Help: Prompt Segment Update

[mayurankv]

I'm trying to integrate Kanata (a keyboard remapping software) with poweerlevel10k via the prompt. I'd like it to indicate which layer Kanata is in at a given moment. I was able to get a prompt section working fine with the following code:

zmodload zsh/net/tcp

typeset -gA unicode_map=(
	qwerty 'QWE'
	colemak 'COL'
	dvorak 'DVO'
	layers $'\ueea8'
	numpad '123'
	symbols 'SYMB'
	delimiters '()'
)
default_value=$'\uf12a'

# function redraw_prompt() {
# 	local f
# 	for f in chpwd "${chpwd_functions[@]}" precmd "${precmd_functions[@]}"; do
# 		[[ "${+functions[$f]}" == 0 ]] || "$f" &>/dev/null || true
# 	done
# 	p10k display -r
# }

function prompt_my_kanata() {
ztcp 127.0.0.1 ${MYKANATAPORT-5829} &> /dev/null
if [[ -n "${REPLY:-}" ]]; then
	read -r line <&$REPLY
	if [[ "$line" =~ \{\"LayerChange\":\{\"new\":\"([^\"]+)\"\}\} ]]; then
		layer="${match[1]}"
		icon=${unicode_map[$layer]:-$default_value}
		p10k segment -c "$layer" -s "$layer" -i '' -f blue -t "$icon"
	fi
	exec {REPLY}<&-
fi
}

This works fine, but doesn't update (refers/redraw) the prompt when kanata changes a layer (via keybinding or TCP server or whatever). I've looked at issue #2048 but that appears to be related to zle widget behaviour a la #72. This made me think I need some sort of asynchronous update similar to #609.

My attempt is as follows:

#!/usr/bin/env zsh

zmodload zsh/net/tcp

typeset -gA unicode_map=(
	qwerty 'QWE'
	colemak 'COL'
	dvorak 'DVO'
	layers $'\ueea8'
	numpad '123'
	symbols 'SYMB'
	delimiters '()'
)
typeset -g MY_P10K_KANATA_LAYER=""


function check_kanata_layer() {
	ztcp 127.0.0.1 ${MYKANATAPORT-5829} &> /dev/null
	if [[ -n "${REPLY:-}" ]]; then
		read -r line <&$REPLY
		if [[ "$line" =~ \{\"LayerChange\":\{\"new\":\"([^\"]+)\"\}\} ]]; then
			MY_P10K_KANATA_LAYER="${match[1]}"
		fi
		exec {REPLY}<&-
	fi
}

function my_p10k_refresh() {
	zle reset-prompt
	zle -R
}

async_init
async_start_worker kanata_layer -n
async_register_callback kanata_layer my_p10k_refresh

function prompt_my_kanata() {
	local default_value=$'\uf12a'
	# (( $+commands[docker-compose] )) || return
	async_job kanata_layer check_kanata_layer
	local layer="$MY_P10K_KANATA_LAYER"
	local icon=${unicode_map[$MY_P10K_KANATA_LAYER]:-$default_value}
	p10k segment -e -c "$MY_P10K_KANATA_LAYER" -s "$MY_P10K_KANATA_LAYER" -i '' -f blue -t "$icon"
}

However, this script (sourced before p10k) doesn't work, it only shows up in the prompt when I manually run check_kanata_layer in the shell. It then doesn't update when new prompts are spawned even if the layer changes, and then needs check_kanata_layer to be run again to update.

One more concern I had is that the use case described in #609 seems to be for a function with large overhead being updated after the prompt is initially rendered, whereas, I want to almost have a constantly running listener that refreshes the prompt every time it receives a certain message - potentially multiple times between shell entry. Hence I'm not sure this is even the right approach.

It's been a while since I did any zsh scripting and I'm by no means proficient at it so I'd really appreciate any help with this!

EDIT: For reference, I have added my_kanata to the right prompt environment variable in my p10k config.