Tldraw/state/commands/direct.ts

import Command from './command'
import history from '../history'
import { DirectionSnapshot } from 'state/sessions/direction-session'
import { Data, LineShape, RayShape } from 'types'
import { getPage } from 'utils/utils'

export default function directCommand(
  data: Data,
  before: DirectionSnapshot,
  after: DirectionSnapshot
): void {
  history.execute(
    data,
    new Command({
      name: 'set_direction',
      category: 'canvas',
      do(data) {
        const { shapes } = getPage(data)

        for (const { id, direction } of after.shapes) {
          const shape = shapes[id] as RayShape | LineShape

          shape.direction = direction
        }
      },
      undo(data) {
        const { shapes } = getPage(data, before.currentPageId)

        for (const { id, direction } of after.shapes) {
          const shape = shapes[id] as RayShape | LineShape

          shape.direction = direction
        }
      },
    })
  )
}