Notification API

For SwitchDataSwitch, I wanted to provide users with a 1-click solution to enable and disable data traffic (2G/3G/...).
I chose the notification bar since it is a very accessible place, visible almost all the time and that can be expanded without stopping the running activity :

 
The notification bar is usually presented in its reduced form (here the dark bar at the top of the screen with the smallest icons) but can be expanded by sliding it downwards.

Unfortunately, Android's Notification API is really made for instant notifications, not persistent ones, and that implies several inconveniences :

• when creating a notification, the developer has to put an icon in the reduced notification bar, taking some precious space
• by default an 'event timestamp' is shown next to the expanded content of the notification, which means nothing for a permanent service
• there is no programmatic way to know if a notification is currently displayed or not

This article describes a way to create a notification that :

• doesn't show up in the reduced notification bar
• doesn't have a timestamp in the expanded notification bar