Use normal key as modifier

To use a normal key like Capslock as a modifier it needs to be declared in virtual_modifiers, which also means its normal behavior is suppressed. It must be filtered out, to make sure pressing Capslock-L only emits left.

virtual_modifiers:
  - Capslock

keymap:
  - remap:
      Capslock-H: left
      Capslock-J: down
      Capslock-K: up
      Capslock-L: right

Emit the virtual modifier

It's possible to emit Capslock from keymap, even though the physical press is filtered out. It just needs a new key combo, like Capslock-A:

virtual_modifiers:
  - Capslock

keymap:
  - remap:
      Capslock-A: Capslock

Restoring the normal function

It's possible emit an action (e.g. esc), when the virtual modifier is released alone (i.e. without being interrupted by another key):

modmap:
  - remap:
      Capslock:
        alone: esc
        held: Capslock

virtual_modifiers:
  - Capslock

keymap:
  - remap:
      Capslock-H: left
      # etc

Note:

• It can be troublesome when esc isn't emitted before it is released.
• Works for v0.15.0 See example prior to that

It's also possible to emit the virtual modifier key itself, but it's more complicated:

modmap:
  - remap:
      Capslock:
        # Emitted when physically released alone.
        alone: BTN_TRIGGER_HAPPY1
        held: Capslock

virtual_modifiers:
  - Capslock

keymap:
  - remap:
      # Turn the pseudo key into a real Capslock.
      BTN_TRIGGER_HAPPY1: Capslock
      Capslock-H: left
      # etc

Note: Works for v0.15.0 See example prior to that

Using a more normal key, like tab

Capslock is a little special. It doesn't have a repeat-action, and its action can be moved from press of capslock to release of capslock without loss of convenience.

tab is an example of a key with repeat-action, and its action can't be moved from press to release, without loss of convenience. Fx alt-tab will change window when tab is released, which is inconvenient. tab also becomes fragile when alt-tab is typed fast, because alt can be released before tab is released, which will look like tab, because it's alt:1 alt:0 tab:1 tab:0.

Repeating tab with key combo

It's possible to repeat tab, by emitting tab when pressing a combo, fx tab-q.

Repeating tab with double tap

experimental_map:
  - remap:
      tab:
        double: BTN_TRIGGER_HAPPY1

modmap:
  - remap:
      tab:
        alone: BTN_TRIGGER_HAPPY1
        held: tab

virtual_modifiers:
  - tab

keymap:
  - remap:
      BTN_TRIGGER_HAPPY1: tab
      tab-H: left

Note: Working since v0.14.18

Convenient alt-tab

Not currently possible in xremap, but is theoretically possible:

1. A timeout could emit a normal tab, so it functions normally, just after a timeout.
2. tab pressed when other keys are held, will make it function normally, not as virtual modifier. This way will alt-tab work completely normal, because alt is pressed before tab.