src/Tools/freecad-thumbnailer.in

#!/usr/bin/python3
# SPDX-License-Identifier: LGPL-2.1-or-later

"""Support file to show FreeCAD thumbnails on Free Desktop Environments (like GNOME or KDE)

Installation:
- This executable file should be on the PATH so it can be found
    "$ sudo cp freecad-thumbnailer /usr/bin"
  and must have execution rights
    "$ sudo chmod +x /usr/bin/freecad-thumbnailer"

- If a FreeCAD project file doesn't include a thumbnail the file org.freecad.FreeCAD.png is used.
  Thus, the file src/Gui/Icons/freecad-icon-48.png must be installed.
    "$ sudo cp freecad-icon-48.png /usr/share/icons/hicolor/48x48/apps/org.freecad.FreeCAD.png"

- The application/x-extension-fcstd MIME type should be registered
    Check that a corresponding /usr/share/mime/packages/freecad.xml file exists
    Make sure the MIME database is up to date
    "$ sudo update-mime-database /usr/share/mime"

- Register this thumbnailer
    Adding a file /usr/share/thumbnailers/FreeCAD.thumbnailer with the following content:

    [Thumbnailer Entry]
    TryExec=freecad-thumbnailer
    Exec=freecad-thumbnailer -s %s %i %o
    MimeType=application/x-extension-fcstd;

HINT: Make sure that the symlink /usr/bin/python exists and points to the Python executable

NOTE: To make sure FreeCAD saves thumbnail information:

    Edit → Preferences → Document → Save thumbnail into project when saving document
"""
import sys
import zipfile
import getopt

opt, par = getopt.getopt(sys.argv[1:], "-s:")
input_file = par[0]
output_file = par[1]
default_icon = "@CMAKE_INSTALL_DATAROOTDIR@/icons/hicolor/48x48/apps/org.freecad.FreeCAD.png"

try:
    # Read compressed file
    zfile = zipfile.ZipFile(input_file)
    files = zfile.namelist()

    # Check whether we have a FreeCAD document
    if "Document.xml" not in files:
        print(input_file, " doesn't look like a FreeCAD file")
        sys.exit(1)

    # Read thumbnail from file or use default icon
    image = "thumbnails/Thumbnail.png"
    if image in files:
        image = zfile.read(image)
    else:
        # apps should have at least 48x48 icons
        freecad = open(default_icon, "rb")
        image = freecad.read()

    # Write icon to output_file
    thumb = open(output_file, "wb")
    thumb.write(image)
    thumb.close()

except Exception:
    print("Error creating FreeCAD thumbnail for file ", input_file)
    sys.exit(1)