Support for automatically dimming screen after inactivity

[hanaral]

Problem

The OS should be aware that laptops do in fact, have finite amount of battery life, and that human beings are (generally) incapable of bothering to suspend or close the lid of their laptops. On macOS, inactivity will cause the screen to dim by about 40%(not sure how correct that is), which not only saves energy but also shows that the computer is going to sleep just by looking at the device. For whatever reason this isn't commonplace in open source OSes, so instead in elementary OS, the user gets a notification that;

• Doesn't go away
• Requires you to walk up to the computer and read what its tiny text says, since apparently inactivity = using the device
• Requires you to disable all "other" notifications if you have had enough of it

Proposal

The device should dim its display by at least 40% after a minute or so of inactivity. The display can then turn off entirely whenever the default/user set timout is.

Edit: So apparently the gnome-settings-daemon already has settings for this, and they are all disabled except for the low power one. This could possibly even be reimplemented in the elementary settings-daemon with nice ramp ups/downs between idle and active brightnesses.

Prior Art

Watch a MacBook fall asleep

@danrabbit I want to give whoever implements this $15, is there any way apart from a direct PayPal transfer?

[danirabbit]

There is a idle-dim key in GSD settings, we're just not connecting to it, so this is pretty trivial