The addEventListener() method of the EventTarget interface sets up a function that will be called whenever the specified event is delivered to the target.
Optionaloptions: boolean | AddEventListenerOptionsAdds an observer for a specific setting.
The name of the setting to observe.
The function to call when the setting changes.
The dispatchEvent() method of the EventTarget sends an Event to the object, (synchronously) invoking the affected event listeners in the appropriate order.
The removeEventListener() method of the EventTarget interface removes an event listener previously registered with EventTarget.addEventListener() from the target.
Optionaloptions: boolean | EventListenerOptionsRemoves an observer for a specific setting.
The name of the setting being observed.
The function to remove.
Navigator Property
mozSettings
Preference
dom.mozSettings.enabled
Permissions
settings-api-read, settings-api-write