Best way to use Caps Lock as a custom modifier

[sapphire-bt]

Monterey 12.2.1
Karabiner-Elements 14.4.0

I'm trying to achieve the following mapping using "Complex modifications":

• caps_lock + w = Up
• caps_lock + a = Left
• caps_lock + s = Down
• caps_lock + d = Right

My karabiner.json for the a key looks like the following:

[
    {
        "from": {
            "key_code": "a",
            "modifiers": {
                "mandatory": [
                    "caps_lock"
                ],
                "optional": [
                    "any"
                ]
            }
        },
        "to": [
            {
                "key_code": "left_arrow"
            }
        ],
        "type": "basic"
    }
]

If, for example, I'm using a text editor, when I press caps_lock + a it moves the text insertion point to the left - so far so good. Unfortunately, the caps lock key is now active (the LED is on) and pressing caps_lock + a just sends a rather than moving left.

I tried experimenting with the "simultaneous" option but then I found I was unable to keep caps lock held down while pressing a multiple times (to move left several characters).

It feels like I'm close but I'm not sure which combination of options/conditions/etc. is best for what I'm trying to achieve.

Any help would be much appreciated.

Thanks for all the hard work 👍

[MuhammedZakir]

That seems like a bug to me.

You can do this in a different way:

1. When caps_lock is pressed, set a variable, and unset it when caps_lock is released.
2. Remap w/a/s/d to corresponing keys when that variable is set.
   • You will have to add caps_lock to from.modifiers.optional for these manipulators. Otherwise, it won't work when caps lock is on.

References:

• https://karabiner-elements.pqrs.org/docs/json/complex-modifications-manipulator-definition/to/set-variable/
• https://karabiner-elements.pqrs.org/docs/json/complex-modifications-manipulator-definition/to-after-key-up/
• https://karabiner-elements.pqrs.org/docs/json/complex-modifications-manipulator-definition/conditions/variable/
• e.g. https://karabiner-elements.pqrs.org/docs/json/typical-complex-modifications-examples/#change-right_shift-x2-to-mission_control

[sapphire-bt]

Thank you for the quick response @MuhammedZakir! This is very very close to the solution I'm after.

Do you know if it's possible to disable the default behaviour of the caps lock key without actually disabling the key?

The only issue now is that after I've used caps_lock + w/a/s/d, the caps lock key is active and I accidentally type in all caps (unless I've pressed caps lock an even number of times which turns it back off).

[MuhammedZakir]

You're welcome! :-)

Do you know if it's possible to disable the default behaviour of the caps lock key without actually disabling the key?

You can do that by not sending caps_lock in to event; only set the variable. Additionally, if you use to_if_alone[1], you can get caps lock's normal behavior when pressed alone, and use it as a custom modifier otherwise.

[1] https://karabiner-elements.pqrs.org/docs/json/complex-modifications-manipulator-definition/to-if-alone/

[sapphire-bt]

Brilliant - it's now working perfectly; thanks again for your help.

Just in case it helps anyone else, my final config JSON was:

{
    "description": "Caps Lock WASD",
    "manipulators": [
        {
            "from": {
                "key_code": "caps_lock",
                "modifiers": {
                    "optional": [
                        "any"
                    ]
                }
            },
            "to": [
                {
                    "set_variable": {
                        "name": "caps_lock pressed",
                        "value": 1
                    }
                }
            ],
            "to_after_key_up": [
                {
                    "set_variable": {
                        "name": "caps_lock pressed",
                        "value": 0
                    }
                }
            ],
            "to_if_alone": [
                {
                    "key_code": "caps_lock"
                }
            ],
            "type": "basic"
        },
        {
            "conditions": [
                {
                    "name": "caps_lock pressed",
                    "type": "variable_if",
                    "value": 1
                }
            ],
            "from": {
                "key_code": "a",
                "modifiers": {
                    "optional": [
                        "any"
                    ]
                }
            },
            "to": [
                {
                    "key_code": "left_arrow"
                }
            ],
            "type": "basic"
        },
        {
            "conditions": [
                {
                    "name": "caps_lock pressed",
                    "type": "variable_if",
                    "value": 1
                }
            ],
            "from": {
                "key_code": "s",
                "modifiers": {
                    "optional": [
                        "any"
                    ]
                }
            },
            "to": [
                {
                    "key_code": "down_arrow"
                }
            ],
            "type": "basic"
        },
        {
            "conditions": [
                {
                    "name": "caps_lock pressed",
                    "type": "variable_if",
                    "value": 1
                }
            ],
            "from": {
                "key_code": "w",
                "modifiers": {
                    "optional": [
                        "any"
                    ]
                }
            },
            "to": [
                {
                    "key_code": "up_arrow"
                }
            ],
            "type": "basic"
        },
        {
            "conditions": [
                {
                    "name": "caps_lock pressed",
                    "type": "variable_if",
                    "value": 1
                }
            ],
            "from": {
                "key_code": "d",
                "modifiers": {
                    "optional": [
                        "any"
                    ]
                }
            },
            "to": [
                {
                    "key_code": "right_arrow"
                }
            ],
            "type": "basic"
        }
    ]
}

[teplo1337]

if u don't wan't caps_lock modify this

  "to_if_alone": [
                {
                    "key_code": "vk_none"
                }
            ],

[joosep10]

It helped me. I mapped this to vim movement keys. Thanks a lot!

[bitxeno]

Thank you for the configuration. If caps_lock Lock alone does not work, need to add hold_down_milliseconds.

"to_if_alone": [
                {
                    "key_code": "caps_lock",
                    "hold_down_milliseconds": 200
                }
            ]

[VojtechVitek]

I've set up Caps Lock to modify j/i/k/l as my arrows this way:

{
  "description": "Capslock Arrows (j k l i → arrow keys, u → backspace, o → delete forward)",
  "manipulators": [
    {
      "type": "basic",
      "from": { "key_code": "j", "modifiers": { "mandatory": ["caps_lock"], "optional": ["any"] } },
      "to": [{ "key_code": "left_arrow", "modifiers": ["caps_lock"] }]
    },
    {
      "type": "basic",
      "from": { "key_code": "k", "modifiers": { "mandatory": ["caps_lock"], "optional": ["any"] } },
      "to": [{ "key_code": "down_arrow", "modifiers": ["caps_lock"] }]
    },
    {
      "type": "basic",
      "from": { "key_code": "l", "modifiers": { "mandatory": ["caps_lock"], "optional": ["any"] } },
      "to": [{ "key_code": "right_arrow", "modifiers": ["caps_lock"] }]
    },
    {
      "type": "basic",
      "from": { "key_code": "i", "modifiers": { "mandatory": ["caps_lock"], "optional": ["any"] } },
      "to": [{ "key_code": "up_arrow", "modifiers": ["caps_lock"] }]
    },
    {
      "type": "basic",
      "from": { "key_code": "u", "modifiers": { "mandatory": ["caps_lock"], "optional": ["any"] } },
      "to": [{ "key_code": "delete_or_backspace", "modifiers": ["caps_lock"] }]
    },
    {
      "type": "basic",
      "from": { "key_code": "o", "modifiers": { "mandatory": ["caps_lock"], "optional": ["any"] } },
      "to": [{ "key_code": "delete_forward", "modifiers": ["caps_lock"] }]
    }
  ]
}

[3zra47]

Does anyone know how to set it up so that if I press the caps lock key, then while the caps lock key's green button is on whenever I press the return key it functions as if I'm pressing the shift and return key at the same time (I want this to only function in the obsidian app)? I don't know how to code.