91 lines
2.3 KiB
Python
91 lines
2.3 KiB
Python
# SPDX-FileCopyrightText: 2024 geisserml <geisserml@gmail.com>
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# SPDX-License-Identifier: Apache-2.0 OR BSD-3-Clause
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import ctypes
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import pypdfium2.raw as pdfium_c
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def color_tohex(color, rev_byteorder):
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if len(color) != 4:
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raise ValueError("Color must consist of exactly 4 values.")
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if not all(0 <= c <= 255 for c in color):
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raise ValueError("Color value exceeds boundaries.")
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# different color interpretation with FPDF_REVERSE_BYTE_ORDER might be a bug? at least it's not documented.
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r, g, b, a = color
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channels = (a, b, g, r) if rev_byteorder else (a, r, g, b)
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c_color = 0
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shift = 24
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for c in channels:
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c_color |= c << shift
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shift -= 8
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return c_color
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def set_callback(struct, fname, callback):
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setattr(struct, fname, type( getattr(struct, fname) )(callback))
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def is_buffer(buf, spec="r"):
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methods = []
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assert set(spec).issubset( set("rw") )
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if "r" in spec:
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methods += ["seek", "tell", "read", "readinto"]
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if "w" in spec:
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methods += ["write"]
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return all(callable(getattr(buf, a, None)) for a in methods)
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class _buffer_reader:
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def __init__(self, buffer):
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self.buffer = buffer
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def __call__(self, _, position, p_buf, size):
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c_buf = ctypes.cast(p_buf, ctypes.POINTER(ctypes.c_char * size))
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self.buffer.seek(position)
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self.buffer.readinto(c_buf.contents)
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return 1
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class _buffer_writer:
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def __init__(self, buffer):
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self.buffer = buffer
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def __call__(self, _, data, size):
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block = ctypes.cast(data, ctypes.POINTER(ctypes.c_ubyte * size))
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self.buffer.write(block.contents)
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return 1
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def get_bufreader(buffer):
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file_len = buffer.seek(0, 2)
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buffer.seek(0)
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reader = pdfium_c.FPDF_FILEACCESS()
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reader.m_FileLen = file_len
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set_callback(reader, "m_GetBlock", _buffer_reader(buffer))
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reader.m_Param = None
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to_hold = (reader.m_GetBlock, )
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return reader, to_hold
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def get_bufwriter(buffer):
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writer = pdfium_c.FPDF_FILEWRITE(version=1)
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set_callback(writer, "WriteBlock", _buffer_writer(buffer))
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return writer
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def pages_c_array(pages):
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if not pages:
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return None, 0
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count = len(pages)
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c_array = (pdfium_c.FPDF_PAGE * count)(*[p.raw for p in pages])
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return c_array, count
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