Some keys are invalid on emacs when using German keyboard

emacskdekeyboard

When I am using emacs 23.3 on KDE, I can not input ^, ´ and ~ from my German keyboard. If I press these keys, then emacs says that <dead-circumflex>, <dead-acute> and <dead-tilde> are undefined.

I can input ^, ´ and ~ on other applications (e.g. Konsole, Kwrite and firefox), and I can also paste these letters on emacs.

I have tried to type C-x ret C-\ latin-1-postfix, but there is no change.

Could anyone tell me how to solve this problem?

Best Answer

I don't know what's causing this problem or how to fix this, but I can offer a workaround for most purposes.

Normally, dead keys are processed at a very low input layer, not even visible from Lisp. But you can do the processing in Lisp.

If you want the keys to act as dead keys:

There is already a limited mechanism for dead keys in Lisp, designed for 8-bit character sets on machines that don't have any way to input non-ASCII characters. If you type C-x 8 followed by an accent and a letter, the corresponding accented letter is inserted, thanks to the iso-transl library. We can copy this mechanism. Put this in your .emacs:

(define-key key-translation-map [dead-grave] (lookup-key key-translation-map "\C-x8`"))
(define-key key-translation-map [dead-acute] (lookup-key key-translation-map "\C-x8'"))
(define-key key-translation-map [dead-circumflex] (lookup-key key-translation-map "\C-x8^"))
(define-key key-translation-map [dead-diaeresis] (lookup-key key-translation-map "\C-x8\""))
(define-key key-translation-map [dead-tilde] (lookup-key key-translation-map "\C-x8~"))
(define-key isearch-mode-map [dead-grave] nil)
(define-key isearch-mode-map [dead-acute] nil)
(define-key isearch-mode-map [dead-circumflex] nil)
(define-key isearch-mode-map [dead-diaeresis] nil)
(define-key isearch-mode-map [dead-tilde] nil)

The map key-translation-map rewrites key sequences as they are entered, so this will make dead ` a equivalent to à for most purposes. Explicitly setting entries in isearch-mode-map to nil is necessary because otherwise pressing a dead key would exit isearch before the translation could kick in.

If you want the accent characters to be inserted immediately

(define-key key-translation-map [dead-grave] "`")
(define-key key-translation-map [dead-acute] "'")
(define-key key-translation-map [dead-circumflex] "^")
(define-key key-translation-map [dead-diaeresis] "\"")
(define-key key-translation-map [dead-tilde] "~")

Related Solutions

Use M-C, M-V, M-A for Copy, Paste, Select All

The Linux kernel generates a code each time a key is pressed on a keyboard. That code is compared to a table of keycodes defining a figure that is then displayed.

This process is complicated by Xorg, which starts its own table of keycodes. Each keycode can belong to a keysym. A keysym is like a function, started by typing a key. Xmodmap allows you to edit these keycode-keysym relations.

To get the current keymap table using Xmodmap use:

xmodmap -pke

This will print out the full table in the following format:

keycode <keycode#> = <boundkey> <boundkey>

Before moving anything around be sure to backup the original keycode layout using xmodmap -pke >> $HOME/Xmodmap.orig This will place the file Xmodmap.orig in your users home directory.

Tip: There are also some predefined keycodes (e.g. XF86AudioMute, XF86Mail). Those keycodes can be found in: /usr/include/X11/XF86keysym.h

You can also also edit the keys: Shift, Ctrl, Alt and Super (there always exists a left and a right one (Alt_R=AltGr)).

Here's a quick example of how your configuration would look if you wanted to swap CTRL and Super (Windows Key):

keycode 255  =
!add Shift   = Shift_L Shift_R
!add Lock    = Caps_Lock
add Control  = Super_L Super_R
!add Mod1    = Alt_L Alt_R
!add Mod2    = Mode_switch
!add Mod3    =
add Mod4     = Control_L Control_R
!add Mod5    =

(the ! is used to comment / ignore the line. in this example only Super and Control keys get adjusted)

This configuration would be saved in $HOME/.Xmodmap and loaded with

xmodmap ~/.Xmodmap

You could also start this with xwindows by adding it to your ~/.xinitrc

And if things get hairy you can always revert back to Xmodmap.org.

Any bindings for applications that rely on these keys would also be moved. So make sure that everything remains bound so you don't lose any functionality. It's a tug-of-war match.

Compose Key Issues – Some Apps Don’t Accept Characters from Compose Key

Thanks to @Gilles, I found an answer. So, the problem was with different Input Methods, used by different applications; and IMs in turn use different Compose files — ones used by X are /usr/share/X11/locale/<your-locale>/Compose and ~/.XCompose (the last isn't present by default, but you may create it for custom combinations), and the one used by Qt is in… Well, looks like nobody knows.

The solution is to set xim to be used as default input method by all applications. You can call im-config, and choose there xim as the default input method, or you can manually edit /etc/profile file to add these lines:

export GTK_IM_MODULE=xim
export XMODIFIERS=@im=xim
export QT_IM_MODULE=xim

Not sure about im-config, but for the way with /etc/profile reboot will be needed.