Class LayoutEngine

Protectedconfig

ProtectedfallbackFonts

Protectedfont

ProtectedfontPromise

Protectedruntime

ProtectedcalculateEffectiveLineHeight

• calculateEffectiveLineHeight(
      line: RichLine,
      baseFontSize: number,
      lineHeight: number,
  ): number

  Calculates the effective line height for a single line, accounting for baseline alignment spread in mixed-script lines.

  Parameters

  • line: RichLine
  • baseFontSize: number
  • lineHeight: number

  Returns number

ProtectedcalculateLinesHeight

• calculateLinesHeight(lines: RichLine[], style: any): number

  Calculates the total height of a set of wrapped lines. Uses a UNIFORM line height across all lines in the element (the max effective height of any single line) so that mixed-script paragraphs have consistent vertical spacing throughout.

  Parameters

  • lines: RichLine[]
  • style: any

  Returns number

ProtectedcloneGlyphs

• cloneGlyphs(
      glyphs: { char: string; x: number; y: number }[],
  ): { char: string; x: number; y: number }[]

  Parameters

  • glyphs: { char: string; x: number; y: number }[]

  Returns { char: string; x: number; y: number }[]

ProtectedfontSupportsCluster

• fontSupportsCluster(font: any, cluster: string): boolean

  Parameters

  • font: any
  • cluster: string

  Returns boolean

ProtectedgetClusterCodePoints

• getClusterCodePoints(cluster: string): number[]

  Parameters

  • cluster: string

  Returns number[]

ProtectedgetContentWidth

• getContentWidth(style?: any): number

  Calculates the available content width for a style definition.

  Parameters

  • Optionalstyle: any

  Returns number

ProtectedgetElementText

• getElementText(element: Element): string

  Parameters

  • element: Element

  Returns string

ProtectedgetGraphemeClusters

• getGraphemeClusters(text: string): string[]

  Parameters

  • text: string

  Returns string[]

ProtectedgetNodeText

• getNodeText(node: any): string

  Parameters

  • node: any

  Returns string

ProtectedgetOpticalScale

• getOpticalScale(scriptClass: string): number

  Returns the optical scaling factor for a given script class. These factors adjust the rendered font size so secondary scripts appear visually harmonious with the primary (Latin) text.

  Parameters

  • scriptClass: string

  Returns number

ProtectedgetPageDimensions

• getPageDimensions(): { height: number; width: number }

  Returns { height: number; width: number }

ProtectedgetRichSegments

• getRichSegments(element: Element, inheritedStyle?: any): TextSegment[]

  Recursively collects text segments from an element's children, preserving styles.

  Parameters

  • element: Element
  • inheritedStyle: any = {}

  Returns TextSegment[]

ProtectedgetScriptClass

• getScriptClass(text: string): string

  Classifies the dominant script of a text string based on its first non-space character's Unicode code point.

  Parameters

  • text: string

  Returns string

ProtectedgetStyle

• getStyle(element: Element): ElementStyle

  Parameters

  • element: Element

  Returns ElementStyle

ProtectedinitializeFont

• initializeFont(): Promise<void>

  Returns Promise<void>

ProtectedisCJKChar

• isCJKChar(code: number): boolean

  Parameters

  • code: number

  Returns boolean

ProtectedisIgnorableCodePoint

• isIgnorableCodePoint(codePoint: number): boolean

  Parameters

  • codePoint: number

  Returns boolean

ProtectedlogError

• logError(message: string, error?: unknown): void

  Parameters

  • message: string
  • Optionalerror: unknown

  Returns void

ProtectedlogWarn

• logWarn(message: string, error?: unknown): void

  Parameters

  • message: string
  • Optionalerror: unknown

  Returns void

ProtectedmaterializeFlowBox

• materializeFlowBox(unit: FlowBox, context?: FlowMaterializationContext): FlowBox

  Parameters

  • unit: FlowBox
  • Optionalcontext: FlowMaterializationContext

  Returns FlowBox

ProtectedmeasureRichLine

• measureRichLine(line: RichLine, letterSpacing?: number): number

  Calculates the total width of a RichLine by summing its segments.

  Parameters

  • line: RichLine
  • letterSpacing: number = 0

  Returns number

ProtectedmeasureText

• measureText(
      text: string,
      font?: any,
      fontSize?: number,
      letterSpacing?: number,
      populateSegment?: TextSegment,
  ): number

  Returns the width in points of a given string using fontkit's layout. Optionally populates the glyph positions if a segment object is provided.

  Parameters

  • text: string
  • Optionalfont: any
  • OptionalfontSize: number
  • letterSpacing: number = 0
  • OptionalpopulateSegment: TextSegment

  Returns number

ProtectedpositionFlowBox

• positionFlowBox(
      unit: FlowBox,
      currentY: number,
      layoutBefore: number,
      margins: { left: number },
      _pageWidth: number,
      pageIndex: number,
  ): Box | Box[]

  Parameters

  • unit: FlowBox
  • currentY: number
  • layoutBefore: number
  • margins: { left: number }
  • _pageWidth: number
  • pageIndex: number

  Returns Box | Box[]

ProtectedrebuildFlowBox

• rebuildFlowBox(
      base: FlowBox,
      lines: RichLine[],
      style: ElementStyle,
      meta: BoxMeta,
      properties: Record<string, any>,
  ): FlowBox

  Parameters

  • base: FlowBox
  • lines: RichLine[]
  • style: ElementStyle
  • meta: BoxMeta
  • properties: Record<string, any>

  Returns FlowBox

ProtectedresolveLines

• resolveLines(
      element: Element,
      style: ElementStyle,
      fontSize: number,
      context?: FlowMaterializationContext,
  ): ResolvedLinesResult

  Parameters

  • element: Element
  • style: ElementStyle
  • fontSize: number
  • Optionalcontext: FlowMaterializationContext

  Returns ResolvedLinesResult

ProtectedresolveLoadedFamilyFont

• resolveLoadedFamilyFont(
      familyName: string,
      weight: string | number,
      style?: string,
  ): any

  Parameters

  • familyName: string
  • weight: string | number
  • style: string = 'normal'

  Returns any

ProtectedsegmentTextByFont

• segmentTextByFont(
      text: string,
      preferredFamily?: string,
      preferredLocale?: string,
      fallbackFamiliesOverride?: string[],
      sharedFontCache?: Map<string, any>,
  ): { fontName?: string; fontObject?: any; text: string }[]

  Segments text into chunks based on which enabled font supports the characters.

  Parameters

  • text: string
  • OptionalpreferredFamily: string
  • OptionalpreferredLocale: string
  • OptionalfallbackFamiliesOverride: string[]
  • OptionalsharedFontCache: Map<string, any>

  Returns { fontName?: string; fontObject?: any; text: string }[]

ProtectedshapeElement

• shapeElement(element: Element, identitySeed?: FlowIdentitySeed): FlowBox

  Parameters

  • element: Element
  • OptionalidentitySeed: FlowIdentitySeed

  Returns FlowBox

ProtectedsliceElements

• sliceElements(elements: Element[], start: number, end: number): Element[]

  Slices a stream of elements by character offsets.

  Parameters

  • elements: Element[]
  • start: number
  • end: number

  Returns Element[]

ProtectedsplitByScriptType

• splitByScriptType(text: string): { isCJK: boolean; text: string }[]

  Parameters

  • text: string

  Returns { isCJK: boolean; text: string }[]

ProtectedsplitFlowBox

• splitFlowBox(
      box: FlowBox,
      availableHeight: number,
      layoutBefore: number,
  ): { partA: FlowBox; partB: FlowBox } | null

  Parameters

  • box: FlowBox
  • availableHeight: number
  • layoutBefore: number

  Returns { partA: FlowBox; partB: FlowBox } | null

ProtectedwrapRichSegments

• wrapRichSegments(
      segments: TextSegment[],
      maxWidth: number,
      font: any,
      fontSize: number,
      letterSpacing?: number,
      textIndent?: number,
      lineLayoutResolver?: (
          lineIndex: number,
      ) => { width: number; xOffset: number; yOffset?: number },
      lineLayoutOut?: { offsets: number[]; widths: number[]; yOffsets: number[] },
  ): RichLine[]

  Specialized word-wrapper for rich text segments.

  Parameters

  • segments: TextSegment[]
  • maxWidth: number
  • font: any
  • fontSize: number
  • letterSpacing: number = 0
  • textIndent: number = 0
  • OptionallineLayoutResolver: (lineIndex: number) => { width: number; xOffset: number; yOffset?: number }
  • OptionallineLayoutOut: { offsets: number[]; widths: number[]; yOffsets: number[] }

  Returns RichLine[]