Change resolution when enabling/disabling external monitor

Question

I use my laptop with a second display. Sometimes I should take my laptop with me, but I can't take my second display with me. How can I setup my ubuntu 10.04 so that it changes the resolution automatically when I disable the second display?

My normal resolution (with the second display) is 2646*800. My resolution without the second display (laptop resolution) 1280*800.

What I want is:

• When i disable second display, my resolution automatically (or by running some script) changes to 1280*800
• When i connect second display resolution change to 2646*800.

Answer 1

You can use xrandr (assumming your driver supports it), for a nice guide check http://www.ubuntugeek.com/how-change-display-resolution-settings-using-xrandr.html .

Answer 2

A simple way to use xrandr is with --preferred to use the detected settings.

Run xrandr to get the names of your outputs (I use LVDS1 and VGA1 below) and then you can use something like the following:

# enable both screens and put external left of laptop
xrandr --output LVDS1 --preferred --output VGA1 --left-of LVDS1 --primary --preferred

# enable laptop screen only
xrandr --output LVDS1 --preferred --output VGA1 --off

---

This is the script I use:

#! /bin/bash

# LVDS1 is my laptop monitor and VGA1 is my external monitor.
# These names can be found by running xrandr with no arguments.

# auto detect all connected monitors
xrandr --auto

if [ "$1" == "both" ] ; then
    # use best settings for both monitors
    xrandr --output LVDS1 --preferred --output VGA1 --above LVDS1 --primary --preferred
else
    # only use external monitor
    xrandr --output LVDS1 --off --output VGA1 --primary --preferred
fi