# SPDX-FileCopyrightText: 2026 geisserml <geisserml@gmail.com>
# SPDX-License-Identifier: Apache-2.0 OR BSD-3-Clause
import os
import ctypes
import pypdfium2.raw as pdfium_c
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def color_tohex(color, rev_byteorder):
if not all(0 <= c <= 255 for c in color):
raise ValueError("Color value exceeds boundaries.")
# different color interpretation with FPDF_REVERSE_BYTE_ORDER might be a bug? at least it's not documented.
r, g, b, a = color
channels = (a, b, g, r) if rev_byteorder else (a, r, g, b)
c_color = 0
shift = 24
for c in channels:
c_color |= c << shift
shift -= 8
return c_color
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def set_callback(struct, fname, callback):
setattr(struct, fname, type(getattr(struct, fname))(callback))
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def set_callbacks(struct, **kwargs):
for fname, callback in kwargs.items():
setattr(struct, fname, type(getattr(struct, fname))(callback))
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def is_stream(buf, spec="r"):
methods = []
assert set(spec).issubset( set("rw") )
if "r" in spec:
methods += ("seek", "tell", "read", "readinto")
if "w" in spec:
methods.append("write")
return all(callable(getattr(buf, a, None)) for a in methods)
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def get_buffer(ptr, size):
obj = ptr.contents
return (type(obj) * size).from_address( ctypes.addressof(obj) )
class _buffer_reader:
def __init__(self, py_buffer):
self.py_buffer = py_buffer
def __call__(self, _, position, p_buf_first, size):
c_buffer = get_buffer(p_buf_first, size)
self.py_buffer.seek(position)
self.py_buffer.readinto(c_buffer)
return 1
class _buffer_writer:
def __init__(self, py_buffer):
self.py_buffer = py_buffer
def __call__(self, _, p_data_first, size):
# c_void_p has no .contents, need to cast
p_data_first = ctypes.cast(p_data_first, ctypes.POINTER(ctypes.c_ubyte))
c_buffer = get_buffer(p_data_first, size)
self.py_buffer.write(c_buffer)
return 1
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def get_bufreader(buffer):
file_len = buffer.seek(0, os.SEEK_END)
buffer.seek(0)
reader = pdfium_c.FPDF_FILEACCESS()
reader.m_FileLen = file_len
set_callback(reader, "m_GetBlock", _buffer_reader(buffer))
reader.m_Param = None
to_hold = (reader.m_GetBlock, )
return reader, to_hold
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def get_bufwriter(buffer):
writer = pdfium_c.FPDF_FILEWRITE(version=1)
set_callback(writer, "WriteBlock", _buffer_writer(buffer))
return writer
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def pages_c_array(pages):
if not pages:
return None, 0
count = len(pages)
c_array = (pdfium_c.FPDF_PAGE * count)(*(p.raw for p in pages))
return c_array, count
FPDF_WCHAR_size = ctypes.sizeof(pdfium_c.FPDF_WCHAR)