i3-lock-wrapper



    1 #!/usr/bin/env bash
    2 #
    3 # Performs a standard screen lock, with an extra bit of style. Before locking
    4 # the screen, takes a screenshot of the current display and programatically
    5 # blurs and desaturates the image, using that for the lock screen background. A
    6 # mighty neat effect. 
    7 #
    8 # Requirements: i3-lock imagemagick [scrot] [xbacklight]
    9 #
   10 
   11 
   12 #
   13 # Generates the command to execute for taking a screenshot and applying affects
   14 # for use as the lockscreen wallpaper. Note that this does not execute the
   15 # command. It only generates it.
   16 #
   17 # @param out_file Path to save the lockscreen wallpaper to
   18 #
   19 function gen_wallpaper_cmd {
   20   # Return early if argument 1 not specified
   21   [[ -z ${1} ]] && return
   22 
   23   out_file=${1}
   24   tmp_file="/tmp/i3lock$(date '+%s')screen.jpg"
   25 
   26   screenshot_cmd=""
   27   if [[ $(which import 2>/dev/null) ]]; then
   28     screenshot_cmd="$(which import) -window root ${tmp_file}"
   29   elif [[ $(which scrot 2>/dev/null) ]]; then
   30     screenshot_cmd="$(which scrot) -d0 ${tmp_file}"
   31   fi
   32 
   33   # Generate the wallpaper gen command
   34   if [[ ${screenshot_cmd} != "" ]]; then
   35     # Generate the lockscreen background/screenshot (blurred and slightly less
   36     # saturated)
   37     out=${screenshot_cmd}
   38     # Add the image blur command
   39     out=${out}' && '
   40     out=${out}"convert ${tmp_file} -blur 0x4 -modulate 110,50 ${out_file}"
   41     # Add command to clean up the original screenshot file
   42     out="${out} && "
   43     out="${out} rm ${tmp_file}"
   44     echo "${out}"
   45   fi
   46   # Else we echo nothing, indicating no screenshotter was found
   47 }
   48 
   49 
   50 #
   51 # Locks the screen using i3lock command. Sets 
   52 #
   53 # @param bg Path to image to be used for the lockscreen wallpaper
   54 #
   55 function lock_screen {
   56   # Return early if argument 1 not specified
   57   [[ -z ${1} ]] && return
   58 
   59   bg=${1}
   60   dim=0
   61   [[ $(which xbacklight) ]] && dim=1
   62 
   63   if [[ ${dim} == 1 ]]; then
   64     # Get the previous brightness so we can return to it.
   65     prev_bright=$(xbacklight | cut -d '.' -f 1)
   66 
   67     # Dim the screen, backgrounded so it continues fading after lock
   68     xbacklight -set 3% -time 2000 -steps 150&
   69   fi
   70 
   71   # Lock, but remain in foreground so the unlock processes aren't executed yet
   72   i3lock -i "${bg}" -n
   73 
   74   # Resume original brightness
   75   [[ ${dim} == 1 ]] && xbacklight -set ${prev_bright}% -time 2000 -steps 150
   76 }
   77 
   78 
   79 #
   80 # La fonction primaire
   81 #
   82 function main {
   83   blurry_wallpaper='/tmp/i3lockwall.png'
   84   # Get the program path that will screenshot for the background image
   85   lock_wallpaper_cmd=$(gen_wallpaper_cmd ${blurry_wallpaper})
   86 
   87   if [[ ${lock_wallpaper_cmd} == "" ]]; then
   88     echo "Screenshot command not found (scrot or import). Exiting."
   89     exit 1
   90   fi
   91 
   92   # Execute in a subshell, or the double amperstands (&&) will fail. Seems I've
   93   # discovered a querk of bash.
   94   bash -c "${lock_wallpaper_cmd}"
   95 
   96   # Execute the lock screen with the new fancy wallpaper
   97   lock_screen ${blurry_wallpaper}
   98 
   99   # Cleanup the original screenshot and blurred counterpart
  100   rm "${bg}"
  101 }
  102 
  103 
  104 # Enter the script here
  105 main ${ARGV}