[maemo-developers] [maemo-developers] Maemo Alarm/Notifier Interface

[From: Florian Boor]

Hello!

Devesh Kothari wrote:
> I am currently looking for what developer requirements would be from
> such an Alarm/Notifier interface. Specially lot of developers working on
> applications which need to schedule events and notifications like PIM
> aplications need this functionality, and it is just not there yet in the
> Maemo Development Platform.

This is a feature i really missed porting gpe-calendar. I'm convinced that there
are some more applications which could need a feature like this.
The most important reason to introduce a notifier interface is that you can
easily introduce a battery drain problem with applications doing frequent
updates/checks. That would have a negative influence on the reputation on the
770 and maemo.

> Some starters
> 
> 1. API to
>    - enable notifier/alarm events
>    - cancel previously scheduled events
>    - ability to specify sound file to be played for events [I guess this
> can be done by the application handling the notifier event, so maybe not
> relevant]

I'd keep the interface as simple as possible. Call a function to schedule an
event and get back an unique id. This is used to identify the event in a
callback function and to cancel it. Playing sounds should be the job of the
calling application, it usually needs to do some more action anyway.
I can imagine that this might be useful for scheduling tasks which are not
related with user interaction too.

> 2. Alarm/Notifier sub system features
> - ability to schedule multiple notifier alarm event
> - ability to wake up device on events

Waking up the device would be important, yes. Another feature to think about
would be to set some command to run (and pass information to) or a dbus service
to fire if the event time is reached. That would make it possible to have timed
events without the need to have the calling application running all the time.
For calendar applications this would be very useful.

I had some discussion with Kimmo about this topic some time ago. One idea was
just to use atd. This one would need to become part of the default filesystem
because we can't start it automatically. In addition to this we would need to
extend it by some feature to wake up the device.
I suggested to extend the libosso time API which currently covers system clock
changes. Making it a comprehensive interface for time-related tasks would be an
option if it really fits into the intended purpose of libosso.

Greetings

Florian

-- 
The dream of yesterday                  Florian Boor
is the hope of today                    Tel: 0271-771091-14
and the reality of tomorrow.            Fax: 0271-771091-19
[Robert Hutchings Goddard, 1904]        florian.boor at kernelconcepts.de

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