My pseudo Presentation Mode

[Nio Wiklund]

Den 2014-12-19 19:22, John Hupp skrev:
> 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.
> 
> 
> 
Hi John,

Thank you for sharing :-)

Best regards
Nio