bool FDetailLayoutBuilderImpl::IsPropertyVisible( TSharedRef<IPropertyHandle> PropertyHandle ) const
{
	if( PropertyHandle->IsValidHandle() )
	{
		FPropertyAndParent PropertyAndParent(*PropertyHandle->GetProperty(), PropertyHandle->GetParentHandle().IsValid() ? PropertyHandle->GetParentHandle()->GetProperty() : nullptr );

		return IsPropertyVisible(PropertyAndParent);
	}
	
	return false;
}
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;
					}

					if (IsPropertyReadOnly(PropertyAndParent))
					{
						ChildNode.SetNodeFlags(EPropertyNodeFlags::IsReadOnly, true);
					}

					// 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::UpdateSinglePropertyMapRecursive(FPropertyNode& InNode, FDetailLayoutData& LayoutData, FName CurCategory, FComplexPropertyNode* CurObjectNode, bool bEnableFavoriteSystem, bool bUpdateFavoriteSystemOnly)
{
	FDetailLayoutBuilderImpl& DetailLayout = *LayoutData.DetailLayout;

	UProperty* ParentProperty = InNode.GetProperty();
	UStructProperty* ParentStructProp = Cast<UStructProperty>(ParentProperty);
	for(int32 ChildIndex = 0; ChildIndex < InNode.GetNumChildNodes(); ++ChildIndex)
	{
		//Use the original value for each child
		bool LocalUpdateFavoriteSystemOnly = bUpdateFavoriteSystemOnly;

		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.
				UpdateSinglePropertyMapRecursive(ChildNode, LayoutData, CurCategory, ObjNode, bEnableFavoriteSystem, LocalUpdateFavoriteSystemOnly);
			}
			else if(CategoryNode)
			{
				if(!LocalUpdateFavoriteSystemOnly)
				{
					FName InstanceName = NAME_None;
					FName CategoryName = CurCategory;
					FString CategoryDelimiterString;
					CategoryDelimiterString.AppendChar(FPropertyNodeConstants::CategoryDelimiterChar);
					if(CurCategory != NAME_None && CategoryNode->GetCategoryName().ToString().Contains(CategoryDelimiterString))
					{
						// This property is child of another property so add it to the parent detail category
						FDetailCategoryImpl& CategoryImpl = DetailLayout.DefaultCategory(CategoryName);
						CategoryImpl.AddPropertyNode(ChildNodePtr.ToSharedRef(), InstanceName);
					}
				}

				// For category nodes, we just set the current category and recurse through the children
				UpdateSinglePropertyMapRecursive(ChildNode, LayoutData, CategoryNode->GetCategoryName(), CurObjectNode, bEnableFavoriteSystem, LocalUpdateFavoriteSystemOnly);
			}
			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 = ChildNode.HasNodeFlags(EPropertyNodeFlags::ShowInnerObjectProperties) || SPropertyEditorEditInline::Supports(&ChildNode, ChildNode.GetArrayIndex());

				// Is this a property of a container property
				bool bIsChildOfContainer = PropertyEditorHelpers::IsChildOfArray(ChildNode) || PropertyEditorHelpers::IsChildOfSet(ChildNode) || PropertyEditorHelpers::IsChildOfMap(ChildNode);

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

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

				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 && !LocalUpdateFavoriteSystemOnly)
				{
					// Add any object classes with properties so we can ask them for custom property layouts later
					LayoutData.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 && !bIsChildOfContainer && !LocalUpdateFavoriteSystemOnly)
				{
					// Get the class property map
					FClassInstanceToPropertyMap& ClassInstanceMap = LayoutData.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);
				}
				bool bCanDisplayFavorite = false;
				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;
					}

					if(!LocalUpdateFavoriteSystemOnly)
					{
						if(IsPropertyReadOnly(PropertyAndParent))
						{
							ChildNode.SetNodeFlags(EPropertyNodeFlags::IsReadOnly, true);
						}

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

					bCanDisplayFavorite = true;
					if(bEnableFavoriteSystem)
					{
						if(bIsCustomizedStruct)
						{
							bCanDisplayFavorite = false;
							//CustomizedStruct child are not categorize since they are under an object but we have to put them in favorite category if the user want to favorite them
							LocalUpdateFavoriteSystemOnly = true;
						}
						else if(ChildNodePtr->IsFavorite())
						{
							//Find or create the favorite category, we have to duplicate favorite property row under this category
							FString CategoryFavoritesName = TEXT("Favorites");
							FName CatFavName = *CategoryFavoritesName;
							FDetailCategoryImpl& CategoryFavImpl = DetailLayout.DefaultCategory(CatFavName);
							CategoryFavImpl.SetSortOrder(0);
							CategoryFavImpl.SetCategoryAsSpecialFavorite();

							//Add the property to the favorite
							FObjectPropertyNode *RootObjectParent = ChildNodePtr->FindRootObjectItemParent();
							FName RootInstanceName = NAME_None;
							if(RootObjectParent != nullptr)
							{
								RootInstanceName = RootObjectParent->GetObjectBaseClass()->GetFName();
							}

							if(LocalUpdateFavoriteSystemOnly)
							{
								if(IsPropertyReadOnly(PropertyAndParent))
								{
									ChildNode.SetNodeFlags(EPropertyNodeFlags::IsReadOnly, true);
								}
								else
								{
									//If the parent has a condition that is not met, make the child as readonly
									FDetailLayoutCustomization ParentTmpCustomization;
									ParentTmpCustomization.PropertyRow = MakeShareable(new FDetailPropertyRow(InNode.AsShared(), CategoryFavImpl.AsShared()));
									if(ParentTmpCustomization.PropertyRow->GetPropertyEditor()->IsPropertyEditingEnabled() == false)
									{
										ChildNode.SetNodeFlags(EPropertyNodeFlags::IsReadOnly, true);
									}
								}
							}

							//Duplicate the row
							CategoryFavImpl.AddPropertyNode(ChildNodePtr.ToSharedRef(), RootInstanceName);
						}

						if(bIsStruct)
						{
							LocalUpdateFavoriteSystemOnly = true;
						}
					}
				}
				ChildNodePtr->SetCanDisplayFavorite(bCanDisplayFavorite);

				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
					&&	!bIsChildOfContainer // Do not recurse into containers, the children are drawn by the container 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 || LocalUpdateFavoriteSystemOnly)
				{
					// Built in struct properties or children of arras 
					UpdateSinglePropertyMapRecursive(ChildNode, LayoutData, CurCategory, CurObjectNode, bEnableFavoriteSystem, LocalUpdateFavoriteSystemOnly);
				}
			}
		}
	}
}