* Electron version: 1.6.10
* Operating system: macOS Sierra 10.12.4 (16E195)

# Improve Handoff API support

Hi!

Today the API of Handoff provides the methods: `setUserActivity`, `getCurrentActivityType` and dispatch the event `continue-activity`

I'm using Handoff and noticed that in some circumstances the broadcast takes a long time to update its userInfo which does not happen on the native iOS client

1. To invalidate or resign the current activity we currently need to create a non-existing activity type and set it as the current activity. There's no way to handle the activity life cycle through electron.
2. When we need to update a given user activity userInfo frequently (i.e in response to a search bar's text changes), we have no efficient way. Setting a new userActivity with the updated information takes several seconds to bridge, whereas doing this on iOS native app is instantaneous.

I believe that exposing a bit more of the NSUserActivity API to Electron would help, namely `becomeCurrent`, `resignCurrent` and `invalidate` which would address point 1, and `needsSave` and a new event to allow updating an activity when needed to address point 2.
These are described in more detail in https://developer.apple.com/reference/foundation/nsuseractivity.

I'm are open to help in any way i can such as explaining how the native API work, providing sample code or testing possible implementations

Thank you!
atom/browser/api/atom_api_app.cc
if (name == "appData")
    return DIR_APP_DATA;
  else if (name == "userData")
    return DIR_USER_DATA;
  else if (name == "cache")
    return DIR_CACHE;
  else if (name == "userCache")
    return DIR_USER_CACHE;
  else if (name == "logs")
    return DIR_APP_LOGS;
  else if (name == "home")
    return base::DIR_HOME;
  else if (name == "temp")
    return base::DIR_TEMP;
  else if (name == "userDesktop" || name == "desktop")
    return base::DIR_USER_DESKTOP;
  else if (name == "exe")
    return base::FILE_EXE;
  else if (name == "module")
    return base::FILE_MODULE;
  else if (name == "documents")
    return chrome::DIR_USER_DOCUMENTS;
  else if (name == "downloads")
    return chrome::DIR_DEFAULT_DOWNLOADS;