desktop-app-generator

#!/bin/bash
#
# History:
# 2019.05 beta release.
# 2019.10 allow user to type in custom commands.
#         update application categories.
#
vsn=2019.10

# ----------------------------------------------------------------------------
OPTS=$(getopt -o hv --long help,version -n "${0##*/}" -- "$@") \
              || { echo "Terminating..." >&2; exit 1; }
eval set -- "$OPTS"

version(){
cat<<EOF
${0##*/} $vsn

Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Written by Yaswant Pradhan.
EOF
}

usage(){
cat<<EOF
Generate GNOME desktop application launcher.

Usage: ${0##*/} [OPTION]

Options:
  -h, --help        print this help and exit
  -v, --version     print version and exit

GUI Options:
  See https://developer.gnome.org/desktop-entry-spec for detailed desktop entry specs.

  Filename          Name of the desktop launcher filename. default: newapp.desktop
  Type              Type of desktop entry: Application (type 1)
  Name              Specific name of the application, for example "MyFunkyApp"
  Version           Version of the Desktop Entry Specification that the desktop entry conforms with.
                    Entries that confirm with this version of the specification should use 1.0.
  Comment           Tooltip for the entry, for example "Does Funky things.."
  Command           Program to execute, possibly with arguments
  Optional Args     %f -  A single file name, even if multiple files are selected.
                          The system reading the desktop entry should recognize that the program
                          in question cannot handle multiple file arguments, and it should should
                          probably spawn and execute multiple copies of a program for each selected
                          file if the program is not able to handle additional file arguments.
                          If files are not on the local file system (i.e. are on HTTP or FTP
                          locations), the files will be copied to the local file system and
                          %f will be expanded to point at the temporary file. Used for programs
                          that do not understand the URL syntax.
                    %F -  A list of files. Use for apps that can open several local files at once.
                          Each file is passed as a separate argument to the executable program.
                    %u -  A single URL. Local files may either be passed as file: URLs or as file path.
                    %U -  A list of URLs. Each URL is passed as a separate argument to the executable
                          program. Local files may either be passed as file: URLs or as file path.
                    %c -  The translated name of the application as listed in the appropriate Name key
                          in the desktop entry.
                    %k -  The location of the desktop file as either a URI (if for example gotten from
                          the vfolder system) or a local filename or empty if no location is known.
  Icon              Icon to display in file manager, menus, etc. If the name is an absolute path,
                    the given file will be used
  Caregory          Categories in which the entry should be shown in a menu (for possible values
                    see http://www.freedesktop.org/Standards/menu-spec)
  In terminal       If selected, the program will run in a terminal window
  Install for user  If selected, the application will be installed in user
                    ~/.local/share/applications directory so that it is discoverable from GNOME menu

Report bugs to <yaswant.pradhan@metoffice.gov.uk>

EOF
}

while true; do
  case "$1" in
    -h |--help )    usage; exit 0 ;;
    -v |--version ) version; exit 0 ;;
    -- )            shift; break ;;
    * )             break ;;
  esac
done
# ----------------------------------------------------------------------------


command -v yad 1>/dev/null || { echo "yad: command not found" && exit 127; }

# \nSee https://developer.gnome.org/desktop-entry-spec/" --show-uri
  # --text="<i>Edit fields below to create and install a custom desktop launcher</i>\nhttps://developer.gnome.org/desktop-entry-spec" \

# collect form data
data=$(yad --title="Desktop Entry Generator $vsn" --width=450 --posx=10 --posy=10 \
  --text-align=center --show-uri\
  --form --align=right \
  --field=" Filename" "newapp.desktop" \
  --field=" Type:RO" "Application" \
  --field=" Name" "LauncherName" \
  --field=" Version" "1.0" \
  --field=" Comment" "Generate and install desktop application launcher" \
  --field=" Command" "$HOME/bin/" \
  --field=" Optional Args:CB" "!%f!%F!%u!%U!%c!%k" \
  --field=" Icon:FL" "/usr/share/icons/hicolor/48x48/apps/system-logo-icon.png" \
  --field=" Categories:CBE" "Utility!AudioVideo!Development!Education!Game!Graphics!Network!Office!Science!Settings!System" \
  --field=" In terminal:CHK" FALSE \
  --field=" Install for user: ${USER}:CHK" FALSE)
ret=$?
[[ "$ret" -eq 1 || "$ret" -eq 252 ]] && { echo "Cancelled"; exit $ret; }


# retrieve fields array
IFS='|' read -ra fields <<< "$data"


# validate command
exe="${fields[5]%% *}"
if command -v "$exe" &>/dev/null; then :
else
  yad --image dialog-error --title 'Error' \
      --text "<b> ${exe}: command not found</b>\n\nPlease try again and input a valid Command" \
      --width=450 --posx=10 --posy=10 \
      --button=gtk-cancel:127
  exit $?
fi


# parse application file path
if [[ ${fields[10]} = TRUE ]]; then
  filepath="${HOME}/.local/share/applications/${fields[0]}"
  mkdir -p "${filepath%/*}"
else
  filepath="${fields[0]}"
fi

# prompt overwrite
overwrite=0
if [ -f "$filepath" ]; then
  yad --image dialog-question \
      --title Overwite --width=450 --posx=10 --posy=10 \
      --button=gtk-no:1 \
      --button=gtk-yes:0 \
      --text "<b> ${filepath##*/} exists</b>\n\n Overwrite file?"
  overwrite=$?
fi

# write desktop entry file
(( overwrite == 0 )) && \
cat > "$filepath" <<EOF
[Desktop Entry]
Type=${fields[1]}
Name=${fields[2]}
Version=${fields[3]}
Comment=${fields[4]}
Exec=${fields[5]} ${fields[6]}
Icon=${fields[7]}
Terminal=${fields[9],,}
Categories=${fields[8]}
EOF

# make the app executable
[ -f "$filepath" ] && chmod +x "$filepath"