SBackgroundBlur.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "Framework/SlateDelegates.h"
#include "Widgets/DeclarativeSyntaxSupport.h"
#include "Widgets/SWidget.h"
#include "Layout/Margin.h"
#include "Widgets/SCompoundWidget.h"
class SBackgroundBlur : public SCompoundWidget
{
    SLATE_DECLARE_WIDGET_API(SBackgroundBlur, SCompoundWidget, SLATE_API)
 
public:
    SLATE_BEGIN_ARGS(SBackgroundBlur)
        : _HAlign(HAlign_Fill)
        , _VAlign(VAlign_Fill)
        , _Padding(FMargin(2.0f))
        , _bApplyAlphaToBlur(true)
        , _BlurStrength(0.f)
        , _BlurRadius()
        , _CornerRadius(FVector4(0,0,0,0))
        , _LowQualityFallbackBrush(nullptr)
    {
        _Visibility = EVisibility::SelfHitTestInvisible;
    }
        SLATE_DEFAULT_SLOT(FArguments, Content)
        
        SLATE_ARGUMENT(EHorizontalAlignment, HAlign)
        SLATE_ARGUMENT(EVerticalAlignment, VAlign)
        SLATE_ATTRIBUTE(FMargin, Padding)
 
        SLATE_ARGUMENT(bool, bApplyAlphaToBlur)
        SLATE_ATTRIBUTE(float, BlurStrength)
        SLATE_ATTRIBUTE(TOptional<int32>, BlurRadius)
        SLATE_ATTRIBUTE(FVector4, CornerRadius)
        SLATE_ARGUMENT(const FSlateBrush*, LowQualityFallbackBrush)
    SLATE_END_ARGS()
 
public:
    SLATE_API SBackgroundBlur();
    SLATE_API virtual ~SBackgroundBlur();
    SLATE_API void Construct(const FArguments& InArgs);
    SLATE_API virtual int32 OnPaint(const FPaintArgs& Args, const FGeometry& AllottedGeometry, const FSlateRect& MyCullingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled) const override;
 
    SLATE_API void SetContent(const TSharedRef<SWidget>& InContent);
    SLATE_API void SetApplyAlphaToBlur(bool bInApplyAlphaToBlur);
    SLATE_API void SetBlurRadius(TAttribute<TOptional<int32>> InBlurRadius);
    SLATE_API void SetBlurStrength(TAttribute<float> InStrength);
    SLATE_API void SetCornerRadius(TAttribute<FVector4> InCornerRadius);
    SLATE_API void SetLowQualityBackgroundBrush(const FSlateBrush* InBrush);
    
    SLATE_API void SetHAlign(EHorizontalAlignment HAlign);
    SLATE_API void SetVAlign(EVerticalAlignment VAlign);
    SLATE_API void SetPadding(TAttribute<FMargin> InPadding);
 
    SLATE_API bool IsUsingLowQualityFallbackBrush() const;
 
protected:
    SLATE_API void ComputeEffectiveKernelSize(float Strength, int32& OutKernelSize, int32& OutDownsampleAmount) const;
 
 
    TSlateAttributeRef<float> GetBlurStrengthAttribute() const { return TSlateAttributeRef<float>{SharedThis(this), BlurStrengthAttribute}; }
 
    TSlateAttributeRef<TOptional<int32>> GetBlurRadiusAttribute() const { return TSlateAttributeRef<TOptional<int32>>{SharedThis(this), BlurRadiusAttribute}; }
 
#if WITH_EDITORONLY_DATA
    TSlateDeprecatedTAttribute<float> BlurStrength;
    TSlateDeprecatedTAttribute<TOptional<int32>> BlurRadius;
#endif
 
    bool bApplyAlphaToBlur;
    const FSlateBrush* LowQualityFallbackBrush;
 
private:
    TSlateAttribute<float> BlurStrengthAttribute;
    TSlateAttribute<TOptional<int32>> BlurRadiusAttribute;
    TSlateAttribute<FVector4> CornerRadiusAttribute;
};