pyx/pdfextra.py

   1 # -*- encoding: utf-8 -*-
   2 #
   3 #
   4 # Copyright (C) 2006 Michael Schindler <m-schindler@users.sourceforge.net>
   5 #
   6 # This file is part of PyX (http://pyx.sourceforge.net/).
   7 #
   8 # PyX is free software; you can redistribute it and/or modify
   9 # it under the terms of the GNU General Public License as published by
  10 # the Free Software Foundation; either version 2 of the License, or
  11 # (at your option) any later version.
  12 #
  13 # PyX is distributed in the hope that it will be useful,
  14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 # GNU General Public License for more details.
  17 #
  18 # You should have received a copy of the GNU General Public License
  19 # along with PyX; if not, write to the Free Software
  20 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  21
  22 import cStringIO, math
  23 import canvasitem, bbox, pdfwriter, color, unit
  24 from font.font import PDFHelvetica, PDFZapfDingbats
  25
  26 # TODO:
  27 # - discuss behaviour under transformations with André and Jörg
  28 # - what about fillstyles here?
  29 # - where should e.g. a font be added to the registry:
  30 #   in processPDF or in __init__ of the PDF-item?
  31 # - test for double occurrance of field names:
  32 #   this leads to wrong/no display
  33 #
  34 # TODO horizontal alignment in textfields
  35
  36
  37 # flags for annotations:
  38 PDFannotflags = [("invisible", 0), ("hidden", 1), ("printable", 2),
  39     ("nozoom", 3), ("norotate", 4), ("noview", 5), ("readonly", 6)]
  40
  41 # flags for form fields
  42 PDFformflags = [("readonly", 0), ("required", 1), ("noexport", 2),
  43     # flags for the button field
  44     ("notoggletooff", 14), ("radio", 15), ("pushbutton", 16),
  45     # flags for the choice list field
  46     ("combo", 17), ("edit", 18), ("sort", 19), ("multiselect", 21),
  47     # flags for the text field
  48     ("multiline", 12), ("password", 13), ("fileselect", 20), ("donotspellcheck", 22),
  49     ("donotscroll", 23)]
  50
  51
  52 class flag: # <<<
  53     """A helper class for handling flags in pdf forms and annotations"""
  54
  55     def __init__(self, value=None):
  56         self.value = value
  57
  58     def is_set(self, bit):
  59         return self.value is not None and (self.value & 1<<bit) == 1<<bit
  60
  61     def set(self, bit):
  62         if self.value is None:
  63             self.value = 1<<bit
  64         else:
  65             self.value = self.value | 1<<bit
  66
  67     def unset(self, bit):
  68         if self.value is not None:
  69             self.value = self.value & ~(1<<bit)
  70
  71     def __int__(self):
  72         return self.value
  73
  74     def __str__(self):
  75         return self.value.__str__()
  76 # >>>
  77 def _pdfflags(flags): # <<<
  78     """Splits flags into annotation/form part
  79      the flag for the annotation dictionary
  80      the flag for the form (field) dictionary
  81
  82     All flags are handled equally here, independent of their use
  83     for the specific form field.
  84     """
  85
  86     # we initialize with 0 and set only those flags which are not 0
  87     annotflag = flag(value=0)
  88     formflag = flag(value=0)
  89
  90     for key, value in PDFannotflags:
  91         if flags.has_key(key) and flags[key]:
  92             annotflag.set(value)
  93
  94     for key, value in PDFformflags:
  95         if flags.has_key(key) and flags[key]:
  96             formflag.set(value)
  97
  98     return int(annotflag), int(formflag)
  99 # >>>
 100 def _pdfalignment(string): # <<<
 101     alignflag = 0
 102     if string == "c":
 103         alignflag = 1
 104     elif string == "r":
 105         alignflag = 2
 106     return alignflag
 107 # >>>
 108 def _topt(value, type="u", un="cm"): # <<<
 109     if isinstance(value, unit.length):
 110         return unit.topt(value)
 111     else:
 112         return unit.topt(unit.length(value, type, un))
 113 # >>>
 114 def _simplestring(text): # <<<
 115     result = ""
 116     for x in text:
 117         if x.isalnum():
 118             result += x
 119     return result
 120 # >>>
 121 def _sizetrafo(s, tr): # <<<
 122     x1, y1 = tr.apply_pt(s, s)
 123     x0, y0 = tr.apply_pt(0, 0)
 124     return math.hypot(x1 - x0, y1 - y0) * math.sqrt(0.5)
 125 # >>>
 126
 127
 128 class formfield(canvasitem.canvasitem): # <<<
 129     """Base class for acroforms"""
 130
 131     defaultflags = dict()
 132
 133     def selectflags(self, flags):
 134         newflags = dict(**self.defaultflags)
 135         # overwrite the default flags with given values:
 136         for key, value in flags.items():
 137             if newflags.has_key(key):
 138                 newflags[key] = value
 139             else:
 140                 raise RuntimeError("unknown argument \"%s\" to formfield" % key)
 141         return newflags
 142
 143     def bbox(self):
 144         return bbox.bbox_pt(self.llx_pt, self.lly_pt, self.urx_pt, self.ury_pt)
 145
 146     def processPS(self, file, writer, context, registry, bbox):
 147         raise RuntimeError("postscript output of forms is not supported")
 148 # >>>
 149
 150
 151 class textfield(formfield): # <<<
 152     """An interactive pdf form field for text input.
 153
 154     The "name" is used for the graphical user interface and for exporing the input data.
 155     Note that the behaviour under rotations is undefined."""
 156
 157     defaultflags = dict(invisible=0, hidden=0, printable=1, nozoom=0, norotate=0, noview=0,
 158         readonly=0, required=0, noexport=0, multiline=0, password=0, fileselect=0,
 159         donotspellcheck=1, donotscroll=0)
 160
 161     def __init__(self, x, y, width, height, name, defaultvalue="", fontsize=10, font=PDFHelvetica,
 162         fontrelleading=1.16, borderwidth=0, align="l", **flags):
 163
 164         self.llx_pt, self.lly_pt = _topt(x), _topt(y)
 165         self.urx_pt, self.ury_pt = _topt(x+width), _topt(y+height)
 166         self.name = name
 167         self.defaultvalue = defaultvalue
 168         self.fontsize_pt = _topt(fontsize, "x", "pt")
 169         self.font = font
 170         self.fontrelleading = fontrelleading
 171         self.borderwidth_pt = _topt(borderwidth, "x", "pt")
 172         self.align = align
 173         self.flags = self.selectflags(flags)
 174
 175     def processPDF(self, file, writer, context, registry, bbox):
 176         # the bounding box is transformed by the canvas
 177         bbox += self.bbox()
 178
 179         # the annotation rectangle must be transformed separately:
 180         llx_pt, lly_pt = context.trafo.apply_pt(self.llx_pt, self.lly_pt)
 181         urx_pt, ury_pt = context.trafo.apply_pt(self.urx_pt, self.ury_pt)
 182         fontsize_pt = _sizetrafo(self.fontsize_pt, context.trafo)
 183         borderwidth_pt = _sizetrafo(self.borderwidth_pt, context.trafo)
 184
 185         # we create numbers from the flags given
 186         annotflag, formflag = _pdfflags(self.flags)
 187         alignflag = _pdfalignment(self.align)
 188
 189         registry.add(PDFtextfield((llx_pt, lly_pt, urx_pt, ury_pt), self.name, self.defaultvalue,
 190           fontsize_pt, self.font, self.fontrelleading*fontsize_pt,
 191           borderwidth_pt, (not self.flags["multiline"]),
 192           alignflag, annotflag, formflag, context.fillstyles, writer, registry))
 193 # >>>
 194 class PDFtextfield(pdfwriter.PDFobject): # <<<
 195
 196     def __init__(self, bb_pt, name, defaultvalue, fontsize, font, fontleading,
 197         borderwidth, vcenter,
 198         alignflag, annotflag, formflag, fillstyles, writer, registry):
 199
 200         pdfwriter.PDFobject.__init__(self, "formfield_text")
 201
 202         # append this formfield to the global document form
 203         # and to the annotation list of the page:
 204         self.PDFform = None
 205         for object in registry.objects:
 206             if object.type == "form":
 207                 object.append(self)
 208                 self.PDFform = object
 209             elif object.type == "annotations":
 210                 object.append(self)
 211
 212         self.name = name
 213         self.bb_pt = bb_pt
 214         self.defaultvalue = defaultvalue
 215         self.fontsize = fontsize
 216         self.font = font
 217         if self.font is None:
 218             self.font = PDFHelvetica
 219         self.fontleading = fontleading
 220         self.borderwidth = borderwidth
 221         self.alignflag = alignflag
 222         self.formflag = formflag
 223         self.annotflag = annotflag
 224
 225         self.registry = pdfwriter.PDFregistry()
 226         self.registry.addresource("Font", self.font.name, self.font, procset="Text")
 227         self.registry.add(self.font)
 228
 229         if self.defaultvalue:
 230             text = self.defaultvalue.split("\n")
 231             self.defaulttext = PDFdefaulttext(writer, registry, self.fontsize, self.font,
 232                 self.fontleading, text, self.bb_pt, self.borderwidth, vcenter)
 233             self.registry.add(self.defaulttext)
 234         else:
 235             self.defaulttext = None
 236
 237         # process some fillstyles:
 238         fillstring = cStringIO.StringIO()
 239         for attr in fillstyles:
 240             if 1:#isinstance(attr, color.color):
 241                 cont = pdfwriter.context()
 242                 cont.fillattr = 1
 243                 cont.strokeattr = 0
 244                 attr.processPDF(fillstring, writer, cont, self.registry, bbox)
 245         self.fillstyles = fillstring.getvalue()
 246         fillstring.close()
 247
 248         registry.mergeregistry(self.registry)
 249
 250     def write(self, file, writer, registry):
 251         ### the dictionary entries for the annotation
 252         file.write("<</Type /Annot\n")
 253         file.write("/P %d 0 R\n" % registry.getrefno(self.PDFform)) # reference to the page objects
 254         file.write("/Rect [%f %f %f %f]\n" % self.bb_pt) # the annotation rectangle
 255         #ile.write("/BS <</W 0 /S /S>>\n") # border style dictionary
 256         file.write("/Border [0 0 %f]\n" % self.borderwidth) # border style
 257         file.write("/F %d\n" % self.annotflag)
 258         ### the dictionary entries for the widget annotations
 259         file.write("/Subtype /Widget\n")
 260         file.write("/H /N\n") # highlight behaviour
 261         if self.defaulttext:
 262             file.write("/AP <</N %d 0 R >>\n" % registry.getrefno(self.defaulttext)) # appearance dictionary
 263         ### the dictionary entries for the form field
 264         file.write("/FT /Tx\n") # type of the form field
 265         file.write("/T (%s)\n" % self.name) # partial field name
 266         file.write("/TU (%s)\n" % self.name) # field name for the user-interface
 267         file.write("/TM (%s)\n" % self.name) # field name for exporting the data
 268         file.write("/V (%s)\n" % self.defaultvalue) # starting value
 269         file.write("/DV (%s)\n" % self.defaultvalue) # reset value
 270         file.write("/Ff %d\n" % self.formflag) # flags for various purposes
 271         ### the dictionary entries for the text field
 272         file.write("/DR ")
 273         self.registry.writeresources(file) # default resources for appearance
 274         file.write("/DA (%s /%s %f Tf %f TL)\n" % (self.fillstyles, self.font.name, self.fontsize, self.fontleading)) # default appearance string
 275         file.write("/Q %d\n" % self.alignflag)
 276         file.write(">>\n")
 277 # >>>
 278 class PDFdefaulttext(pdfwriter.PDFobject): # <<<
 279
 280     def __init__(self, writer, registry, fontsize, font, fontleading, texts, bb, borderwidth, vcenter):
 281
 282         pdfwriter.PDFobject.__init__(self, "defaulttext")
 283         self.font = font
 284         self.fontsize = fontsize
 285         self.fontleading = fontleading
 286
 287         self.registry = pdfwriter.PDFregistry()
 288         self.registry.addresource("Font", self.font.name, self.font, procset="Text")
 289         self.registry.add(self.font)
 290
 291         self.bb = (0, 0, bb[2] - bb[0], bb[3] - bb[1])
 292         self.texts = [t for t in texts if t]
 293
 294         self.borderwidth = borderwidth
 295         # try to imitate the shifting of PDF:
 296         # the font orientation point is on the baseline of the text
 297         self.hshift = 2*self.borderwidth
 298         if vcenter:
 299             baselinevrel = 0.215
 300             self.vshift = 0.5 * (bb[3] - bb[1]) + (len(self.texts) / 2.0 - 1)*self.fontleading + baselinevrel*self.fontsize
 301         elif (bb[3] - bb[1]) < self.fontleading + 4*self.borderwidth:
 302             baselinevrel = 0.215
 303             self.vshift = 2*self.borderwidth + baselinevrel * self.fontsize
 304             #self.vshift = 0.5 * (bb[3] - bb[1]) - (0.5 - baselinevrel - 0.5*addrelshift)*self.fontsize
 305         else:
 306             baselinevrel = 0.215
 307             addrelshift = 0.215
 308             self.vshift = (bb[3] - bb[1]) - 2*self.borderwidth - self.fontleading + (baselinevrel - addrelshift)*self.fontsize
 309
 310         registry.mergeregistry(self.registry)
 311
 312
 313     def write(self, file, writer, registry):
 314         content = "/Tx BMC q BT /%s %f Tf %f TL %f %f Td (%s) Tj" % (self.font.name, self.fontsize, self.fontleading, self.hshift, self.vshift, self.texts[0])
 315         for text in self.texts[1:]:
 316             content += " (%s)'" % (text)
 317         content += " ET Q EMC\n"
 318         if writer.compress:
 319             import zlib
 320             content = zlib.compress(content)
 321
 322         file.write("<<\n")
 323         file.write("/Type /XObject\n")
 324         file.write("/Subtype /Form\n")
 325         file.write("/BBox [%f %f %f %f]\n" % self.bb)
 326         #ile.write("/Matrix [0.98 0.17 -0.17 0.98 0 0]\n")
 327         file.write("/Resources ")
 328         self.registry.writeresources(file) # default resources for appearance
 329         file.write("/Length %i\n" % len(content))
 330         if writer.compress:
 331             file.write("/Filter /FlateDecode\n")
 332         file.write(">>\n"
 333                    "stream\n")
 334         file.write(content)
 335         file.write("endstream\n")
 336 # >>>
 337
 338
 339 class radiobuttons(formfield): # <<<
 340
 341     """A set of related buttons that can each be on or off.
 342
 343     Typically, at most one radio button in a set may be on at any
 344     given time, and selecting any one of the buttons
 345     automatically deselects all the others.
 346
 347     Note that the behaviour under rotations is undefined."""
 348
 349     defaultflags = dict(invisible=0, hidden=0, printable=1, nozoom=0,
 350         norotate=0, noview=0, readonly=0, required=0, noexport=0, notoggletooff=0)
 351
 352     def __init__(self, positions, name, values, defaultvalue=None, size=10, baselinerelpos=0.2, **flags):
 353
 354         self.name = name
 355         self.size_pt = _topt(size, "x", "pt")
 356         self.positions_pt = [(_topt(x), _topt(y) - baselinerelpos*self.size_pt) for x, y in positions]
 357         self.flags = self.selectflags(flags)
 358         self.flags["radio"] = 1
 359         self.values = values
 360         self.defaultvalue = defaultvalue
 361
 362     def bbox(self):
 363         llx = min([x[0] for x in self.positions_pt])
 364         lly = min([x[1] for x in self.positions_pt])
 365         urx = max([x[0] for x in self.positions_pt]) + self.size_pt
 366         ury = max([x[1] for x in self.positions_pt]) + self.size_pt
 367         return bbox.bbox_pt(llx, lly, urx, ury)
 368
 369     def processPDF(self, file, writer, context, registry, bbox):
 370         # the bbox is transformed by the canvas
 371         bbox += self.bbox()
 372
 373         # the annotation rectangle must be transformed separately:
 374         positions_pt = [context.trafo.apply_pt(x, y) for x, y in self.positions_pt]
 375         size_pt = _sizetrafo(self.size_pt, context.trafo)
 376
 377         # we create numbers from the flags given
 378         annotflag, formflag = _pdfflags(self.flags)
 379
 380         onstate = PDFButtonState(writer, registry,
 381             10, PDFZapfDingbats, bgchar="m", fgchar="8",
 382             bgscale=1.1, bgrelshift=(0, 0.18), fgrelshift=(0.12, 0.26))
 383         offstate = PDFButtonState(writer, registry,
 384             10, PDFZapfDingbats, bgchar="m", fgchar=None,
 385             bgscale=1.1, bgrelshift=(0, 0.18))
 386         registry.add(onstate)
 387         registry.add(offstate)
 388
 389         registry.add(PDFbuttonlist(positions_pt, self.name, size_pt, self.values, self.defaultvalue,
 390             annotflag, formflag, onstate, offstate, writer, registry))
 391 # >>>
 392 class checkbox(formfield): # <<<
 393
 394     """Toggles between two states, on and off
 395
 396     Note that the behaviour under rotations is undefined."""
 397
 398     defaultflags = dict(invisible=0, hidden=0, printable=1, nozoom=0,
 399         norotate=0, noview=0, readonly=0, required=0, noexport=0)
 400
 401     def __init__(self, x, y, name, defaulton=0, size=10, baselinerelpos=0.2, **flags):
 402
 403         self.name = name
 404         self.size_pt = _topt(size, "x", "pt")
 405         self.llx_pt, self.lly_pt = _topt(x), _topt(y) - baselinerelpos*self.size_pt
 406         self.urx_pt, self.ury_pt = self.llx_pt + self.size_pt, self.lly_pt + self.size_pt
 407         self.flags = self.selectflags(flags)
 408         self.defaulton = defaulton
 409
 410     def processPDF(self, file, writer, context, registry, bbox):
 411         # the bbox is transformed by the canvas
 412         bbox += self.bbox()
 413
 414         # the annotation rectangle must be transformed separately:
 415         positions_pt = [context.trafo.apply_pt(self.llx_pt, self.lly_pt)]
 416         size_pt = _sizetrafo(self.size_pt, context.trafo)
 417
 418         # we create numbers from the flags given
 419         annotflag, formflag = _pdfflags(self.flags)
 420
 421         onstate = PDFButtonState(writer, registry,
 422             10, PDFZapfDingbats, bgchar="o", fgchar="4",
 423             bgscale=1.2, bgrelshift=(0, 0.08), fgscale=0.9, fgrelshift=(0.15, 0.25))
 424         offstate = PDFButtonState(writer, registry,
 425             10, PDFZapfDingbats, bgchar="o", fgchar=None,
 426             bgscale=1.2, bgrelshift=(0, 0.08))
 427         registry.add(onstate)
 428         registry.add(offstate)
 429
 430         if self.defaulton:
 431             default = "Yes"
 432         else:
 433             default = "Off"
 434
 435         registry.add(PDFbuttonlist(positions_pt, self.name, size_pt, ["Yes"], default,
 436             annotflag, formflag, onstate, offstate, writer, registry))
 437 # >>>
 438 class PDFbuttonlist(pdfwriter.PDFobject): # <<<
 439
 440     def __init__(self, positions_pt, name, size_pt, values, defaultvalue, annotflag, formflag,
 441         onstate, offstate, writer, registry):
 442
 443         pdfwriter.PDFobject.__init__(self, "formfield_buttonlist")
 444
 445         # append this formfield to the global document form
 446         # but we do not treat this as a fully valid annotation field
 447         for object in registry.objects:
 448             if object.type == "form":
 449                 object.append(self)
 450
 451         self.name = name
 452         self.formflag = formflag
 453         self.annotflag = annotflag
 454
 455         self.size_pt = size_pt
 456         self.defaultvalue = defaultvalue
 457         self.onstate = onstate
 458         self.offstate = offstate
 459
 460         self.checkboxes = []
 461         for i, pos_pt, value in zip(range(len(values)), positions_pt, values):
 462             chbox = PDFcheckboxfield(pos_pt, value, size_pt, _simplestring(value), (value == defaultvalue),
 463                 self, self.onstate, self.offstate, self.annotflag, self.formflag, writer, registry)
 464             self.checkboxes.append(chbox)
 465             registry.add(chbox)
 466
 467     def write(self, file, writer, registry):
 468         ### implementation note: There are some (undocumented) PDF flaws which
 469         ### do not allow to inherit certain variables:
 470         ### * The parent button may not have /Ff (otherwise, notoggletooff fails)
 471         ### * The Kids of a radio button may not have a /T on their own (otherwise, they are not displayed)
 472         ### * The /BS and /Border do not draw anything.
 473         ###   Nevertheless, the border width of /Border is used
 474
 475         ### the dictionary entries for the annotation
 476         file.write("<<\n")
 477         ### the dictionary entries for the form field
 478         file.write("/FT /Btn\n") # type of the form field
 479         file.write("/Kids [%s]\n" % " ".join(["%d 0 R" % registry.getrefno(x) for x in self.checkboxes]))
 480         file.write("/T (%s)\n" % self.name) # partial field name
 481         file.write("/TU (%s)\n" % self.name) # field name for the user-interface
 482         file.write("/TM (%s)\n" % self.name) # field name for exporting the data
 483         ### the dictionary entries for the radiobuttons field
 484         file.write("/V /%s\n" % self.defaultvalue)
 485         file.write(">>\n")
 486 # >>>
 487 class PDFcheckboxfield(pdfwriter.PDFobject): # <<<
 488
 489     def __init__(self, pos_pt, name, size_pt, valuename, defaulton, parent, onstate, offstate, annotflag, formflag, writer, registry):
 490
 491         pdfwriter.PDFobject.__init__(self, "formfield_checkbox")
 492
 493         # we treat this as an annotation only, since the parent is
 494         # already in the form field
 495         self.PDFform = None
 496         for object in registry.objects:
 497             if object.type == "form":
 498                 assert self.PDFform is None
 499                 self.PDFform = object
 500             if object.type == "annotations":
 501                 object.append(self)
 502
 503         self.bb_pt = (pos_pt[0], pos_pt[1], pos_pt[0] + size_pt, pos_pt[1] + size_pt)
 504         self.name = name
 505         self.size_pt = size_pt
 506         self.valuename = valuename
 507         if defaulton:
 508             self.defaultvalue = self.valuename
 509         else:
 510             self.defaultvalue = "Off"
 511         self.parent = parent
 512         self.onstate = onstate
 513         self.offstate = offstate
 514         self.annotflag = annotflag
 515         self.formflag = formflag
 516
 517     def write(self, file, writer, registry):
 518         ### the dictionary entries for the annotation
 519         file.write("<<\n")
 520         file.write("/Type /Annot\n")
 521         file.write("/Subtype /Widget\n")
 522         file.write("/P %d 0 R\n" % registry.getrefno(self.PDFform)) # reference to the page objects
 523         file.write("/Rect [%f %f %f %f]\n" % self.bb_pt) # the annotation rectangle
 524         file.write("/F %d\n" % self.annotflag) # flags
 525         ### the dictionary entries for the widget annotations
 526         file.write("/H /N\n") # hightlight behaviour
 527         ### the dictionary entries for the form field
 528         file.write("/FT /Btn\n") # type of the form field
 529         file.write("/Parent %d 0 R\n" % registry.getrefno(self.parent)) # only for hierarchy
 530         file.write("/AP << /N << /%s %d 0 R /Off %d 0 R >> >>\n" % (self.valuename, registry.getrefno(self.onstate), registry.getrefno(self.offstate)))
 531         file.write("/AS /%s\n" % self.defaultvalue)
 532         file.write("/Ff %d\n" % self.formflag) # Ff may not come from parent!
 533         file.write(">>\n")
 534 # >>>
 535 class PDFButtonState(pdfwriter.PDFobject): # <<<
 536
 537     def __init__(self, writer, registry, fontsize, font, bgchar, fgchar,
 538         bgscale=None, bgrelshift=None, fgscale=None, fgrelshift=None):
 539
 540         pdfwriter.PDFobject.__init__(self, "buttonstate", "buttonstate" + "_".join(map(str, map(id, [fontsize, font, bgchar, fgchar, bgscale, bgrelshift, fgscale, fgrelshift]))))
 541         self.font = font
 542         self.fontsize = fontsize
 543         registry.addresource("Font", self.font.name, self.font, procset="Text")
 544         registry.add(self.font)
 545         self.bb = 0, 0, fontsize, fontsize
 546         self.bgchar = bgchar
 547         self.fgchar = fgchar
 548
 549         if bgscale is None and bgrelshift is not None:
 550             bgscale = 1
 551         if bgscale is not None and bgrelshift is None:
 552             bgrelshift = 0, 0
 553         if bgscale is not None:
 554             self.bgtrafo = "%f 0 0 %f %f %f Tm" % (bgscale, bgscale, bgrelshift[0]*self.fontsize, bgrelshift[1]*self.fontsize)
 555         else:
 556             self.bgtrafo = ""
 557
 558         if fgscale is None and fgrelshift is not None:
 559             fgscale = 1
 560         if fgscale is not None and fgrelshift is None:
 561             fgrelshift = 0, 0
 562         if fgscale is not None:
 563             self.fgtrafo = "%f 0 0 %f %f %f Tm" % (fgscale, fgscale, fgrelshift[0]*self.fontsize, fgrelshift[1]*self.fontsize)
 564         else:
 565             self.fgtrafo = ""
 566
 567     def write(self, file, writer, registry):
 568         content = ""
 569         if self.bgchar:
 570             content += "q BT /%s %f Tf %s (%s) Tj ET Q\n" % (self.font.name, self.fontsize, self.bgtrafo, self.bgchar)
 571         if self.fgchar:
 572             content += "q BT /%s %f Tf %s (%s) Tj ET Q\n" % (self.font.name, self.fontsize, self.fgtrafo, self.fgchar)
 573         if writer.compress:
 574             import zlib
 575             content = zlib.compress(content)
 576
 577         file.write("<<\n")
 578         file.write("/Type /XObject\n")
 579         file.write("/Subtype /Form\n")
 580         file.write("/BBox [%f %f %f %f]\n" % self.bb)
 581         #ile.write("/Matrix [0.98 0.17 -0.17 0.98 0 0]\n")
 582         file.write("/Resources <</Font << /%s %d 0 R >> /ProcSet [/PDF /Text] >>\n" %
 583                    (self.font.name, registry.getrefno(self.font)))
 584         file.write("/Length %i\n" % len(content))
 585         if writer.compress:
 586             file.write("/Filter /FlateDecode\n")
 587         file.write(">>\n"
 588                    "stream\n")
 589         file.write(content)
 590         file.write("endstream\n")
 591
 592
 593 ## Zapf Dingbats symbols for further buttonstates:
 594 # "3" = thin checkmark
 595 # "4" = thick checkmark
 596 # "5" = thin large cross
 597 # "6" = thick large cross
 598 # "7" = thin small cross
 599 # "8" = thick small cross
 600 # "l" = filled circle
 601 # "m" = empty circle
 602 # "n" = filled rectangle
 603 # "o" = empty rectangle (shadow bottom right)
 604 # "p" = empty rectangle (shadow top right)
 605 # "q" = empty box (to bottom right)
 606 # "r" = empty box (to top right)
 607 # >>>
 608
 609
 610 class choicefield(formfield): # <<<
 611     """An interactive pdf form field for text input.
 612
 613     The name is used for the graphical user interface and for exporing the input data.
 614     Note that the behaviour under rotations is undefined."""
 615
 616     defaultflags = dict(invisible=0, hidden=0, printable=1, nozoom=0,
 617         norotate=0, noview=0, readonly=0, required=0, noexport=0, combo=1,
 618         edit=0, sort=0, multiselect=0, donotspellcheck=1)
 619
 620     def __init__(self, x, y, width, height, name, values, defaultvalue=None, fontsize=10, font=None,
 621         borderwidth=0, align="l", **flags):
 622
 623         self.llx_pt, self.lly_pt = _topt(x), _topt(y)
 624         self.urx_pt, self.ury_pt = _topt(x+width), _topt(y+height)
 625         self.name = name
 626         self.values = values
 627         self.defaultvalue = defaultvalue
 628         self.fontsize_pt = _topt(fontsize, "x", "pt")
 629         self.font = font # TODO: add the generic fonts
 630         self.borderwidth_pt = _topt(borderwidth, "x", "pt")
 631         self.flags = self.selectflags(flags)
 632         self.align = align
 633
 634     def processPDF(self, file, writer, context, registry, bbox):
 635         # the bounding box is transformed by the canvas
 636         bbox += self.bbox()
 637
 638         # the annotation rectangle must be transformed separately:
 639         llx_pt, lly_pt = context.trafo.apply_pt(self.llx_pt, self.lly_pt)
 640         urx_pt, ury_pt = context.trafo.apply_pt(self.urx_pt, self.ury_pt)
 641         fontsize_pt = _sizetrafo(self.fontsize_pt, context.trafo)
 642         borderwidth_pt = _sizetrafo(self.borderwidth_pt, context.trafo)
 643
 644         # we create numbers from the flags given
 645         annotflag, formflag = _pdfflags(self.flags)
 646         alignflag = _pdfalignment(self.align)
 647
 648         registry.add(PDFchoicefield((llx_pt, lly_pt, urx_pt, ury_pt),
 649             self.name, self.values, self.defaultvalue, fontsize_pt, self.font,
 650             borderwidth_pt, alignflag, annotflag, formflag, writer, registry))
 651 # >>>
 652 class PDFchoicefield(pdfwriter.PDFobject): # <<<
 653
 654     def __init__(self, bb_pt, name, values, defaultvalue, fontsize, font,
 655         borderwidth_pt, alignflag, annotflag, formflag, writer, registry):
 656
 657         pdfwriter.PDFobject.__init__(self, "formfield_choice")
 658
 659         # append this formfield to the global document form
 660         # and to the annotation list of the page:
 661         self.PDFform = None
 662         for object in registry.objects:
 663             if object.type == "form":
 664                 object.append(self)
 665                 self.PDFform = object
 666             elif object.type == "annotations":
 667                 object.append(self)
 668
 669         self.name = name
 670         self.bb_pt = bb_pt
 671         self.values = values
 672         self.defaultvalue = defaultvalue
 673         self.fontsize = fontsize
 674         self.font = font
 675         if self.font is None:
 676             self.font = PDFHelvetica
 677         registry.addresource("Font", self.font.name, self.font, procset="Text")
 678         registry.add(self.font)
 679         self.borderwidth_pt = borderwidth_pt
 680         self.alignflag = alignflag
 681         self.formflag = formflag
 682         self.annotflag = annotflag
 683
 684     def write(self, file, writer, registry):
 685         ### the dictionary entries for the annotation
 686         file.write("<</Type /Annot\n")
 687         file.write("/P %d 0 R\n" % registry.getrefno(self.PDFform)) # reference to the page objects
 688         file.write("/Rect [%f %f %f %f]\n" % self.bb_pt) # the annotation rectangle
 689         #ile.write("/BS << ... >>\n" # border style dictionary
 690         file.write("/Border [0 0 %f]\n" % self.borderwidth_pt) # border style
 691         file.write("/F %d\n" % self.annotflag)
 692         ### the dictionary entries for the widget annotations
 693         file.write("/Subtype /Widget\n")
 694         file.write("/H /N\n") # highlight behaviour
 695         #ile.write("/AP <</N  >>\n") # appearance dictionary TODO
 696         ### the dictionary entries for the form field
 697         file.write("/FT /Ch\n") # type of the form field
 698         file.write("/T (%s)\n" % self.name) # partial field name
 699         file.write("/TU (%s)\n" % self.name) # field name for the user-interface
 700         file.write("/TM (%s)\n" % self.name) # field name for exporting the data
 701         if self.defaultvalue in self.values:
 702             file.write("/V (%s)\n" % self.defaultvalue) # starting value
 703         file.write("/Ff %d\n" % self.formflag) # flags for various purposes
 704         ### the dictionary entries for the text field
 705         file.write("/DR <</Font <</%s %d 0 R >> >>\n" % (self.font.name, registry.getrefno(self.font))) # default resources for appearance
 706         file.write("/DA (/%s %f Tf)\n" % (self.font.name, self.fontsize)) # default appearance string
 707         file.write("/Q %d\n" % self.alignflag)
 708         file.write("/Opt [")
 709         for value in self.values:
 710             file.write(" (%s)" % value)
 711         file.write(" ]\n")
 712         file.write(">>\n")
 713 # >>>
 714
 715
 716 # vim:foldmethod=marker:foldmarker=<<<,>>>
 717