home/bin/wallpapers_preview

   1 #! /bin/bash
   2
   3 ### XXX Chose not to 'set -e' because arithmetic evaluation can cause a non-zero exit.
   4 ### XXX Chose not to 'set -u' because unset params ($1, $2, ...) cause failures.
   5 ### Solutions to the above are ugly.
   6
   7 declare -a paths
   8 declare -i n=0
   9
  10 read_command() {
  11     local char
  12
  13     read -rsn 1 char
  14     case "$char" in
  15         q | Q) echo 'CMD_QUIT';;
  16         h | H) echo 'CMD_MOVE_BACK';;
  17         l | L) echo 'CMD_MOVE_FORWARD';;
  18         f | F) echo 'CMD_FAVORITE';;
  19             *) echo 'CMD_UKNOWN';;
  20     esac
  21 }
  22
  23 paths_find() {
  24     local -r root_dir="$1"
  25     local path
  26
  27     IFS=$'\n'
  28     for path in $(find "$root_dir" -type f)
  29     do
  30         if file "$path" | grep 'image data' > /dev/null
  31         then
  32             (( n++ ))
  33             # \r jumps to the beginning of the line:
  34             printf '\rFound %d images.' "$n" >&2
  35             paths["$(( n - 1 ))"]="$path"
  36         fi
  37     done
  38     unset IFS
  39     printf '\n' >&2
  40 }
  41
  42 set_wallpaper() {
  43     local -ri i="$1"
  44     local -r path="$2"
  45
  46     printf '%d of %d %s\n' "$(( i + 1 ))" "$n" "$path"
  47     feh --bg-scale "$path"
  48 }
  49
  50 paths_preview() {
  51     local -i i=0
  52     local path="${paths[$i]}"
  53
  54     set_wallpaper "$i" "$path"
  55
  56     while :
  57     do
  58         if [[ "${paths[$i]}" != "$path" ]]
  59         then
  60             path="${paths[$i]}"
  61             set_wallpaper "$i" "$path"
  62         fi
  63
  64         case "$(read_command)" in
  65             CMD_QUIT)
  66                 exit 0;;
  67             CMD_MOVE_BACK)
  68                 (( i = i == 0 ? (n - 1) : i - 1));;
  69             CMD_MOVE_FORWARD)
  70                 (( i = (i + 1) % n ));;
  71             CMD_FAVORITE)
  72                 wallpaper_fav;;
  73             CMD_UKNOWN)
  74                 continue;;
  75         esac
  76     done
  77 }
  78
  79 main() {
  80     local root_dir
  81
  82     case "$1" in
  83         '') root_dir="$DIR_WALLPAPERS";;
  84         *) root_dir="$1";;
  85     esac
  86
  87     paths_find "$root_dir"
  88     paths_preview
  89 }
  90
  91 main "$@"