@searsuite/sear-render-metrics API reference

classRenderContextTextShaper source ↗

class RenderContextTextShaper extends TextShaper

Portable fallback backed by the host's render-neutral text measurements.

constructorconstructor

RenderContextTextShaper(context: RenderContext): RenderContextTextShaper

context: RenderContext

Inherited members 3

Inherited from TextShaper.

classTextMeasurementManager source ↗

class TextMeasurementManager

Owns reusable semantic text measurements for one editor runtime.

constructorconstructor

TextMeasurementManager(textShaper: TextShaper): TextMeasurementManager

textShaper: TextShaper

propertysymbolstatic

readonly symbol: typeof symbol

DI token for resolving the editor-local text measurement manager.

methodclear

clear(): void

Clears semantic measurements without taking ownership of the text shaper.

methodmeasureSpace

measureSpace(font: string): TextShapeResult

Measures one space for a font and reuses the editor-local result.

font: string

classTextShaper source ↗

class TextShaper

Abstract adapter boundary for HarfBuzz, Skia, browser-native, or platform text-shaping implementations.

Concrete adapters translate the normalized request to their shaping library and return engine-neutral glyph/cluster data.

constructorconstructor

TextShaper(): TextShaper

propertysymbolstatic

readonly symbol: symbol

DI token for resolving the editor-local text-shaper provider.

methodclearCache

clearCache(): void

Clears all cached shaping results owned by this adapter.

methodshape

shape(input: TextShapeInput): TextShapeResult

Shapes one homogeneous text run, reusing an identical cached request.

input: TextShapeInput

classWebTextShaper source ↗

class WebTextShaper extends TextShaper

Browser-native TextShaper backed by Canvas2D.

Canvas2D preserves the browser's native shaping for complete text runs but does not expose glyph ids or glyph ranges. Results therefore contain grapheme clusters and caret measurements while leaving glyphs empty. Call clearCache() after an asynchronously loaded font becomes available.

constructorconstructor

WebTextShaper(context: WebTextShaperContext): WebTextShaper

Creates a Web text shaper over a host-owned Canvas2D context.

context: WebTextShaperContext

Inherited members 3

Inherited from TextShaper.

classWebTextShaperError source ↗

class WebTextShaperError extends SearError

Error raised when a Web text-shaping request cannot be represented by Canvas2D.

constructorconstructor

WebTextShaperError(message: string, details?: SearErrorDetails): WebTextShaperError

Creates a Web text-shaper error with stable diagnostics.

message: string
details: SearErrorDetails

propertycode

readonly code: "WEB_TEXT_SHAPER_ERROR"

Stable machine-readable identifier for this error category.

Inherited members 9

Inherited from SearError.

interfaceFontDescriptorInput source ↗

interface FontDescriptorInput

Structured font values supplied by editor configuration and host contexts.

propertyfontFamily

readonly fontFamily: string

propertyfontSize

readonly fontSize: number

interfaceShapedCaretStop source ↗

interface ShapedCaretStop

A logical caret boundary produced by the shaping implementation.

propertytextOffset

readonly textOffset: number

UTF-16 source-text offset for this caret boundary.

propertyx

readonly x: number

Advance position in the shaped run's logical direction.

interfaceShapedGlyph source ↗

interface ShapedGlyph

One positioned glyph returned by a text-shaping implementation.

propertycluster

readonly cluster: number

UTF-16 offset of the source text cluster represented by this glyph.

propertyglyphId

readonly glyphId: number

propertyxAdvance

readonly xAdvance: number

propertyxOffset

readonly xOffset: number

propertyyAdvance

readonly yAdvance: number

propertyyOffset

readonly yOffset: number

interfaceShapedTextCluster source ↗

interface ShapedTextCluster

Mapping between source text and the glyph range generated for it.

propertyglyphEnd

readonly glyphEnd: number

propertyglyphStart

readonly glyphStart: number

propertytextEnd

readonly textEnd: number

propertytextStart

readonly textStart: number

interfaceTextShapeInput source ↗

interface TextShapeInput

Input passed to a text-shaper implementation. Offsets are UTF-16 offsets.

propertydirection

readonly direction?: TextShapeDirection

propertyfeatures

readonly features?: Readonly<Record<string, TextShapeFeatureValue>>

Explicit OpenType feature settings, for example { liga: true, kern: true }.

propertyfont

readonly font: string

Font descriptor understood by the selected shaping implementation.

propertylanguage

readonly language?: string

ISO/BCP language tag, when known.

propertyscript

readonly script?: string

OpenType script tag, when known.

propertytext

readonly text: string

propertyvariations

readonly variations?: Readonly<Record<string, number>>

Variation-axis values for variable fonts, keyed by four-character axis tag.

interfaceTextShapeResult source ↗

interface TextShapeResult

Engine-neutral result of shaping one homogeneous text run.

propertycaretStops

readonly caretStops: readonly ShapedCaretStop[]

propertyclusters

readonly clusters: readonly ShapedTextCluster[]

propertyfontAscent

readonly fontAscent?: number

propertyfontDescent

readonly fontDescent?: number

propertyfontLineGap

readonly fontLineGap?: number

propertyglyphs

readonly glyphs: readonly ShapedGlyph[]

propertyheight

readonly height: number

Total vertical advance, normally zero for horizontal text.

propertywidth

readonly width: number

Total horizontal advance of the shaped run.

interfaceWebTextShaperContext source ↗

interface WebTextShaperContext

Native text settings and operations required by the Web adapter.

propertydirection

direction: CanvasDirection

propertyfont

font: string

propertyfontKerning

fontKerning?: CanvasFontKerning

methodmeasureText

measureText(text: string): TextMetrics

text: string

methodrestore

restore(): void

methodsave

save(): void

typeTextShapeDirection source ↗

type TextShapeDirection = "ltr" | "rtl"

Direction of a shaped text run in logical document order.

typeTextShapeFeatureValue source ↗

type TextShapeFeatureValue = boolean | number

OpenType feature value accepted by a text-shaper adapter.

functioncreateFontDescriptor source ↗

createFontDescriptor(input: FontDescriptorInput): string

Creates the low-level font descriptor consumed by text shaping and rendering.

input: FontDescriptorInput

functioncreateWebTextShaperContext source ↗

createWebTextShaperContext(renderContext: RenderContext): WebTextShaperContext

Adapts the shared render context to the Web shaper contract.

renderContext: RenderContext