SScaleBox.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "UObject/ObjectMacros.h"
#include "Misc/Attribute.h"
#include "Widgets/DeclarativeSyntaxSupport.h"
#include "Widgets/SWidget.h"
#include "Widgets/SCompoundWidget.h"
#include "SScaleBox.generated.h"
 
class FArrangedChildren;
class FPaintArgs;
class FSlateWindowElementList;
 
UENUM(BlueprintType)
namespace EStretchDirection
{
    enum Type : int
    {
        Both,
        DownOnly,
        UpOnly
    };
}
 
UENUM(BlueprintType)
namespace EStretch
{
    enum Type : int
    {
        None,
        Fill,
        ScaleToFit,
        ScaleToFitX,
        ScaleToFitY,
        ScaleToFill,
        ScaleBySafeZone,
        UserSpecified,
        UserSpecifiedWithClipping
    };
}
 
class SScaleBox : public SCompoundWidget
{
    SLATE_DECLARE_WIDGET_API(SScaleBox, SCompoundWidget, SLATE_API)
 
public:
    SLATE_BEGIN_ARGS(SScaleBox)
    : _Content()
    , _HAlign(HAlign_Center)
    , _VAlign(VAlign_Center)
    , _StretchDirection(EStretchDirection::Both)
    , _Stretch(EStretch::None)
    , _UserSpecifiedScale(1.0f)
    , _IgnoreInheritedScale(false)
    {}
        SLATE_DEFAULT_SLOT(FArguments, Content)
 
        
        SLATE_ARGUMENT(EHorizontalAlignment, HAlign)
 
        
        SLATE_ARGUMENT(EVerticalAlignment, VAlign)
        
        
        SLATE_ATTRIBUTE(EStretchDirection::Type, StretchDirection)
        
        
        SLATE_ATTRIBUTE(EStretch::Type, Stretch)
 
        
        SLATE_ATTRIBUTE(float, UserSpecifiedScale)
 
        
        SLATE_ATTRIBUTE(bool, IgnoreInheritedScale)
 
#if WITH_EDITOR
        SLATE_ARGUMENT(TOptional<FVector2D>, OverrideScreenSize)
#endif
 
    SLATE_END_ARGS()
 
protected:
    SLATE_API SScaleBox();
 
public:
    SLATE_API virtual ~SScaleBox();
 
    SLATE_API void Construct(const FArguments& InArgs);
    
    // SWidget interface
    SLATE_API virtual void OnArrangeChildren(const FGeometry& AllottedGeometry, FArrangedChildren& ArrangedChildren) const override;
    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;
    // End SWidget of interface
 
    SLATE_API void SetContent(TSharedRef<SWidget> InContent);
 
    SLATE_API void SetHAlign(EHorizontalAlignment HAlign);
 
    SLATE_API void SetVAlign(EVerticalAlignment VAlign);
 
    SLATE_API void SetStretchDirection(EStretchDirection::Type InStretchDirection);
 
    SLATE_API void SetStretch(EStretch::Type InStretch);
 
    SLATE_API void SetUserSpecifiedScale(float InUserSpecifiedScale);
 
    SLATE_API void SetIgnoreInheritedScale(bool InIgnoreInheritedScale);
 
#if WITH_EDITOR
    SLATE_API void SetOverrideScreenInformation(TOptional<FVector2D> InScreenSize);
#endif
    
protected:
    // Begin SWidget overrides.
    SLATE_API virtual bool CustomPrepass(float LayoutScaleMultiplier) override;
    SLATE_API virtual FVector2D ComputeDesiredSize(float InScale) const override;
    SLATE_API virtual float GetRelativeLayoutScale(int32 ChildIndex, float LayoutScaleMultiplier) const override;
    // End SWidget overrides.
 
    SLATE_API bool DoesScaleRequireNormalizingPrepassOrLocalGeometry() const;
    SLATE_API bool IsDesiredSizeDependentOnAreaAndScale() const;
    SLATE_API float ComputeContentScale(const FGeometry& PaintGeometry) const;
 
    SLATE_API void RefreshSafeZoneScale();
    SLATE_API void HandleSafeFrameChangedEvent();
 
#if WITH_EDITOR
    SLATE_API void DebugSafeAreaUpdated(const FMargin& NewSafeZone, bool bShouldRecacheMetrics);
#endif
 
private:
    TSlateAttribute<EStretchDirection::Type> StretchDirectionAttribute;
 
    TSlateAttribute<EStretch::Type> StretchAttribute;
 
    TSlateAttribute<float> UserSpecifiedScaleAttribute;
 
    TSlateAttribute<bool> IgnoreInheritedScaleAttribute;
 
    float SafeZoneScale;
 
    FDelegateHandle OnSafeFrameChangedHandle;
 
    mutable TOptional<FVector2D> LastAllocatedArea;
    mutable TOptional<FGeometry> LastPaintGeometry;
 
    mutable TOptional<FVector2D> NormalizedContentDesiredSize;
 
    mutable TOptional<float> ComputedContentScale;
 
 
 
 
    mutable FVector2D LastFinalOffset;
 
    mutable FVector2D LastSlotWidgetDesiredSize;
 
#if WITH_EDITOR
    TOptional<FVector2D> OverrideScreenSize;
#endif
};