Pillow/src/PIL/GribStubImagePlugin.py

75 lines
1.5 KiB
Python
Raw Normal View History

2010-07-31 06:52:47 +04:00
#
# The Python Imaging Library
# $Id$
#
# GRIB stub adapter
#
# Copyright (c) 1996-2003 by Fredrik Lundh
#
# See the README file for information on usage and redistribution.
#
from . import Image, ImageFile
2017-03-04 14:52:14 +03:00
from ._binary import i8
2010-07-31 06:52:47 +04:00
_handler = None
2014-08-26 17:47:10 +04:00
2010-07-31 06:52:47 +04:00
def register_handler(handler):
2016-09-24 12:10:46 +03:00
"""
Install application-specific GRIB image handler.
:param handler: Handler object.
"""
2010-07-31 06:52:47 +04:00
global _handler
_handler = handler
2014-08-26 17:47:10 +04:00
2010-07-31 06:52:47 +04:00
# --------------------------------------------------------------------
# Image adapter
2019-03-21 16:28:20 +03:00
2010-07-31 06:52:47 +04:00
def _accept(prefix):
2017-03-04 14:52:14 +03:00
return prefix[0:4] == b"GRIB" and i8(prefix[7]) == 1
2010-07-31 06:52:47 +04:00
2014-08-26 17:47:10 +04:00
2010-07-31 06:52:47 +04:00
class GribStubImageFile(ImageFile.StubImageFile):
format = "GRIB"
format_description = "GRIB"
def _open(self):
offset = self.fp.tell()
if not _accept(self.fp.read(8)):
raise SyntaxError("Not a GRIB file")
self.fp.seek(offset)
# make something up
self.mode = "F"
self._size = 1, 1
2010-07-31 06:52:47 +04:00
loader = self._load()
if loader:
loader.open(self)
def _load(self):
return _handler
2014-08-26 17:47:10 +04:00
2010-07-31 06:52:47 +04:00
def _save(im, fp, filename):
if _handler is None or not hasattr("_handler", "save"):
raise IOError("GRIB save handler not installed")
_handler.save(im, fp, filename)
# --------------------------------------------------------------------
# Registry
Image.register_open(GribStubImageFile.format, GribStubImageFile, _accept)
Image.register_save(GribStubImageFile.format, _save)
Image.register_extension(GribStubImageFile.format, ".grib")