Dear Lazyweb...

... I ran "yum update", and the following started happening:

The transient always disappers before I am able to aim xwininfo at it. Usually it occurs when I'm watching my anime, but not always. What in the world is this?

Somehow this reminds me the old joke about GUIs: First humans moved out of caves; then they invented writing; now they invented intuitive GUIs; all that remains is to return to caves.

UPDATE: Thanks everyone for the comments. Apparently, gnome-power-manager gets a dbus signal that the brightness needs adjustment, then attempts to adjust it. The window is a brightness indicator, similar to the volume indicator (although I cannot grab the slider with the cursor). Since gnome-power-manager is utterly useless, I always apply rpm -e to it, but this time I wanted to report a bug when it crashed in a default F7 install, so I left it in. Also, fortunately for me, it is too broken to adjust the brightness and so it never hurt anything. The adjustment is done through /proc/acpi on this laptop, and works perfectly with echo(1). BIOS even remembers it across reboots.

UPDATE: Richard Hughes replied in comments, with the official word, so thanks. By the way, he also was upset at insufficient appreciation... Although his comment was not personally directed at me calling gnome-power-manager "useless", I should not have written that. I own an Inspiron 1501, where brightness keys deliver keypresses instead of being intercepted by SMM BIOS, and thus a software brightness adjustment daemon would be quite useful indeed if it worked.

To clarify, personally, I do not think that the brightness change on idle is a good idea, because it does not fit the use profile which I think typical. If I want to see something on the screen the brightness is already lowered. Lowering it further is entirely pointless, because I would not be able to see anything, and so it would do more good to power down the display completely. X already does that. But perhaps someone might want the feature... I cannot think under what scenario, but display technology varies so much that I do not presume to know all use cases. Just think of something innovative like OLPC.