how to know if user denied access?

[or-dvir]

hi.
i am looking into integrating some functionality of google drive in my app and i have immediately noticed something that's missing.
if the app is not yet authorized, i get this error message:
GoogleApiClient connection failed: ConnectionResult{statusCode=SIGN_IN_REQUIRED, resolution=PendingIntent{a846aa3: android.os.BinderProxy@ff141a0}, message=null}

assuming this is the first time the user is trying to connect, then the "choose account" and permission dialogs will display. in the permission dialog, the user can choose to either accept or deny. i would like to catch the event where a user denies the permission and display an appropriate message - however,
the exact same error message is logged.
how can i differentiate between "user denied permissions" event to other events? (like the first time the user is trying to connect)