Backlight control

[John Watlington]

On Jan 29, 2009, at 2:11 PM, Tomeu Vizoso wrote:

> On Tue, Jan 27, 2009 at 06:10, John Watlington <wad at laptop.org> wrote:
>>
>> On Jan 24, 2009, at 5:18 AM, Marco Pesenti Gritti wrote:
>>
>>> On Sat, Jan 24, 2009 at 5:23 AM, John Watlington <wad at laptop.org>
>>> wrote:
>>>>
>>>> What can I call from an activity (in python) to indicate that the
>>>> backlight
>>>> should be turned off ?
>>>>
>>>> I'm playing with a photoframe app, and want to have the ability to
>>>> deliberately
>>>> control the backlight level from the UI.
>>>
>>> See
>>>
>>> http://git.sugarlabs.org/projects/sugar/repos/mainline/blobs/master/
>>> src/jarabe/model/screen.py
>>>
>>> Marco
>>
>> Thanks for the pointer.
>>
>> When using those functions I receive the following error message:
>> RuntimeError: To make asynchronous calls, receive signals or export
>> objects, D-Bus connections must
>> be attached to a main loop by passing mainloop=... to the constructor
>> or calling dbus.set_default_main_loop(...)
>
> Is it an activity?

A Pippy derived activity for now.   At some point, I will probably  
discard
the Pippy framework but it was great for getting started.

> Activities shouldn't need it, but you can see how
> the DS sets a main loop for dbus-python to use:
>
> http://git.sugarlabs.org/projects/sugar-datastore/repos/mainline/ 
> blobs/master/bin/datastore-service
Thx

>> It seems like a code fragment was missing from the file,
>> and in my particular application, I wouldn't mind if those calls were
>> synchronous --- how do I do so ?
>
> All the func calls in that example seem to be sync, and there's no
> signals neither. So perhaps what raises that issue is
> "follow_name_owner_changes=True"?
You caught it.   Removing that option removes the error.

Thanks,
wad