Xmonad, Ubuntu 12.04 and Display Resizing/Mirroring
I've just spent a fair while with an infuriating screen resizing behaviour in Ubuntu 12.04, so I thought I'd document it here.
For my work machine, I use Ubuntu with a dual-screen setup (using Nvidia's TwinView), with a mixture of Gnome and Xmonad for my window manager/desktop requirements. A handy key-binding that I use frequently is Super-p (that's the "Windows" key followed by p) used to bring up a program-launch menu.
After upgrading from Ubuntu 11.10 to 12.04 I was annoyed to find that using this short-cut would cause the screen to flicker and the two displays to become mirrored.
After spending a good amount of time recompiling Xmonad and checking various NVidia/Xorg settings, to no avail, I discovered that this is an intentional behaviour of Gnome (!).
Apparently this is due to a Microsoft recommendation that hardware manufacturers map the various ways of controlling projector/external displays onto a "simple" key-press of super-p! This has led gnome-settings-daemon to implement super-p as a short-cut to xrandr, hence my display resizing/mirroring symptoms.
The solution is simple - prevent gnome-settings-daemon from making the call to xrandr by disabling its plugin:
- Run dconf-editor
- Expand org.gnome.settings-daemon.plugins.xrandr
- Uncheck 'active'