Re: [gpm] Using HAL: reporting.low and reporting.warning

[Richard Hughes <hughsient gmail com>]

On Tue, 2006-01-10 at 04:38 +0100, Jaap Haitsma wrote:
> Richard Hughes wrote:
> > On Sat, 2006-01-07 at 05:11 +0100, Jaap Haitsma wrote:
> > 
> >>Hi Richard,
> >>
> >>My batteries have as properties in HAL a reporting.low and 
> >>reporting.warning (also charge_level.low and charge_level.warning and 
> >>these have the same number so I guess they are the same thing)
> > 
> > 
> > Yes, defined by ACPI, and exported by HAL. I'm not sure if these are set
> > at manufacture time, or change with the battery lifetime.
> 
> These settings are fixed. Low or critical battery capacity remains low 
> no matter how old your batteries are.
> 
> The thing that changes is the last_full capacity. These decrease due to 
> aging of the battery.

Hmm, it's a shame low and critical are not updated for the lifetime of
the battery.

> >>Can't we use these properties instead of the sliders? Or are these 
> >>properties not present for all type of batteries?
> > 
> > 
> > I think maybe these values could set the default for the sliders, but I
> > think the sliders should remain -- as people have different preferences
> 
> Let me try to convince you that people do not have different preferences 
> here.
> 
> When batteries are getting low people just want a warning which says 
> that their batteries are low and that they have let's say 10, 20 or 30 
> minutes more.

The thing is, I'm pretty good at ignoring the first few warnings, rather
than scrambling to find the ac_adapter. I'm sure other people are just
the opposite.

>  If batteries are critical there should be a warning dialog 
> and the laptop should hibernate within 10 seconds if the user does not 
> cancel it. (We should still add this option that a user can cancel 
> hibernation, a user might want to hit the send button of his mail 
> program before hibernating )

We need to use the libnotify callbacks for this I think.

> The sliders with percentages do not work well if you for example now and 
> then use 2 batteries now or use batteries with different capacities.

Yes, this is a valid point. What about we just throw these sliders away,
and define a per-time warning, like a lot of people want.

As long as we have a sufficiently long warning time, compared to the
resolution of the updates and the changing of the cpu load, the aliasing
and inaccuracy shouldn't be a problem.

What about:

1 notice at 20 minutes
1 warning at 10 minutes
1 critical warning at 5 minutes, with a link that lets the user abort
the action?
2 minutes later, the action is performed regardless

Does this have to be configurable? What is everyones opinions on this?

> The unit for setting the thresholds for the batteries should be mAh or 
> mWh instead. But that's far too technical to display in a UI, but they 
> should be the units we calculate with.
> 
> > -- and ACPI values are famously unreliable/wrong.
> > 
> If the ACPI values are unreliable/wrong then also the charge percentage 
> will be wrong.

Point taken.

Richard.