# # 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[0:4] == 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)): raise SyntaxError("Not a GRIB file") 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"): raise OSError("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")