# A part of pdfrw (https://github.com/pmaupin/pdfrw) # Copyright (C) 2006-2009 Patrick Maupin, Austin, Texas # MIT license -- See LICENSE.txt for details ''' This file is an example parser that will parse a graphics stream into a reportlab canvas. Needs work on fonts and unicode, but works on a few PDFs. Better to use Form XObjects for most things (see the example in rl1). ''' from inspect import getargspec from pdfrw import PdfTokens from pdfrw.objects import PdfString ############################################################################# # Graphics parsing def parse_array(self, token='[', params=None): mylist = [] for token in self.tokens: if token == ']': break mylist.append(token) self.params.append(mylist) def parse_savestate(self, token='q', params=''): self.canv.saveState() def parse_restorestate(self, token='Q', params=''): self.canv.restoreState() def parse_transform(self, token='cm', params='ffffff'): self.canv.transform(*params) def parse_linewidth(self, token='w', params='f'): self.canv.setLineWidth(*params) def parse_linecap(self, token='J', params='i'): self.canv.setLineCap(*params) def parse_linejoin(self, token='j', params='i'): self.canv.setLineJoin(*params) def parse_miterlimit(self, token='M', params='f'): self.canv.setMiterLimit(*params) def parse_dash(self, token='d', params='as'): # Array, string self.canv.setDash(*params) def parse_intent(self, token='ri', params='n'): # TODO: add logging pass def parse_flatness(self, token='i', params='i'): # TODO: add logging pass def parse_gstate(self, token='gs', params='n'): # TODO: add logging # Could parse stuff we care about from here later pass def parse_move(self, token='m', params='ff'): if self.gpath is None: self.gpath = self.canv.beginPath() self.gpath.moveTo(*params) self.current_point = params def parse_line(self, token='l', params='ff'): self.gpath.lineTo(*params) self.current_point = params def parse_curve(self, token='c', params='ffffff'): self.gpath.curveTo(*params) self.current_point = params[-2:] def parse_curve1(self, token='v', params='ffff'): parse_curve(self, token, tuple(self.current_point) + tuple(params)) def parse_curve2(self, token='y', params='ffff'): parse_curve(self, token, tuple(params) + tuple(params[-2:])) def parse_close(self, token='h', params=''): self.gpath.close() def parse_rect(self, token='re', params='ffff'): if self.gpath is None: self.gpath = self.canv.beginPath() self.gpath.rect(*params) self.current_point = params[-2:] def parse_stroke(self, token='S', params=''): finish_path(self, 1, 0, 0) def parse_close_stroke(self, token='s', params=''): self.gpath.close() finish_path(self, 1, 0, 0) def parse_fill(self, token='f', params=''): finish_path(self, 0, 1, 1) def parse_fill_compat(self, token='F', params=''): finish_path(self, 0, 1, 1) def parse_fill_even_odd(self, token='f*', params=''): finish_path(self, 0, 1, 0) def parse_fill_stroke_even_odd(self, token='B*', params=''): finish_path(self, 1, 1, 0) def parse_fill_stroke(self, token='B', params=''): finish_path(self, 1, 1, 1) def parse_close_fill_stroke_even_odd(self, token='b*', params=''): self.gpath.close() finish_path(self, 1, 1, 0) def parse_close_fill_stroke(self, token='b', params=''): self.gpath.close() finish_path(self, 1, 1, 1) def parse_nop(self, token='n', params=''): finish_path(self, 0, 0, 0) def finish_path(self, stroke, fill, fillmode): if self.gpath is not None: canv = self.canv canv._fillMode, oldmode = fillmode, canv._fillMode canv.drawPath(self.gpath, stroke, fill) canv._fillMode = oldmode self.gpath = None def parse_clip_path(self, token='W', params=''): # TODO: add logging pass def parse_clip_path_even_odd(self, token='W*', params=''): # TODO: add logging pass def parse_stroke_gray(self, token='G', params='f'): self.canv.setStrokeGray(*params) def parse_fill_gray(self, token='g', params='f'): self.canv.setFillGray(*params) def parse_stroke_rgb(self, token='RG', params='fff'): self.canv.setStrokeColorRGB(*params) def parse_fill_rgb(self, token='rg', params='fff'): self.canv.setFillColorRGB(*params) def parse_stroke_cmyk(self, token='K', params='ffff'): self.canv.setStrokeColorCMYK(*params) def parse_fill_cmyk(self, token='k', params='ffff'): self.canv.setFillColorCMYK(*params) ############################################################################# # Text parsing def parse_begin_text(self, token='BT', params=''): assert self.tpath is None self.tpath = self.canv.beginText() def parse_text_transform(self, token='Tm', params='ffffff'): path = self.tpath # Stoopid optimization to remove nop try: code = path._code except AttributeError: pass else: if code[-1] == '1 0 0 1 0 0 Tm': code.pop() path.setTextTransform(*params) def parse_setfont(self, token='Tf', params='nf'): fontinfo = self.fontdict[params[0]] self.tpath._setFont(fontinfo.name, params[1]) self.curfont = fontinfo def parse_text_out(self, token='Tj', params='t'): text = params[0].decode(self.curfont.remap, self.curfont.twobyte) self.tpath.textOut(text) def parse_TJ(self, token='TJ', params='a'): remap = self.curfont.remap twobyte = self.curfont.twobyte result = [] for x in params[0]: if isinstance(x, PdfString): result.append(x.decode(remap, twobyte)) else: # TODO: Adjust spacing between characters here int(x) text = ''.join(result) self.tpath.textOut(text) def parse_end_text(self, token='ET', params=''): assert self.tpath is not None self.canv.drawText(self.tpath) self.tpath = None def parse_move_cursor(self, token='Td', params='ff'): self.tpath.moveCursor(params[0], -params[1]) def parse_set_leading(self, token='TL', params='f'): self.tpath.setLeading(*params) def parse_text_line(self, token='T*', params=''): self.tpath.textLine() def parse_set_char_space(self, token='Tc', params='f'): self.tpath.setCharSpace(*params) def parse_set_word_space(self, token='Tw', params='f'): self.tpath.setWordSpace(*params) def parse_set_hscale(self, token='Tz', params='f'): self.tpath.setHorizScale(params[0] - 100) def parse_set_rise(self, token='Ts', params='f'): self.tpath.setRise(*params) def parse_xobject(self, token='Do', params='n'): # TODO: Need to do this pass class FontInfo(object): ''' Pretty basic -- needs a lot of work to work right for all fonts ''' lookup = { # WRONG -- have to learn about font stuff... 'BitstreamVeraSans': 'Helvetica', } def __init__(self, source): name = source.BaseFont[1:] self.name = self.lookup.get(name, name) self.remap = chr self.twobyte = False info = source.ToUnicode if not info: return info = info.stream.split('beginbfchar')[1].split('endbfchar')[0] info = list(PdfTokens(info)) assert not len(info) & 1 info2 = [] for x in info: assert x[0] == '<' and x[-1] == '>' and len(x) in (4, 6), x i = int(x[1:-1], 16) info2.append(i) self.remap = dict((x, chr(y)) for (x, y) in zip(info2[::2], info2[1::2])).get self.twobyte = len(info[0]) > 4 ############################################################################# # Control structures def findparsefuncs(): def checkname(n): assert n.startswith('/') return n def checkarray(a): assert isinstance(a, list), a return a def checktext(t): assert isinstance(t, PdfString) return t fixparam = dict(f=float, i=int, n=checkname, a=checkarray, s=str, t=checktext) fixcache = {} def fixlist(params): try: result = fixcache[params] except KeyError: result = tuple(fixparam[x] for x in params) fixcache[params] = result return result dispatch = {} expected_args = 'self token params'.split() for key, func in globals().items(): if key.startswith('parse_'): args, varargs, keywords, defaults = getargspec(func) assert (args == expected_args and varargs is None and keywords is None and len(defaults) == 2), ( key, args, varargs, keywords, defaults) token, params = defaults if params is not None: params = fixlist(params) value = func, params assert dispatch.setdefault(token, value) is value, repr(token) return dispatch class _ParseClass(object): dispatch = findparsefuncs() @classmethod def parsepage(cls, page, canvas=None): self = cls() contents = page.Contents if contents.Filter is not None: raise SystemExit('Cannot parse graphics -- page encoded with %s' % contents.Filter) dispatch = cls.dispatch.get self.tokens = tokens = iter(PdfTokens(contents.stream)) self.params = params = [] self.canv = canvas self.gpath = None self.tpath = None self.fontdict = dict((x, FontInfo(y)) for (x, y) in page.Resources.Font.iteritems()) for token in self.tokens: info = dispatch(token) if info is None: params.append(token) continue func, paraminfo = info if paraminfo is None: func(self, token, ()) continue delta = len(params) - len(paraminfo) if delta: if delta < 0: print ('Operator %s expected %s parameters, got %s' % (token, len(paraminfo), params)) params[:] = [] continue else: print ("Unparsed parameters/commands: %s" % params[:delta]) del params[:delta] paraminfo = zip(paraminfo, params) try: params[:] = [x(y) for (x, y) in paraminfo] except: for i, (x, y) in enumerate(paraminfo): try: x(y) except: raise # For now continue func(self, token, params) params[:] = [] def debugparser(undisturbed=set('parse_array'.split())): def debugdispatch(): def getvalue(oldval): name = oldval[0].__name__ def myfunc(self, token, params): print ('%s called %s(%s)' % (token, name, ', '.join(str(x) for x in params))) if name in undisturbed: myfunc = oldval[0] return myfunc, oldval[1] return dict((x, getvalue(y)) for (x, y) in _ParseClass.dispatch.iteritems()) class _DebugParse(_ParseClass): dispatch = debugdispatch() return _DebugParse.parsepage parsepage = _ParseClass.parsepage if __name__ == '__main__': import sys from pdfreader import PdfReader parse = debugparser() fname, = sys.argv[1:] pdf = PdfReader(fname) for i, page in enumerate(pdf.pages): print ('\nPage %s ------------------------------------' % i) parse(page)