Merge commit '4ee2f341dc0dc709aedb446b57d5cca61b86160d' into junbo/gitflow_211123_o3de

AutomatedTesting/Gem/PythonTests/editor/EditorScripts/EntityOutliner_EntityOrdering.py

@@ -95,7 +95,8 @@ def EntityOutliner_EntityOrdering():
         entity_outliner_model.dropMimeData(
             mime_data, QtCore.Qt.MoveAction, target_row, 0, target_index.parent()
         )
-        QtWidgets.QApplication.processEvents()
+        # Wait after move to let events (i.e. prefab propagation) process
+        general.idle_wait(1.0)
 
     # Move an entity before another entity in the order by dragging the source above the target
     move_entity_before = lambda source_name, target_name: _move_entity(
@@ -119,24 +120,24 @@ def EntityOutliner_EntityOrdering():
 
         # Our new entity should be given a name with a number automatically
         new_entity = f"Entity{i+1}"
-        # The new entity should be added to the top of its parent entity
-        expected_order = [new_entity] + expected_order
+        # The new entity should be added to the bottom of its parent entity
+        expected_order = expected_order + [new_entity]
 
         verify_entities_sorted(expected_order)
 
-    # 3) Move "Entity1" to the top of the order
-    move_entity_before("Entity1", "Entity5")
-    expected_order = ["Entity1", "Entity5", "Entity4", "Entity3", "Entity2"]
+    # 3) Move "Entity5" to the top of the order
+    move_entity_before("Entity5", "Entity1")
+    expected_order = ["Entity5", "Entity1", "Entity2", "Entity3", "Entity4"]
     verify_entities_sorted(expected_order)
 
-    # 4) Move "Entity4" to the bottom of the order
-    move_entity_after("Entity4", "Entity2")
-    expected_order = ["Entity1", "Entity5", "Entity3", "Entity2", "Entity4"]
+    # 4) Move "Entity2" to the bottom of the order
+    move_entity_after("Entity2", "Entity4")
+    expected_order = ["Entity5", "Entity1", "Entity3", "Entity4", "Entity2"]
     verify_entities_sorted(expected_order)
 
     # 5) Add another new entity, ensure the rest of the order is unchanged
     create_entity()
-    expected_order = ["Entity6", "Entity1", "Entity5", "Entity3", "Entity2", "Entity4"]
+    expected_order = ["Entity5", "Entity1", "Entity3", "Entity4", "Entity2", "Entity6"]
     verify_entities_sorted(expected_order)
 
 

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

@@ -239,12 +239,14 @@ namespace AzToolsFramework
         , m_isInIsolationMode(false)
     {
         ToolsApplicationRequests::Bus::Handler::BusConnect();
+        AzToolsFramework::Prefab::PrefabPublicNotificationBus::Handler::BusConnect();
 
         m_undoCache.RegisterToUndoCacheInterface();
     }
 
     ToolsApplication::~ToolsApplication()
     {
+        AzToolsFramework::Prefab::PrefabPublicNotificationBus::Handler::BusDisconnect();
         ToolsApplicationRequests::Bus::Handler::BusDisconnect();
         Stop();
     }
@@ -566,6 +568,12 @@ namespace AzToolsFramework
     void ToolsApplication::MarkEntitySelected(AZ::EntityId entityId)
     {
         AZ_PROFILE_FUNCTION(AzToolsFramework);
+
+        if (m_freezeSelectionUpdates)
+        {
+            return;
+        }
+
         AZ_Assert(entityId.IsValid(), "Invalid entity Id being marked as selected.");
 
         EntityIdList::iterator foundIter = AZStd::find(m_selectedEntities.begin(), m_selectedEntities.end(), entityId);
@@ -585,6 +593,11 @@ namespace AzToolsFramework
     {
         AZ_PROFILE_FUNCTION(AzToolsFramework);
 
+        if (m_freezeSelectionUpdates)
+        {
+            return;
+        }
+
         EntityIdList entitiesSelected;
         entitiesSelected.reserve(entitiesToSelect.size());
 
@@ -608,6 +621,12 @@ namespace AzToolsFramework
     void ToolsApplication::MarkEntityDeselected(AZ::EntityId entityId)
     {
         AZ_PROFILE_FUNCTION(AzToolsFramework);
+
+        if (m_freezeSelectionUpdates)
+        {
+            return;
+        }
+
         auto foundIter = AZStd::find(m_selectedEntities.begin(), m_selectedEntities.end(), entityId);
         if (foundIter != m_selectedEntities.end())
         {
@@ -625,6 +644,11 @@ namespace AzToolsFramework
     {
         AZ_PROFILE_FUNCTION(AzToolsFramework);
 
+        if (m_freezeSelectionUpdates)
+        {
+            return;
+        }
+
         ToolsApplicationEvents::Bus::Broadcast(&ToolsApplicationEvents::BeforeEntitySelectionChanged);
 
         EntityIdSet entitySetToDeselect(entitiesToDeselect.begin(), entitiesToDeselect.end());
@@ -679,6 +703,11 @@ namespace AzToolsFramework
     {
         AZ_PROFILE_FUNCTION(AzToolsFramework);
 
+        if (m_freezeSelectionUpdates)
+        {
+            return;
+        }
+
         // We're setting the selection set as a batch from an external caller.
         // * Filter out any unselectable entities
         // * Calculate selection/deselection delta so we can notify specific entities only on change.
@@ -1569,6 +1598,16 @@ namespace AzToolsFramework
         }
     }
 
+    void ToolsApplication::OnPrefabInstancePropagationBegin()
+    {
+        m_freezeSelectionUpdates = true;
+    }
+
+    void ToolsApplication::OnPrefabInstancePropagationEnd()
+    {
+        m_freezeSelectionUpdates = false;
+    }
+
     void ToolsApplication::CreateUndosForDirtyEntities()
     {
         AZ_PROFILE_FUNCTION(AzToolsFramework);

Code/Framework/AzToolsFramework/AzToolsFramework/Application/ToolsApplication.h

@@ -16,6 +16,7 @@
 #include <AzToolsFramework/API/EditorEntityAPI.h>
 #include <AzToolsFramework/Application/EditorEntityManager.h>
 #include <AzToolsFramework/Commands/PreemptiveUndoCache.h>
+#include <AzToolsFramework/Prefab/PrefabPublicNotificationBus.h>
 
 #pragma once
 
@@ -29,6 +30,7 @@ namespace AzToolsFramework
     class ToolsApplication
         : public AzFramework::Application
         , public ToolsApplicationRequests::Bus::Handler
+        , public AzToolsFramework::Prefab::PrefabPublicNotificationBus::Handler
     {
     public:
         AZ_RTTI(ToolsApplication, "{2895561E-BE90-4CC3-8370-DD46FCF74C01}", AzFramework::Application);
@@ -169,6 +171,14 @@ namespace AzToolsFramework
         };
         //////////////////////////////////////////////////////////////////////////
 
+        //////////////////////////////////////////////////////////////////////////
+        // PrefabPublicNotificationBus::Handler
+
+        void OnPrefabInstancePropagationBegin() override;
+        void OnPrefabInstancePropagationEnd() override;
+
+        //////////////////////////////////////////////////////////////////////////
+
         void CreateUndosForDirtyEntities();
         void ConsistencyCheckUndoCache();
         AZ::Aabb                            m_selectionBounds;
@@ -181,6 +191,7 @@ namespace AzToolsFramework
         bool                                m_isDuringUndoRedo;
         bool                                m_isInIsolationMode;
         EntityIdSet                         m_isolatedEntityIdSet;
+        bool                                m_freezeSelectionUpdates = false;
 
         EditorEntityAPI* m_editorEntityAPI = nullptr;
 

Code/Framework/AzToolsFramework/AzToolsFramework/Entity/EditorEntityModel.cpp

@@ -449,16 +449,23 @@ namespace AzToolsFramework
         AZStd::unordered_map<AZ::EntityId, AZStd::pair<AZ::EntityId, AZ::u64>>::const_iterator orderItr = m_savedOrderInfo.find(childId);
         if (orderItr != m_savedOrderInfo.end() && orderItr->second.first == parentId)
         {
-            bool sortOrderUpdated = AzToolsFramework::RecoverEntitySortInfo(parentId, childId, orderItr->second.second);
-            m_savedOrderInfo.erase(childId);
-
-            // force notify the child sort order changed on the parent entity info, but only if the restore didn't actually modify
-            // the order internally (and sent ChildEntityOrderArrayUpdated).  that may seem heavy handed, and it is, but necessary
-            // to combat scenarios when the initial override detection returns a false positive (see comment about IDH comparisons
-            // in OnChildSortOrderChanged) and the slice instance source-to-live mapping hasn't been fully reconstructed yet.
-            if (!sortOrderUpdated)
+            bool isPrefabEnabled = false;
+            AzFramework::ApplicationRequests::Bus::BroadcastResult(
+                isPrefabEnabled, &AzFramework::ApplicationRequests::IsPrefabSystemEnabled);
+            // If prefabs are enabled, rely on the component to do a sanity check instead of restoring the order from the model
+            if (!isPrefabEnabled)
             {
-                parentInfo.OnChildSortOrderChanged();
+                bool sortOrderUpdated = AzToolsFramework::RecoverEntitySortInfo(parentId, childId, orderItr->second.second);
+                m_savedOrderInfo.erase(childId);
+
+                // force notify the child sort order changed on the parent entity info, but only if the restore didn't actually modify
+                // the order internally (and sent ChildEntityOrderArrayUpdated).  that may seem heavy handed, and it is, but necessary
+                // to combat scenarios when the initial override detection returns a false positive (see comment about IDH comparisons
+                // in OnChildSortOrderChanged) and the slice instance source-to-live mapping hasn't been fully reconstructed yet.
+                if (!sortOrderUpdated)
+                {
+                    parentInfo.OnChildSortOrderChanged();
+                }
             }
         }
         else

Code/Framework/AzToolsFramework/AzToolsFramework/Entity/EditorEntitySortComponent.cpp

@@ -8,11 +8,17 @@
 #include "EditorEntitySortComponent.h"
 #include "EditorEntityInfoBus.h"
 #include "EditorEntityHelpers.h"
+#include <AzCore/Component/TransformBus.h>
 #include <AzCore/Debug/Profiler.h>
 #include <AzCore/Serialization/EditContext.h>
+#include <AzCore/Serialization/Json/RegistrationContext.h>
 #include <AzCore/std/sort.h>
 #include <AzFramework/API/ApplicationAPI.h>
 #include <AzToolsFramework/Prefab/PrefabPublicInterface.h>
+#include <AzToolsFramework/Prefab/PrefabPublicRequestBus.h>
+#include <AzToolsFramework/Undo/UndoSystem.h>
+#include <AzCore/Serialization/Json/RegistrationContext.h>
+#include <AzToolsFramework/Entity/EditorEntitySortComponentSerializer.h>
 
 static_assert(sizeof(AZ::u64) == sizeof(AZ::EntityId), "We use AZ::EntityId for Persistent ID, which is a u64 under the hood. These must be the same size otherwise the persistent id will have to be rewritten");
 
@@ -51,6 +57,12 @@ namespace AzToolsFramework
                         ;
                 }
             }
+
+            AZ::JsonRegistrationContext* jsonRegistration = azrtti_cast<AZ::JsonRegistrationContext*>(context);
+            if (jsonRegistration)
+            {
+                jsonRegistration->Serializer<JsonEditorEntitySortComponentSerializer>()->HandlesType<EditorEntitySortComponent>();
+            }
         }
 
         void EditorEntitySortComponent::GetProvidedServices(AZ::ComponentDescriptor::DependencyArrayType& services)
@@ -167,9 +179,6 @@ namespace AzToolsFramework
                 }
 
                 MarkDirtyAndSendChangedEvent();
-
-                // Use the ToolsApplication to mark the entity dirty, this will only do something if we already have an undo batch
-                ToolsApplicationRequestBus::Broadcast(&ToolsApplicationRequestBus::Events::AddDirtyEntity, GetEntityId());
                 
                 return true;
             }
@@ -187,6 +196,10 @@ namespace AzToolsFramework
             else
             {
                 EntityOrderArray::iterator insertPosition = GetFirstSelectedEntityPosition();
+                if (insertPosition != m_childEntityOrderArray.end())
+                {
+                    ++insertPosition;
+                }
                 retval = AddChildEntityInternal(entityId, false, insertPosition);
             }
 
@@ -220,9 +233,6 @@ namespace AzToolsFramework
 
                 MarkDirtyAndSendChangedEvent();
 
-                // Use the ToolsApplication to mark the entity dirty, this will only do something if we already have an undo batch
-                ToolsApplicationRequestBus::Broadcast(&ToolsApplicationRequestBus::Events::AddDirtyEntity, GetEntityId());
-
                 return true;
             }
             return false;
@@ -272,6 +282,12 @@ namespace AzToolsFramework
         void EditorEntitySortComponent::OnPrefabInstancePropagationEnd()
         {
             m_ignoreIncomingOrderChanges = false;
+
+            if (m_shouldSanityCheckStateAfterPropagation)
+            {
+                SanitizeOrderEntryArray();
+                m_shouldSanityCheckStateAfterPropagation = false;
+            }
         }
 
         void EditorEntitySortComponent::MarkDirtyAndSendChangedEvent()
@@ -280,14 +296,8 @@ namespace AzToolsFramework
             // one of the event listeners needs to build the InstanceDataHierarchy
             m_entityOrderIsDirty = true;
 
-            // Force an immediate update for prefabs, which won't receive PrepareSave
-            bool isPrefabEnabled = false;
-            AzFramework::ApplicationRequests::Bus::BroadcastResult(
-                isPrefabEnabled, &AzFramework::ApplicationRequests::IsPrefabSystemEnabled);
-            if (isPrefabEnabled)
-            {
-                PrepareSave();
-            }
+            // Use the ToolsApplication to mark the entity dirty, this will only do something if we already have an undo batch
+            ToolsApplicationRequestBus::Broadcast(&ToolsApplicationRequestBus::Events::AddDirtyEntity, GetEntityId());
             EditorEntitySortNotificationBus::Event(GetEntityId(), &EditorEntitySortNotificationBus::Events::ChildEntityOrderArrayUpdated);
         }
 
@@ -308,9 +318,8 @@ namespace AzToolsFramework
                 isPrefabEnabled, &AzFramework::ApplicationRequests::IsPrefabSystemEnabled);
             if (isPrefabEnabled)
             {
-                PostLoad();
+                m_shouldSanityCheckStateAfterPropagation = true;
             }
-
             // Send out that the order for our entity is now updated
             EditorEntitySortNotificationBus::Event(GetEntityId(), &EditorEntitySortNotificationBus::Events::ChildEntityOrderArrayUpdated);
         }
@@ -336,6 +345,73 @@ namespace AzToolsFramework
             m_entityOrderIsDirty = false;
         }
 
+        void EditorEntitySortComponent::SanitizeOrderEntryArray()
+        {
+            bool shouldEmitDirtyState = false;
+
+            // Remove invalid and duplicate entries that point at non-existent entities
+            AZStd::unordered_set<AZ::EntityId> duplicateIds;
+            for (auto it = m_childEntityOrderArray.begin(); it != m_childEntityOrderArray.end();)
+            {
+                if (!it->IsValid() || GetEntityById(*it) == nullptr || duplicateIds.contains(*it))
+                {
+                    it = m_childEntityOrderArray.erase(it);
+                    shouldEmitDirtyState = true;
+                }
+                else
+                {
+                    duplicateIds.insert(*it);
+                    ++it;
+                }
+            }
+
+            // Append any missing children
+            EntityIdList children;
+            AZ::TransformBus::EventResult(children, GetEntityId(), &AZ::TransformBus::Events::GetChildren);
+            for (auto it = m_childEntityOrderArray.begin(); it != m_childEntityOrderArray.end(); ++it)
+            {
+                if (auto removedChildrenIt = AZStd::remove(children.begin(), children.end(), *it); removedChildrenIt != children.end())
+                {
+                    children.erase(removedChildrenIt);
+                }
+            }
+
+            AZStd::sort(children.begin(), children.end(), [](AZ::EntityId lhs, AZ::EntityId rhs)
+            {
+                return GetEntityById(lhs)->GetName() < GetEntityById(rhs)->GetName();
+            });
+
+            if (!children.empty())
+            {
+                shouldEmitDirtyState = true;
+                EntityOrderArray::iterator insertPosition = GetFirstSelectedEntityPosition();
+                if (insertPosition != m_childEntityOrderArray.end())
+                {
+                    ++insertPosition;
+                }
+                m_childEntityOrderArray.insert(insertPosition, children.begin(), children.end());
+            }
+
+            // Clear out the vector to be rebuilt from persistent id
+            m_childEntityOrderEntryArray.resize(m_childEntityOrderArray.size());
+            for (size_t i = 0; i < m_childEntityOrderArray.size(); ++i)
+            {
+                m_childEntityOrderEntryArray[i] = {
+                    m_childEntityOrderArray[i],
+                    static_cast<AZ::u64>(i)
+                };
+            }
+
+            RebuildEntityOrderCache();
+
+            if (shouldEmitDirtyState)
+            {
+                ToolsApplicationRequests::Bus::Broadcast(&ToolsApplicationRequests::Bus::Events::AddDirtyEntity, GetEntityId());
+            }
+
+            m_entityOrderIsDirty = false;
+        }
+
         void EditorEntitySortComponent::PostLoad()
         {
             // Clear out the vector to be rebuilt from persistent id
@@ -383,7 +459,7 @@ namespace AzToolsFramework
                 firstSelectedEntityPos = selectedEntityPos < firstSelectedEntityPos ? selectedEntityPos : firstSelectedEntityPos;
             }
 
-            return firstSelectedEntityPos == m_childEntityOrderArray.end() ? m_childEntityOrderArray.begin() : firstSelectedEntityPos;
+            return firstSelectedEntityPos;
         }
     }
 } // namespace AzToolsFramework

Code/Framework/AzToolsFramework/AzToolsFramework/Entity/EditorEntitySortComponent.h

@@ -23,6 +23,8 @@ namespace AzToolsFramework
             , public EditorEntityContextNotificationBus::Handler
             , public AzToolsFramework::Prefab::PrefabPublicNotificationBus::Handler
         {
+            friend class JsonEditorEntitySortComponentSerializer;
+
         public:
             AZ_COMPONENT(EditorEntitySortComponent, "{6EA1E03D-68B2-466D-97F7-83998C8C27F0}", EditorComponentBase);
 
@@ -64,6 +66,8 @@ namespace AzToolsFramework
             void PrepareSave();
             void PostLoad();
 
+            void SanitizeOrderEntryArray();
+
             class EntitySortSerializationEvents
                 : public AZ::SerializeContext::IEventHandler
             {
@@ -112,6 +116,7 @@ namespace AzToolsFramework
 
             bool m_entityOrderIsDirty = true; ///< This flag indicates our stored serialization order data is out of date and must be rebuilt before serialization occurs
             bool m_ignoreIncomingOrderChanges = false; ///< This is set when prefab propagation occurs so that non-authored order changes can be ignored
+            bool m_shouldSanityCheckStateAfterPropagation = false; //< This is set after activation, to queue a cleanup of any invalid state after the next prefab propagation.
         };
     }
 } // namespace AzToolsFramework

Code/Framework/AzToolsFramework/AzToolsFramework/Entity/EditorEntitySortComponentSerializer.cpp

@@ -0,0 +1,137 @@
+/*
+ * 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 <AzCore/Serialization/Json/JsonSerializationResult.h>
+#include <AzCore/std/sort.h>
+#include <AzToolsFramework/Entity/EditorEntitySortComponent.h>
+#include <AzToolsFramework/Entity/EditorEntitySortComponentSerializer.h>
+
+namespace AzToolsFramework::Components
+{
+    AZ_CLASS_ALLOCATOR_IMPL(JsonEditorEntitySortComponentSerializer, AZ::SystemAllocator, 0);
+
+    AZ::JsonSerializationResult::Result JsonEditorEntitySortComponentSerializer::Load(
+        void* outputValue,
+        [[maybe_unused]] const AZ::Uuid& outputValueTypeId,
+        const rapidjson::Value& inputValue,
+        AZ::JsonDeserializerContext& context)
+    {
+        namespace JSR = AZ::JsonSerializationResult;
+
+        AZ_Assert(
+            azrtti_typeid<EditorEntitySortComponent>() == outputValueTypeId,
+            "Unable to deserialize EditorEntitySortComponent from json because the provided type is %s.",
+            outputValueTypeId.ToString<AZStd::string>().c_str());
+
+        EditorEntitySortComponent* sortComponentInstance = reinterpret_cast<EditorEntitySortComponent*>(outputValue);
+        AZ_Assert(sortComponentInstance, "Output value for JsonEditorEntitySortComponentSerializer can't be null.");
+
+        JSR::ResultCode result(JSR::Tasks::ReadField);
+        {
+            JSR::ResultCode componentIdLoadResult = ContinueLoadingFromJsonObjectField(
+                &sortComponentInstance->m_id, azrtti_typeid<decltype(sortComponentInstance->m_id)>(), inputValue,
+                "Id", context);
+
+            result.Combine(componentIdLoadResult);
+        }
+
+        {
+            sortComponentInstance->m_childEntityOrderArray.clear();
+            JSR::ResultCode enryLoadResult = ContinueLoadingFromJsonObjectField(
+                &sortComponentInstance->m_childEntityOrderArray,
+                azrtti_typeid<decltype(sortComponentInstance->m_childEntityOrderArray)>(), inputValue, "Child Entity Order",
+                context);
+
+            // Migrate ChildEntityOrderEntryArray -> ChildEntityOrderArray
+            if (sortComponentInstance->m_childEntityOrderArray.empty())
+            {
+                enryLoadResult = ContinueLoadingFromJsonObjectField(
+                    &sortComponentInstance->m_childEntityOrderEntryArray,
+                    azrtti_typeid<decltype(sortComponentInstance->m_childEntityOrderEntryArray)>(), inputValue,
+                    "ChildEntityOrderEntryArray", context);
+
+                AZStd::sort(
+                    sortComponentInstance->m_childEntityOrderEntryArray.begin(),
+                    sortComponentInstance->m_childEntityOrderEntryArray.end(),
+                    [](const EditorEntitySortComponent::EntityOrderEntry& lhs,
+                       const EditorEntitySortComponent::EntityOrderEntry& rhs) -> bool
+                    {
+                        return lhs.m_sortIndex < rhs.m_sortIndex;
+                    });
+
+                // Sort by index and copy to the order array, any duplicates or invalid entries will be cleaned up by the sanitization pass
+                sortComponentInstance->m_childEntityOrderArray.resize(sortComponentInstance->m_childEntityOrderEntryArray.size());
+                for (size_t i = 0; i < sortComponentInstance->m_childEntityOrderEntryArray.size(); ++i)
+                {
+                    sortComponentInstance->m_childEntityOrderArray[i] = sortComponentInstance->m_childEntityOrderEntryArray[i].m_entityId;
+                }
+            }
+
+            sortComponentInstance->RebuildEntityOrderCache();
+
+            result.Combine(enryLoadResult);
+        }
+
+        return context.Report(
+            result,
+            result.GetProcessing() != JSR::Processing::Halted ? "Successfully loaded EditorEntitySortComponent information."
+                                                              : "Failed to load EditorEntitySortComponent information.");
+    }
+
+    AZ::JsonSerializationResult::Result JsonEditorEntitySortComponentSerializer::Store(
+        rapidjson::Value& outputValue,
+        const void* inputValue,
+        const void* defaultValue,
+        [[maybe_unused]] const AZ::Uuid& valueTypeId,
+        AZ::JsonSerializerContext& context)
+    {
+        namespace JSR = AZ::JsonSerializationResult;
+
+        AZ_Assert(
+            azrtti_typeid<EditorEntitySortComponent>() == valueTypeId,
+            "Unable to Serialize EditorEntitySortComponent because the provided type is %s.",
+            valueTypeId.ToString<AZStd::string>().c_str());
+
+        const EditorEntitySortComponent* sortComponentInstance = reinterpret_cast<const EditorEntitySortComponent*>(inputValue);
+        AZ_Assert(sortComponentInstance, "Input value for JsonEditorEntitySortComponentSerializer can't be null.");
+        const EditorEntitySortComponent* defaultsortComponentInstance =
+            reinterpret_cast<const EditorEntitySortComponent*>(defaultValue);
+
+        JSR::ResultCode result(JSR::Tasks::WriteValue);
+        {
+            AZ::ScopedContextPath subPathName(context, "m_id");
+            const AZ::ComponentId* componentId = &sortComponentInstance->m_id;
+            const AZ::ComponentId* defaultComponentId =
+                defaultsortComponentInstance ? &defaultsortComponentInstance->m_id : nullptr;
+
+            JSR::ResultCode resultComponentId = ContinueStoringToJsonObjectField(
+                outputValue, "Id", componentId, defaultComponentId, azrtti_typeid<decltype(sortComponentInstance->m_id)>(),
+                context);
+
+            result.Combine(resultComponentId);
+        }
+
+        {
+            AZ::ScopedContextPath subPathName(context, "m_childEntityOrderArray");
+            const EntityOrderArray* childEntityOrderArray = &sortComponentInstance->m_childEntityOrderArray;
+            const EntityOrderArray* defaultChildEntityOrderArray =
+                defaultsortComponentInstance ? &defaultsortComponentInstance->m_childEntityOrderArray : nullptr;
+
+            JSR::ResultCode resultParentEntityId = ContinueStoringToJsonObjectField(
+                outputValue, "Child Entity Order", childEntityOrderArray, defaultChildEntityOrderArray,
+                azrtti_typeid<decltype(sortComponentInstance->m_childEntityOrderArray)>(), context);
+
+            result.Combine(resultParentEntityId);
+        }
+
+        return context.Report(
+            result,
+            result.GetProcessing() != JSR::Processing::Halted ? "Successfully stored EditorEntitySortComponent information."
+                                                              : "Failed to store EditorEntitySortComponent information.");
+    }
+} // namespace AzToolsFramework::Components

Code/Framework/AzToolsFramework/AzToolsFramework/Entity/EditorEntitySortComponentSerializer.h

@@ -0,0 +1,31 @@
+/*
+ * 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/Memory.h>
+#include <AzCore/Serialization/Json/BaseJsonSerializer.h>
+
+namespace AzToolsFramework::Components
+{
+    class JsonEditorEntitySortComponentSerializer
+        : public AZ::BaseJsonSerializer
+    {
+    public:
+        AZ_RTTI(JsonEditorEntitySortComponentSerializer, "{5104782E-B34F-4D87-B1DF-BDFB1AF20D58}", BaseJsonSerializer);
+        AZ_CLASS_ALLOCATOR_DECL;
+
+        AZ::JsonSerializationResult::Result Load(
+            void* outputValue, const AZ::Uuid& outputValueTypeId, const rapidjson::Value& inputValue,
+            AZ::JsonDeserializerContext& context) override;
+
+        AZ::JsonSerializationResult::Result Store(
+            rapidjson::Value& outputValue, const void* inputValue, const void* defaultValue, const AZ::Uuid& valueTypeId,
+            AZ::JsonSerializerContext& context) override;
+    };
+} // namespace AzToolsFramework::Components

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Instance/InstanceUpdateExecutor.cpp

@@ -20,6 +20,7 @@
 #include <AzToolsFramework/Prefab/PrefabPublicNotificationBus.h>
 #include <AzToolsFramework/Prefab/PrefabSystemComponentInterface.h>
 #include <AzToolsFramework/Prefab/Template/Template.h>
+#include <AzToolsFramework/Prefab/PrefabPublicRequestBus.h>
 
 namespace AzToolsFramework
 {
@@ -244,10 +245,10 @@ namespace AzToolsFramework
                             selectedEntityIds.erase(entityIdIterator--);
                         }
                     }
-                    ToolsApplicationRequestBus::Broadcast(&ToolsApplicationRequests::SetSelectedEntities, selectedEntityIds);
 
-                    // Notify Propagation has ended
+                    // Notify Propagation has ended, then update selection (which is frozen during propagation, so this order matters)
                     PrefabPublicNotificationBus::Broadcast(&PrefabPublicNotifications::OnPrefabInstancePropagationEnd);
+                    ToolsApplicationRequestBus::Broadcast(&ToolsApplicationRequests::SetSelectedEntities, selectedEntityIds);
                 }
 
                 m_updatingTemplateInstancesInQueue = false;

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabDomUtils.h

@@ -28,6 +28,9 @@ namespace AzToolsFramework
             inline static const char* EntityIdName = "Id";
             inline static const char* EntitiesName = "Entities";
             inline static const char* ContainerEntityName = "ContainerEntity";
+            inline static const char* ComponentsName = "Components";
+            inline static const char* EntityOrderName = "Child Entity Order";
+            inline static const char* TypeName = "$type";
 
             /**
             * Find Prefab value from given parent value and target value's name.

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabPublicHandler.cpp

@@ -9,6 +9,7 @@
 #include <AzCore/Component/TransformBus.h>
 #include <AzCore/JSON/stringbuffer.h>
 #include <AzCore/JSON/writer.h>
+#include <AzCore/Serialization/Json/JsonSerialization.h>
 #include <AzCore/Utils/TypeHash.h>
 
 #include <AzToolsFramework/API/ToolsApplicationAPI.h>
@@ -29,6 +30,7 @@
 #include <AzToolsFramework/Prefab/PrefabUndo.h>
 #include <AzToolsFramework/Prefab/PrefabUndoHelpers.h>
 #include <AzToolsFramework/ToolsComponents/TransformComponent.h>
+#include <AzToolsFramework/Entity/EditorEntitySortComponent.h>
 
 #include <QString>
 
@@ -595,8 +597,41 @@ namespace AzToolsFramework
             
             Instance& entityOwningInstance = owningInstanceOfParentEntity->get();
 
+            // Get the template for our owning instance from the root prefab DOM and use that to generate our patch
+            AZStd::vector<InstanceOptionalConstReference> pathOfInstances;
+
+            InstanceOptionalReference rootInstance = owningInstanceOfParentEntity;
+            while (rootInstance->get().GetParentInstance() != AZStd::nullopt)
+            {
+                pathOfInstances.emplace_back(rootInstance);
+                rootInstance = rootInstance->get().GetParentInstance();
+            }
+
+            AZStd::string aliasPathResult = "";
+            for (auto instanceIter = pathOfInstances.rbegin(); instanceIter != pathOfInstances.rend(); ++instanceIter)
+            {
+                aliasPathResult.append("/Instances/");
+                aliasPathResult.append((*instanceIter)->get().GetInstanceAlias());
+            }
+
+            PrefabDomPath rootPrefabDomPath(aliasPathResult.c_str());
+
+            PrefabDom& rootPrefabTemplateDom = m_prefabSystemComponentInterface->FindTemplateDom(rootInstance->get().GetTemplateId());
+
+            auto instanceDomFromRootValue = rootPrefabDomPath.Get(rootPrefabTemplateDom);
+            if (!instanceDomFromRootValue)
+            {
+                return AZ::Failure<AZStd::string>("Could not load Instance DOM from the top level ancestor's DOM.");
+            }
+
+            PrefabDomValueReference instanceDomFromRoot = *instanceDomFromRootValue;
+            if (!instanceDomFromRoot.has_value())
+            {
+                return AZ::Failure<AZStd::string>("Could not load Instance DOM from the top level ancestor's DOM.");
+            }
+
             PrefabDom instanceDomBeforeUpdate;
-            m_instanceToTemplateInterface->GenerateDomForInstance(instanceDomBeforeUpdate, entityOwningInstance);
+            instanceDomBeforeUpdate.CopyFrom(instanceDomFromRoot.value().get(), instanceDomBeforeUpdate.GetAllocator());
 
             ScopedUndoBatch undoBatch("Add Entity");
 
@@ -674,6 +709,9 @@ namespace AzToolsFramework
                 bool isInstanceContainerEntity = IsInstanceContainerEntity(entityId) && !IsLevelInstanceContainerEntity(entityId);
                 bool isNewParentOwnedByDifferentInstance = false;
 
+                bool isInFocusTree = m_prefabFocusPublicInterface->IsOwningPrefabInFocusHierarchy(entityId);
+                bool isOwnedByFocusedPrefabInstance = m_prefabFocusPublicInterface->IsOwningPrefabBeingFocused(entityId);
+
                 if (beforeParentId != afterParentId)
                 {
                     // If the entity parent changed, verify if the owning instance changed too
@@ -727,7 +765,7 @@ namespace AzToolsFramework
                     }
                 }
 
-                if (isInstanceContainerEntity)
+                if (isInFocusTree && !isOwnedByFocusedPrefabInstance)
                 {
                     if (isNewParentOwnedByDifferentInstance)
                     {
@@ -1648,6 +1686,144 @@ namespace AzToolsFramework
             return true;
         }
 
+        void PrefabPublicHandler::AddNewEntityToSortOrder(
+            Instance& owningInstance,
+            PrefabDom& domToAddEntityUnder,
+            const EntityAlias& parentEntityAlias,
+            const EntityAlias& entityToAddAlias)
+        {
+            // Find the parent entity to get its sort order component
+            auto findParentEntity = [&]() -> rapidjson::Value*
+            {
+                if (auto containerEntityIter = domToAddEntityUnder.FindMember(PrefabDomUtils::ContainerEntityName);
+                    containerEntityIter != domToAddEntityUnder.MemberEnd())
+                {
+                    if (parentEntityAlias == containerEntityIter->value[PrefabDomUtils::EntityIdName].GetString())
+                    {
+                        return &containerEntityIter->value;
+                    }
+                }
+
+                if (auto entitiesIter = domToAddEntityUnder.FindMember(PrefabDomUtils::EntitiesName);
+                    entitiesIter != domToAddEntityUnder.MemberEnd())
+                {
+                    for (auto entityIter = entitiesIter->value.MemberBegin(); entityIter != entitiesIter->value.MemberEnd(); ++entityIter)
+                    {
+                        if (parentEntityAlias == entityIter->value[PrefabDomUtils::EntityIdName].GetString())
+                        {
+                            return &entityIter->value;
+                        }
+                    }
+                }
+
+                return nullptr;
+            };
+
+            rapidjson::Value* parentEntityValue = findParentEntity();
+            if (parentEntityValue == nullptr)
+            {
+                return;
+            }
+
+            // Get the list of selected entities, we'll insert our duplicated entities after the last selected
+            // sibling in their parent's list, e.g. for:
+            // - Entity1
+            // - Entity2 (selected)
+            // - Entity3
+            // - Entity4 (selected)
+            // - Entity5
+            // Our duplicate selection command would create duplicate Entity2 and Entity4 and insert them after Entity4:
+            // - Entity1
+            // - Entity2
+            // - Entity3
+            // - Entity4
+            // - Entity2 (new, selected after duplicate)
+            // - Entity4 (new, selected after duplicate)
+            // - Entity5
+            AzToolsFramework::EntityIdList selectedEntities;
+            AzToolsFramework::ToolsApplicationRequestBus::BroadcastResult(
+                selectedEntities, &AzToolsFramework::ToolsApplicationRequests::GetSelectedEntities);
+
+            // Find the EditorEntitySortComponent DOM
+            auto componentsIter = parentEntityValue->FindMember(PrefabDomUtils::ComponentsName);
+            if (componentsIter == parentEntityValue->MemberEnd())
+            {
+                return;
+            }
+
+            for (auto componentIter = componentsIter->value.MemberBegin(); componentIter != componentIter->value.MemberEnd();
+                 ++componentIter)
+            {
+                // Check the component type
+                auto typeFieldIter = componentIter->value.FindMember(PrefabDomUtils::TypeName);
+                if (typeFieldIter == componentIter->value.MemberEnd())
+                {
+                    continue;
+                }
+
+                AZ::JsonDeserializerSettings jsonDeserializerSettings;
+                AZ::Uuid typeId = AZ::Uuid::CreateNull();
+                AZ::JsonSerialization::LoadTypeId(typeId, typeFieldIter->value);
+
+                if (typeId != azrtti_typeid<Components::EditorEntitySortComponent>())
+                {
+                    continue;
+                }
+
+                // Check for the entity order field
+                auto orderMembersIter = componentIter->value.FindMember(PrefabDomUtils::EntityOrderName);
+                if (orderMembersIter == componentIter->value.MemberEnd() || !orderMembersIter->value.IsArray())
+                {
+                    continue;
+                }
+
+                // Scan for the last selected entity in the list (if any) to determine where to add our entries
+                rapidjson::Value newOrder(rapidjson::kArrayType);
+                auto insertValuesAfter = orderMembersIter->value.End();
+                for (auto orderMemberIter = orderMembersIter->value.Begin(); orderMemberIter != orderMembersIter->value.End();
+                     ++orderMemberIter)
+                {
+                    if (!orderMemberIter->IsString())
+                    {
+                        continue;
+                    }
+                    const char* value = orderMemberIter->GetString();
+                    for (AZ::EntityId selectedEntity : selectedEntities)
+                    {
+                        auto alias = owningInstance.GetEntityAlias(selectedEntity);
+                        if (alias.has_value() && alias.value().get() == value)
+                        {
+                            insertValuesAfter = orderMemberIter;
+                            break;
+                        }
+                    }
+                }
+
+                // Construct our new array with the new order - insertion may happen at end, so check for that in the loop itself
+                for (auto orderMemberIter = orderMembersIter->value.Begin();; ++orderMemberIter)
+                {
+                    if (orderMemberIter != orderMembersIter->value.End())
+                    {
+                        newOrder.PushBack(orderMemberIter->Move(), domToAddEntityUnder.GetAllocator());
+                    }
+                    if (orderMemberIter == insertValuesAfter)
+                    {
+                        newOrder.PushBack(
+                            rapidjson::Value(entityToAddAlias.c_str(), domToAddEntityUnder.GetAllocator()),
+                            domToAddEntityUnder.GetAllocator());
+                    }
+                    if (orderMemberIter == orderMembersIter->value.End())
+                    {
+                        break;
+                    }
+                }
+
+                // Replace the order with our newly constructed one
+                orderMembersIter->value.Swap(newOrder);
+                break;
+            }
+        }
+
         void PrefabPublicHandler::DuplicateNestedEntitiesInInstance(Instance& commonOwningInstance,
             const AZStd::vector<AZ::Entity*>& entities, PrefabDom& domToAddDuplicatedEntitiesUnder,
             EntityIdList& duplicatedEntityIds, AZStd::unordered_map<EntityAlias, EntityAlias>& oldAliasToNewAliasMap)
@@ -1705,6 +1881,73 @@ namespace AzToolsFramework
                 PrefabDom entityDomAfter(&domToAddDuplicatedEntitiesUnder.GetAllocator());
                 entityDomAfter.Parse(newEntityDomString.toUtf8().constData());
 
+                EntityAlias parentEntityAlias;
+                if (auto componentsIter = entityDomAfter.FindMember(PrefabDomUtils::ComponentsName);
+                    componentsIter != entityDomAfter.MemberEnd())
+                {
+                    auto checkComponent = [&](const rapidjson::Value& value) -> bool
+                    {
+                        if (!value.IsObject())
+                        {
+                            return false;
+                        }
+
+                        // Check the component type
+                        auto typeFieldIter = value.FindMember(PrefabDomUtils::TypeName);
+                        if (typeFieldIter == value.MemberEnd())
+                        {
+                            return false;
+                        }
+
+                        AZ::JsonDeserializerSettings jsonDeserializerSettings;
+                        AZ::Uuid typeId = AZ::Uuid::CreateNull();
+                        AZ::JsonSerialization::LoadTypeId(typeId, typeFieldIter->value);
+
+                        // Prefabs get serialized with the Editor transform component type, check for that
+                        if (typeId != azrtti_typeid<Components::TransformComponent>())
+                        {
+                            return false;
+                        }
+
+                        if (auto parentEntityIter = value.FindMember("Parent Entity");
+                            parentEntityIter != value.MemberEnd())
+                        {
+                            parentEntityAlias = parentEntityIter->value.GetString();
+                            return true;
+                        }
+                        return false;
+                    };
+
+                    if (componentsIter->value.IsObject())
+                    {
+                        for (auto componentIter = componentsIter->value.MemberBegin(); componentIter != componentsIter->value.MemberEnd();
+                             ++componentIter)
+                        {
+                            if (checkComponent(componentIter->value))
+                            {
+                                break;
+                            }
+                        }
+                    }
+                    else if (componentsIter->value.IsArray())
+                    {
+                        for (auto componentIter = componentsIter->value.Begin(); componentIter != componentsIter->value.End();
+                             ++componentIter)
+                        {
+                            if (checkComponent(*componentIter))
+                            {
+                                break;
+                            }
+                        }
+                    }
+                }
+
+                // Insert our entity into its parent's sort order
+                if (!parentEntityAlias.empty())
+                {
+                    AddNewEntityToSortOrder(commonOwningInstance, domToAddDuplicatedEntitiesUnder, parentEntityAlias, newEntityAlias);
+                }
+
                 // Add the new Entity DOM to the Entities member of the instance
                 rapidjson::Value aliasName(newEntityAlias.c_str(), static_cast<rapidjson::SizeType>(newEntityAlias.length()), domToAddDuplicatedEntitiesUnder.GetAllocator());
                 entitiesIter->value.AddMember(AZStd::move(aliasName), entityDomAfter, domToAddDuplicatedEntitiesUnder.GetAllocator());

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabPublicHandler.h

@@ -78,6 +78,8 @@ namespace AzToolsFramework
 
             InstanceOptionalReference GetOwnerInstanceByEntityId(AZ::EntityId entityId) const;
             bool EntitiesBelongToSameInstance(const EntityIdList& entityIds) const;
+            void AddNewEntityToSortOrder(Instance& owningInstance, PrefabDom& domToAddEntityUnder,
+                const EntityAlias& parentEntityAlias, const EntityAlias& entityToAddAlias);
 
             /**
              * Duplicate a list of entities owned by a common owning instance by directly

Code/Framework/AzToolsFramework/AzToolsFramework/UI/PropertyEditor/EntityPropertyEditor.cpp

@@ -1599,7 +1599,6 @@ namespace AzToolsFramework
         for (size_t entityIndex = 1; entityIndex < m_selectedEntityIds.size(); ++entityIndex)
         {
             entity = GetSelectedEntityById(m_selectedEntityIds[entityIndex]);
-            AZ_Assert(entity, "Entity id selected for display but no such entity exists");
             if (!entity)
             {
                 continue;

Code/Framework/AzToolsFramework/AzToolsFramework/aztoolsframework_files.cmake

@@ -148,6 +148,8 @@ set(FILES
     Entity/EditorEntitySortBus.h
     Entity/EditorEntitySortComponent.cpp
     Entity/EditorEntitySortComponent.h
+    Entity/EditorEntitySortComponentSerializer.cpp
+    Entity/EditorEntitySortComponentSerializer.h
     Entity/EditorEntityTransformBus.h
     Entity/PrefabEditorEntityOwnershipInterface.h
     Entity/PrefabEditorEntityOwnershipService.h