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_ADD';;
  19         r | R) echo 'CMD_FAVORITE_REMOVE';;
  20             *) echo 'CMD_UKNOWN';;
  21     esac
  22 }
  23
  24 paths_set() {
  25     local path
  26
  27     while read -r path
  28     do
  29         if file "$path" | grep 'image data' > /dev/null
  30         then
  31             (( n++ ))
  32             # \r jumps to the beginning of the line:
  33             printf '\rFound %d images.' "$n" >&2
  34             paths["$(( n - 1 ))"]="$path"
  35         fi
  36     done
  37     printf '\n' >&2
  38 }
  39
  40 paths_set_from_dir_find() {
  41     paths_set < <(find "$1" -type f)
  42 }
  43
  44 paths_set_from_favs() {
  45     paths_set < <(sort -k 2 "$FILE_WALLPAPER_FAVS" | awk '{sub("^" $1 " +", ""); print}')
  46 }
  47
  48 set_wallpaper() {
  49     local -ri i="$1"
  50     local -r path="$2"
  51
  52     printf '%d of %d %s\n' "$(( i + 1 ))" "$n" "$path"
  53     feh --bg-scale "$path"
  54 }
  55
  56 paths_preview() {
  57     local -i i=0
  58     local path="${paths[$i]}"
  59
  60     set_wallpaper "$i" "$path"
  61
  62     while :
  63     do
  64         if [[ "${paths[$i]}" != "$path" ]]
  65         then
  66             path="${paths[$i]}"
  67             set_wallpaper "$i" "$path"
  68         fi
  69
  70         case "$(read_command)" in
  71             CMD_QUIT)
  72                 exit 0;;
  73             CMD_MOVE_BACK)
  74                 (( i = i == 0 ? (n - 1) : i - 1));;
  75             CMD_MOVE_FORWARD)
  76                 (( i = (i + 1) % n ));;
  77             CMD_FAVORITE_ADD)
  78                 printf 'Adding to favorites set: "%s"\n' "$path" >&2
  79                 wallpaper_fav;;
  80             CMD_FAVORITE_REMOVE)
  81                 printf 'Removing from favorites set: "%s"\n' "$path" >&2
  82                 digest=$(sha256sum "$path" | awk '{print $1}')
  83                 grep -v "$digest" "$FILE_WALLPAPER_FAVS" \
  84                 | sort -u \
  85                 | sponge "$FILE_WALLPAPER_FAVS"
  86                 ;;
  87             CMD_UKNOWN)
  88                 continue;;
  89         esac
  90     done
  91 }
  92
  93 main() {
  94     case "$1" in
  95         f | fav) paths_set_from_favs;;
  96         d | dir) paths_set_from_dir_find "$2";;
  97         a | all) paths_set_from_dir_find "$DIR_WALLPAPERS";;
  98         '')
  99             paths_set_from_dir_find "$DIR_WALLPAPERS";;
 100         *)
 101             printf 'Error: unknown source "%s"\n' "$1" >&2
 102             exit 1;;
 103     esac
 104
 105     paths_preview
 106 }
 107
 108 main "$@"