.dotfiles/helpers/multiselect.sh

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2020-11-08 21:55:05 +01:00
#!/bin/bash
# from SO: https://stackoverflow.com/a/54261882/317605 (by https://stackoverflow.com/users/8207842/dols3m)
function multiselect() {
# little helpers for terminal print control and key input
ESC=$(printf "\033")
cursor_blink_on() { printf "$ESC[?25h"; }
cursor_blink_off() { printf "$ESC[?25l"; }
cursor_to() { printf "$ESC[$1;${2:-1}H"; }
print_inactive() { printf "$2 $1 "; }
print_active() { printf "$2 $ESC[7m $1 $ESC[27m"; }
get_cursor_row() {
IFS=';' read -sdR -p $'\E[6n' ROW COL
echo ${ROW#*[}
}
key_input() {
local key
IFS= read -rsn1 key 2>/dev/null >&2
if [[ $key = "" ]]; then echo enter; fi
if [[ $key = $'\x20' ]]; then echo space; fi
if [[ $key = $'\x1b' ]]; then
read -rsn2 key
if [[ $key = [A ]]; then echo up; fi
if [[ $key = [B ]]; then echo down; fi
fi
}
toggle_option() {
local arr_name=$1
eval "local arr=(\"\${${arr_name}[@]}\")"
local option=$2
if [[ ${arr[option]} == true ]]; then
arr[option]=
else
arr[option]=true
fi
eval $arr_name='("${arr[@]}")'
}
local retval=$1
local options
local defaults
IFS=';' read -r -a options <<<"$2"
if [[ -z $3 ]]; then
defaults=()
else
IFS=';' read -r -a defaults <<<"$3"
fi
local selected=()
for ((i = 0; i < ${#options[@]}; i++)); do
selected+=("${defaults[i]:-false}")
printf "\n"
done
# determine current screen position for overwriting the options
local lastrow=$(get_cursor_row)
local startrow=$(($lastrow - ${#options[@]}))
# ensure cursor and input echoing back on upon a ctrl+c during read -s
trap "cursor_blink_on; stty echo; printf '\n'; exit" 2
cursor_blink_off
local active=0
while true; do
# print options by overwriting the last lines
local idx=0
for option in "${options[@]}"; do
local prefix=" [ ]"
if [[ ${selected[idx]} == true ]]; then
prefix=" [x]"
fi
cursor_to $(($startrow + $idx))
if [ $idx -eq $active ]; then
print_active "$option" "$prefix"
else
print_inactive "$option" "$prefix"
fi
((idx++))
done
# user key control
case $(key_input) in
space) toggle_option selected $active ;;
enter) break ;;
up)
((active--))
if [ $active -lt 0 ]; then active=$((${#options[@]} - 1)); fi
;;
down)
((active++))
if [ $active -ge ${#options[@]} ]; then active=0; fi
;;
esac
done
# cursor position back to normal
cursor_to $lastrow
printf "\n"
cursor_blink_on
eval $retval='("${selected[@]}")'
}
[[ "${1}" != "--source-only" ]] && multiselect "${@}"