My most-hated-bugs list includes
https://bugs.launchpad.net/ubuntu/+source/xfce4-power-manager/+bug/1193716.
If you are streaming video in your browser, after 10 minutes it will
blank and then lock the screen (unless you keep moving the mouse). The
bug has been fixed for 14.10, but policy has prevented the fix from
being back-ported to the LTS. Worry about a regression I suppose, but a
usability black eye for the LTS.
I wrote a script that toggles to a pseudo Presentation Mode (and back to
Normal Mode if you run it again) and notifies the user of the present
mode. I also made up a desktop entry file named Power Mode Toggler that
will run the script from the Preferences menu.
Note that the Presentation Mode settings are not permanent, but expire
with the session.
To use these, install the very small libnotify-bin package, which is
required for the user notifications. Then as root, create both files in
/usr/local/share/applications (or an equivalent location). Remember to
make the script executable.
------------------------------------------------------------------------
#!/bin/bash
# /usr/local/share/applications/xset-mode.sh
# A script to toggle between Presentation and Normal mode and notify the
user of the mode
STATUS_MONITOR=$(xset q | grep "DPMS is" | awk '{print $3}')
if [ "$STATUS_MONITOR" == "Enabled" ]; then
xset s off
xset -dpms
notify-send -t 5000 “The computer is now in Presentation Mode”
else
xset s on
xset +dpms
notify-send -t 5000 “The computer is now in Normal Mode”
fi
------------------------------------------------------------------------
A desktop entry file to run the script and appear in the Preferences
menu as Power Mode Toggler:
/usr/local/share/applications/power-mode-toggler.desktop
[Desktop Entry]
Version=1.0
Type=Application
Name=Power Mode Toggle
Icon=xfpm-ac-adapter
Exec=bash /usr/local/share/applications/xset-mode.sh
Terminal=false
Categories=Settings
Name[en_US]=Power Mode Toggler
Comment[en_US]=Toggle between Presentation and Normal Mode
------------------------------------------------------------------------
*Arcane Background Reading*
A summary of my research into this problem:
/*Command Line Behavior*/
Command line utility xset sets the X user preferences
Some commands:
xset q - queries the current settings for the X user preferences
xset s on/off - turn the screen saver functions on or off
xset -dpms/+dpms - disables/enables the DPMS functions
xset q output includes these two sections which determine the screen
behavior:
Screen Saver:
prefer blanking: yes allow exposures: yes
timeout: 600 cycle: 600
DPMS (Energy Star):
Standby: 600 Suspend: 0 Off: 900
DPMS is Enabled
Monitor is On
This xset output is the reliable indicator of behavior, not the GUI
interfaces.
An ad hoc Presentation Mode:
$ xset s off # sets Screen Saver timeout: 0
$ xset -dpms # disables DPMS, though leaving the Standby, Suspend,
Off values unaffected
This works!
An ad hoc Normal Mode:
$ xset s on # sets Screen Saver timeout to the X default: 600
$ xset +dpms # enables DPMS with whatever Standby, Suspend, Off
values are current
------------------------------------------------------------------------
/*GUI Interface Behavior (A Mess)*/
Menu: Preferences: Power Manager, Light Locker
(xfce4-power-manager-settings, light-locker-settings)
Changing settings in LL/XPM will also change the output of xset q, but
changing settings via xset does not result in changes to the LL/XPM
interfaces. Perhaps a reboot would effect that.
If you set XPM systray icon to always appear and right-click it, you can
choose Mode: Normal/Presentation. But Presentation Mode merely disables
DPMS and does not turn off the screen saver.
Note that light-locker-settings and xfce4-power-manager-settings both
offer sliders to set monitor blank/sleep and monitor switched off. But
these operate in lock-step: changing a slider setting in LL will also
change it in XPM. However, the effects in xset depend on which
interface you made the change from!!!
XPM: By default the monitor-sleep slider affects DPMS Standby, but the
Extended tab can set it to affect DPMS Suspend instead. The
monitor-offs slider affects DPMS Off. XPM has no effect on the Screen
Saver section.
LL: The monitor-blank slider affects Screen Saver timeout. The
monitor-off slider affects DPMS Standby and sets DPMS Off: 0. Setting
Enable Light Locker On/Off has varying effects depending on the initial
state. Enabling LL after it had been disabled set the Screen Saver
timeout: 600 and DPMS Off: 0. I thought I found a case that set Screen
Saver timeout: 0, but couldn’t duplicate that result.
An Ad Hoc Presentation Mode: Set XPM systray icon to always appear;
right-click it and choose Mode: Presentation. Set LL monitor-blank
slider to Never and Apply.
An Ad Hoc Normal Mode: Right-click XPM systray icon and choose Mode:
Normal. Set LL monitor-blank slider to 10 minutes and Apply.
--
Lubuntu-users mailing list
[email protected]
Modify settings or unsubscribe at:
https://lists.ubuntu.com/mailman/listinfo/lubuntu-users
