<html> <head> <meta content="text/html; charset=utf-8" http-equiv="Content-Type"> </head> <body bgcolor="#FFFFFF" text="#000000"> My most-hated-bugs list includes <a href="https://bugs.launchpad.net/ubuntu/+source/xfce4-power-manager/+bug/1193716">https://bugs.launchpad.net/ubuntu/+source/xfce4-power-manager/+bug/1193716</a>. 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. <hr size="2" width="100%"> #!/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 <hr size="2" width="100%"> 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 <hr size="2" width="100%"> 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 <hr size="2" width="100%"> 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. </body> </html>