i3lock-wrapper

#!/bin/bash

# Copyright (c) 2013-2020 Artem Shinkarov <artyom.shinkaroff@gmail.com>
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

set -e

script_name=$(basename $0)
params=$(getopt \
         -o vnbup:eflh \
         -l version,nofork,beep,no-unlock-indicator,pointer:,ignore-empty-password,show-failed-attempts,logo,help \
         -n "$script_name" -- "$@")
eval set -- "$params"
# exit on bad arguments
if [ $? -ne 0 ]; then
    exit 1
fi

usage () {
    cat <<EOF
A wrapper around i3lock that sets a blurred screenshot
as a background image for the screen saver.

Usage: $script_name [options]

    -v, --version                 version of the i3lock.
    -n, --nofork                  don't fork i3lock after start.
    -b, --beep                    enable beeping.
    -u, --no-unlock-indicator     disable the unlock indicator.
    -p win|default,
    --pointer=win|default         do not hide the mouse pointer on default
                                  or the current position of the mouse pointer.
    -e, --ignore-empty-password   when an empty password is provided by the user,
                                  do  not  validate  it.
    -f, --show-failed-attempts    Show the number of failed attempts, if any.
    -l, --logo                    superimpose the padlock logo

    Please note, that all the options except "-l" or "--logo" are being passed
    directly to i3lock.  See "man i3lock" for more details.
EOF
}

arg_test () {
    # Filter out arguments that are invalid
    while true; do
       case "$1" in
           -v|--version)
               i3lock -v
               exit
               ;;
           -n|--nofork)
               shift;;
           -b|--beep)
               shift;;
           -u|--no-unlock-indicator)
               shift;;
           -p|--pointer)
               shift
               case "$1" in
                   win|default)
                       shift;;
                   *)
                       echo "$script_name: invalid option \"$1\" for argument -p" >&2
                       exit 1
                       ;;
               esac
               ;;
           -e|--ignore-empty-password)
               shift;;
           -f|--show-failed-attempts)
               shift;;
           -l|--logo)
               use_logo=1
               shift;;
           -h|--help)
               usage
               exit
               ;;
           --)
               shift
               break ;;

           *)
               echo "$script_name: invalid argument \"$1\"" >&2
               exit 1
               ;;
       esac
    done

    if [ $# -ne 0 ]; then
       echo "$script_name: invalid arguments \"$@\""
       exit 1
    fi
}

# This is a gzipped i3lock-icon.svg converted into pdf with base64 applied
img_pdf_gz () {
    cat <<EOF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EOF
}

superimpose_padlock() {
    scale=.8
    lockimage=$(mktemp --tmpdir i3lock-logo-XXXXXXXXXX)
    img_pdf_gz | base64 -d | gunzip > "${lockimage}.pdf"
    height=$(identify -format "($scale * %H + .5)/1\n" "$file2" | bc)
    width=$(identify -format "scale=4; t=%W/%H; scale=0; (t * $height + .5)/1\n" "${lockimage}.pdf" | bc)
    convert -density 600 -background none -resize ${height}x${width} "${lockimage}.pdf" "${lockimage}.png"
    convert -compose Exclusion -composite -gravity center "$file2" "${lockimage}.png" "$file2"
    rm "${lockimage}" "${lockimage}.png" "${lockimage}.pdf"
}

function version_gt() { 
        test "$(printf '%s\n' "$@" | sort -V | head -n 1)" != "$1";\
}

use_logo=0
arg_test $@

file1=$(mktemp --tmpdir i3lock-wrapper-XXXXXXXXXX.png)
file2=$(mktemp --tmpdir i3lock-wrapper-XXXXXXXXXX.png)

# As noticed by #50, scrot >=1.0 requires -o flag to overwrite
# existing files.
if version_gt "$(scrot --version | cut -d' ' -f3)" "0.9"; then
        scrot -o -z -d0 "$file1"
else
        scrot -z -d0 "$file1"
fi

convert "$file1" -blur 0x3 "$file2"
rm "$file1" # Remove for security

if [ $use_logo -eq 1 ]; then
    superimpose_padlock
fi

cmd=()
for i in $@; do
    if [[ $i != '-l'  &&  $i != '--logo' && $i != '--' ]]; then
        cmd+="$i "
    fi
done

# drop the last "--" introduced by getopt
i3lock -i "$file2" ${cmd}

trap "rm '$file2'" EXIT