Method measureTargetText

src/Document/TextElement.ts:487–536

(
    ctx: RenderingContext2D,
    targetText: string
  )

  }

  protected measureTargetText(
    ctx: RenderingContext2D,
    targetText: string
  ) {
    if (!targetText.length) {
      return 0
    }

    const { parent } = this
    const customFont = parent.getStyle('font-family').getDefinition<FontElement>()

    if (customFont) {
      const fontSize = this.getFontSize()
      const text = customFont.isRTL
        ? targetText.split('').reverse().join('')
        : targetText
      const dx = toNumbers(parent.getAttribute('dx').getString())
      const len = text.length
      let measure = 0

      for (let i = 0; i < len; i++) {
        const glyph = this.getGlyph(customFont, text, i)

        measure += (glyph.horizAdvX || customFont.horizAdvX)
          * fontSize
          / customFont.fontFace.unitsPerEm

        if (typeof dx[i] !== 'undefined' && !isNaN(dx[i])) {
          measure += dx[i]
        }
      }

      return measure
    }

    // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
    if (!ctx.measureText) {
      return targetText.length * 10
    }

    ctx.save()
    this.setContext(ctx, true)

    const { width: measure } = ctx.measureText(targetText)

    this.clearContext(ctx)
    ctx.restore()

    return measure
  }

  /**
   * Inherits positional attributes from {@link TextElement} parent(s). Attributes