| # | |
| # 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 | |
| _handler = None | |
| def register_handler(handler): | |
| """ | |
| Install application-specific GRIB image handler. | |
| :param handler: Handler object. | |
| """ | |
| global _handler | |
| _handler = handler | |
| # -------------------------------------------------------------------- | |
| # Image adapter | |
| def _accept(prefix): | |
| return prefix[:4] == b"GRIB" and prefix[7] == 1 | |
| class GribStubImageFile(ImageFile.StubImageFile): | |
| format = "GRIB" | |
| format_description = "GRIB" | |
| def _open(self): | |
| offset = self.fp.tell() | |
| if not _accept(self.fp.read(8)): | |
| msg = "Not a GRIB file" | |
| raise SyntaxError(msg) | |
| self.fp.seek(offset) | |
| # make something up | |
| self.mode = "F" | |
| self._size = 1, 1 | |
| loader = self._load() | |
| if loader: | |
| loader.open(self) | |
| def _load(self): | |
| return _handler | |
| def _save(im, fp, filename): | |
| if _handler is None or not hasattr(_handler, "save"): | |
| msg = "GRIB save handler not installed" | |
| raise OSError(msg) | |
| _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") | |