Ubuntu – How to have xfce automatically adjust to changing available outputs

multiple-monitorsxfcexrandrxubuntu

In xfce, I can run Settings -> Display to change my preferred output monitor. What I haven't found an option for is to have it automatically adjust to a change in available outputs.

For example, if I'm using a DVI display, but undock my laptop, XFCE will not automatically realize that I no longer have a working display and change the output. Gnome did do this, though I'm not sure through what service. I'd like to have some way of making sure I always have at least one working output automatically.

SIDE NOTE: This is related to another question of mine, If I just use a window manager and not a desktop environment, how do I get automatic dock/undock resolution updates?, but is for xfce, not any generic window manager.

Best Answer

$ xrandr --auto

From xrandr man page:

--auto: For connected but disabled outputs, this will enable them using their preferred mode (or, something close to 96dpi if they have no preferred mode). For disconnected but enabled outputs, this will disable them.

Dock/UnDock Scripts

I have finally put together a complete script setup that will detect my dock status and switch the monitors automatically.

The first thing I did was to get rid of my Xorg.conf as it caused more issues that it solved. Since I am using an nvdia card I eventually found that using disper was the best way to go. I had discounted it before as its standard commands could not achieve my dualview setup but then I found I could create a custom metamode to use with disper.

To create the custom metamode I used the values stored in Xorg.conf along with previous testing with nv-control-dpy and xrandr as a guide. This metamode and other twinview values were added to a file that can be passed to disper through stdin.

Due to having different sized monitors with Twinview I need to use XCreateMouseVoid, as described in this question.

Below is a complete breakdown of the scripts and files with their contents.

Scripts

Create XCreateMouseVoid script:

Script Name: ~/.mousevoid

#!/bin/bash
echo "Mouse Void"
/opt/XCreateMouseVoid/XCreateMouseVoid 0 1112 1280 88 &
/opt/XCreateMouseVoid/XCreateMouseVoid 0 0 1280 88 &

chmod +x ~/.mousevoid

Create Disper settings file:

File Name: ~/.disperDocked

backend: nvidia
associated displays: CRT-0, DFP-0, DFP-1
metamode: CRT-0: 1280x1024_60 @1280x1024 +0+88, DFP-1: 1920x1200 @1920x1200 +1280+0
scaling: default, default, stretched
xinerama info order: DFP-1, CRT-0, DFP-0

Create the export dbus session script:

Script Name: ~/.export_x_info

#!/bin/bash
# Export the dbus session address on startup so it can be used by any other environment
sleep 5
touch $HOME/.Xdbus
chmod 600 $HOME/.Xdbus
env | grep DBUS_SESSION_BUS_ADDRESS > $HOME/.Xdbus
echo 'export DBUS_SESSION_BUS_ADDRESS' >> $HOME/.Xdbus
# Export XAUTHORITY value on startup so it can be used by cron
env | grep XAUTHORITY >> $HOME/.Xdbus
echo 'export XAUTHORITY' >> $HOME/.Xdbus

Set to user executable only: chmod 700 ~/.export_x_info

Then put it in Startup Applications:

Name: X Environment Variables
Command: /home/your_user/.export_x_info

Unless you restart you need to run ~/.export_x_info to create the .Xdbus file

Create the udev rule that will run with upon a dock event:

Script Name: /etc/udev/rules.d/81-dell-dock.rules

KERNEL=="dock.0", ACTION=="change", RUN+="/usr/local/sbin/dell-dock"

chmod +x /etc/udev/rules.d/81-dell-dock.rules

Create the script that is associated with the udev rule:

Script Name: /usr/local/sbin/dell-dock

#!/bin/sh
# wait for the dock state to change
sleep 0.5
DOCKED=$(cat /sys/devices/platform/dock.0/docked)
case "$DOCKED" in
   "0")
       echo "Run UnDocking Script..."
        /usr/local/sbin/undock
        ;;
    "1") 
        echo "Run Docking Script..."
        /usr/local/sbin/dock
        ;;
esac
exit 0

chmod +x /usr/local/sbin/dell-dock

Create the undock script (change your_user to match your user name):

Script Name: /usr/local/sbin/undock

#!/bin/bash
USER=your_user
export HOME=/home/$USER
source $HOME/.Xdbus
export DISPLAY=:0
echo "UnDocking Script"
echo "Switch primary monitor"
sudo -u $USER disper -s
echo "Killall XCreateMouseVoid"
pkill XCreate
echo "Restart conky"
pkill conky
sudo -u $USER conky &

chmod +x /usr/local/sbin/undock

Create the dock script (change your_user to match your user name):

Script Name: /usr/local/sbin/dock

#!/bin/bash
USER=your_user
export HOME=/home/$USER
source $HOME/.Xdbus
export DISPLAY=:0
echo "Docking Script"
echo "Switch to Dualview"
sudo -u $USER disper -i < $HOME/.disperDocked
echo "Start XCreateMouseVoid"
pkill XCreate
sudo -u $USER $HOME/.mousevoid
echo "Restart conky"
pkill conky
sudo -u $USER conky &

chmod +x /usr/local/sbin/dock

Debug

To debug the dock scripts you have to enable udev debug logging:

udevadm control --log-priority=debug

Then open syslog in Log File Viewer

Resources

nVidia Readme: Config Twinview, X Config Options
Autorandr
Disper PPA
nv-control-dpy
Ubuntu Forum - Un/Dock Scripts
Thinkwiki
udevadm

Ubuntu – How to make Ubuntu recognize an unknown external display (so I can adjust its resolution)

The monitor cable was loose.
When I removed the cable and firmly plugged it in again, everything suddenly worked.
The monitor was recognized, and now I am using my previously desired resolution:

I feel kind of silly, because I never thought merely touching a loose cable would be of any help.

Best Answer

Related Solutions

Ubuntu – How to automatically switch monitors with the laptop dock

Dock/UnDock Scripts

Scripts

Debug

Resources

Ubuntu – How to make Ubuntu recognize an unknown external display (so I can adjust its resolution)

Related Question