SlateTextBlockLayout.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "Misc/Attribute.h"
#include "Layout/Margin.h"
#include "Styling/SlateTypes.h"
#include "Framework/Text/ITextLayoutMarshaller.h"
#include "Framework/Text/SlateTextLayoutFactory.h"
 
class FArrangedChildren;
class FPaintArgs;
class FSlateWindowElementList;
class IBreakIterator;
class ISlateRunRenderer;
enum class ETextShapingMethod : uint8;
 
class FSlateTextBlockLayout
{
public:
    struct FWidgetDesiredSizeArgs
    {
        inline FWidgetDesiredSizeArgs(
            const FText& InText,
            const FText& InHighlightText,
            const float InWrapTextAt,
            const bool InAutoWrapText,
            const ETextWrappingPolicy InWrappingPolicy,
            const ETextTransformPolicy InTransformPolicy,
            const FMargin& InMargin,
            const float InLineHeightPercentage,
            const bool InApplyLineHeightToBottomLine,
            const ETextJustify::Type InJustification
        )
            : Text(InText)
            , HighlightText(InHighlightText)
            , Margin(InMargin)
            , WrapTextAt(InWrapTextAt)
            , LineHeightPercentage(InLineHeightPercentage)
            , ApplyLineHeightToBottomLine(InApplyLineHeightToBottomLine)
            , WrappingPolicy(InWrappingPolicy)
            , TransformPolicy(InTransformPolicy)
            , Justification(InJustification)
            , AutoWrapText(InAutoWrapText)
        {
        }
 
        inline FWidgetDesiredSizeArgs(
            const FText& InText,
            const FText& InHighlightText,
            const float InWrapTextAt,
            const bool InAutoWrapText,
            const ETextWrappingPolicy InWrappingPolicy,
            const ETextTransformPolicy InTransformPolicy,
            const FMargin& InMargin,
            const float InLineHeightPercentage,
            const ETextJustify::Type InJustification
        )
            : Text(InText)
            , HighlightText(InHighlightText)
            , Margin(InMargin)
            , WrapTextAt(InWrapTextAt)
            , LineHeightPercentage(InLineHeightPercentage)
            , ApplyLineHeightToBottomLine(true)
            , WrappingPolicy(InWrappingPolicy)
            , TransformPolicy(InTransformPolicy)
            , Justification(InJustification)
            , AutoWrapText(InAutoWrapText)
        {
        }
 
        const FText Text = FText::GetEmpty();
        const FText HighlightText = FText::GetEmpty();
        const FMargin Margin;
        const float WrapTextAt = 0.f;
        const float LineHeightPercentage;
        const bool ApplyLineHeightToBottomLine;
        const ETextWrappingPolicy WrappingPolicy;
        const ETextTransformPolicy TransformPolicy;
        const ETextJustify::Type Justification;
        const bool AutoWrapText = false;
    };
 
    struct
        UE_DEPRECATED(5.0, "FWidgetArgs is deprecated. Upgrade to FWidgetDesiredSizeArgs instead.")
        FWidgetArgs
    {
        inline FWidgetArgs(
            const TAttribute<FText>& InText, 
            const TAttribute<FText>& InHighlightText, 
            const TAttribute<float>& InWrapTextAt, 
            const TAttribute<bool>& InAutoWrapText, 
            const TAttribute<ETextWrappingPolicy>& InWrappingPolicy, 
            const TAttribute<ETextTransformPolicy>& InTransformPolicy,
            const TAttribute<FMargin>& InMargin, 
            const TAttribute<float>& InLineHeightPercentage, 
            const TAttribute<ETextJustify::Type>& InJustification
        )
            : Text(InText)
            , HighlightText(InHighlightText)
            , WrapTextAt(InWrapTextAt)
            , AutoWrapText(InAutoWrapText)
            , WrappingPolicy(InWrappingPolicy)
            , TransformPolicy(InTransformPolicy)
            , Margin(InMargin)
            , LineHeightPercentage(InLineHeightPercentage)
            , Justification(InJustification)
        {
        }
 
        const TAttribute<FText>& Text;
        const TAttribute<FText>& HighlightText;
        const TAttribute<float>& WrapTextAt;
        const TAttribute<bool>& AutoWrapText;
        const TAttribute<ETextWrappingPolicy> WrappingPolicy;
        const TAttribute<ETextTransformPolicy> TransformPolicy;
        const TAttribute<FMargin>& Margin;
        const TAttribute<float>& LineHeightPercentage;
        const TAttribute<ETextJustify::Type>& Justification;
    };
 
    SLATE_API FSlateTextBlockLayout(SWidget* InOwner, FTextBlockStyle InDefaultTextStyle, const TOptional<ETextShapingMethod> InTextShapingMethod, const TOptional<ETextFlowDirection> InTextFlowDirection, const FCreateSlateTextLayout& InCreateSlateTextLayout, TSharedRef<ITextLayoutMarshaller> InMarshaller, TSharedPtr<IBreakIterator> InLineBreakPolicy);
 
    SLATE_API void ConditionallyUpdateTextStyle(const FTextBlockStyle& InTextStyle);
 
    SLATE_API void ConditionallyUpdateTextStyle(const FTextBlockStyle::CompareParams& InNewStyleParams);
    
    SLATE_API void UpdateTextStyle(const FTextBlockStyle& InTextStyle);
 
    SLATE_API void UpdateTextStyle(const FTextBlockStyle::CompareParams& InNewStyleParams);
 
    SLATE_API FVector2D ComputeDesiredSize(const FWidgetDesiredSizeArgs& InWidgetArgs, const float InScale);
 
    SLATE_API FVector2D ComputeDesiredSize(const FWidgetDesiredSizeArgs& InWidgetArgs, const float InScale, const FTextBlockStyle& InTextStyle);
 
    PRAGMA_DISABLE_DEPRECATION_WARNINGS
    UE_DEPRECATED(5.0, "FWidgetArgs is deprecated. Upgrade to FWidgetDesiredSizeArgs instead.")
    SLATE_API FVector2D ComputeDesiredSize(const FWidgetArgs& InWidgetArgs, const float InScale, const FTextBlockStyle& InTextStyle);
 
    PRAGMA_ENABLE_DEPRECATION_WARNINGS
 
    SLATE_API FVector2D GetDesiredSize() const;
 
 
    SLATE_API float GetLayoutScale() const;
 
 
    SLATE_API int32 OnPaint(const FPaintArgs& InPaintArgs, const FGeometry& InAllottedGeometry, const FSlateRect& InClippingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled);
 
    SLATE_API void DirtyLayout();
 
    SLATE_API void DirtyContent();
 
    SLATE_API void OverrideTextStyle(const FTextBlockStyle& InTextStyle);
 
    SLATE_API void SetTextShapingMethod(const TOptional<ETextShapingMethod>& InTextShapingMethod);
 
    SLATE_API void SetTextFlowDirection(const TOptional<ETextFlowDirection>& InTextFlowDirection);
 
    SLATE_API void SetTextOverflowPolicy(const TOptional<ETextOverflowPolicy> InTextOverflowPolicy);
 
    SLATE_API void SetDebugSourceInfo(const TAttribute<FString>& InDebugSourceInfo);
 
    SLATE_API FChildren* GetChildren();
 
    SLATE_API void ArrangeChildren(const FGeometry& AllottedGeometry, FArrangedChildren& ArrangedChildren) const;
 
private:
    void UpdateTextLayout(const FText& InText);
 
    void UpdateTextLayout(const FString& InText);
 
    void UpdateTextHighlights(const FText& InHighlightText);
 
    bool IsStyleUpToDate(const FTextBlockStyle& NewStyle) const;
 
    bool IsStyleUpToDate(const FTextBlockStyle::CompareParams& InNewStyleParams) const;
 
    float CalculateWrappingWidth() const;
 
    TSharedPtr<FSlateTextLayout> TextLayout;
 
    TSharedPtr<ITextLayoutMarshaller> Marshaller;
 
    TSharedPtr<ISlateRunRenderer> TextHighlighter;
 
    FVector2f CachedSize;
 
    float CachedWrapTextAt;
 
    bool bCachedAutoWrapText;
 
    FTextSnapshot TextLastUpdate;
 
    FTextSnapshot HighlightTextLastUpdate;
};