ipcOn (cb) {
    const handler = cb._handler = ({ data, emit }) => {
      if (data._projectId) {
        if (data._projectId === this.project.id) {
          data = data._data
        } else {
          return
        }
      }
      // eslint-disable-next-line node/no-callback-literal
      cb({ data, emit })
    }
    this.ipcHandlers.push(handler)
    return ipc.on(handler)
  }
Add a listener to the IPC messages.

@param {function} cb Callback with 'data' param