Adding upstream version 0.1.1.
Signed-off-by: Daniel Baumann <daniel@debian.org>
This commit is contained in:
parent
a042d54ff1
commit
00981dc324
GPG key ID:
FBB4F0E80A80222F
17 changed files with 2130 additions and 0 deletions
502
pydyf/__init__.py
Executable file
502
pydyf/__init__.py
Executable file
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@ -0,0 +1,502 @@
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"""
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A low-level PDF generator.
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"""
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import zlib
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from codecs import BOM_UTF16_BE
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VERSION = __version__ = '0.1.1'
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def _to_bytes(item):
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"""Convert item to bytes."""
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if isinstance(item, bytes):
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return item
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elif isinstance(item, Object):
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return item.data
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elif isinstance(item, float):
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if item.is_integer():
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return f'{int(item):d}'.encode('ascii')
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else:
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return f'{item:f}'.encode('ascii')
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elif isinstance(item, int):
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return f'{item:d}'.encode('ascii')
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return str(item).encode('ascii')
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class Object:
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"""Base class for PDF objects."""
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def __init__(self):
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#: Number of the object.
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self.number = None
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#: Position in the PDF of the object.
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self.offset = 0
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#: Version number of the object, non-negative.
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self.generation = 0
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#: Indicate if an object is used (``'n'``), or has been deleted
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#: and therefore is free (``'f'``).
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self.free = 'n'
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@property
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def indirect(self):
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"""Indirect representation of an object."""
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return b'\n'.join((
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str(self.number).encode() + b' ' +
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str(self.generation).encode() + b' obj',
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self.data,
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b'endobj',
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))
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@property
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def reference(self):
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"""Object identifier."""
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return (
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str(self.number).encode() + b' ' +
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str(self.generation).encode() + b' R')
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@property
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def data(self):
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"""Data contained in the object. Shall be defined in each subclass."""
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raise NotImplementedError()
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class Dictionary(Object, dict):
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"""PDF Dictionary object.
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Inherits from :class:`Object` and Python :obj:`dict`.
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"""
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def __init__(self, values=None):
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Object.__init__(self)
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dict.__init__(self, values or {})
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@property
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def data(self):
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result = [b'<<']
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for key, value in self.items():
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result.append(b'/' + _to_bytes(key) + b' ' + _to_bytes(value))
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result.append(b'>>')
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return b'\n'.join(result)
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class Stream(Object):
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"""PDF Stream object.
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Inherits from :class:`Object`.
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"""
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def __init__(self, stream=None, extra=None, compress=False):
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super().__init__()
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#: Python array of data composing stream.
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self.stream = stream or []
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#: Metadata containing at least the length of the Stream.
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self.extra = extra or {}
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#: Compress the stream data if set to ``True``. Default is ``False``.
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self.compress = compress
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def begin_text(self):
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"""Begin a text object."""
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self.stream.append(b'BT')
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def clip(self, even_odd=False):
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"""Modify current clipping path by intersecting it with current path.
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Use the nonzero winding number rule to determine which regions lie
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inside the clipping path by default.
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Use the even-odd rule if ``even_odd`` set to ``True``.
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"""
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self.stream.append(b'W*' if even_odd else b'W')
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def close(self):
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"""Close current subpath.
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Append a straight line segment from the current point to the starting
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point of the subpath.
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"""
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self.stream.append(b'h')
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def color_space(self, space, stroke=False):
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"""Set the nonstroking color space.
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If stroke is set to ``True``, set the stroking color space instead.
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"""
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self.stream.append(
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b'/' + _to_bytes(space) + b' ' + (b'CS' if stroke else b'cs'))
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def curve_to(self, x1, y1, x2, y2, x3, y3):
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"""Add cubic Bézier curve to current path.
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The curve shall extend from ``(x3, y3)`` using ``(x1, y1)`` and ``(x2,
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y2)`` as the Bézier control points.
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"""
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self.stream.append(b' '.join((
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_to_bytes(x1), _to_bytes(y1),
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_to_bytes(x2), _to_bytes(y2),
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_to_bytes(x3), _to_bytes(y3), b'c')))
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def curve_start_to(self, x2, y2, x3, y3):
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"""Add cubic Bézier curve to current path
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The curve shall extend to ``(x3, y3)`` using the current point and
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``(x2, y2)`` as the Bézier control points.
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"""
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self.stream.append(b' '.join((
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_to_bytes(x2), _to_bytes(y2),
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_to_bytes(x3), _to_bytes(y3), b'v')))
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def curve_end_to(self, x1, y1, x3, y3):
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"""Add cubic Bézier curve to current path
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The curve shall extend to ``(x3, y3)`` using `(x1, y1)`` and ``(x3,
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y3)`` as the Bézier control points.
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"""
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self.stream.append(b' '.join((
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_to_bytes(x1), _to_bytes(y1),
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_to_bytes(x3), _to_bytes(y3), b'y')))
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def draw_x_object(self, reference):
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"""Draw object given by reference."""
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self.stream.append(b'/' + _to_bytes(reference) + b' Do')
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def end(self):
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"""End path without filling or stroking."""
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self.stream.append(b'n')
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def end_text(self):
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"""End text object."""
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self.stream.append(b'ET')
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def fill(self, even_odd=False):
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"""Fill path using nonzero winding rule.
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Use even-odd rule if ``even_odd`` is set to ``True``.
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"""
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self.stream.append(b'f*' if even_odd else b'f')
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def fill_and_stroke(self, even_odd=False):
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"""Fill and stroke path usign nonzero winding rule.
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Use even-odd rule if ``even_odd`` is set to ``True``.
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"""
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self.stream.append(b'B*' if even_odd else b'B')
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def fill_stroke_and_close(self, even_odd=False):
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"""Fill, stroke and close path using nonzero winding rule.
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Use even-odd rule if ``even_odd`` is set to ``True``.
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"""
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self.stream.append(b'b*' if even_odd else b'b')
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def line_to(self, x, y):
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"""Add line from current point to point ``(x, y)``."""
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self.stream.append(b' '.join((_to_bytes(x), _to_bytes(y), b'l')))
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def move_to(self, x, y):
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"""Begin new subpath by moving current point to ``(x, y)``."""
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self.stream.append(b' '.join((_to_bytes(x), _to_bytes(y), b'm')))
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def shading(self, name):
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"""Paint shape and color shading using shading dictionary ``name``."""
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self.stream.append(b'/' + _to_bytes(name) + b' sh')
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def pop_state(self):
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"""Restore graphic state."""
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self.stream.append(b'Q')
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def push_state(self):
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"""Save graphic state."""
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self.stream.append(b'q')
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def rectangle(self, x, y, width, height):
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"""Add rectangle to current path as complete subpath.
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``(x, y)`` is the lower-left corner and width and height the
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dimensions.
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"""
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self.stream.append(b' '.join((
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_to_bytes(x), _to_bytes(y),
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_to_bytes(width), _to_bytes(height), b're')))
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def set_color_rgb(self, r, g, b, stroke=False):
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"""Set RGB color for nonstroking operations.
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Set RGB color for stroking operations instead if ``stroke`` is set to
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``True``.
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"""
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self.stream.append(b' '.join((
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_to_bytes(r), _to_bytes(g), _to_bytes(b),
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(b'RG' if stroke else b'rg'))))
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def set_color_special(self, name, stroke=False):
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"""Set color for nonstroking operations.
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Set color for stroking operation if ``stroke`` is set to ``True``.
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"""
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self.stream.append(
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b'/' + _to_bytes(name) + b' ' + (b'SCN' if stroke else b'scn'))
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def set_dash(self, dash_array, dash_phase):
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"""Set dash line pattern.
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:param dash_array: Dash pattern.
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:type dash_array: :term:`iterable`
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:param dash_phase: Start of dash phase.
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:type dash_phase: :obj:`int`
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"""
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self.stream.append(b' '.join((
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Array(dash_array).data, _to_bytes(dash_phase), b'd')))
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def set_font_size(self, font, size):
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"""Set font name and size."""
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self.stream.append(
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b'/' + _to_bytes(font) + b' ' + _to_bytes(size) + b' Tf')
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def set_text_rendering(self, mode):
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"""Set text rendering mode."""
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self.stream.append(_to_bytes(mode) + b' Tr')
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def set_line_cap(self, line_cap):
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"""Set line cap style."""
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self.stream.append(_to_bytes(line_cap) + b' J')
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def set_line_join(self, line_join):
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"""Set line join style."""
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self.stream.append(_to_bytes(line_join) + b' j')
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def set_line_width(self, width):
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"""Set line width."""
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self.stream.append(_to_bytes(width) + b' w')
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def set_miter_limit(self, miter_limit):
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"""Set miter limit."""
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self.stream.append(_to_bytes(miter_limit) + b' M')
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def set_state(self, state_name):
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"""Set specified parameters in graphic state.
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:param state_name: Name of the graphic state.
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"""
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self.stream.append(b'/' + _to_bytes(state_name) + b' gs')
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def show_text(self, text):
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"""Show text."""
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self.stream.append(b'[' + _to_bytes(text) + b'] TJ')
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def stroke(self):
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"""Stroke path."""
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self.stream.append(b'S')
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def stroke_and_close(self):
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"""Stroke and close path."""
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self.stream.append(b's')
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def text_matrix(self, a, b, c, d, e, f):
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"""Set text matrix and text line matrix.
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:param a: Top left number in the matrix.
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:type a: :obj:`int` or :obj:`float`
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:param b: Top middle number in the matrix.
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:type b: :obj:`int` or :obj:`float`
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:param c: Middle left number in the matrix.
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:type c: :obj:`int` or :obj:`float`
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:param d: Middle middle number in the matrix.
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:type d: :obj:`int` or :obj:`float`
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:param e: Bottom left number in the matrix.
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:type e: :obj:`int` or :obj:`float`
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:param f: Bottom middle number in the matrix.
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:type f: :obj:`int` or :obj:`float`
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"""
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self.stream.append(b' '.join((
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_to_bytes(a), _to_bytes(b), _to_bytes(c),
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_to_bytes(d), _to_bytes(e), _to_bytes(f), b'Tm')))
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def transform(self, a, b, c, d, e, f):
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"""Modify current transformation matrix.
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:param a: Top left number in the matrix.
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:type a: :obj:`int` or :obj:`float`
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:param b: Top middle number in the matrix.
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:type b: :obj:`int` or :obj:`float`
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:param c: Middle left number in the matrix.
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:type c: :obj:`int` or :obj:`float`
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:param d: Middle middle number in the matrix.
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:type d: :obj:`int` or :obj:`float`
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:param e: Bottom left number in the matrix.
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:type e: :obj:`int` or :obj:`float`
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:param f: Bottom middle number in the matrix.
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:type f: :obj:`int` or :obj:`float`
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"""
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self.stream.append(b' '.join((
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_to_bytes(a), _to_bytes(b), _to_bytes(c),
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_to_bytes(d), _to_bytes(e), _to_bytes(f), b'cm')))
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@property
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def data(self):
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stream = b'\n'.join(_to_bytes(item) for item in self.stream)
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extra = Dictionary(self.extra.copy())
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if self.compress:
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extra['Filter'] = '/FlateDecode'
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compressobj = zlib.compressobj()
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stream = compressobj.compress(stream)
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stream += compressobj.flush()
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extra['Length'] = len(stream)
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return b'\n'.join((extra.data, b'stream', stream, b'endstream'))
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class String(Object):
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"""PDF String object.
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Inherits from :class:`Object`.
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"""
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def __init__(self, string=''):
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super().__init__()
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#: Unicode string.
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self.string = string
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@property
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def data(self):
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try:
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return b'(' + _to_bytes(self.string) + b')'
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except UnicodeEncodeError:
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encoded = BOM_UTF16_BE + str(self.string).encode('utf-16-be')
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return b'<' + encoded.hex().encode() + b'>'
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class Array(Object, list):
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"""PDF Array object.
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Inherits from :class:`Object` and Python :obj:`list`.
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"""
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def __init__(self, array=None):
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Object.__init__(self)
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list.__init__(self, array or [])
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@property
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def data(self):
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result = [b'[']
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for child in self:
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result.append(_to_bytes(child))
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result.append(b']')
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return b' '.join(result)
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class PDF:
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"""PDF document."""
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def __init__(self):
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#: Python :obj:`list` containing the PDF’s objects.
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self.objects = []
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zero_object = Object()
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zero_object.generation = 65535
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zero_object.free = 'f'
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self.add_object(zero_object)
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#: PDF :class:`Dictionary` containing the PDF’s pages.
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self.pages = Dictionary({
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'Type': '/Pages',
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'Kids': Array([]),
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'Count': 0,
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})
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self.add_object(self.pages)
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#: PDF :class:`Dictionary` containing the PDF’s metadata.
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self.info = Dictionary({})
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self.add_object(self.info)
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#: PDF :class:`Dictionary` containing references to the other objects.
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self.catalog = Dictionary({
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'Type': '/Catalog',
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'Pages': self.pages.reference,
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})
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self.add_object(self.catalog)
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#: Current position in the PDF.
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self.current_position = 0
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#: Position of the cross reference table.
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self.xref_position = None
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def add_page(self, page):
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"""Add page to the PDF.
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:param page: New page.
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:type page: :class:`Dictionary`
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"""
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self.pages['Count'] += 1
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self.add_object(page)
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self.pages['Kids'].extend([page.number, 0, 'R'])
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def add_object(self, object_):
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"""Add object to the PDF."""
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object_.number = len(self.objects)
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self.objects.append(object_)
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def write_line(self, content, output):
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"""Write line to output.
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:param content: Content to write.
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:type content: :obj:`bytes`
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:param output: Output stream.
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:type output: binary :term:`file object`
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"""
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self.current_position += len(content) + 1
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output.write(content + b'\n')
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def write(self, output):
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"""Write PDF to output.
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:param output: Output stream.
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:type output: binary :term:`file object`
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|
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"""
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# Write header
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self.write_line(b'%PDF-1.7', output)
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self.write_line(b'%\xf0\x9f\x96\xa4', output)
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# Write all non-free PDF objects
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for object_ in self.objects:
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if object_.free == 'f':
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continue
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object_.offset = self.current_position
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self.write_line(object_.indirect, output)
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# Write cross reference table
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self.xref_position = self.current_position
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self.write_line(b'xref', output)
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self.write_line(f'0 {len(self.objects)}'.encode(), output)
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for object_ in self.objects:
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self.write_line(
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(f'{object_.offset:010} {object_.generation:05} '
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f'{object_.free} ').encode(), output)
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# Write trailer
|
||||
self.write_line(b'trailer', output)
|
||||
self.write_line(b'<<', output)
|
||||
self.write_line(f'/Size {len(self.objects)}'.encode(), output)
|
||||
self.write_line(b'/Root ' + self.catalog.reference, output)
|
||||
self.write_line(b'/Info ' + self.info.reference, output)
|
||||
self.write_line(b'>>', output)
|
||||
self.write_line(b'startxref', output)
|
||||
self.write_line(f'{self.xref_position}'.encode(), output)
|
||||
self.write_line(b'%%EOF', output)
|
||||
Loading…
Add table
Add a link
Reference in a new issue