UnrealEngineUWP/Engine/Source/Editor/MaterialEditor/Private/MaterialEditorDetailCustomization.h

// Copyright 1998-2019 Epic Games, Inc. All Rights Reserved.

#pragma once

#include "CoreMinimal.h"
#include "Widgets/Views/STableViewBase.h"
#include "Widgets/Views/STableRow.h"
#include "IDetailCustomization.h"
#include "PropertyHandle.h"

class IDetailLayoutBuilder;
class SComboButton;
class SEditableText;

DECLARE_DELEGATE_OneParam(FOnCollectParameterGroups, TArray<FString>*);

class FMaterialEditorParameterDetails : public IDetailCustomization
{

public:
	/** Makes a new instance of this detail layout class for a specific detail view requesting it */
	static TSharedRef<class IDetailCustomization> MakeInstance(class UMaterialEditorPreviewParameters* Material);

	/** Constructor */
	FMaterialEditorParameterDetails(class UMaterialEditorPreviewParameters* Material);

	/** IDetailCustomization interface */
	virtual void CustomizeDetails(IDetailLayoutBuilder& DetailLayout) override;

	static TOptional<float> OnGetValue(TSharedRef<IPropertyHandle> PropertyHandle);
	static void OnValueCommitted(float NewValue, ETextCommit::Type CommitType, TSharedRef<IPropertyHandle> PropertyHandle);

private:
	/** Builds the custom parameter groups category */
	void CreateGroupsWidget(TSharedRef<IPropertyHandle> ParameterGroupsProperty, class IDetailCategoryBuilder& GroupsCategory);

	/** Builds the widget for an individual parameter group */
	void CreateSingleGroupWidget(struct FEditorParameterGroup& ParameterGroup, TSharedPtr<IPropertyHandle> ParameterGroupProperty, class IDetailGroup& DetailGroup);

	/** These methods generate the custom widgets for the various parameter types */
	void CreateParameterValueWidget(class UDEditorParameterValue* Parameter, TSharedPtr<IPropertyHandle> ParameterProperty, IDetailGroup& DetailGroup);
	void CreateMaskParameterValueWidget(class UDEditorParameterValue* Parameter, TSharedPtr<IPropertyHandle> ParameterProperty, IDetailGroup& DetailGroup);
	void CreateVectorChannelMaskParameterValueWidget(class UDEditorParameterValue* Parameter, TSharedPtr<IPropertyHandle> ParameterProperty, IDetailGroup& DetailGroup);
	void CreateScalarAtlasPositionParameterValueWidget(class UDEditorParameterValue* Parameter, TSharedPtr<IPropertyHandle> ParameterProperty, IDetailGroup& DetailGroup);
	FString GetCurvePath(class UDEditorScalarParameterValue* Parameter) const;
	/** Gets the expression description of this parameter from the the base material */
	FText GetParameterExpressionDescription(class UDEditorParameterValue* Parameter) const;

private:
	/** Object that stores all of the possible parameters we can edit */
	UMaterialEditorPreviewParameters* MaterialEditorInstance;

	/** Associated UMaterialEditorPreviewParameters utilities */
	TWeakPtr<class IPropertyUtilities> PropertyUtilities;

};

class FMaterialExpressionParameterDetails : public IDetailCustomization
{
public:

	/** Makes a new instance of this detail layout class for a specific detail view requesting it */
	static TSharedRef<class IDetailCustomization> MakeInstance(FOnCollectParameterGroups InCollectGroupsDelegate);
	
	/** Constructor requires a delegate to populate group names with */
	FMaterialExpressionParameterDetails(FOnCollectParameterGroups InCollectGroupsDelegate);

	/** IDetailCustomization interface */
	virtual void CustomizeDetails( IDetailLayoutBuilder& DetailLayout ) override;

protected:
	/** Default constructor for child overrides */
	FMaterialExpressionParameterDetails();

	/** Populates the group name that this parameter details uses */
	void PopulateGroups();

	/** Functions used to make the custom combo button with editable text */
	TSharedRef< ITableRow > MakeDetailsGroupViewWidget( TSharedPtr<FString> Item, const TSharedRef< STableViewBase >& OwnerTable );
	void OnSelectionChanged( TSharedPtr<FString> ProposedSelection, ESelectInfo::Type SelectInfo );
	void OnTextCommitted( const FText& InText, ETextCommit::Type CommitInfo);
	FString OnGetString() const;
	FText OnGetText() const;
	void OnSliderMinMaxEdited();

protected:
	/** The property handle to the groups */
	TSharedPtr<class IPropertyHandle> GroupPropertyHandle;

	/** Custom widgets (combo button with editable text) to access the property with */
	TWeakPtr<SComboButton> GroupComboButton;
	TWeakPtr<SEditableText> GroupEditBox;
	TWeakPtr<SListView<TSharedPtr<FString>>> GroupListView;

	/** Delegate to call to collect a list of groups with */
	FOnCollectParameterGroups CollectGroupsDelegate;

	/** A list of all group names to choose from */
	TArray<TSharedPtr<FString>> GroupsSource;

	TArray<TWeakObjectPtr<UObject>> ScalarParameterObjects;
	TArray<TSharedPtr<IPropertyHandle>> DefaultValueHandles;
};

class FMaterialExpressionLayersParameterDetails : public FMaterialExpressionParameterDetails
{
public:

	/** Makes a new instance of this detail layout class for a specific detail view requesting it */
	static TSharedRef<class IDetailCustomization> MakeInstance(FOnCollectParameterGroups InCollectGroupsDelegate);

	/** Constructor requires a delegate to populate group names with */
	FMaterialExpressionLayersParameterDetails(FOnCollectParameterGroups InCollectGroupsDelegate);

	/** IDetailCustomization interface */
	virtual void CustomizeDetails(IDetailLayoutBuilder& DetailLayout) override;

	void ResetCategory(IDetailLayoutBuilder* DetailLayout);
};

/** 
 * Customizes the details of a CollectionParameter node, 
 * specifically creating a vertical box for ParameterName with only valid entries based on the current collection. 
 */
class FMaterialExpressionCollectionParameterDetails : public IDetailCustomization
{
public:

	/** Makes a new instance of this detail layout class for a specific detail view requesting it */
	static TSharedRef<class IDetailCustomization> MakeInstance();

	/** Constructor requires a delegate to populate group names with */
	FMaterialExpressionCollectionParameterDetails();

	/** IDetailCustomization interface */
	virtual void CustomizeDetails( IDetailLayoutBuilder& DetailLayout ) override;

private:
	/** Populates the group name that this parameter details uses */
	void PopulateParameters();

	/** Functions used to make the custom combo button with editable text */
	TSharedRef< ITableRow > MakeDetailsGroupViewWidget( TSharedPtr<FString> Item, const TSharedRef< STableViewBase >& OwnerTable );
	void OnSelectionChanged( TSharedPtr<FString> ProposedSelection, ESelectInfo::Type SelectInfo );

	FText GetToolTipText() const;
	FText GetParameterNameString() const;
	bool IsParameterNameComboEnabled() const;
	void OnCollectionChanged();

private:

	TSharedPtr<class IPropertyHandle> CollectionPropertyHandle;

	/** The property handle to the parameter name */
	TSharedPtr<class IPropertyHandle> ParameterNamePropertyHandle;

	TWeakPtr<SComboButton> ParameterComboButton;
	TWeakPtr<SListView<TSharedPtr<FString>>> ParameterListView;

	/** A list of all parameter names to choose from */
	TArray<TSharedPtr<FString>> ParametersSource;
};

class FMaterialDetailCustomization : public IDetailCustomization
{
public:

	/** Makes a new instance of this detail layout class for a specific detail view requesting it */
	static TSharedRef<class IDetailCustomization> MakeInstance();

	/** IDetailCustomization interface */
	virtual void CustomizeDetails( IDetailLayoutBuilder& DetailLayout ) override;
};