Using the Numlock key as an equals key with XKB

Question

The Numlock key sees little action in today's day and age, yet it's location in the (standard) keyboard layout is quite prominent.

Since I use a lot of spreadsheets, using the keypad for data entry is very convenient, with one caveat: the equal sign is quite hard to reach, when your right hand is on the keypad.

My idea was to re-map Numlock, such that it can act as both, Numlock and equals, with the former accessible through a modifier.

For this purpose I decided to make my own xkb keymap, as I tried the same thing with xmodmap but I had similarly bad results.

(file name is pb)

default partial alphanumeric_keys
xkb_symbols "basic" {
    
    name[Group1] = "PB (US intl with level 3 and level 5";
    key.type[Group1] = "EIGHT_LEVEL";

    include "us(altgr-intl)"

    //              (norm)     NLOCK     AltGr
    key.type[Group1] = "FOUR_LEVEL_MIXED_KEYPAD";
    key <NMLK> { [ KP_Equal, KP_Equal,  Num_Lock, Q ] };

    include "level3(ralt_switch)"
    include "level5(rctrl_switch)"
};

Now, as you can see, I added level 3 and level 5, when I want to expand my custom layout later, but I tested withou it, and it doesn't interfere with Numlock.

The behavior resulting from this is as follows when pressing the Numlock key:

(numlock is off)

• Numlock: '='
• Shift + Numlock: '='
• AltGr + Numlock: (switches Num lock on)
• AltGr + Shift + Numlock: 'Q' (I added this for testing)

This is alright, printing 'Q' when holding down AltGr and Shift was just to see if I can reach that shift level. However when Num lock is on, the behavior not satisfactory at all:

(numlock is on)

• Numlock: (switches Num lock off)
• Shift + Numlock: (switches Num lock off)
• AltGr + Numlock: (switches Num lock off)
• AltGr + Shift + Numlock: (switches Num lock off)

It seems to be impossible to make Num lock behave like a KP_Equal key, no matter what I try.

Originally, I wanted pressing Numlock to print an equal sign, and when holding Shift, to operate Num Lock on and off. Since that didn't seem to be possible, I opted for ISO level 3 (AltGr), but that doesn't seem to work either. What I want is that Numlock prints an equal sign no matter if Num lock is on or off, and switch Num Lock when holding down a mod key (which one, isn't really important to me, preferably Shift or AltGr).

Answer 1

So. If you look at the ouput of `xev', take attention to the state,

• If yo keep the keysym Num_Lock on this key, you will see a state of 10 even when pressing the key for the keysym KP_equal , without being locked. And because of it, when you are locked, pressing KP_Equal will unlock you.
• Now you want to get rid of Num_Lock on this key so it will not generate this pesky state, while still locking on the appropriate layer, it is done like this :

replace key <NMLK> {
type[Group1]= "FOUR_LEVEL_MIXED_KEYPAD",
symbols[Group1]= [ KP_Equal, KP_Equal,  Num_Lock, Q ],
actions[Group1]= [ NoAction(), NoAction(), 
                   LockMods(modifiers=NumLock), NoAction()
};

Take care of the absence of underscore, otherwise it will not work.

• Now you can verify the state; it should be ok in any case, but oviously this state doesn't mean anything anymore since you have deleted the Num_Lock keysym from your map. So you need to find a spare keycode you do not use, and assign him the Num_Lock keysym. In this example, I'll take the keycode 249

replace key <I249> { symbols[Group1]= [ Num_Lock ] };

Now it should correctly work :)