How to make ISO_Level5_Shift work

xkb

I wanted to add more levels to my keyboard layouts, so I decided to enable level5 key. I’ve already had level3 on Menu, and would like to map RAlt to ISO_Level5_Shift.

However, setxkbmap has no option for that. /usr/share/X11/xkb/rules/evdev.lst contains only the following options in regard to lv5 switch:

lv5:lsgt_switch_lock
lv5:ralt_switch_lock
lv5:lwin_switch_lock
lv5:rwin_switch_lock

As if mapping a simple key is not possible. This already hinted on troubles.
Knowing what setxkbmap does internally, it’s easy to construct an option to enable lv5 switch and set to right Alt:

-option "lv5:ralt_switch"

And, despite that setxkbmap takes this option and returns with success, there’s no mapping.

After finding an answer to a similar question here I’ve constructed a custom xkbcomp file.

xkb_keymap {

    xkb_geometry {
        include "pc(pc104)"
    };


    xkb_keycodes {
        include "evdev"
        include "aliases(qwerty)"
    };


    xkb_types {
        include "complete"
    };


    xkb_compatibility {
        include "complete"
        include "ledscroll(group_lock)"
    };


    xkb_symbols {
        include "pc+us+ru:2+inet(evdev)"
        include "group(rctrl_rshift_toggle)"
        include "ctrl(swapcaps)"
        include "keypad(oss)"
        include "kpdl(dot)"
        include "terminate(ctrl_alt_bksp)"
        include "level3(modifier_mapping)"
        include "level3(menu_switch)"
        include "level5(modifier_mapping)"
        include "level5(ralt_switch)"

        key <AB06> {
            type= "EIGHT_LEVEL",
            symbols[Group1]= [               n,               N, n, n, u, i, o, p ],
            symbols[Group2]= [     Cyrillic_te,     Cyrillic_TE, n, n, u, i, o, p ]
        };

    };


};

This should assign Menu key to be ISO_Level3_Shift and RAlt to be ISO_Level5_Shift. And the keys are assigned, but there is an error:

$ xkbcomp  ~/new.xkbcomp.xkb :0
Error:            Key <MDSW> added to map for multiple modifiers
                  Using Mod3, ignoring Mod5.

xkbcomp returns with code 0, despite that there was an error.

The mapping on key N should have made levels 5 to 8 “u”, “i”, “o” and “p”, but instead RAlt sends the usual n and N on all eight levels (if levels >4 actually work).

In attempt to determine, how to solve this error, I’ve found, that <MDSW> is set in… the very rules file for “pc”.

/usr/share/X11/xkb/symbols/pc:

xkb_symbols "pc105" {
    …
    // Fake keys for virtual<->real modifiers mapping:
    key <LVL3> {    [ ISO_Level3_Shift  ]   };
    key <MDSW> {    [ Mode_switch       ]   };
    modifier_map Mod5   { <LVL3>, <MDSW> };
    …
};

And here is another weird thing: I include pc104 keyboard model, but this code refers to pc105 and shouldn’t be sourced at all. However… xkb_symbols "pc104" is nowhere to be found. And this “symbols/pc” file is the only other file in /usr/share/X11/xkb/ that sets or modifies <MDSW> assignment to Mod* keys. The other file being “symbols/level5” file, which does it in xkb_symbols "modifier_mapping".

// Ensure a mapping to a real modifier for LevelFive.
partial modifier_keys
xkb_symbols "modifier_mapping" {
  replace key <MDSW> {
    type[Group1] = "ONE_LEVEL",
    symbols[Group1] = [ ISO_Level5_Shift ]
  };
  modifier_map Mod3 { <MDSW> };
};

I think, that this conflict may prevent both lv3 switch and lv5 switch to work at the same time, but I’m not sure. It’s concerning, that in another answer, Mode_switch key is present among Mod* keys, and after loading my new.xkbcomp.xkb I don’t see it anywhere:

$  xmodmap -pm
xmodmap:  up to 4 keys per modifier, (keycodes in parentheses):

shift       Shift_L (0x32),  Shift_R (0x3e)
lock        Caps_Lock (0x25)
control     Control_L (0x42),  Control_R (0x69)
mod1        Alt_L (0x40),  Meta_L (0xcd)
mod2        Num_Lock (0x4d)
mod3        ISO_Level5_Shift (0xcb)
mod4        Super_L (0x85),  Super_R (0x86),  Super_L (0xce),  Hyper_L (0xcf)
mod5        ISO_Level3_Shift (0x5c)

Best Answer

Here is my working solution for putting ISO_Level5_Shift on Control_R. You would need to apply the same logic.

Run xev to find the keycode of the key you want to associate with ISO_Level5_Shift. Move the mouse cursor over the little scare in the window, press a key to see its keycode in the output. In my case the code was 105.
Second, I ran xmodmap. I saw that Control_R was associated with mod4.
So I did xmodmap -e "clear mod4 to free the key. Note that it frees all keys so you may need to associate the other keys back if you need them.
Then xmodmap -e "keycode 105 = ISO_Level5_Shift" to associate Control_R with the modifier.
And finally, xmodmap -e "add mod3 = ISO_Level5_Shift" to enable level 5.

Related Solutions

AltGr Keys – How to Make AltGr+i,j,k,l Work Properly as Cursor Keys

The problem is that when you use a common modifier like AltGr, programs actually see it as being pressed when you use the AltGr arrows. So Shift + AltGr + i actually appears to a program as if you are pressing Shift + Alt + Up and it's the addition of the extra Alt that confuses the program. You can avoid this by either adding more shortcuts to the program if possible, so Shift + Alt + Up does the same action as Shift + Up, or you can use an uncommon modifier that the program is not aware of.

There are other ways of doing this, but this was one of the simpler ways and works well for me. It creates a "Group2" overlay on the alphanumeric keys, such that when you switch to Group2 you will have arrows there instead of letters. You can switch to Group2 with a toggle (on/off like Caps Lock normally works) or a momentary (press to activate, like Shift normally works)

partial alphanumeric_keys
xkb_symbols "alpha_arrows" {
    key <AD07> {
        symbols[Group2]= [            Home ]  # u
    };
    key <AD08> {
        symbols[Group2]= [              Up ]  # i
    };
    key <AD09> {
        symbols[Group2]= [             End ]  # o
    };
    key <AD10> {
        symbols[Group2]= [           Prior ]  # p
    };
    key <AC07> {
        symbols[Group2]= [            Left ]  # j
    };
    key <AC08> {
        symbols[Group2]= [            Down ]  # k
    };
    key <AC09> {
        symbols[Group2]= [           Right ]  # l
    };
    key <AC10> {
        symbols[Group2]= [            Next ]  # ;
    };
    key <AB06> {
        symbols[Group2]= [          Delete ]  # n
    };
};

You can then pick a key to use as a Group2 activation key. You can see all the options (if you don't want to roll your own) with this:

$ grep grp /usr/share/X11/xkb/rules/base.lst

Then pick an option, for example this one activates the arrows only while Caps Lock is being held. It also adds a new combination Alt + Caps Lock to actually switch caps lock on and off:

$ setxkbmap -option grp:caps_switch

You can add this into your Xorg config file to make the change permanent - there are plenty of guides online about how to do this.

Note that:

key is used, as opposed to replace key because we want to add to the existing definition, not replace it.
If you actually have an alternate keyboard layout (possibly some international keyboards that can also type Latin/English letters), this method may not work for you. You will have to define a new type based on ALPHANUMERIC with extended modifiers (e.g. Hyper) to activate the arrow keys.

Use xkb to make shift insert parenthesis

One way is to use xcape.

xcape [-d] [-t timeout] [-e map-expression]

This should do the trick:

xcape -e 'Shift_L=parenleft;Shift_R=parenright'

xcape is included as a package for some distributions.

Notes:

It has a default delay of 500ms after which the mapped key will not be emitted. It can be set by the -t option.

Each map-expression run as a daemon and has it's own PID.

Best Answer

Related Solutions

AltGr Keys – How to Make AltGr+i,j,k,l Work Properly as Cursor Keys

Use xkb to make shift insert parenthesis

Notes:

Related Question