pkgs/build-support/setup-hooks/desktop-to-darwin-bundle.sh

   1 # shellcheck shell=bash
   2 fixupOutputHooks+=('convertDesktopFiles $prefix')
   3
   4 # Get a param out of a desktop file. First parameter is the file and the second
   5 # is the key who's value we should fetch.
   6 getDesktopParam() {
   7     local file="$1"
   8     local key="$2"
   9     local line k v
  10
  11     while read -r line; do
  12         if [[ "$line" = *=* ]]; then
  13             k="${line%%=*}"
  14             v="${line#*=}"
  15
  16             if [[ "$k" = "$key" ]]; then
  17                 echo "$v"
  18                 return
  19             fi
  20         fi
  21     done < "$file"
  22
  23     return 1
  24 }
  25
  26 # Convert a freedesktop.org icon theme for a given app to a .icns file. When possible, missing
  27 # icons are synthesized from SVG or rescaled from existing ones (when within the size threshold).
  28 convertIconTheme() {
  29     local -r out=$1
  30     local -r sharePath=$2
  31     local -r iconName=$3
  32     local -r theme=${4:-hicolor}
  33
  34     # Sizes based on archived Apple documentation:
  35     # https://developer.apple.com/design/human-interface-guidelines/macos/icons-and-images/app-icon#app-icon-sizes
  36     local -ra iconSizes=(16 32 128 256 512)
  37     local -ra scales=([1]="" [2]="@2")
  38
  39     # Based loosely on the algorithm at:
  40     # https://specifications.freedesktop.org/icon-theme-spec/latest/#icon_lookup
  41     # Assumes threshold = 2 for ease of implementation.
  42     function findIcon() {
  43         local -r iconSize=$1
  44         local -r scale=$2
  45
  46         local scaleSuffix=${scales[$scale]}
  47         local exactSize=${iconSize}x${iconSize}${scaleSuffix}
  48
  49         local -a validSizes=(
  50             ${exactSize}
  51             $((iconSize + 1))x$((iconSize + 1))${scaleSuffix}
  52             $((iconSize + 2))x$((iconSize + 2))${scaleSuffix}
  53             $((iconSize - 1))x$((iconSize - 1))${scaleSuffix}
  54             $((iconSize - 2))x$((iconSize - 2))${scaleSuffix}
  55         )
  56
  57         local fallbackIcon=
  58
  59         for iconIndex in "${!candidateIcons[@]}"; do
  60             for maybeSize in "${validSizes[@]}"; do
  61                 icon=${candidateIcons[$iconIndex]}
  62                 if [[ $icon = */$maybeSize/* ]]; then
  63                     if [[ $maybeSize = $exactSize ]]; then
  64                         echo "fixed $icon"
  65                         return 0
  66                     else
  67                         echo "threshold $icon"
  68                         return 0
  69                     fi
  70                 elif [[ -a $icon && -z "$fallbackIcon" ]]; then
  71                     fallbackIcon="$icon"
  72                 fi
  73             done
  74         done
  75
  76         if [[ -n "$fallbackIcon" ]]; then
  77             echo "fallback $fallbackIcon"
  78             return 0
  79         fi
  80
  81         echo "scalable"
  82     }
  83
  84     function resizeIcon() {
  85         local -r in=$1
  86         local -r out=$2
  87         local -r iconSize=$3
  88         local -r scale=$4
  89
  90         local density=$((72 * scale))x$((72 * scale))
  91         local dim=$((iconSize * scale))
  92
  93         echo "desktopToDarwinBundle: resizing icon $in to $out, size $dim" >&2
  94         magick convert -scale "${dim}x${dim}" -density "$density" -units PixelsPerInch "$in" "$out"
  95     }
  96
  97     function synthesizeIcon() {
  98         local -r in=$1
  99         local -r out=$2
 100         local -r iconSize=$3
 101         local -r scale=$4
 102
 103         if [[ $in != '-' ]]; then
 104             local density=$((72 * scale))x$((72 * scale))
 105             local dim=$((iconSize * scale))
 106
 107             echo "desktopToDarwinBundle: rasterizing svg $in to $out, size $dim" >&2
 108             rsvg-convert --keep-aspect-ratio --width "$dim" --height "$dim" "$in" --output "$out"
 109             magick convert -density "$density" -units PixelsPerInch "$out" "$out"
 110         else
 111             return 1
 112         fi
 113     }
 114
 115     function getIcons() {
 116         local -r sharePath=$1
 117         local -r iconname=$2
 118         local -r theme=$3
 119         local -r resultdir=$(mktemp -d)
 120
 121         local -ar candidateIcons=(
 122             "${sharePath}/icons/${theme}/"*"/${iconname}.png"
 123             "${sharePath}/icons/${theme}/"*"/${iconname}.xpm"
 124         )
 125
 126         local -a scalableIcon=("${sharePath}/icons/${theme}/scalable/${iconname}.svg"*)
 127         if [[ ${#scalableIcon[@]} = 0 ]]; then
 128             scalableIcon=('-')
 129         fi
 130
 131         # Tri-state variable, NONE means no icons have been found, an empty
 132         # icns file will be generated, not sure that's necessary because macOS
 133         # will default to a generic icon if no icon can be found.
 134         #
 135         # OTHER means an appropriate icon was found.
 136         #
 137         # Any other value is a path to an icon file that isn't scalable or
 138         # within the threshold. This is used as a fallback in case no better
 139         # icon can be found and will be scaled as much as
 140         # necessary to result in appropriate icon sizes.
 141         local foundIcon=NONE
 142         for iconSize in "${iconSizes[@]}"; do
 143             for scale in "${!scales[@]}"; do
 144                 local iconResult=$(findIcon $iconSize $scale)
 145                 local type=${iconResult%% *}
 146                 local icon=${iconResult#* }
 147                 local scaleSuffix=${scales[$scale]}
 148                 local result=${resultdir}/${iconSize}x${iconSize}${scales[$scale]}${scaleSuffix:+x}.png
 149                 echo "desktopToDarwinBundle: using $type icon $icon for size $iconSize$scaleSuffix" >&2
 150                 case $type in
 151                     fixed)
 152                         local density=$((72 * scale))x$((72 * scale))
 153                         magick convert -density "$density" -units PixelsPerInch "$icon" "$result"
 154                         foundIcon=OTHER
 155                         ;;
 156                     threshold)
 157                         # Synthesize an icon of the exact size if a scalable icon is available
 158                         # instead of scaling one and ending up with a fuzzy icon.
 159                         if ! synthesizeIcon "${scalableIcon[0]}" "$result" "$iconSize" "$scale"; then
 160                             resizeIcon "$icon" "$result" "$iconSize" "$scale"
 161                         fi
 162                         foundIcon=OTHER
 163                         ;;
 164                     scalable)
 165                         synthesizeIcon "${scalableIcon[0]}" "$result" "$iconSize" "$scale" || true
 166                         foundIcon=OTHER
 167                         ;;
 168                     fallback)
 169                         # Use the largest size available to scale to
 170                         # appropriate sizes.
 171                         if [[ $foundIcon != OTHER ]]; then
 172                           foundIcon=$icon
 173                         fi
 174                         ;;
 175                     *)
 176                         ;;
 177                 esac
 178             done
 179         done
 180         if [[ $foundIcon != NONE && $foundIcon != OTHER ]]; then
 181             # Ideally we'd only resize to whatever the closest sizes are,
 182             # starting from whatever icon sizes are available.
 183             for iconSize in 16 32 128 256 512; do
 184               local result=${resultdir}/${iconSize}x${iconSize}.png
 185               resizeIcon "$foundIcon" "$result" "$iconSize" 1
 186             done
 187         fi
 188         echo "$resultdir"
 189     }
 190
 191     iconsdir=$(getIcons "$sharePath" "apps/${iconName}" "$theme")
 192     if [[ -n "$(ls -A1 "$iconsdir")" ]]; then
 193         icnsutil compose --toc "$out/${iconName}.icns" "$iconsdir/"*
 194     else
 195         echo "Warning: no icons were found. Creating an empty icon for ${iconName}.icns."
 196         touch "$out/${iconName}.icns"
 197     fi
 198 }
 199
 200 processExecFieldCodes() {
 201   local -r file=$1
 202   local -r execRaw=$(getDesktopParam "${file}" "Exec")
 203   local -r execNoK="${execRaw/\%k/${file}}"
 204   local -r execNoKC="${execNoK/\%c/$(getDesktopParam "${file}" "Name")}"
 205   local -r icon=$(getDesktopParam "${file}" "Icon")
 206   local -r execNoKCI="${execNoKC/\%i/${icon:+--icon }${icon}}"
 207   local -r execNoKCIfu="${execNoKCI/ \%[fu]/}"
 208   local -r exec="${execNoKCIfu/ \%[FU]/}"
 209   if [[ "$exec" != "$execRaw" ]]; then
 210     echo 1>&2 "desktopToDarwinBundle: Application bundles do not understand desktop entry field codes. Changed '$execRaw' to '$exec'."
 211   fi
 212   echo "$exec"
 213 }
 214
 215 # For a given .desktop file, generate a darwin '.app' bundle for it.
 216 convertDesktopFile() {
 217     local -r file=$1
 218     local -r sharePath=$(dirname "$(dirname "$file")")
 219     local -r name=$(getDesktopParam "${file}" "Name")
 220     local -r macOSExec=$(getDesktopParam "${file}" "X-macOS-Exec")
 221     if [[ "$macOSExec" ]]; then
 222       local -r exec="$macOSExec"
 223     else
 224       local -r exec=$(processExecFieldCodes "${file}")
 225     fi
 226     local -r iconName=$(getDesktopParam "${file}" "Icon")
 227     local -r squircle=$(getDesktopParam "${file}" "X-macOS-SquircleIcon")
 228
 229     mkdir -p "${!outputBin}/Applications/${name}.app/Contents/MacOS"
 230     mkdir -p "${!outputBin}/Applications/${name}.app/Contents/Resources"
 231
 232     convertIconTheme "${!outputBin}/Applications/${name}.app/Contents/Resources" "$sharePath" "$iconName"
 233
 234     write-darwin-bundle "${!outputBin}" "$name" "$exec" "$iconName" "$squircle"
 235 }
 236
 237 convertDesktopFiles() {
 238     local dir="$1/share/applications/"
 239
 240     if [ -d "${dir}" ]; then
 241         for desktopFile in $(find "$dir" -iname "*.desktop"); do
 242             convertDesktopFile "$desktopFile";
 243         done
 244     fi
 245 }