Custom RichTextBlockDecorator example code #2

RichTextBlockSomeWidgetDecorator.cpp

// https://baemincheon.github.io/2022/07/28/how-the-rich-text-block-works-in-unrealengine/

#include "UObject/SoftObjectPtr.h"
#include "Rendering/DrawElements.h"
#include "Framework/Text/SlateTextRun.h"
#include "Framework/Text/SlateTextLayout.h"
#include "Slate/SlateGameResources.h"
#include "Widgets/SCompoundWidget.h"
#include "Widgets/DeclarativeSyntaxSupport.h"
#include "Framework/Application/SlateApplication.h"
#include "Fonts/FontMeasure.h"
#include "Math/UnrealMathUtility.h"
#include "Widgets/Images/SImage.h"
#include "Widgets/Layout/SScaleBox.h"
#include "Widgets/Layout/SBox.h"
#include "Misc/DefaultValueHelper.h"
#include "UObject/UObjectGlobals.h"
#include "UObject/Package.h"
#include "RichTextBlockSomeWidgetDecorator.h"

class SRichInlineSomeWidget : public SCompoundWidget
{
public:
	SLATE_BEGIN_ARGS(SRichInlineSomeWidget)
	{}
	SLATE_END_ARGS()

public:
	void Construct(const FArguments& InArgs, const FRichSomeWidgetRow* Row, const FTextBlockStyle& TextStyle, TOptional<int32> Width, TOptional<int32> Height, EStretch::Type Stretch);
};

void SRichInlineSomeWidget::Construct(const FArguments& InArgs, const FRichSomeWidgetRow* Row, const FTextBlockStyle& TextStyle, TOptional<int32> Width, TOptional<int32> Height, EStretch::Type Stretch)
{
	const FSlateBrush* InBrush = &(Row->Brush);
	check(InBrush)
	const FText InText = Row->Text;
	const TSharedRef<FSlateFontMeasure> FontMeasure = FSlateApplication::Get().GetRenderer()->GetFontMeasureService();
	const float MaxHeight = FontMeasure->GetMaxCharacterHeight(TextStyle.Font, 1.0f);
	float IconHeight = FMath::Max(MaxHeight, InBrush->ImageSize.Y);
	if (Height.IsSet())
	{
		IconHeight = Height.GetValue();
	}
	float IconWidth = IconHeight;
	if (Width.IsSet())
	{
		IconWidth = Width.GetValue();
	}
	ChildSlot
	[
		SNew(SBox)
		[
			SNew(SHorizontalBox)

			+SHorizontalBox::Slot()
			.AutoWidth()
			.VAlign(VAlign_Center)
			[
				SNew(SImage)
				.Image(InBrush)
			]

			+SHorizontalBox::Slot()
			.AutoWidth()
			.VAlign(VAlign_Center)
			[
				SNew(STextBlock)
				.Text(InText)
			]
		]
	];
}

class FRichInlineSomeWidget : public FRichTextDecorator
{
public:
	FRichInlineSomeWidget(URichTextBlock* InOwner, URichTextBlockSomeWidgetDecorator* InDecorator)
		: FRichTextDecorator(InOwner)
		, Decorator(InDecorator)
	{
	}

	virtual bool Supports(const FTextRunParseResults& RunParseResult, const FString& Text) const override;

protected:
	virtual TSharedPtr<SWidget> CreateDecoratorWidget(const FTextRunInfo& RunInfo, const FTextBlockStyle& TextStyle) const override;

private:
	URichTextBlockSomeWidgetDecorator* Decorator;
};

bool FRichInlineSomeWidget::Supports(const FTextRunParseResults& RunParseResult, const FString& Text) const
{
	bool Result = false;
	const bool IsContainId = RunParseResult.MetaData.Contains(TEXT("id"));
	const bool IsNameSomeWidget = RunParseResult.Name == TEXT("somewidget");
	if (IsContainId && IsNameSomeWidget)
	{
		const FTextRange& IdRange = RunParseResult.MetaData[TEXT("id")];
		const FString TagId = Text.Mid(IdRange.BeginIndex, IdRange.EndIndex - IdRange.BeginIndex);
		const bool bWarnIfMissing = false;
		Result = Decorator->FindSomeWidgetRow(*TagId, bWarnIfMissing) != nullptr;
	}
	return Result;
}

TSharedPtr<SWidget> FRichInlineSomeWidget::CreateDecoratorWidget(const FTextRunInfo& RunInfo, const FTextBlockStyle& TextStyle) const
{
	TSharedPtr<SWidget> Result;
	const bool bWarnIfMissing = true;
	const FString IDString = RunInfo.MetaData[TEXT("id")];
	const FRichSomeWidgetRow* SomeWidgetRow = Decorator->FindSomeWidgetRow(*IDString, bWarnIfMissing);
	const FSlateBrush* Brush = &(SomeWidgetRow->Brush);
	const FText Text = SomeWidgetRow->Text;
	if (ensure(Brush))
	{
		TOptional<int32> Width;
		if (const FString* WidthString = RunInfo.MetaData.Find(TEXT("width")))
		{
			int32 WidthTemp;
			if (FDefaultValueHelper::ParseInt(*WidthString, WidthTemp))
			{
				Width = WidthTemp;
			}
			else if (FCString::Stricmp(GetData(*WidthString), TEXT("desired")) == 0)
			{
				Width = Brush->ImageSize.X;
			}
		}
		TOptional<int32> Height;
		if (const FString* HeightString = RunInfo.MetaData.Find(TEXT("height")))
		{
			int32 HeightTemp;
			if (FDefaultValueHelper::ParseInt(*HeightString, HeightTemp))
			{
				Height = HeightTemp;
			}
			else if (FCString::Stricmp(GetData(*HeightString), TEXT("desired")) == 0)
			{
				Height = Brush->ImageSize.Y;
			}
		}
		EStretch::Type Stretch = EStretch::ScaleToFit;
		if (const FString* StretchString = RunInfo.MetaData.Find(TEXT("stretch")))
		{
			const UEnum* StretchEnum = StaticEnum<EStretch::Type>();
			const int64 StretchValue = StretchEnum->GetValueByNameString(*StretchString);
			if (StretchValue != INDEX_NONE)
			{
				Stretch = static_cast<EStretch::Type>(StretchValue);
			}
		}
		Result = SNew(SRichInlineSomeWidget, SomeWidgetRow, TextStyle, Width, Height, Stretch);
	}
	return Result;
}

URichTextBlockSomeWidgetDecorator::URichTextBlockSomeWidgetDecorator(const FObjectInitializer& ObjectInitializer)
	: Super(ObjectInitializer)
{
}

TSharedPtr<ITextDecorator> URichTextBlockSomeWidgetDecorator::CreateDecorator(URichTextBlock* InOwner)
{
	return MakeShareable(new FRichInlineSomeWidget(InOwner, this));
}

const FRichSomeWidgetRow* URichTextBlockSomeWidgetDecorator::FindSomeWidgetRow(FName TagOrId, bool bWarnIfMissing)
{
	return FindRow(TagOrId, bWarnIfMissing);
}

FRichSomeWidgetRow* URichTextBlockSomeWidgetDecorator::FindRow(FName TagOrId, bool bWarnIfMissing)
{
	FRichSomeWidgetRow* Result = nullptr;
	if (ImageSet)
	{
		FString ContextString;
		Result = ImageSet->FindRow<FRichSomeWidgetRow>(TagOrId, ContextString, bWarnIfMissing);
	}
	return Result;
}