3rd party application integration guidelines - how to be a good shell citizen?

[Holger Berndt <berndth gmx de>]

I wonder what the recommended integration for a mail user agent is if it
wants to be a good GNOME Shell citizen. I've read the tray design
guideline [1] and looked at the mockups [2], but am still not clear.

I'd like the following uses to be possible:

1. Be gently notified of incomming messages, and access the new messages
2. Make it easy to get the application out of the user's sight without
   ending it, so that it can continue to fetch mail in the background
3. Quickly and easily access the "hidden" application to start writing a
   message or read up on older messages
4. Have some visual feedback to see if the application is running in the
   background (and thus incomming mail would be announced), or not

Point 1 is quite nicely handled with the notification system. Points 2,
3 and 4 are traditionally taken care of with a tray icon, or with newer
systems like Canonical's indicators.

I agree that the tray is a mess, and can see why its use is discouraged.
However, dropping the tray icon for persistent notifications doesn't seem
like a proper replacement, as they don't solve 2, 3 and 4. Point 2 became
even harder without the minimize button.

I assume that 3rd party instant messengers and telephony programs
face similar questions.

Is there a more elaborate integration design guideline?

Thanks,
Holger

[1] http://live.gnome.org/GnomeShell/Design/Guidelines/MessageTray/Compatibility
[2] http://live.gnome.org/GnomeShell/Design/Guidelines/MessageTray/Email