idle.queryState()

detectionIntervalInSeconds

integer. The system is considered idle if detectionIntervalInSeconds seconds have elapsed since the last user input detected.

A Promise that will be fulfilled with an idle.IdleState string, indicating the current state.

In this simple snippet, we call queryState() and then check if the returned newState is idle or active, logging a message as appropriate. Because we have specified a detectionIntervalInSeconds of 15, an idle state will only be reported if there has been no user activity for at least 15 seconds

function onGot(newState) {
  if (newState === "idle") {
    console.log("Please come back — we miss you!");
  } else if (newState === "active") {
    console.log("Glad to still have you with us!");
  }
}

let querying = browser.idle.queryState(15);
querying.then(onGot);