Compose indicator LED not supported
Coming from xkeyboard-config/xkeyboard-config#204 (comment 460261), I would like to get a LED indicator that Compose mode is active working, if possible. The Kana and Compose indicators are supposedly supported by keyboards running QMK, among others.
Now, I tried running hid-recorder
but it really only showed the key press and release of Caps Lock (since I am setting setxkbmap -option compose:caps
). When I disabled the Compose with setxkbmap -option
the hid-recorder
output did not change (except for timestamps). I saw some SET_REPORT
USB HID packets in Wireshark (also when pressing Scroll Lock after enabling it with xmodmap -e "add mod3 = Scroll_Lock"
), which I presume actually control the LED status.
According to HID Usage Tables FOR Universal Serial Bus (USB), Version 1.3, the AT-101 code for Compose is 127. That matches what libinput has but apparently, the key is officially named “Keyboard Left GUI” and doubles as Windows key. When I use its Usage ID as per HID 0xE3
in QMK, hid-recorder
in fact reports it as a modifier:
# LeftControl: 0 | LeftShift: 0 | LeftAlt: 0 | Left GUI: 1 | RightControl: 0 | RightShift: 0 | RightAlt: 0 | Right GUI: 0 | # |Keyboard ['0x70000', '0x70000', '0x70000', '0x70000', '0x70000', '0x70000']
E: 000003.433255 8 08 00 00 00 00 00 00 00
And it appears to the system as Super key so I am not really sure creating a key that will be recognized as Compose is possible.
And either way, it will likely require cooperation with input method, as unlike the “Locks”, the Compose mode ends when a typed Compose sequence does (or invalid sequence is entered).
Not even sure if the Compose indicator is worth it, as it would most likely be only useful in TTY – modern desktops already visually indicate it next to cursor.