UnrealEngineUWP/Engine/Source/Editor/CurveEditor/Private/RichCurveKeyProxy.h

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

#pragma once

#include "CoreTypes.h"
#include "UObject/WeakObjectPtr.h"
#include "UObject/WeakObjectPtrTemplates.h"
#include "CurveEditorKeyProxy.h"
#include "Curves/RichCurve.h"
#include "RichCurveEditorModel.h"

#include "RichCurveKeyProxy.generated.h"

UCLASS()
class URichCurveKeyProxy : public UObject, public ICurveEditorKeyProxy
{
public:
	GENERATED_BODY()

	/**
	 * Initialize this key proxy object by caching the underlying key object, and retrieving the time/value each tick
	 */
	void Initialize(FKeyHandle InKeyHandle, FRichCurveEditorModel* InModel, TWeakObjectPtr<UObject> InWeakOwner)
	{
		KeyHandle  = InKeyHandle;
		WeakOwner  = InWeakOwner;
		Model      = InModel;

		if(UObject* Owner = WeakOwner.Get())
		{
			if(Model->IsValid())
			{
				const FRichCurve& RichCurve = Model->GetReadOnlyRichCurve();
				if (RichCurve.IsKeyHandleValid(KeyHandle))
				{
					Value = RichCurve.GetKey(KeyHandle);
				}
			}
		}
	}

private:

	virtual void PostEditChangeProperty(FPropertyChangedEvent& PropertyChangedEvent) override
	{
		Super::PostEditChangeProperty(PropertyChangedEvent);

		if(UObject* Owner = WeakOwner.Get())
		{
			if(Model->IsValid())
			{
				FRichCurve& RichCurve = Model->GetRichCurve();
				if(RichCurve.IsKeyHandleValid(KeyHandle))
				{
					Owner->Modify();

					FRichCurveKey& ActualKey = RichCurve.GetKey(KeyHandle);
					const FKeyPosition KeyPosition(Value.Time, Value.Value);
					Model->SetKeyPositions({KeyHandle}, {KeyPosition}, PropertyChangedEvent.ChangeType);
				
					Owner->PostEditChangeProperty(PropertyChangedEvent);
					Model->OnCurveModified().Broadcast();
				}
			}
		}	
	}

	virtual void UpdateValuesFromRawData() override
	{
		if(UObject* Owner = WeakOwner.Get())
		{
			if(Model->IsValid())
			{
				const FRichCurve& RichCurve = Model->GetReadOnlyRichCurve();
				if (RichCurve.IsKeyHandleValid(KeyHandle))
				{
					Value = RichCurve.GetKey(KeyHandle);
				}
			}
		}
	}

private:

	/** User-facing value of the key, applied to the actual key on PostEditChange, and updated every tick */
	UPROPERTY(EditAnywhere, Category="Key", meta=(ShowOnlyInnerProperties))
	FRichCurveKey Value;

private:

	/** Cached key handle that this key proxy relates to */
	FKeyHandle KeyHandle;
	/** Cached model that created this proxy */
	FRichCurveEditorModel* Model;
	/** Cached owner in which the raw curve resides */
	TWeakObjectPtr<UObject> WeakOwner;
};