How to install a new keyboard layout in KDE 4

The KDE keyboard layouts seemed to not work when kded was not running. Restarting the kdm service got it back up and running, but I'm not sure why it wasn't running in the first place... To kick-start kded without rebooting the whole system, log out of KDE, and log in to a Console Session. Then run:-

sudo service kdm restart

This can be done when logged into KDE, but you'll be automatically and abruptly logged out.

I have the same issue. From the doc, one could guess that the correct syntax would be something like that :

$ setxkbmap -I$HOME/.config/xkb -option mine:accent

Note : ~ doesn't work with the -I option

with

~/.config/xkb/symbols/azerty_altgr

partial default
xkb_symbols "accent" {
    include "level3(ralt_switch)"
    key <AE02>  { [  NoSymbol, NoSymbol, eacute,      NoSymbol ] };
    key <AE07>  { [  NoSymbol, NoSymbol, egrave,      NoSymbol ] };
    key <AE09>  { [  NoSymbol, NoSymbol, asciicircum, NoSymbol ] };
    key <AE10>  { [  NoSymbol, NoSymbol, agrave,      NoSymbol ] };
};

or whatever symbole file you have and

~/.config/xkb/rules/evdev

! option        =   symbols
  mine:accent   =   +azerty_altgr(accent)

Unfortunately, it doesn't work.

The only solution I found is the following : Use the same files described above. Set all native option using setxkbmap -option caps:swapescape,whatever. Then :

$ setxkbmap -print > tempfile.txt

and edit tempfile.txt in order to add your custom option in the xkb_symbols line :

xkb_keymap {
    xkb_keycodes  { include "evdev+aliases(qwerty)" };
    xkb_types     { include "complete"  };
    xkb_compat    { include "complete"  };
    xkb_symbols   { include "pc+us+fr:2+inet(evdev)+capslock(swapescape)+azerty_altgr(accent)"  };
    xkb_geometry  { include "pc(pc104)" };
};

and finaly :

xkbcomp -I$HOME/.config/xkb tempfile.txt $DISPLAY

It can be generalised for any number of options. This solution is deprecated according to Archlinux wiki.