SlateEditableTextTypes.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "Misc/Attribute.h"
#include "Framework/Text/TextLayout.h"
#include "Framework/Text/ISlateLineHighlighter.h"
 
class FPaintArgs;
class FSlateRect;
class FSlateWindowElementList;
class FWidgetStyle;
struct FGeometry;
struct FSlateBrush;
struct FTextBlockStyle;
 
namespace SlateEditableTextTypes
{
 
enum class ECursorAlignment : uint8
{
    Left,
 
    Right,
};
 
class FCursorInfo
{
public:
    FCursorInfo()
        : CursorPosition()
        , CursorAlignment(ECursorAlignment::Left)
        , CursorTextDirection(TextBiDi::ETextDirection::LeftToRight)
        , LastCursorInteractionTime(0)
    {
    }
 
    inline FTextLocation GetCursorLocation() const
    {
        return CursorPosition;
    }
 
    inline ECursorAlignment GetCursorAlignment() const
    {
        return CursorAlignment;
    }
 
    inline TextBiDi::ETextDirection GetCursorTextDirection() const
    {
        return CursorTextDirection;
    }
 
    inline FTextLocation GetCursorInteractionLocation() const
    {
        // If the cursor is right aligned, we treat it as if it were one character further along for insert/delete purposes
        return FTextLocation(CursorPosition, (CursorAlignment == ECursorAlignment::Right) ? 1 : 0);
    }
 
    inline double GetLastCursorInteractionTime() const
    {
        return LastCursorInteractionTime;
    }
 
    SLATE_API void UpdateLastCursorInteractionTime();
 
    SLATE_API void SetCursorLocationAndCalculateAlignment(const FTextLayout& InTextLayout, const FTextLocation& InCursorPosition);
 
    SLATE_API void SetCursorLocationAndAlignment(const FTextLayout& InTextLayout, const FTextLocation& InCursorPosition, const ECursorAlignment InCursorAlignment);
 
    SLATE_API FCursorInfo CreateUndo() const;
 
    SLATE_API void RestoreFromUndo(const FCursorInfo& UndoData);
 
private:
    FTextLocation CursorPosition;
 
    ECursorAlignment CursorAlignment;
 
    TextBiDi::ETextDirection CursorTextDirection;
 
    double LastCursorInteractionTime;
};
 
struct FUndoState
{
    FText Text;
 
    TOptional<FTextLocation> SelectionStart;
 
    FCursorInfo CursorInfo;
};
 
struct FScrollInfo
{
    FScrollInfo()
        : Position()
        , Alignment(ECursorAlignment::Left)
    {
    }
 
    FScrollInfo(const FTextLocation InPosition, const ECursorAlignment InAlignment)
        : Position(InPosition)
        , Alignment(InAlignment)
    {
    }
 
    FTextLocation Position;
 
    ECursorAlignment Alignment;
};
 
class FCursorLineHighlighter : public ISlateLineHighlighter
{
public:
    static SLATE_API TSharedRef< FCursorLineHighlighter > Create(const FCursorInfo* InCursorInfo);
 
    SLATE_API void SetCursorBrush(const TAttribute<const FSlateBrush*>& InCursorBrush);
 
    SLATE_API virtual int32 OnPaint(const FPaintArgs& Args, const FTextLayout::FLineView& Line, const FVector2D Offset, const float Width, const FTextBlockStyle& DefaultStyle, const FGeometry& AllottedGeometry, const FSlateRect& MyCullingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled) const override;
 
protected:
    SLATE_API FCursorLineHighlighter(const FCursorInfo* InCursorInfo);
 
    const FCursorInfo* CursorInfo;
 
    TAttribute<const FSlateBrush*> CursorBrush;
};
 
class FTextCompositionHighlighter : public ISlateLineHighlighter
{
public:
    static SLATE_API TSharedRef< FTextCompositionHighlighter > Create();
 
    SLATE_API void SetCompositionBrush(const TAttribute<const FSlateBrush*>& InCompositionBrush);
 
    SLATE_API virtual int32 OnPaint(const FPaintArgs& Args, const FTextLayout::FLineView& Line, const FVector2D Offset, const float Width, const FTextBlockStyle& DefaultStyle, const FGeometry& AllottedGeometry, const FSlateRect& MyCullingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled) const override;
 
protected:
    SLATE_API FTextCompositionHighlighter();
 
    TAttribute<const FSlateBrush*> CompositionBrush;
};
 
class FTextSelectionHighlighter : public ISlateLineHighlighter
{
public:
    static SLATE_API TSharedRef< FTextSelectionHighlighter > Create();
 
    SLATE_API virtual int32 OnPaint(const FPaintArgs& Args, const FTextLayout::FLineView& Line, const FVector2D Offset, const float Width, const FTextBlockStyle& DefaultStyle, const FGeometry& AllottedGeometry, const FSlateRect& MyCullingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled) const override;
 
    void SetHasKeyboardFocus(const bool bInHasKeyboardFocus)
    {
        bHasKeyboardFocus = bInHasKeyboardFocus;
    }
 
protected:
    SLATE_API FTextSelectionHighlighter();
 
    bool bHasKeyboardFocus;
};
 
class FTextSearchHighlighter : public ISlateLineHighlighter
{
public:
    static SLATE_API TSharedRef< FTextSearchHighlighter > Create();
 
    SLATE_API virtual int32 OnPaint(const FPaintArgs& Args, const FTextLayout::FLineView& Line, const FVector2D Offset, const float Width, const FTextBlockStyle& DefaultStyle, const FGeometry& AllottedGeometry, const FSlateRect& MyCullingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled) const override;
 
    void SetHasKeyboardFocus(const bool bInHasKeyboardFocus)
    {
        bHasKeyboardFocus = bInHasKeyboardFocus;
    }
 
protected:
    SLATE_API FTextSearchHighlighter();
 
    bool bHasKeyboardFocus;
};
 
} // namespace SlateEditableTextTypes