A method to retrieve the system idle time would definitely be useful, right now you have to poke X to provide this.

I'd also include more options for device powermanagement, for example CPU, harddisks, wireless card and others as you already included with display. And while at it, shouldn't the screensaver be able to told to lock the display?

Use the gnome-screensaver methods for this, they do exactly as you describe. If g-s and g-p-m ever merge, then this will me added to the spec.

I'm one of the developers of the power manager application in Kubuntu, and we're currently indeed using the screensaver. For better cross-desktop interoperability, it would be useful to have those methods available via one unified interface.

cpufreq support has just been added to HAL, so that should be considered as another item as well -- with keeping an eye on other hardware's powermanagement features for the future.

>it would be useful to have those methods

Sure, I'll see what I can do.

>cpufreq support has just been added to HAL

Already supported in 2.17.x... :-)

...I hope you meant it about the feedback. I noticed a couple of typos, but then ended up reading the whole thing. I'm not a developer of anything in particular, so feel free to ignore any and/or all of the following.


User Interface Frontends:
* "i.e. the icon and description": should be parenthesised?
* "a abstract power interface" -> "an abstract power interface"

GetLowPowerMode():
* "depending on the users policy" -> "depending on the user's policy"
* ", and only perform cache-updates when absolutely required.": What does this refer to? If it's just an example of something you shouldn't do in low power mode, that should probably be stated.

Inhibit System Sleep:
* "detects an idle session and system": Is there a difference between an idle session and an idle system as far as the API is concerned?
* RequestCookie() and ClearCookie() aren't the most intuitive names. Similarly for IsValid() and IsValidChanged; 'valid' seems to be a roundabout way of saying 'has been inhibited by someone'.
* ClearCookie(): "Allows the computer to perform the idle sleep action." Presumably if there are three cookies outstanding, clearing one cookie doesn't allow sleep.
* IsValid(): The description makes it sound like the function will always return False if there have ever been any inhibit cookies taken, regardless of whether they've been returned or not.


Statistics Data:
* GetAxisType(): "(and entry from GetTypes())" -> "(an entry from GetTypes())" I think?
* "for instancing showing" -> "for instance showing"

The "Statistics Data" section is the only one that, for me, fails the "descriptions that don't make sense to mere mortals" criteria. I see that it's not a required interface, so this may not matter much to you. My basic issue with the interface is that it would seem that the most common usage would be to pass in a dependant variable and get back a time vs. that variable dataset, and this API doesn't make it obvious how to do that. Without going into details, unclear parts are:
* What constitutes a 'type of data' in GetTypes()?
* In what situation is your Y-axis from GetAxisType() *not* going to be the type you passed in; and in what situation is your X-axis type *not* going to be time?
* GetData() reads like it returns 4 dimensional data: time, X, Y and value.

this applet prompts "Cannot get laptop panel brightness" on my Dell 1405/640m laptop (fedora 6). It has been a long time that I cannot adjust brightness by press the Fn+up/down key. I guess this has something to do with udev because the function keys works when booting, but not after udev service has been loaded. Besides that, I still could echo brightness values to proc interface, to adjust brightness; but the initial "current" value is "0". Where can I find a bugzilla ticker for this?

[root@mstar LCD]# pwd
/proc/acpi/video/VID/LCD
[root@mstar LCD]# cat brightness
levels: 84 72 12 24 36 48 60 72 84 100
current: 0

Do you use libsmbios to change the brightness? What does "lshal |grep laptop_panel" print?

1. no, I don't use libsmbios.
2. nothing for "panel", only 1 found for "laptop": "system.formfactor = 'laptop' (string)"

I'm mixing fedora 6 and rawhide packages on my laptop, maybe there is some incompatible? What can I help?

previously was using kernel-2.6.18 from fc6 updates repo. Now switch to rawhide kernel-2.6.20-2942, it works! :D

Great resource. keep it up!!Thanks a lot for interesting discussion, I found a lot of useful information!With the best regards!
David