[maemo-developers] Inhibiting device auto-lock on N900

[From: Kimmo Hämäläinen]

On Tue, 2010-04-20 at 11:05 +0200, ext Per von Zweigbergk wrote:
> Thank you for this information. It is close to what I've been looking
> for. 
> 
> However, is this really what happens for example if there is an
> incoming call - that the phone app sends a request to the phone to
> unlock? Rather than use an API to show information "above" the lockout
> screen... if so this could be a security problem. 
> 
> I did not find any API call which allows me to turn off the backlight
> but still keep the application responsive however. Hmm. 

Media Player uses the "Do not disturb" flag(* in its window to prevent
the screen going off when you are watching a video.  hildon-desktop
notices the flag in the window and periodically sends "do not blank the
screen yet, please" D-Bus messages to the MCE daemon.

You could use this flag in your window, or send the D-Bus messages
yourself.

*) libhildon has hildon_gtk_window_set_do_not_disturb() convenience
function. Or you can set the window property using the x11 API directly.

-Kimmo

> ----- Ursprungsmeddelande ----- 
> > Hello. 
> > 
> > To unlock the device : 
> > http://wiki.maemo.org/User:Jebba/DBUS#dbus-send-unlock 
> > 
> > To keep the display on and device unlocked : 
> >
> http://maemo.org/api_refs/4.0/libosso/group__Devstate.html#g93fe32aeb992e128c94b890d6f801bfd 
> > 
> > David. 
> > 
> > Per von Zweigbergk wrote: 
> > > I'm writing a "talking clock" application. The purpose of this
> application is 
> > > to answer the ever-so-frequent question "mghhnm, what time is it"
> in the 
> > > morning, just before you've been able to open your eyes properly
> much less put 
> > > on your glasses. 
> > > 
> > > I've already written the application itself, it was a fairly
> simple project 
> > > that took a couple of hours. In testing, however, I discovered a
> slight 
> > > drawback to my planned approach of "start the program before
> falling asleep, 
> > > mash the screen in the morning and it'll tell me the time". 
> > > 
> > > 1. The screen itself will stop accepting taps when the device is
> turned off. 
> > > It seems this particular feature can be inhibited by leaving the
> phone slided 
> > > open (with the qwerty keyboard exposed) or by setting the gconf
> setting 
> > > /system/osso/dsm/locks/touchscreen_keypad_autolock_enabled to
> false. This 
> > > requires you to slide the lock button on the side of the phone to
> unlock the 
> > > screen. Annoying, but still doable even in a half-awake stupor.
> And besides, 
> > > you can always leave the phone activated in its "opened" mode. 
> > > 
> > > 2. The device will automatically lock itself after 5 minutes, for
> security 
> > > purposes. Now, remembering and correctly entering the device lock
> code in a 
> > > half-awake stupor is considerably more difficult. This can be
> disabled by 
> > > setting the gconf
> setting /system/osso/dsm/locks/devicelock_autolock_enabled. 
> > > 
> > > However - I don't really like this approach of changing gconf user
> settings to 
> > > inhibit device locks. The last thing I want is for the phone or my
> application 
> > > to crash (or more likely, to run out of battery) while the program
> is running 
> > > and leaving the device unlocked, requiring the user to set the
> automatic lock 
> > > option on again (if he even notices it's been disabled). 
> > > 
> > > Whoever coded the built-in media player agrees with this. He's
> found some way 
> > > to tell the system not to automatically lock itself without
> changing the gconf 
> > > settings. I have not yet figured out how. 
> > > 
> > > One other option worth considering is the fact that some
> applications, such as 
> > > the phone (for an incoming call) and the alarm application (to
> silence the 
> > > infernal bleeping of an alarm) will allow you to throw up a screen
> to the user 
> > > that'll be accessible even if the lock code has not been entered.
> This would 
> > > also solve the potential security issue of somebody stealing your
> phone while 
> > > you're sleeping to get to it while it's unlocked. :-) 
> > > 
> > > So, does anybody have any ideas as to how I might acheive this in
> some way? 
> > > _______________________________________________ 
> > > maemo-developers mailing list 
> > > maemo-developers at maemo.org 
> > > https://lists.maemo.org/mailman/listinfo/maemo-developers 
> > >    
> 
> 
>