UnrealEngineUWP/Engine/Source/Editor/PropertyEditor/Private/DetailLayoutBuilderImpl.h

// Copyright 1998-2015 Epic Games, Inc. All Rights Reserved.
#pragma once

class FDetailCategoryImpl;

class FDetailLayoutBuilderImpl : public IDetailLayoutBuilder, public TSharedFromThis<FDetailLayoutBuilderImpl>
{
public:
	FDetailLayoutBuilderImpl(FClassToPropertyMap& InPropertyMap, const TSharedRef< class IPropertyUtilities >& InPropertyUtilities, const TSharedRef< IDetailsViewPrivate >& InDetailsView);

	/** IDetailLayoutBuilder Interface */
	virtual const IDetailsView& GetDetailsView() const override;
	virtual void GetObjectsBeingCustomized( TArray< TWeakObjectPtr<UObject> >& OutObjects ) const override;
	virtual IDetailCategoryBuilder& EditCategory( FName CategoryName, const FText& NewLocalizedDisplayName = FText::GetEmpty(), ECategoryPriority::Type CategoryType = ECategoryPriority::Default ) override;
	virtual TSharedRef<IPropertyHandle> GetProperty( const FName PropertyPath, const UClass* ClassOutermost, FName InInstanceName ) override;
	virtual void HideProperty( const TSharedPtr<IPropertyHandle> Property ) override;
	virtual void HideProperty( FName PropertyPath, const UClass* ClassOutermost = NULL, FName InstanceName = NAME_None ) override;
	virtual void ForceRefreshDetails() override;
	virtual TSharedPtr<FAssetThumbnailPool> GetThumbnailPool() const override;
	virtual bool IsPropertyVisible( TSharedRef<IPropertyHandle> PropertyHandle ) const override;
	virtual bool IsPropertyVisible( const struct FPropertyAndParent& PropertyAndParent ) const override;
	virtual void HideCategory( FName CategoryName ) override;
	virtual const TSharedRef< IPropertyUtilities >& GetPropertyUtilities() const override; 

	/**
	 * Creates a default category. The SDetails view will generate widgets in default categories 
	 *
	 * @param CategoryName	The name of the category to create
	 */
	FDetailCategoryImpl& DefaultCategory( FName CategoryName );

	/**
	 * Generates the layout for this detail builder                                                              
	 */
	void GenerateDetailLayout();

	/**
	 * Filters the layout based on the passed in filter                                                          
	 */
	void FilterDetailLayout( const FDetailFilter& InFilter );

	/**
	 * Sets the current class being asked for customization
	 * Used for looking up properties if a class is not provided
	 *
	 * @param CurrentClass	The current class being customized
	 * @param VariableName The variable name of the class being customized (used for inner classes/structs where there can be multiple instances of them)
	 */
	void SetCurrentCustomizationClass( UClass* CurrentClass, FName VariableName );

	/** @return The current class variable name being customized */
	FName GetCurrentCustomizationVariableName() const { return CurrentCustomizationVariableName; }

	/**
	 * Finds a property node for the current property
	 *
	 * @param PropertyPath	The path to the property
	 * @param ClassOutermost	The outer class of the property
	 * @param bMarkPropertyAsCustomized	Whether or not to mark the property as customized so it does not appear in the default layout
	 * @return The found property node
	 */
	TSharedPtr<FPropertyNode> GetPropertyNode( FName PropertyPath, const UClass* ClassOutermost, FName InstanceName ) const;

	/**
	 * Gets the property node from the provided handle
 	 *
	 * @param PropertyHandle	The property handle to get the node from
	 * @param bMarkAsCustomized	Whether or not to mark the value as customized
	 */
	TSharedPtr<FPropertyNode> GetPropertyNode( TSharedPtr<IPropertyHandle> PropertyHandle ) const;

	/**
	 * Marks a property as customized
	 *
	 * @param PropertyNode	The property node to mark as customized
	 */
	void SetCustomProperty( const TSharedPtr<FPropertyNode>& PropertyNode );

	/**
	 * @return All tree nodes that should be visible in the tree                                                              
	 */
	TArray< TSharedRef<IDetailTreeNode> >& GetRootTreeNodes() { return FilteredRootTreeNodes; }

	/**
	 * @return true if the layout has any details
	 */
	bool HasDetails() const { return AllRootTreeNodes.Num() > 0; }

	/**
	 * Ticks tickable nodes (if any)
	 */
	void Tick( float DeltaTime );
	
	/**
	 * Adds a node that should be ticked each frame
	 *
	 * @param TickableNode	The node to tick
	 */
	void AddTickableNode( IDetailTreeNode& TickableNode );

	/**
	 * Removes a node that should no longer be ticked each frame
	 *
	 * @param TickableNode	The node to remove
	 */
	void RemoveTickableNode( IDetailTreeNode& TickableNode );

	/**
	 * @return The current filter that is being used to show or hide rows
	 */
	const FDetailFilter& GetCurrentFilter() const { return CurrentFilter; }

	/**
	 * Saves the expansion state of a tree node
	 *
	 * @param NodePath	The path to the detail node to save
	 * @param bIsExpanded	true if the node is expanded, false otherwise
	 */
	void SaveExpansionState( const FString& NodePath, bool bIsExpanded );

	/**
	 * Gets the saved expansion state of a tree node in this category	
	 *
	 * @param NodePath	The path to the detail node to get
	 * @return true if the node should be expanded, false otherwise
	 */	
	bool GetSavedExpansionState( const FString& NodePath ) const;
	
	/**
	 * Makes a property handle from a property node
	 * 
	 * @param PropertyNodePtr	The property node to make a handle for.
	 */
	TSharedRef<IPropertyHandle> GetPropertyHandle( TSharedPtr<FPropertyNode> PropertyNodePtr );

	/**
	 * Adds an external property root node to the list of root nodes that the details new needs to manage
	 *
	 * @param InExternalRootNode	The node to add
	 */
	void AddExternalRootPropertyNode( TSharedRef<FPropertyNode> InExternalRootNode );

	/** @return The details view that owns this layout */
	IDetailsViewPrivate& GetDetailsView() { return DetailsView; }
private:
	/**
	 * Finds a property node for the current property by searching in a fast lookup map or a path search if required
	 *
	 * @param PropertyPath	The path to the property
	 * @param ClassOutermost	The outer class of the property
	 * @param bMarkPropertyAsCustomized	Whether or not to mark the property as customized so it does not appear in the default layout
	 * @return The found property node
	 */
	TSharedPtr<FPropertyNode> GetPropertyNodeInternal( FName PropertyPath, const UClass* ClassOutermost, FName InstanceName ) const;

	/**
	 * Builds a list of simple and advanced categories that should be displayed
	 */
	void BuildCategories( const FCategoryMap& CategoryMap, TArray< TSharedRef<FDetailCategoryImpl> >& OutSimpleCategories, TArray< TSharedRef<FDetailCategoryImpl> >& OutAdvancedCategories );

private:
	/** A mapping of category names to categories which have been customized */
	FCategoryMap CustomCategoryMap;
	/** A mapping of category names to categories which have been not customized */
	FCategoryMap DefaultCategoryMap;
	/** A mapping of classes to top level properties in that class */
	FClassToPropertyMap& PropertyMap;
	/** Force hidden categories set by the user */
	TSet<FName> ForceHiddenCategories;
	/** Nodes that require ticking */
	TSet<IDetailTreeNode*> TickableNodes;
	/** Current filter applied to the view */
	FDetailFilter CurrentFilter;
	/** All RootTreeNodes */
	FDetailNodeList AllRootTreeNodes;
	/** All generated category widgets for rebuilding them if needed */
	FDetailNodeList FilteredRootTreeNodes;
	/** The current variable name of the class being customized (inner class instances)*/
	FName CurrentCustomizationVariableName;
	/** The global property settings */
	const TSharedRef< class IPropertyUtilities > PropertyDetailsUtilities;
	/** The view where this detail customizer resides */
	class IDetailsViewPrivate& DetailsView;
	/** The current class being customized */
	UClass* CurrentCustomizationClass;
};