UnrealEngineUWP/Engine/Source/Editor/PropertyEditor/Private/SDetailsViewBase.cpp

#include "PropertyEditorPrivatePCH.h"
#include "SDetailsViewBase.h"
#include "AssetSelection.h"
#include "PropertyNode.h"
#include "ItemPropertyNode.h"
#include "CategoryPropertyNode.h"
#include "ObjectPropertyNode.h"
#include "ScopedTransaction.h"
#include "AssetThumbnail.h"
#include "SDetailNameArea.h"
#include "IPropertyUtilities.h"
#include "PropertyEditorHelpers.h"
#include "PropertyEditor.h"
#include "PropertyDetailsUtilities.h"
#include "SPropertyEditorEditInline.h"
#include "ObjectEditorUtils.h"
#include "SColorPicker.h"


SDetailsViewBase::~SDetailsViewBase()
{
	if (ThumbnailPool.IsValid())
	{
		ThumbnailPool->ReleaseResources();
	}
}


void SDetailsViewBase::OnGetChildrenForDetailTree(TSharedRef<IDetailTreeNode> InTreeNode, TArray< TSharedRef<IDetailTreeNode> >& OutChildren)
{
	InTreeNode->GetChildren(OutChildren);
}

TSharedRef<ITableRow> SDetailsViewBase::OnGenerateRowForDetailTree(TSharedRef<IDetailTreeNode> InTreeNode, const TSharedRef<STableViewBase>& OwnerTable)
{
	return InTreeNode->GenerateNodeWidget(OwnerTable, ColumnSizeData, PropertyUtilities.ToSharedRef());
}

void SDetailsViewBase::SetRootExpansionStates(const bool bExpand, const bool bRecurse)
{
	for (auto Iter = RootTreeNodes.CreateIterator(); Iter; ++Iter)
	{
		SetNodeExpansionState(*Iter, bExpand, bRecurse);
	}
}

void SDetailsViewBase::SetNodeExpansionState(TSharedRef<IDetailTreeNode> InTreeNode, bool bIsItemExpanded, bool bRecursive)
{
	TArray< TSharedRef<IDetailTreeNode> > Children;
	InTreeNode->GetChildren(Children);

	if (Children.Num())
	{
		RequestItemExpanded(InTreeNode, bIsItemExpanded);
		InTreeNode->OnItemExpansionChanged(bIsItemExpanded);

		if (bRecursive)
		{
			for (int32 ChildIndex = 0; ChildIndex < Children.Num(); ++ChildIndex)
			{
				TSharedRef<IDetailTreeNode> Child = Children[ChildIndex];

				SetNodeExpansionState(Child, bIsItemExpanded, bRecursive);
			}
		}
	}
}

void SDetailsViewBase::SetNodeExpansionStateRecursive(TSharedRef<IDetailTreeNode> InTreeNode, bool bIsItemExpanded)
{
	SetNodeExpansionState(InTreeNode, bIsItemExpanded, true);
}

void SDetailsViewBase::OnItemExpansionChanged(TSharedRef<IDetailTreeNode> InTreeNode, bool bIsItemExpanded)
{
	SetNodeExpansionState(InTreeNode, bIsItemExpanded, false);
}

FReply SDetailsViewBase::OnLockButtonClicked()
{
	bIsLocked = !bIsLocked;
	return FReply::Handled();
}

void SDetailsViewBase::HideFilterArea(bool bHide)
{
	DetailsViewArgs.bAllowSearch = !bHide;
}

void SDetailsViewBase::HighlightProperty(const UProperty* Property)
{
	// Clear the previously enabled highlight:
	auto PrevPropertyPtr = PrevHighlightedProperty.Pin();
	if( PrevPropertyPtr.IsValid() )
	{
		PrevPropertyPtr->SetIsHighlighted( false );
	}

	if( !Property )
	{
		return;
	}

	// Find the newly highlighted node, and enable the highlight:
	FName PropertyOwnerFName = Property->GetOwnerStruct()->GetFName();
	FClassInstanceToPropertyMap* PropertyNodeMap = ClassToPropertyMap.Find(PropertyOwnerFName);
	if( PropertyNodeMap )
	{
		FName InstanceName = NAME_None;
		FPropertyNodeMap* NodeMap = PropertyNodeMap->Find(InstanceName);
		if( NodeMap )
		{
			TSharedPtr<FPropertyNode>* PropertyNode = NodeMap->PropertyNameToNode.Find(Property->GetFName());
			if( PropertyNode )
			{
				(*PropertyNode)->SetIsHighlighted( true );
				PrevHighlightedProperty = *PropertyNode;
				auto TreeNodePtr = (*PropertyNode)->GetTreeNode();
				if ( TreeNodePtr.IsValid() )
				{
					DetailTree->RequestScrollIntoView(TreeNodePtr.ToSharedRef());
				}
			}
		}
	}
}

EVisibility SDetailsViewBase::GetTreeVisibility() const
{
	return DetailLayout.IsValid() && DetailLayout->HasDetails() ? EVisibility::Visible : EVisibility::Collapsed;
}

/** Returns the image used for the icon on the filter button */
const FSlateBrush* SDetailsViewBase::OnGetFilterButtonImageResource() const
{
	if (bHasActiveFilter)
	{
		return FEditorStyle::GetBrush(TEXT("PropertyWindow.FilterCancel"));
	}
	else
	{
		return FEditorStyle::GetBrush(TEXT("PropertyWindow.FilterSearch"));
	}
}

void SDetailsViewBase::EnqueueDeferredAction(FSimpleDelegate& DeferredAction)
{
	DeferredActions.AddUnique(DeferredAction);
}

/**
* Creates the color picker window for this property view.
*
* @param Node				The slate property node to edit.
* @param bUseAlpha			Whether or not alpha is supported
*/
void SDetailsViewBase::CreateColorPickerWindow(const TSharedRef< FPropertyEditor >& PropertyEditor, bool bUseAlpha)
{
	const TSharedRef< FPropertyNode > PinnedColorPropertyNode = PropertyEditor->GetPropertyNode();
	ColorPropertyNode = PinnedColorPropertyNode;

	UProperty* Property = PinnedColorPropertyNode->GetProperty();
	check(Property);

	FReadAddressList ReadAddresses;
	PinnedColorPropertyNode->GetReadAddress(false, ReadAddresses, false);

	TArray<FLinearColor*> LinearColor;
	TArray<FColor*> DWORDColor;
	for (int32 ColorIndex = 0; ColorIndex < ReadAddresses.Num(); ++ColorIndex)
	{
		const uint8* Addr = ReadAddresses.GetAddress(ColorIndex);
		if (Addr)
		{
			if (Cast<UStructProperty>(Property)->Struct->GetFName() == NAME_Color)
			{
				DWORDColor.Add((FColor*)Addr);
			}
			else
			{
				check(Cast<UStructProperty>(Property)->Struct->GetFName() == NAME_LinearColor);
				LinearColor.Add((FLinearColor*)Addr);
			}
		}
	}

	bHasOpenColorPicker = true;

	FColorPickerArgs PickerArgs;
	PickerArgs.ParentWidget = AsShared();
	PickerArgs.bUseAlpha = bUseAlpha;
	PickerArgs.DisplayGamma = TAttribute<float>::Create(TAttribute<float>::FGetter::CreateUObject(GEngine, &UEngine::GetDisplayGamma));
	PickerArgs.ColorArray = &DWORDColor;
	PickerArgs.LinearColorArray = &LinearColor;
	PickerArgs.OnColorCommitted = FOnLinearColorValueChanged::CreateSP(this, &SDetailsViewBase::SetColorPropertyFromColorPicker);
	PickerArgs.OnColorPickerWindowClosed = FOnWindowClosed::CreateSP(this, &SDetailsViewBase::OnColorPickerWindowClosed);

	OpenColorPicker(PickerArgs);
}


void SDetailsViewBase::SetColorPropertyFromColorPicker(FLinearColor NewColor)
{
	const TSharedPtr< FPropertyNode > PinnedColorPropertyNode = ColorPropertyNode.Pin();
	if (ensure(PinnedColorPropertyNode.IsValid()))
	{
		UProperty* Property = PinnedColorPropertyNode->GetProperty();
		check(Property);

		FObjectPropertyNode* ObjectNode = PinnedColorPropertyNode->FindObjectItemParent();

		if (ObjectNode && ObjectNode->GetNumObjects())
		{
			FScopedTransaction Transaction(NSLOCTEXT("UnrealEd", "SetColorProperty", "Set Color Property"));

			PinnedColorPropertyNode->NotifyPreChange(Property, GetNotifyHook());

			FPropertyChangedEvent ChangeEvent(Property, EPropertyChangeType::ValueSet);
			PinnedColorPropertyNode->NotifyPostChange(ChangeEvent, GetNotifyHook());
		}
	}
}

void SDetailsViewBase::OnColorPickerWindowClosed(const TSharedRef<SWindow>& Window)
{
	const TSharedPtr< FPropertyNode > PinnedColorPropertyNode = ColorPropertyNode.Pin();
	if (ensure(PinnedColorPropertyNode.IsValid()))
	{
		UProperty* Property = PinnedColorPropertyNode->GetProperty();
		if (Property && PropertyUtilities.IsValid())
		{
			FPropertyChangedEvent ChangeEvent(Property, EPropertyChangeType::ArrayAdd);
			PinnedColorPropertyNode->FixPropertiesInEvent(ChangeEvent);
			PropertyUtilities->NotifyFinishedChangingProperties(ChangeEvent);
		}
	}

	// A color picker window is no longer open
	bHasOpenColorPicker = false;
	ColorPropertyNode.Reset();
}


void SDetailsViewBase::SetIsPropertyVisibleDelegate(FIsPropertyVisible InIsPropertyVisible)
{
	IsPropertyVisibleDelegate = InIsPropertyVisible;
}

void SDetailsViewBase::SetIsPropertyEditingEnabledDelegate(FIsPropertyEditingEnabled IsPropertyEditingEnabled)
{
	IsPropertyEditingEnabledDelegate = IsPropertyEditingEnabled;
}

bool SDetailsViewBase::IsPropertyEditingEnabled() const
{
	// If the delegate is not bound assume property editing is enabled, otherwise ask the delegate
	return !IsPropertyEditingEnabledDelegate.IsBound() || IsPropertyEditingEnabledDelegate.Execute();
}


void SDetailsViewBase::SetKeyframeHandler( TSharedPtr<class IDetailKeyframeHandler> InKeyframeHandler )
{
	KeyframeHandler = InKeyframeHandler;
}

TSharedPtr<IDetailKeyframeHandler> SDetailsViewBase::GetKeyframeHandler() 
{
	return KeyframeHandler;
}

void SDetailsViewBase::SetGenericLayoutDetailsDelegate(FOnGetDetailCustomizationInstance OnGetGenericDetails)
{
	GenericLayoutDelegate = OnGetGenericDetails;
}

TSharedPtr<FAssetThumbnailPool> SDetailsViewBase::GetThumbnailPool() const
{
	if (!ThumbnailPool.IsValid())
	{
		// Create a thumbnail pool for the view if it doesnt exist.  This does not use resources of no thumbnails are used
		ThumbnailPool = MakeShareable(new FAssetThumbnailPool(50, TAttribute<bool>::Create(TAttribute<bool>::FGetter::CreateSP(this, &SDetailsView::IsHovered))));
	}

	return ThumbnailPool;
}

void SDetailsViewBase::NotifyFinishedChangingProperties(const FPropertyChangedEvent& PropertyChangedEvent)
{
	OnFinishedChangingPropertiesDelegate.Broadcast(PropertyChangedEvent);
}

void SDetailsViewBase::RequestItemExpanded(TSharedRef<IDetailTreeNode> TreeNode, bool bExpand)
{
	// Don't change expansion state if its already in that state
	if (DetailTree->IsItemExpanded(TreeNode) != bExpand)
	{
		FilteredNodesRequestingExpansionState.Add(TreeNode, bExpand);
	}
}

void SDetailsViewBase::RefreshTree()
{
	DetailTree->RequestTreeRefresh();
}

void SDetailsViewBase::SaveCustomExpansionState(const FString& NodePath, bool bIsExpanded)
{
	if (bIsExpanded)
	{
		ExpandedDetailNodes.Add(NodePath);
	}
	else
	{
		ExpandedDetailNodes.Remove(NodePath);
	}
}

bool SDetailsViewBase::GetCustomSavedExpansionState(const FString& NodePath) const
{
	return ExpandedDetailNodes.Contains(NodePath);
}

bool SDetailsViewBase::IsPropertyVisible( const FPropertyAndParent& PropertyAndParent ) const
{
	return IsPropertyVisibleDelegate.IsBound() ? IsPropertyVisibleDelegate.Execute(PropertyAndParent) : true;
}

TSharedPtr<IPropertyUtilities> SDetailsViewBase::GetPropertyUtilities()
{
	return PropertyUtilities;
}

void SDetailsViewBase::OnShowOnlyModifiedClicked()
{
	CurrentFilter.bShowOnlyModifiedProperties = !CurrentFilter.bShowOnlyModifiedProperties;

	UpdateFilteredDetails();
}

void SDetailsViewBase::OnShowOnlyDifferingClicked()
{
	CurrentFilter.bShowOnlyDiffering = !CurrentFilter.bShowOnlyDiffering;

	UpdateFilteredDetails();
}

void SDetailsViewBase::OnShowAllAdvancedClicked()
{
	CurrentFilter.bShowAllAdvanced = !CurrentFilter.bShowAllAdvanced;

	UpdateFilteredDetails();
}

/** Called when the filter text changes.  This filters specific property nodes out of view */
void SDetailsViewBase::OnFilterTextChanged(const FText& InFilterText)
{
	FString InFilterString = InFilterText.ToString();
	InFilterString.Trim().TrimTrailing();

	// Was the filter just cleared
	bool bFilterCleared = InFilterString.Len() == 0 && CurrentFilter.FilterStrings.Num() > 0;

	FilterView(InFilterString);

}

/** 
 * Hides or shows properties based on the passed in filter text
 * 
 * @param InFilterText	The filter text
 */
void SDetailsViewBase::FilterView(const FString& InFilterText)
{
	TArray<FString> CurrentFilterStrings;

	FString ParseString = InFilterText;
	// Remove whitespace from the front and back of the string
	ParseString.Trim();
	ParseString.TrimTrailing();
	ParseString.ParseIntoArray(&CurrentFilterStrings, TEXT(" "), true);

	bHasActiveFilter = CurrentFilterStrings.Num() > 0;

	CurrentFilter.FilterStrings = CurrentFilterStrings;

	UpdateFilteredDetails();
}

void SDetailsViewBase::QueryLayoutForClass(FDetailLayoutBuilderImpl& CustomDetailLayout, UStruct* Class)
{
	CustomDetailLayout.SetCurrentCustomizationClass(CastChecked<UClass>(Class), NAME_None);

	FPropertyEditorModule& ParentPlugin = FModuleManager::GetModuleChecked<FPropertyEditorModule>("PropertyEditor");
	FCustomDetailLayoutNameMap& GlobalCustomLayoutNameMap = ParentPlugin.ClassNameToDetailLayoutNameMap;

	// Check the instanced map first
	FDetailLayoutCallback* Callback = InstancedClassToDetailLayoutMap.Find(TWeakObjectPtr<UStruct>(Class));

	if (!Callback)
	{
		// callback wasn't found in the per instance map, try the global instances instead
		Callback = GlobalCustomLayoutNameMap.Find(Class->GetFName());
	}

	if (Callback && Callback->DetailLayoutDelegate.IsBound())
	{
		// Create a new instance of the custom detail layout for the current class
		TSharedRef<IDetailCustomization> CustomizationInstance = Callback->DetailLayoutDelegate.Execute();

		// Ask for details immediately
		CustomizationInstance->CustomizeDetails(CustomDetailLayout);

		// Save the instance from destruction until we refresh
		CustomizationClassInstances.Add(CustomizationInstance);
	}
}

void SDetailsViewBase::QueryCustomDetailLayout(FDetailLayoutBuilderImpl& CustomDetailLayout)
{
	FPropertyEditorModule& ParentPlugin = FModuleManager::GetModuleChecked<FPropertyEditorModule>("PropertyEditor");

	// Get the registered classes that customize details
	FCustomDetailLayoutNameMap& GlobalCustomLayoutNameMap = ParentPlugin.ClassNameToDetailLayoutNameMap;

	UStruct* BaseStruct = GetBaseStruct();

	// All the current customization instances need to be deleted when it is safe
	CustomizationClassInstancesPendingDelete = CustomizationClassInstances;

	CustomizationClassInstances.Empty();

	//Ask for generic details not specific to an object being viewed 
	if (GenericLayoutDelegate.IsBound())
	{
		// Create a new instance of the custom detail layout for the current class
		TSharedRef<IDetailCustomization> CustomizationInstance = GenericLayoutDelegate.Execute();

		// Ask for details immediately
		CustomizationInstance->CustomizeDetails(CustomDetailLayout);

		// Save the instance from destruction until we refresh
		CustomizationClassInstances.Add(CustomizationInstance);
	}


	// Sort them by query order.  @todo not good enough
	struct FCompareFDetailLayoutCallback
	{
		FORCEINLINE bool operator()(const FDetailLayoutCallback& A, const FDetailLayoutCallback& B) const
		{
			return A.Order < B.Order;
		}
	};

	TMap< TWeakObjectPtr<UStruct>, FDetailLayoutCallback*> FinalCallbackMap;

	for (auto ClassIt = ClassesWithProperties.CreateConstIterator(); ClassIt; ++ClassIt)
	{
		// Check the instanced map first
		FDetailLayoutCallback* Callback = InstancedClassToDetailLayoutMap.Find(*ClassIt);

		if (!Callback)
		{
			// callback wasn't found in the per instance map, try the global instances instead
			Callback = GlobalCustomLayoutNameMap.Find((*ClassIt)->GetFName());
		}

		if (Callback)
		{
			FinalCallbackMap.Add(*ClassIt, Callback);
		}
	}


	FinalCallbackMap.ValueSort(FCompareFDetailLayoutCallback());

	TSet<UStruct*> QueriedClasses;

	if (FinalCallbackMap.Num() > 0)
	{
		// Ask each class that we have properties for to customize its layout
		for (auto LayoutIt(FinalCallbackMap.CreateConstIterator()); LayoutIt; ++LayoutIt)
		{
			const TWeakObjectPtr<UStruct> WeakClass = LayoutIt.Key();

			if (WeakClass.IsValid())
			{
				UStruct* Class = WeakClass.Get();

				FClassInstanceToPropertyMap& InstancedPropertyMap = ClassToPropertyMap.FindChecked(Class->GetFName());
				for (FClassInstanceToPropertyMap::TIterator InstanceIt(InstancedPropertyMap); InstanceIt; ++InstanceIt)
				{
					CustomDetailLayout.SetCurrentCustomizationClass(CastChecked<UClass>(Class), InstanceIt.Key());

					const FOnGetDetailCustomizationInstance& DetailDelegate = LayoutIt.Value()->DetailLayoutDelegate;

					if (DetailDelegate.IsBound())
					{
						QueriedClasses.Add(Class);

						// Create a new instance of the custom detail layout for the current class
						TSharedRef<IDetailCustomization> CustomizationInstance = DetailDelegate.Execute();

						// Ask for details immediately
						CustomizationInstance->CustomizeDetails(CustomDetailLayout);

						// Save the instance from destruction until we refresh
						CustomizationClassInstances.Add(CustomizationInstance);
					}
				}
			}
		}
	}

	// Ensure that the base class and its parents are always queried
	TSet<UStruct*> ParentClassesToQuery;
	if (BaseStruct && !QueriedClasses.Contains(BaseStruct))
	{
		ParentClassesToQuery.Add(BaseStruct);
		ClassesWithProperties.Add(BaseStruct);
	}

	// Find base classes of queried classes that were not queried and add them to the query list
	// this supports cases where a parent class has no properties but still wants to add customization
	for (auto QueriedClassIt = ClassesWithProperties.CreateConstIterator(); QueriedClassIt; ++QueriedClassIt)
	{
		UStruct* ParentStruct = (*QueriedClassIt)->GetSuperStruct();

		while (ParentStruct && ParentStruct->IsA(UClass::StaticClass()) && !QueriedClasses.Contains(ParentStruct) && !ClassesWithProperties.Contains(ParentStruct))
		{
			ParentClassesToQuery.Add(ParentStruct);
			ParentStruct = ParentStruct->GetSuperStruct();

		}
	}

	// Query extra base classes
	for (auto ParentIt = ParentClassesToQuery.CreateConstIterator(); ParentIt; ++ParentIt)
	{
		if (Cast<UClass>(*ParentIt))
		{
			QueryLayoutForClass(CustomDetailLayout, *ParentIt);
		}
	}
}

EVisibility SDetailsViewBase::GetFilterBoxVisibility() const
{
	// Visible if we allow search and we have anything to search otherwise collapsed so it doesn't take up room
	return (DetailsViewArgs.bAllowSearch && IsConnected()) ? EVisibility::Visible : EVisibility::Collapsed;
}

bool SDetailsViewBase::SupportsKeyboardFocus() const
{
	return DetailsViewArgs.bSearchInitialKeyFocus && SearchBox->SupportsKeyboardFocus() && GetFilterBoxVisibility() == EVisibility::Visible;
}

FReply SDetailsViewBase::OnKeyboardFocusReceived(const FGeometry& MyGeometry, const FKeyboardFocusEvent& InKeyboardFocusEvent)
{
	FReply Reply = FReply::Handled();

	if (InKeyboardFocusEvent.GetCause() != EKeyboardFocusCause::Cleared)
	{
		Reply.SetKeyboardFocus(SearchBox.ToSharedRef(), InKeyboardFocusEvent.GetCause());
	}

	return Reply;
}

/** Ticks the property view.  This function performs a data consistency check */
void SDetailsViewBase::Tick(const FGeometry& AllottedGeometry, const double InCurrentTime, const float InDeltaTime)
{
	for (int32 i = 0; i < CustomizationClassInstancesPendingDelete.Num(); ++i)
	{
		ensure(CustomizationClassInstancesPendingDelete[i].IsUnique());
	}

	if (RootNodePendingKill.IsValid())
	{
		RootNodePendingKill->Disconnect();
		RootNodePendingKill.Reset();
	}

	// Empty all the customization instances that need to be deleted
	CustomizationClassInstancesPendingDelete.Empty();

	auto RootPropertyNode = GetRootNode();
	check(RootPropertyNode.IsValid());

	// Purge any objects that are marked pending kill from the object list
	if (auto ObjectRoot = RootPropertyNode->AsObjectNode())
	{
		ObjectRoot->PurgeKilledObjects();
	}

	if (DeferredActions.Num() > 0)
	{
		// Any deferred actions are likely to cause the node  tree to be at least partially rebuilt
		// Save the expansion state of existing nodes so we can expand them later
		SaveExpandedItems();

		// Execute any deferred actions
		for (int32 ActionIndex = 0; ActionIndex < DeferredActions.Num(); ++ActionIndex)
		{
			DeferredActions[ActionIndex].ExecuteIfBound();
		}
		DeferredActions.Empty();
	}

	if( RootPropertyNode == RootNodePendingKill )
	{
		// Reaquire the root property node.  It may have been changed by the deferred actions if something like a blueprint editor forcefully resets a details panel during a posteditchange
		RootPropertyNode = GetRootNode();

		RestoreExpandedItems();
	}


	bool bValidateExternalNodes = true;
	FPropertyNode::DataValidationResult Result = RootPropertyNode->EnsureDataIsValid();
	if (Result == FPropertyNode::PropertiesChanged || Result == FPropertyNode::EditInlineNewValueChanged)
	{
		RestoreExpandedItems();
		UpdatePropertyMap();
	}
	else if (Result == FPropertyNode::ArraySizeChanged)
	{
		RestoreExpandedItems();
		UpdateFilteredDetails();
	}
	else if (Result == FPropertyNode::ObjectInvalid)
	{
		ForceRefresh();

		// All objects are being reset, no need to validate external nodes
		bValidateExternalNodes = false;
	}

	if (bValidateExternalNodes)
	{
		for (int32 NodeIndex = 0; NodeIndex < ExternalRootPropertyNodes.Num(); ++NodeIndex)
		{
			TSharedPtr<FObjectPropertyNode> ObjectNode = ExternalRootPropertyNodes[NodeIndex].Pin();

			if (ObjectNode.IsValid())
			{
				Result = ObjectNode->EnsureDataIsValid();
				if (Result == FPropertyNode::PropertiesChanged || Result == FPropertyNode::EditInlineNewValueChanged)
				{
					RestoreExpandedItems(ObjectNode);
					UpdatePropertyMap();
					// Note this will invalidate all the external root nodes so there is no need to continue
					ExternalRootPropertyNodes.Empty();
					break;
				}
				else if (Result == FPropertyNode::ArraySizeChanged)
				{
					RestoreExpandedItems(ObjectNode);
					UpdateFilteredDetails();
				}
			}
			else
			{
				// Remove the current node if it is no longer valid
				ExternalRootPropertyNodes.RemoveAt(NodeIndex);
				--NodeIndex;
			}
		}
	}

	if (ThumbnailPool.IsValid())
	{
		ThumbnailPool->Tick(InDeltaTime);
	}

	if (DetailLayout.IsValid())
	{
		DetailLayout->Tick(InDeltaTime);
	}

	if (!ColorPropertyNode.IsValid() && bHasOpenColorPicker)
	{
		// Destroy the color picker window if the color property node has become invalid
		DestroyColorPicker();
		bHasOpenColorPicker = false;
	}


	if (FilteredNodesRequestingExpansionState.Num() > 0)
	{
		// change expansion state on the nodes that request it
		for (TMap<TSharedRef<IDetailTreeNode>, bool >::TConstIterator It(FilteredNodesRequestingExpansionState); It; ++It)
		{
			DetailTree->SetItemExpansion(It.Key(), It.Value());
		}

		FilteredNodesRequestingExpansionState.Empty();
	}
}

/**
* Recursively gets expanded items for a node
*
* @param InPropertyNode			The node to get expanded items from
* @param OutExpandedItems	List of expanded items that were found
*/
void GetExpandedItems(TSharedPtr<FPropertyNode> InPropertyNode, TArray<FString>& OutExpandedItems)
{
	if (InPropertyNode->HasNodeFlags(EPropertyNodeFlags::Expanded))
	{
		const bool bWithArrayIndex = true;
		FString Path;
		Path.Empty(128);
		InPropertyNode->GetQualifiedName(Path, bWithArrayIndex);

		OutExpandedItems.Add(Path);
	}

	for (int32 ChildIndex = 0; ChildIndex < InPropertyNode->GetNumChildNodes(); ++ChildIndex)
	{
		GetExpandedItems(InPropertyNode->GetChildNode(ChildIndex), OutExpandedItems);
	}

}

/**
* Recursively sets expanded items for a node
*
* @param InNode			The node to set expanded items on
* @param OutExpandedItems	List of expanded items to set
*/
void SetExpandedItems(TSharedPtr<FPropertyNode> InPropertyNode, const TArray<FString>& InExpandedItems)
{
	if (InExpandedItems.Num() > 0)
	{
		const bool bWithArrayIndex = true;
		FString Path;
		Path.Empty(128);
		InPropertyNode->GetQualifiedName(Path, bWithArrayIndex);

		for (int32 ItemIndex = 0; ItemIndex < InExpandedItems.Num(); ++ItemIndex)
		{
			if (InExpandedItems[ItemIndex] == Path)
			{
				InPropertyNode->SetNodeFlags(EPropertyNodeFlags::Expanded, true);
				break;
			}
		}

		for (int32 NodeIndex = 0; NodeIndex < InPropertyNode->GetNumChildNodes(); ++NodeIndex)
		{
			SetExpandedItems(InPropertyNode->GetChildNode(NodeIndex), InExpandedItems);
		}
	}
}

void SDetailsViewBase::SaveExpandedItems()
{
	auto RootPropertyNode = GetRootNode();
	check(RootPropertyNode.IsValid());
	UStruct* BestBaseStruct = RootPropertyNode->GetBaseStructure();

	TArray<FString> ExpandedPropertyItems;
	GetExpandedItems(RootPropertyNode, ExpandedPropertyItems);

	// Handle spaces in expanded node names by wrapping them in quotes
	for( FString& String : ExpandedPropertyItems )
	{
		String.InsertAt(0, '"');
		String.AppendChar('"');
	}

	TArray<FString> ExpandedCustomItems = ExpandedDetailNodes.Array();

	// Expanded custom items may have spaces but SetSingleLineArray doesnt support spaces (treats it as another element in the array)
	// Append a '|' after each element instead
	FString ExpandedCustomItemsString;
	for (auto It = ExpandedDetailNodes.CreateConstIterator(); It; ++It)
	{
		ExpandedCustomItemsString += *It;
		ExpandedCustomItemsString += TEXT(",");
	}

	//while a valid class, and we're either the same as the base class (for multiple actors being selected and base class is AActor) OR we're not down to AActor yet)
	for (UStruct* Struct = BestBaseStruct; Struct && ((BestBaseStruct == Struct) || (Struct != AActor::StaticClass())); Struct = Struct->GetSuperStruct())
	{
		if (RootPropertyNode->GetNumChildNodes() > 0)
		{
			bool bShouldSave = ExpandedPropertyItems.Num() > 0;
			if (!bShouldSave)
			{
				TArray<FString> DummyExpandedPropertyItems;
				GConfig->GetSingleLineArray(TEXT("DetailPropertyExpansion"), *Struct->GetName(), DummyExpandedPropertyItems, GEditorUserSettingsIni);
				bShouldSave = DummyExpandedPropertyItems.Num() > 0;
			}

			if (bShouldSave)
			{
				GConfig->SetSingleLineArray(TEXT("DetailPropertyExpansion"), *Struct->GetName(), ExpandedPropertyItems, GEditorUserSettingsIni);
			}
		}
	}

	if (DetailLayout.IsValid() && BestBaseStruct)
	{
		bool bShouldSave = !ExpandedCustomItemsString.IsEmpty();
		if (!bShouldSave)
		{
			FString DummyExpandedCustomItemsString;
			GConfig->GetString(TEXT("DetailCustomWidgetExpansion"), *BestBaseStruct->GetName(), DummyExpandedCustomItemsString, GEditorUserSettingsIni);
			bShouldSave = !DummyExpandedCustomItemsString.IsEmpty();
		}
		if (bShouldSave)
		{
			GConfig->SetString(TEXT("DetailCustomWidgetExpansion"), *BestBaseStruct->GetName(), *ExpandedCustomItemsString, GEditorUserSettingsIni);
		}
	}
}

void SDetailsViewBase::RestoreExpandedItems(TSharedPtr<FPropertyNode> InitialStartNode)
{
	auto RootPropertyNode = GetRootNode();
	check(RootPropertyNode.IsValid());
	TSharedPtr<FPropertyNode> StartNode = InitialStartNode;
	if (!StartNode.IsValid())
	{
		StartNode = RootPropertyNode;
	}

	ExpandedDetailNodes.Empty();

	TArray<FString> ExpandedPropertyItems;
	FString ExpandedCustomItems;
	UStruct* BestBaseStruct = RootPropertyNode->GetBaseStructure();
	//while a valid class, and we're either the same as the base class (for multiple actors being selected and base class is AActor) OR we're not down to AActor yet)
	for (UStruct* Struct = BestBaseStruct; Struct && ((BestBaseStruct == Struct) || (Struct != AActor::StaticClass())); Struct = Struct->GetSuperStruct())
	{
		GConfig->GetSingleLineArray(TEXT("DetailPropertyExpansion"), *Struct->GetName(), ExpandedPropertyItems, GEditorUserSettingsIni);
		SetExpandedItems(StartNode, ExpandedPropertyItems);
	}

	if (BestBaseStruct)
	{
		GConfig->GetString(TEXT("DetailCustomWidgetExpansion"), *BestBaseStruct->GetName(), ExpandedCustomItems, GEditorUserSettingsIni);
		TArray<FString> ExpandedCustomItemsArray;
		ExpandedCustomItems.ParseIntoArray(&ExpandedCustomItemsArray, TEXT(","), true);

		ExpandedDetailNodes.Append(ExpandedCustomItemsArray);
	}
}

void SDetailsViewBase::UpdateFilteredDetails()
{
	auto RootPropertyNode = GetRootNode();
	if (RootPropertyNode.IsValid())
	{
		RootPropertyNode->FilterNodes(CurrentFilter.FilterStrings);
		RootPropertyNode->ProcessSeenFlags(true);

		for (int32 NodeIndex = 0; NodeIndex < ExternalRootPropertyNodes.Num(); ++NodeIndex)
		{
			TSharedPtr<FObjectPropertyNode> ObjectNode = ExternalRootPropertyNodes[NodeIndex].Pin();

			if (ObjectNode.IsValid())
			{
				ObjectNode->FilterNodes(CurrentFilter.FilterStrings);
				ObjectNode->ProcessSeenFlags(true);
			}
		}

		if (DetailLayout.IsValid())
		{
			DetailLayout->FilterDetailLayout(CurrentFilter);
		}

		RootTreeNodes = DetailLayout->GetRootTreeNodes();
	}
	DetailTree->RequestTreeRefresh();
}

/**
* Determines whether or not a property should be visible in the default generated detail layout
*
* @param PropertyNode	The property node to check
* @param ParentNode	The parent property node to check
* @return true if the property should be visible
*/
static bool IsVisibleStandaloneProperty(const FPropertyNode& PropertyNode, const FPropertyNode& ParentNode)
{
	const UProperty* Property = PropertyNode.GetProperty();
	const UArrayProperty* ParentArrayProperty = Cast<const UArrayProperty>(ParentNode.GetProperty());
	bool bIsVisibleStandalone = false;
	if (Property)
	{
		if (Property->IsA(UObjectPropertyBase::StaticClass()))
		{
			// Do not add this child node to the current map if its a single object property in a category (serves no purpose for UI)
			bIsVisibleStandalone = !ParentArrayProperty && (PropertyNode.GetNumChildNodes() == 0 || PropertyNode.GetNumChildNodes() > 1);
		}
		else if (Property->IsA(UArrayProperty::StaticClass()) || Property->ArrayDim > 1 && PropertyNode.GetArrayIndex() == INDEX_NONE)
		{
			// Base array properties are always visible
			bIsVisibleStandalone = true;
		}
		else
		{
			bIsVisibleStandalone = true;
		}

	}

	return bIsVisibleStandalone;
}

void SDetailsViewBase::UpdatePropertyMapRecursive(FPropertyNode& InNode, FDetailLayoutBuilderImpl& InDetailLayout, FName CurCategory, FComplexPropertyNode* CurObjectNode)
{
	UProperty* ParentProperty = InNode.GetProperty();
	UStructProperty* ParentStructProp = Cast<UStructProperty>(ParentProperty);

	for (int32 ChildIndex = 0; ChildIndex < InNode.GetNumChildNodes(); ++ChildIndex)
	{
		TSharedPtr<FPropertyNode> ChildNodePtr = InNode.GetChildNode(ChildIndex);
		FPropertyNode& ChildNode = *ChildNodePtr;
		UProperty* Property = ChildNode.GetProperty();

		{
			FObjectPropertyNode* ObjNode = ChildNode.AsObjectNode();
			FCategoryPropertyNode* CategoryNode = ChildNode.AsCategoryNode();
			if (ObjNode)
			{
				// Currently object property nodes do not provide any useful information other than being a container for its children.  We do not draw anything for them.
				// When we encounter object property nodes, add their children instead of adding them to the tree.
				UpdatePropertyMapRecursive(ChildNode, InDetailLayout, CurCategory, ObjNode);
			}
			else if (CategoryNode)
			{
				// For category nodes, we just set the current category and recurse through the children
				UpdatePropertyMapRecursive(ChildNode, InDetailLayout, CategoryNode->GetCategoryName(), CurObjectNode);
			}
			else
			{
				// Whether or not the property can be visible in the default detail layout
				bool bVisibleByDefault = IsVisibleStandaloneProperty(ChildNode, InNode);

				// Whether or not the property is a struct
				UStructProperty* StructProperty = Cast<UStructProperty>(Property);

				bool bIsStruct = StructProperty != NULL;

				static FName ShowOnlyInners("ShowOnlyInnerProperties");

				bool bIsChildOfCustomizedStruct = false;
				bool bIsCustomizedStruct = false;

				const UStruct* Struct = StructProperty ? StructProperty->Struct : NULL;
				const UStruct* ParentStruct = ParentStructProp ? ParentStructProp->Struct : NULL;
				if (Struct || ParentStruct)
				{
					FPropertyEditorModule& ParentPlugin = FModuleManager::GetModuleChecked<FPropertyEditorModule>("PropertyEditor");
					if (Struct)
					{
						bIsCustomizedStruct = ParentPlugin.IsCustomizedStruct(Struct, SharedThis( this ) );
					}

					if (ParentStruct)
					{
						bIsChildOfCustomizedStruct = ParentPlugin.IsCustomizedStruct(ParentStruct, SharedThis( this ) );
					}
				}

				// Whether or not to push out struct properties to their own categories or show them inside an expandable struct 
				bool bPushOutStructProps = bIsStruct && !bIsCustomizedStruct && !ParentStructProp && Property->HasMetaData(ShowOnlyInners);

				// Is the property edit inline new 
				const bool bIsEditInlineNew = SPropertyEditorEditInline::Supports(&ChildNode, ChildNode.GetArrayIndex());

				// Is this a property of an array
				bool bIsChildOfArray = PropertyEditorHelpers::IsChildOfArray(ChildNode);

				// Edit inline new properties should be visible by default
				bVisibleByDefault |= bIsEditInlineNew;

				// Children of arrays are not visible directly,
				bVisibleByDefault &= !bIsChildOfArray;

				FPropertyAndParent PropertyAndParent(*Property, ParentProperty);
				const bool bIsUserVisible = IsPropertyVisible(PropertyAndParent);

				// Inners of customized in structs should not be taken into consideration for customizing.  They are not designed to be individually customized when their parent is already customized
				if (!bIsChildOfCustomizedStruct)
				{
					// Add any object classes with properties so we can ask them for custom property layouts later
					ClassesWithProperties.Add(Property->GetOwnerStruct());
				}

				// If there is no outer object then the class is the object root and there is only one instance
				FName InstanceName = NAME_None;
				if (CurObjectNode && CurObjectNode->GetParentNode())
				{
					InstanceName = CurObjectNode->GetParentNode()->GetProperty()->GetFName();
				}
				else if (ParentStructProp)
				{
					InstanceName = ParentStructProp->GetFName();
				}

				// Do not add children of customized in struct properties or arrays
				if (!bIsChildOfCustomizedStruct && !bIsChildOfArray)
				{
					// Get the class property map
					FClassInstanceToPropertyMap& ClassInstanceMap = ClassToPropertyMap.FindOrAdd(Property->GetOwnerStruct()->GetFName());

					FPropertyNodeMap& PropertyNodeMap = ClassInstanceMap.FindOrAdd(InstanceName);

					if (!PropertyNodeMap.ParentProperty)
					{
						PropertyNodeMap.ParentProperty = CurObjectNode;
					}
					else
					{
						ensure(PropertyNodeMap.ParentProperty == CurObjectNode);
					}

					checkSlow(!PropertyNodeMap.Contains(Property->GetFName()));

					PropertyNodeMap.Add(Property->GetFName(), ChildNodePtr);
				}

				if (bVisibleByDefault && bIsUserVisible && !bPushOutStructProps)
				{
					FName CategoryName = CurCategory;

					// For properties inside a struct, add them to their own category unless they just take the name of the parent struct.  
					// In that case push them to the parent category
					FName PropertyCatagoryName = FObjectEditorUtils::GetCategoryFName(Property);
					if (!ParentStructProp || (PropertyCatagoryName != ParentStructProp->Struct->GetFName()))
					{
						CategoryName = PropertyCatagoryName;
					}

					// Add a property to the default category
					FDetailCategoryImpl& CategoryImpl = InDetailLayout.DefaultCategory(CategoryName);
					CategoryImpl.AddPropertyNode(ChildNodePtr.ToSharedRef(), InstanceName);
				}

				bool bRecurseIntoChildren =
					!bIsChildOfCustomizedStruct // Don't recurse into built in struct children, we already know what they are and how to display them
					&&  !bIsCustomizedStruct // Don't recurse into customized structs
					&&	!bIsChildOfArray // Do not recurse into arrays, the children are drawn by the array property parent
					&&	!bIsEditInlineNew // Edit inline new children are not supported for customization yet
					&&	bIsUserVisible // Properties must be allowed to be visible by a user if they are not then their children are not visible either
					&& (!bIsStruct || bPushOutStructProps); //  Only recurse into struct properties if they are going to be displayed as standalone properties in categories instead of inside an expandable area inside a category

				if (bRecurseIntoChildren)
				{
					// Built in struct properties or children of arras 
					UpdatePropertyMapRecursive(ChildNode, InDetailLayout, CurCategory, CurObjectNode);
				}
			}
		}
	}
}

void SDetailsViewBase::UpdatePropertyMap()
{
	// Reset everything
	ClassToPropertyMap.Empty();
	ClassesWithProperties.Empty();

	// We need to be able to create a new detail layout and properly clean up the old one in the process
	check(!DetailLayout.IsValid() || DetailLayout.IsUnique());

	RootTreeNodes.Empty();

	DetailLayout = MakeShareable(new FDetailLayoutBuilderImpl(ClassToPropertyMap, PropertyUtilities.ToSharedRef(), SharedThis(this)));


	auto RootPropertyNode = GetRootNode();
	check(RootPropertyNode.IsValid());
	// Currently object property nodes do not provide any useful information other than being a container for its children.  We do not draw anything for them.
	// When we encounter object property nodes, add their children instead of adding them to the tree.
	UpdatePropertyMapRecursive(*RootPropertyNode, *DetailLayout, NAME_None, RootPropertyNode.Get());

	CustomUpdatePropertyMap();

	// Ask for custom detail layouts
	QueryCustomDetailLayout(*DetailLayout);

	DetailLayout->GenerateDetailLayout();

	UpdateFilteredDetails();
}