = m_prefabCapsuleEditColor;
         }

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

@@ -12,9 +12,10 @@
 
 namespace AzToolsFramework
 {
+
     namespace Prefab
     {
-        class PrefabEditInterface;
+        class PrefabFocusInterface;
         class PrefabPublicInterface;
     };
 
@@ -37,7 +38,7 @@ namespace AzToolsFramework
             const QModelIndex& descendantIndex) const override;
 
     private:
-        Prefab::PrefabEditInterface* m_prefabEditInterface = nullptr;
+        Prefab::PrefabFocusInterface* m_prefabFocusInterface = nullptr;
         Prefab::PrefabPublicInterface* m_prefabPublicInterface = nullptr;
 
         static bool IsLastVisibleChild(const QModelIndex& parent, const QModelIndex& child);

Code/Framework/AzToolsFramework/AzToolsFramework/aztoolsframework_files.cmake

@@ -147,6 +147,9 @@ set(FILES
     Entity/SliceEditorEntityOwnershipServiceBus.h
     Fingerprinting/TypeFingerprinter.h
     Fingerprinting/TypeFingerprinter.cpp
+    FocusMode/FocusModeInterface.h
+    FocusMode/FocusModeSystemComponent.h
+    FocusMode/FocusModeSystemComponent.cpp
     Logger/TraceLogger.cpp
     Logger/TraceLogger.h
     Manipulators/AngularManipulator.cpp
@@ -625,6 +628,9 @@ set(FILES
     Prefab/PrefabDomTypes.h
     Prefab/PrefabDomUtils.h
     Prefab/PrefabDomUtils.cpp
+    Prefab/PrefabFocusHandler.h
+    Prefab/PrefabFocusHandler.cpp
+    Prefab/PrefabFocusInterface.h
     Prefab/PrefabIdTypes.h
     Prefab/PrefabLoader.h
     Prefab/PrefabLoader.cpp
@@ -717,9 +723,6 @@ set(FILES
     UI/Layer/LayerUiHandler.cpp
     UI/Prefab/LevelRootUiHandler.h
     UI/Prefab/LevelRootUiHandler.cpp
-    UI/Prefab/PrefabEditInterface.h
-    UI/Prefab/PrefabEditManager.h
-    UI/Prefab/PrefabEditManager.cpp
     UI/Prefab/PrefabIntegrationBus.h
     UI/Prefab/PrefabIntegrationManager.h
     UI/Prefab/PrefabIntegrationManager.cpp