UnrealEngineUWP/Engine/Plugins/Runtime/ModelViewViewModel/Source/ModelViewViewModelBlueprint/Public/MVVMBlueprintViewEvent.h

// Copyright Epic Games, Inc. All Rights Reserved.

#pragma once

#include "MVVMPropertyPath.h"
#include "MVVMBlueprintPin.h"

#include "MVVMBlueprintViewEvent.generated.h"

class UEdGraph;
class UK2Node;
class UWidgetBlueprint;

/**
 *
 */
UCLASS(Within = MVVMBlueprintView)
class MODELVIEWVIEWMODELBLUEPRINT_API UMVVMBlueprintViewEvent : public UObject
{
	GENERATED_BODY()

public:
	enum class EMessageType : uint8
	{
		Info,
		Warning,
		Error
	};

	struct FMessage
	{
		FText MessageText;
		EMessageType MessageType;
	};

	/** @return true if the property path contains a multicast delegate property. */
	static bool Supports(const UWidgetBlueprint* WidgetBlueprint, const FMVVMBlueprintPropertyPath& PropertyPath);

public:
	/** Whether the event is enabled or disabled by default. The instance may enable the event at runtime. */
	UPROPERTY(EditAnywhere, Category = "Viewmodel")
	bool bEnabled = true;

	/** The event is visible in the editor, but is not compiled and cannot be used at runtime. */
	UPROPERTY(EditAnywhere, Category = "Viewmodel")
	bool bCompile = true;

public:
	const FMVVMBlueprintPropertyPath& GetEventPath() const
	{
		return EventPath;
	}
	void SetEventPath(FMVVMBlueprintPropertyPath EventPath);

	const FMVVMBlueprintPropertyPath& GetDestinationPath() const
	{
		return DestinationPath;
	}
	void SetDestinationPath(FMVVMBlueprintPropertyPath DestinationPath);

public:
	UEdGraph* GetWrapperGraph() const
	{
		return CachedWrapperGraph;
	}

	FName GetWrapperGraphName() const
	{
		return GraphName;
	}

	void RemoveWrapperGraph();

	UK2Node* GetWrapperNode() const
	{
		return CachedWrapperNode;
	}

	UEdGraph* GetOrCreateWrapperGraph();

public:
	TArrayView<const FMVVMBlueprintPin> GetPins() const
	{
		return SavedPins;
	}

	/** Generates SavedPins from the wrapper graph, if it exists. */
	void SavePinValues();

	UEdGraphPin* GetOrCreateGraphPin(FName PinName);

	FMVVMBlueprintPropertyPath GetPinPath(FName PinName) const;
	void SetPinPath(FName PinName, const FMVVMBlueprintPropertyPath& Path);
	// To set a pin when loading the asset (no graph generation)
	void SetPinPathNoGraphGeneration(FName PinName, const FMVVMBlueprintPropertyPath& Path);

public:
	TArray<FText> GetCompilationMessages(EMessageType InMessageType) const;
	bool HasCompilationMessage(EMessageType InMessageType) const;
	void AddCompilationToBinding(FMessage MessageToAdd);
	void ResetCompilationMessages();

public:
	/** 
	 * Get a string that identifies this event. 
	 */
	FText GetDisplayName(bool bUseDisplayName) const;

	/**
	 * Get a string that identifies this event and is specifically formatted for search. 
	 * This includes the display name and variable name of all fields and widgets, as well as all function keywords.
	 * For use in the UI, use GetDisplayNameString()
	 */
	FString GetSearchableString() const;

public:
	virtual void PostEditChangeChainProperty(FPropertyChangedChainEvent& PropertyChainEvent) override;

private:
	static const UFunction* GetEventSignature(const UWidgetBlueprint* WidgetBlueprint, const FMVVMBlueprintPropertyPath& PropertyPath);
	const UFunction* GetEventSignature() const;
	UWidgetBlueprint* GetWidgetBlueprintInternal() const;
	UEdGraph* CreateWrapperGraphInternal();
	UEdGraph* CreateWrapperGraphInternal(const UFunction* Signature, const UFunction* Function);
	UEdGraph* CreateWrapperGraphInternal(const UFunction* Signature, const FProperty* Property);
	void LoadPinValuesInternal();

private:
	UPROPERTY(VisibleAnywhere, Category = "Viewmodel")
	FMVVMBlueprintPropertyPath EventPath;

	UPROPERTY(VisibleAnywhere, Category = "Viewmodel")
	FMVVMBlueprintPropertyPath DestinationPath;

	/**
	 * The pin that are modified and we saved data.
	 * The data may not be modified. We used the default value of the K2Node in that case.
	 */
	UPROPERTY(VisibleAnywhere, Category = "Viewmodel")
	TArray<FMVVMBlueprintPin> SavedPins;

	UPROPERTY(VisibleAnywhere, Category = "Viewmodel")
	FName GraphName;

	TArray<FMessage> Messages;

	UPROPERTY(Transient, DuplicateTransient)
	mutable TObjectPtr<UEdGraph> CachedWrapperGraph;

	UPROPERTY(Transient, DuplicateTransient)
	mutable TObjectPtr<UK2Node> CachedWrapperNode;
};