PowerManagementConfiguration

Revision 25 as of 2005-11-08 03:40:23

Clear message

Summary

GNOME Power Preferences should by default only propose controversial options (ie: if we suspend when the lid closes). Other options have sane defaults which we should select for the user and not ask them about. For example, the following events are assumed to behave as follows:

  • power button press -> logout dialog

  • suspend press (if exists) -> suspend

  • ac unplugged -> so what? (do nothing -- but go into laptop mode!)

Scope and rationale

There should be simple, reliable, and understandable methods of:

  • shutting down the computer
  • putting the computer into a low-power-use state
  • going into a low-power-use state after some period of inactivity
  • blanking the screen, instead of using a power-sapping screensaver, when running on battery power
  • preventing data loss when the battery runs out.

Currently people need to edit text files in /etc to enable suspend to RAM, and to select which services will be restarted. Also, it's currently impossible to configure how the system should behave in various situations, such as on lid close. All of these points should be configurable graphically.

Use Cases

Michael just installed Ubuntu 6.04, he doesn't care about Power Preferences, he wants it to just work and do the right thing (tm).

Hubert has different ideas, about how Power Preferences should work by default. He should be able to change the option that make sense.

Implementation Plan

Panel Icon

There will be exactly one power status icon on the panel (either applet or notification icon) that will show the current battery charge status to the user. The icon will only show "primary" battery status (we make no attempt to deal with wireless mouse batteries, for example). The icon will not have its own preference dialog, but rather, a pulldown menu. The preferences item in this menu will lead to the global power preferences dialog (same dialog that is accessed via the System -> Preferences menu). 

+-------------------------+
|    _Preferences         |     -> system power preferences
|(o) No text              |
|( ) Remaining time       |
|( ) Remaining percentage |
+-------------------------+

Power Off Dialog

+-------------------------------------------------------------------------+
|                                                                         |
| [     ]                                                                 |
| [  ?  ] Are you sure you want to power off?                             |
| [     ]                                                                 |
+-------------------------------------------------------------------------+
| (_Log Out) (_Restart) (S_witch User) (_Sleep)  (_Cancel) ((_Power Off)) |
+-------------------------------------------------------------------------+

* Power button -> pop up the power off dialog * all options in dialog are accessible with single (no need to hold alt) keypress. * possibly remove switch user * have ability to remove some items for certain users (admin may not want users shutting down, for example) * default is poweroff, accessible by pressing enter * this poweroff dialog might replace the global logout dialog

Power Preferences Dialog

If Suspend is supported: 

+-----------------Power Preferences-------------------------+
| Sleep                                                     |
|                                                           |
|   Running on batteries:                                   |
|    Put computer to sleep after:    +---------||---+       |
|                                              50min        |
|                                                           |
| Options                                                   |
|   [x] Suspend on lid close:                               |
|   [x] require password when                               | 
|       waking from sleep/hibernate                         |
|                                                           |
| Warnings                                                  |
|    Issue warning:                  +---------||---+       |
|                                         15 min remaining  |
|                                                           |
+-----------------------------------------------------------+
  • one tab
  • if suspend is unsupported then:
    • - hide suspend time slider - hide suspend-on-lid-close option
  • time until automatic suspend
  • checkbox for suspend on lid close
    • - defaults to on if suspend is whitelisted for laptop
  • checkbox for "require password when waking from sleep/hibernate"
    • - defaults to off if user is autologin - essentially, invoke the screensaver just before suspending
  • sliders for battery low in TIME (not percentage)
    • - warnings issued for battery low - automatic shutdown for battery critical
      • - automatic shutdown may be disabled by hidden gconf key

Backend

  • We require a system daemon running as root.
  • Users in group power-config will be able to change power config without password.
  • Users not in this group are prevented from modifying the settings.
  • Use dbus to talk to system daemon, which will make certain they are in the right group.
  • We prefer to have each user able to specify their own settings.
  • If each user can set their own settings then there must be a clear way to set defaults (for new users, login screen) possibly only accessible to admin user.
  • If each user can set their own settings then the new settings must be activated when the user logs in and the default settings must be restored on user logout.

XXX:smurf: OK, that's the user interface. I can implement that in 1h using glade. :-)  But how do we actually implement the back-end? That was discussed in the BoF AFAIR, and it should be reflected here.

Outstanding issues

MatthewPaulThomas:

  • "Remaining percentage" doesn't really make sense when the battery is charging.
  • "Preferences" should have a "...", since the implied action is "change my preferences".

  • There should not be a single alert that has six buttons along the bottom; that's just scary! DapperDesktopPlan talks about a Log Out / Switch button on the screen, which would be a counterpart to the Shut Down / Restart button on the computer itself.

  • Should there be a slider for turning off the screen separately from hibernation? (XP and OS X have that.)

  • There's no preferences for automatic sleep/shutdown when running on mains power (e.g. I went away on holiday and forgot to turn off the computer).

  • It's not obvious what happens when "Suspend on lid close" is turned off.
  • If a password is required when waking the computer, should it automatically be required when unlocking the screensaver? Or when opening the lid when "Suspend on lid close" is turned off? If not, why not?
  • "Issue warning:" about what? (Yes, I know, but Aunt Tillie doesn't.) And what's the use case for turning off this option?
  • What's the point of "one tab"?