How to Map a Key to a key+modifier and then use the mapped value as part of a keyboard shortcut?

[karmeye]

Note

Cross posting my post at Ask Different

I have a Swedish keyboard (with such a layout). Now there are many default keyboard shortcuts in macOS and apps that aren't possible on a Swedish layout because the second key press requires modifier keys, for example, command + [. Here, the open square bracket [, for example, is a character that on a Swedish keyboard require the option key to access and therefore it's not possible to use the shortcut command + [. This problem exists for other symbols as well.

So instead of remapping all predefined shortcuts (and because I sometimes switch to a US keyboard on Windows), I'd like to define specific keys that maps to (in this case [), so that I can use that key in combination with other keys to trigger the default shortcuts (in this case command + [). For example, mapping right_command to [ to be able to combine command + right_command to trigger the command + [ shortcut.

Using Karabiner-Elements, first thing to try is mapping a key to directly to the key code open_bracket:

{
  "manipulators": [
    {
      "from": {
        "key_code": "right_command",
        "modifiers": { "optional": ["any"] }
      },
      "to": [{ "key_code": "open_bracket" }],
      "type": "basic"
    }
  ]
}

This doesn't work as it just maps to that position on the Swedish keyboard, which is å.

If I simulate the key combination that results in a [ , which is opt + 8, it does work:

{
  "manipulators": [
    {
      "from": {
        "key_code": "right_command",
        "modifiers": { "optional": ["any"] }
      },
      "to": [
        {
          "key_code": "8",
          "modifiers": "left_option"
        }
      ],
      "type": "basic"
    }
  ]
}

However, using this to trigger a shortcut like the one mentioned above doesn't work. This is probably because two key presses are simulated. Karabiner-EventViewer outputs the following when pressing right_command:

[
  {
    "type": "down",
    "name": {"key_code":"left_option"},
    "usagePage": "7 (0x0007)",
    "usage": "226 (0x00e2)",
    "misc": "flags left_option"
  },
  {
    "type": "down",
    "name": {"key_code":"8"},
    "usagePage": "7 (0x0007)",
    "usage": "37 (0x0025)",
    "misc": "flags left_option"
  }
]

And with the modifer key to trigger command + [:

[
  {
    "type": "down",
    "name": {"key_code":"left_command"},
    "usagePage": "7 (0x0007)",
    "usage": "227 (0x00e3)",
    "misc": "flags left_command"
  },
  {
    "type": "down",
    "name": {"key_code":"left_option"},
    "usagePage": "7 (0x0007)",
    "usage": "226 (0x00e2)",
    "misc": "flags left_command,left_option"
  },
  {
    "type": "down",
    "name": {"key_code":"8"},
    "usagePage": "7 (0x0007)",
    "usage": "37 (0x0025)",
    "misc": "flags left_command,left_option"
  }
]

Perhaps this is why the keyboard combination does not work, as the second key press would would cancel it.

So my question is

[Using the open bracket example] I wish to be able to map a key to [ (which otherwise would require a modify key) and then also be able to use it in keyboard shortcuts such as cmd + [.

Is there a way to remap a key to output [ and still use it in combination with modifiers for shortcuts, without triggering issues from simulated multiple key presses?

[peterjc]

I believe on a Swedish keyboard you must press option-8 to get "[", and shift-8 to get "("?

Therefore I would try to bind command-option-8 (three keys at once) to the desired output.