Finally I can find an easy and perfect solution for my needs:
I use a local keyboard with us and Thai layout.
The us layout is ok for me, but I like to have some
additional german characters like "äöü ÄÖÜ"
This can easy be implemented with xmodmap, but if
you switch to the second layout, you will observe
some strange results.
After plenty of googling, I found an IMHO easy and
perfect solution: create and use your custom keyboard!
1) /usr/share/X11/xkb/symbols/
choose your nearest preference, in my case "us"
and save it with a new name: "us-de"
2) delete anything, which you don't need, and change,
what ever you like. My file for "us-de":
-----------
default
xkb_symbols "basic" {
name[Group1]= "ASCII with german";
// Alphanumeric section
key <TLDE> { [ grave, asciitilde ] };
key <AE01> { [ 1, exclam ] };
key <AE02> { [ 2, at, twosuperior ] };
key <AE03> { [ 3, numbersign, threesuperior ] };
key <AE04> { [ 4, dollar, onequarter ] };
key <AE05> { [ 5, percent, onehalf ] };
key <AE06> { [ 6, asciicircum, threequarters ] };
key <AE07> { [ 7, ampersand ] };
key <AE08> { [ 8, asterisk, oneeighth ] };
key <AE09> { [ 9, parenleft ] };
key <AE10> { [ 0, parenright, degree ] };
key <AE11> { [ minus, underscore ] };
key <AE12> { [ equal, plus ] };
key <AD01> { [ q, Q ] };
key <AD02> { [ w, W ] };
key <AD03> { [ e, E, EuroSign, cent ] };
key <AD04> { [ r, R ] };
key <AD05> { [ t, T ] };
key <AD06> { [ y, Y ] };
key <AD07> { [ u, U, udiaeresis, Udiaeresis ] };
key <AD08> { [ i, I ] };
key <AD09> { [ o, O, odiaeresis, Odiaeresis ] };
key <AD10> { [ p, P ] };
key <AD11> { [ bracketleft, braceleft ] };
key <AD12> { [ bracketright, braceright ] };
key <AC01> { [ a, A, adiaeresis, Adiaeresis ] };
key <AC02> { [ s, S ] };
key <AC03> { [ d, D ] };
key <AC04> { [ f, F ] };
key <AC05> { [ g, G ] };
key <AC06> { [ h, H ] };
key <AC07> { [ j, J ] };
key <AC08> { [ k, K ] };
key <AC09> { [ l, L ] };
key <AC10> { [ semicolon, colon ] };
key <AC11> { [ apostrophe, quotedbl ] };
key <AB01> { [ z, Z ] };
key <AB02> { [ x, X ] };
key <AB03> { [ c, C ] };
key <AB04> { [ v, V ] };
key <AB05> { [ b, B ] };
key <AB06> { [ n, N ] };
key <AB07> { [ m, M, mu ] };
key <AB08> { [ comma, less ] };
key <AB09> { [ period, greater ] };
key <AB10> { [ slash, question ] };
key <BKSL> { [ backslash, bar ] };
key <CAPS> { [ VoidSymbol ] };
// End alphanumeric section
include "level3(ralt_switch)"
};
-----------
3) /usr/share/X11/xkb/rules/evdev.xml
Modify "evdev.xml" so your custom keyboard will be recognised:
search for "</layoutList>" and
add the following just previous to "</layoutList>"
-----------
<layout>
<configItem>
<name>us-de</name> <!-- 1) -->
<shortDescription>US-DE</shortDescription> <!-- 2) -->
<description>ASCII with german</description> <!-- 3) -->
<languageList><iso639Id>eng</iso639Id></languageList> <!-- 4) -->
</configItem>
</layout>
-----------
<!-- 1) --> "us-de" is the filename of the new keyboard layout in X11/xkb/symbols
<!-- 2) --> "US-DE" this will appear eg. in the indicator applet
<!-- 3) --> "ASCII with german" must coincide with the text at the begin of your file:
name[Group1]= "ASCII with german";
This text will also appear as comment under "Layouts"
<!-- 4) --> if you choose "eng" your layout will be shown in
System->Preferences->Keyboard->tab Layouts->Add->By Language->English
under "Variants"
4) log out and log in again, and check
System->Preferences->Keyboard->tab Layouts->Add->By Language->English
if you can find your custom layout, happy! You are ready to go!
Select your first and second layou here. Add a keyboard switcher applet
here under "options" you can also disable the CapsLock key.
5) the default keyboard will annoy you and sometime reappear...
If you like to get rid of this, edit
/var/cache/gdm/$USER/dmrc
and place one of the existing layout as your new default:
[Desktop]
Language=en_US.utf8
Layout=us-de
then reboot..
I post this, as it is easy, but difficult to find out, and perhaps
to make somebody happy...
Feedback and hints to improve are welcome!
