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

[karmeye]

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"
    }
  ]
}

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.

[karmeye]

Yes, option-8 to get "[". I assume you mean like this?

{
    "from": {
        "key_code": "open_bracket",
        "modifiers": {
            "mandatory": ["left_command"],
            "optional": ["any"]
        }
    },
    "to": [
        {
            "key_code": "8",
            "modifiers": ["left_command", "left_option"]
        }
    ],
    "type": "basic"
}

That's interesting. This is a rule specifically for handling the Cmd+[ shourtcut. I didn't think about that. My approach was to designate a key to be mapped to [ and so I could use that key in all shortcuts featuring [, e.g., Ctrl+[, Shift+Opt+[, etc.

Your reply got me digging a bit more and I found that they both work: you just have to make sure that the shortcut is still Cmd+[ when the input source has changed to Swedish. For example, Safari's History > Back is Cmd+[ when input source is US, but is Cmd+ö, when input source is Swedish. If I override this by going to System Settings > Keyboard > Keyboard Shortcuts and --- with the input source set to US --- assign Cmd+[ to Back in Safari. Then, when switching back to Swedish, both these above rules work.

The problem seems to be with Electron apps, probably because they usually have a Command Palette, where each command can be associated with a shortcut and this command is not necessarily in the menu bar.