Let user choose keyboard layout in login screen

[Jarno Suni]

This option is good to have, since a keyboard could be operating by wrong layout by default, see e.g. Bug #995715 and https://bugs.freedesktop.org/show_bug.cgi?id=49950 concerning Logitech Unifying Receiver, making it impossible to type password in some cases by such input devices.

The layout setting would affect to a possible onscreen keyboard, too.

Currently system seems to try to detect natural keyboard layout, when using a keyboard, but this does not currently work with all keyboards, and it is hard to know, which is user's preferred keyboard for the onscreen keyboard.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: lightdm-gtk-greeter 1.8.5-1ubuntu2~ubuntu14.04.1
ProcVersionSignature: Ubuntu 3.13.0-68.111-lowlatency 3.13.11-ckt27
Uname: Linux 3.13.0-68-lowlatency x86_64
ApportVersion: 2.14.1-0ubuntu3.18
Architecture: amd64
CurrentDesktop: XFCE
Date: Thu Nov 12 18:36:59 2015
EcryptfsInUse: Yes
InstallationDate: Installed on 2014-09-21 (417 days ago)
InstallationMedia: Ubuntu-Studio 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.1)
SourcePackage: lightdm-gtk-greeter
UpgradeStatus: No upgrade log present (probably fresh install)

[Jarno Suni (jarnos)]

Besides, onscreen keyboard could be available by default: http://ubuntuhandbook.org/index.php/2014/06/enable-onscreen-keyboard-in-lightdm-gtk-greeter-in-ubuntu-14-04/

[Jarno Suni (jarnos)]

In 16.04, "LightDM GTK+ Greeter settings" has "Keyboard layout" as an unused item in in Panel settings. If you add it, the right layout will probably be set by default, and it can be altered by user. This should be used by default.