substance/packages/base/UndoCommand.js

Substance is a JavaScript library for web-based content editing. It provides building blocks for realizing custom text editors and web-based publishing systems.

import { Command } from '../../ui'

class Undo extends Command {

  getCommandState(params) {
    let editorSession = params.editorSession
    return {
      disabled: !editorSession.canUndo(),
      active: false
    }
  }

  execute(params) {
    let editorSession = params.editorSession
    if (editorSession.canUndo()) {
      editorSession.undo()
      return true
    }
    return false
  }

}

export default Undo