Method withSelectionBg

src/ink/screen.ts:272–287

(baseId: number)

    this.selectionBgCache.clear()
  }
  withSelectionBg(baseId: number): number {
    const bg = this.selectionBgCode
    if (bg === null) return this.withInverse(baseId)
    let id = this.selectionBgCache.get(baseId)
    if (id === undefined) {
      // Keep everything except bg (49m) and inverse (27m). Fg, bold, dim,
      // italic, underline, strikethrough all preserved.
      const kept = this.get(baseId).filter(
        c => c.endCode !== '\x1b[49m' && c.endCode !== '\x1b[27m',
      )
      kept.push(bg)
      id = this.intern(kept)
      this.selectionBgCache.set(baseId, id)
    }
    return id
  }
}

// endCodes that produce visible effects on space characters