Source code for PIL.XbmImagePlugin

#
# The Python Imaging Library.
# $Id$
#
# XBM File handling
#
# History:
# 1995-09-08 fl   Created
# 1996-11-01 fl   Added save support
# 1997-07-07 fl   Made header parser more tolerant
# 1997-07-22 fl   Fixed yet another parser bug
# 2001-02-17 fl   Use 're' instead of 'regex' (Python 2.1) (0.4)
# 2001-05-13 fl   Added hotspot handling (based on code from Bernhard Herzog)
# 2004-02-24 fl   Allow some whitespace before first #define
#
# Copyright (c) 1997-2004 by Secret Labs AB
# Copyright (c) 1996-1997 by Fredrik Lundh
#
# See the README file for information on usage and redistribution.
#
from __future__ import annotations

import re

from . import Image, ImageFile

TYPE_CHECKING = False
if TYPE_CHECKING:
    from typing import IO

# XBM header
xbm_head = re.compile(
    rb"\s*#define[ \t]+.*_width[ \t]+(?P<width>[0-9]+)[\r\n]+"
    b"#define[ \t]+.*_height[ \t]+(?P<height>[0-9]+)[\r\n]+"
    b"(?P<hotspot>"
    b"#define[ \t]+[^_]*_x_hot[ \t]+(?P<xhot>[0-9]+)[\r\n]+"
    b"#define[ \t]+[^_]*_y_hot[ \t]+(?P<yhot>[0-9]+)[\r\n]+"
    b")?"
    rb"[\000-\377]*_bits\[]"
)


def _accept(prefix: bytes) -> bool:
    return prefix.startswith((b"#define", b"\n#define", b"/*"))


##
# Image plugin for X11 bitmaps.




class XbmImageFile(ImageFile.ImageFile):
    format = "XBM"
    format_description = "X11 Bitmap"

    def _open(self) -> None:
        assert self.fp is not None

        width = None
        height = None
        x_hot = None
        offset = None
        starting = True
        in_block_comment = False
        while True:
            line = self.fp.readline(75)
            if not line:
                break
            line = line.rstrip()
            if in_block_comment:
                if line.endswith(b"*/"):
                    in_block_comment = False
                continue
            if line.startswith(b"/*"):
                in_block_comment = not line.endswith(b"*/")
                continue
            if starting and not line:
                starting = False
                continue
            if not line.startswith(b"#define "):
                if line.endswith(b"_bits[] = {"):
                    offset = self.fp.tell()
                break
            value = int(line.split().pop())
            if b"width " in line:
                width = value
            elif b"height " in line:
                height = value
            elif b"_x_hot " in line:
                x_hot = value
            elif b"_y_hot " in line:
                if x_hot is not None:
                    self.info["hotspot"] = x_hot, value
        if width is None or height is None or offset is None:
            msg = "not a XBM file"
            raise SyntaxError(msg)

        self._mode = "1"
        self._size = width, height

        self.tile = [ImageFile._Tile("xbm", (0, 0, *self.size), offset)]



def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
    if im.mode != "1":
        msg = f"cannot write mode {im.mode} as XBM"
        raise OSError(msg)

    fp.write(f"#define im_width {im.size[0]}\n".encode("ascii"))
    fp.write(f"#define im_height {im.size[1]}\n".encode("ascii"))

    hotspot = im.encoderinfo.get("hotspot")
    if hotspot:
        fp.write(f"#define im_x_hot {hotspot[0]}\n".encode("ascii"))
        fp.write(f"#define im_y_hot {hotspot[1]}\n".encode("ascii"))

    fp.write(b"static char im_bits[] = {\n")

    ImageFile._save(im, fp, [ImageFile._Tile("xbm", (0, 0, *im.size))])

    fp.write(b"};\n")


Image.register_open(XbmImageFile.format, XbmImageFile, _accept)
Image.register_save(XbmImageFile.format, _save)

Image.register_extension(XbmImageFile.format, ".xbm")

Image.register_mime(XbmImageFile.format, "image/xbm")