ROX-Lib2/python/rox/saving.py

   1 """All ROX applications that can save documents should use drag-and-drop saving.
   2 The document itself should use the Saveable mix-in class and override some of the
   3 methods to actually do the save.
   4
   5 If you want to save a selection then you can create a new object specially for
   6 the purpose and pass that to the SaveBox."""
   7
   8 import os, sys
   9 import rox
  10 from rox import alert, g, _, filer, escape
  11 from rox import choices, get_local_path, basedir
  12
  13 gdk = g.gdk
  14
  15 TARGET_XDS = 0
  16 TARGET_RAW = 1
  17
  18 def _chmod(path, mode):
  19         """Like os.chmod, except that permission denied errors are not fatal
  20         (for FAT partitions)."""
  21         try:
  22                 os.chmod(path, mode)
  23         except OSError, ex:
  24                 if ex.errno != 1:
  25                         raise
  26                 # Log the error and continue.
  27                 print >>sys.stderr, "Warning: Failed to set permissions:", ex
  28
  29 def _write_xds_property(context, value):
  30         win = context.source_window
  31         if value:
  32                 win.property_change('XdndDirectSave0', 'text/plain', 8,
  33                                         gdk.PROP_MODE_REPLACE,
  34                                         value)
  35         else:
  36                 win.property_delete('XdndDirectSave0')
  37
  38 def _read_xds_property(context, delete):
  39         """Returns a UTF-8 encoded, non-escaped, URI."""
  40         win = context.source_window
  41         retval = win.property_get('XdndDirectSave0', 'text/plain', delete)
  42         if retval:
  43                 return retval[2]
  44         return None
  45
  46 def image_for_type(type, size=48, flags=0):
  47         'Search <Choices> for a suitable icon. Returns a pixbuf, or None.'
  48         from icon_theme import users_theme
  49
  50         media, subtype = type.split('/', 1)
  51
  52         path=basedir.load_first_config('rox.sourceforge.net', 'MIME-icons',
  53                                        media + '_' + subtype + '.png')
  54         if not path:
  55                 path = choices.load('MIME-icons',
  56                                     media + '_' + subtype + '.png')
  57         icon=None
  58         if not path:
  59                 icon_name = 'mime-%s:%s' % (media, subtype)
  60
  61                 try:
  62                         path=users_theme.lookup_icon(icon_name, size, flags)
  63                         if not path:
  64                                 icon_name = 'mime-%s' % media
  65                                 path = users_theme.lookup_icon(icon_name, size)
  66
  67                 except:
  68                         print "Error loading MIME icon"
  69
  70         if not path:
  71                 path = basedir.load_first_config('rox.sourceforge.net',
  72                                                  'MIME-icons', media + '.png')
  73         if not path:
  74                 path = choices.load('MIME-icons', media + '.png')
  75         if path:
  76                 if hasattr(gdk, 'pixbuf_new_from_file_at_size'):
  77                         return gdk.pixbuf_new_from_file_at_size(path, size, size)
  78                 else:
  79                         return gdk.pixbuf_new_from_file(path)
  80         else:
  81                 return None
  82
  83 def _report_save_error():
  84         "Report a AbortSave nicely, otherwise use report_exception()"
  85         value = sys.exc_info()[1]
  86         if isinstance(value, AbortSave):
  87                 value.show()
  88         else:
  89                 rox.report_exception()
  90
  91 class AbortSave(rox.UserAbort):
  92         """Raise this to cancel a save. If a message is given, it is displayed
  93         in a normal alert box (not in the report_exception style). If the
  94         message is None, no message is shown (you should have already shown
  95         it!)"""
  96         def __init__(self, message):
  97                 self.message = message
  98                 rox.UserAbort.__init__(self, message)
  99
 100         def show(self):
 101                 if self.message:
 102                         rox.alert(self.message)
 103
 104 class Saveable:
 105         """This class describes the interface that an object must provide
 106         to work with the SaveBox/SaveArea widgets. Inherit from it if you
 107         want to save. All methods can be overridden, but normally only
 108         save_to_stream() needs to be. You can also set save_last_stat to
 109         the result of os.stat(filename) when loading a file to make ROX-Lib
 110         restore permissions and warn about other programs editing the file."""
 111
 112         save_last_stat = None
 113
 114         def set_uri(self, uri):
 115                 """When the data is safely saved somewhere this is called
 116                 with its new name. Mark your data as unmodified and update
 117                 the filename for next time. Saving to another application
 118                 won't call this method. Default method does nothing.
 119                 The URI may be in the form of a URI or a local path.
 120                 It is UTF-8, not escaped (% really means %)."""
 121                 pass
 122
 123         def save_to_stream(self, stream):
 124                 """Write the data to save to the stream. When saving to a
 125                 local file, stream will be the actual file, otherwise it is a
 126                 cStringIO object."""
 127                 raise Exception('You forgot to write the save_to_stream() method...'
 128                                 'silly programmer!')
 129
 130         def save_to_file(self, path):
 131                 """Write data to file. Raise an exception on error.
 132                 The default creates a temporary file, uses save_to_stream() to
 133                 write to it, then renames it over the original. If the temporary file
 134                 can't be created, it writes directly over the original."""
 135
 136                 # Ensure the directory exists...
 137                 parent_dir = os.path.dirname(path)
 138                 if not os.path.isdir(parent_dir):
 139                         from rox import fileutils
 140                         try:
 141                                 fileutils.makedirs(parent_dir)
 142                         except OSError:
 143                                 raise AbortSave(None)   # (message already shown)
 144
 145                 import random
 146                 tmp = 'tmp-' + `random.randrange(1000000)`
 147                 tmp = os.path.join(parent_dir, tmp)
 148
 149                 def open_private(path):
 150                         return os.fdopen(os.open(path, os.O_CREAT | os.O_WRONLY, 0600), 'wb')
 151
 152                 try:
 153                         stream = open_private(tmp)
 154                 except:
 155                         # Can't create backup... try a direct write
 156                         tmp = None
 157                         stream = open_private(path)
 158                 try:
 159                         try:
 160                                 self.save_to_stream(stream)
 161                         finally:
 162                                 stream.close()
 163                         if tmp:
 164                                 os.rename(tmp, path)
 165                 except:
 166                         _report_save_error()
 167                         if tmp and os.path.exists(tmp):
 168                                 if os.path.getsize(tmp) == 0 or \
 169                                    rox.confirm(_("Delete temporary file '%s'?") % tmp,
 170                                                 g.STOCK_DELETE):
 171                                         os.unlink(tmp)
 172                         raise AbortSave(None)
 173                 self.save_set_permissions(path)
 174                 filer.examine(path)
 175
 176         def save_to_selection(self, selection_data):
 177                 """Write data to the selection. The default method uses save_to_stream()."""
 178                 from cStringIO import StringIO
 179                 stream = StringIO()
 180                 self.save_to_stream(stream)
 181                 selection_data.set(selection_data.target, 8, stream.getvalue())
 182
 183         save_mode = None        # For backwards compat
 184         def save_set_permissions(self, path):
 185                 """The default save_to_file() creates files with the mode 0600
 186                 (user read/write only). After saving has finished, it calls this
 187                 method to set the final permissions. The save_set_permissions():
 188                 - sets it to 0666 masked with the umask (if save_mode is None), or
 189                 - sets it to save_last_stat.st_mode (not masked) otherwise."""
 190                 if self.save_last_stat is not None:
 191                         save_mode = self.save_last_stat.st_mode
 192                 else:
 193                         save_mode = self.save_mode
 194
 195                 if save_mode is not None:
 196                         _chmod(path, save_mode)
 197                 else:
 198                         mask = os.umask(0077)   # Get the current umask
 199                         os.umask(mask)          # Set it back how it was
 200                         _chmod(path, 0666 & ~mask)
 201
 202         def save_done(self):
 203                 """Time to close the savebox. Default method does nothing."""
 204                 pass
 205
 206         def discard(self):
 207                 """Discard button clicked, or document safely saved. Only called if a SaveBox
 208                 was created with discard=1.
 209                 The user doesn't want the document any more, even if it's modified and unsaved.
 210                 Delete it."""
 211                 raise Exception("Sorry... my programmer forgot to tell me how to handle Discard!")
 212
 213         save_to_stream._rox_default = 1
 214         save_to_file._rox_default = 1
 215         save_to_selection._rox_default = 1
 216         def can_save_to_file(self):
 217                 """Indicates whether we have a working save_to_stream or save_to_file
 218                 method (ie, whether we can save to files). Default method checks that
 219                 one of these two methods has been overridden."""
 220                 if not hasattr(self.save_to_stream, '_rox_default'):
 221                         return 1        # Have user-provided save_to_stream
 222                 if not hasattr(self.save_to_file, '_rox_default'):
 223                         return 1        # Have user-provided save_to_file
 224                 return 0
 225         def can_save_to_selection(self):
 226                 """Indicates whether we have a working save_to_stream or save_to_selection
 227                 method (ie, whether we can save to selections). Default methods checks that
 228                 one of these two methods has been overridden."""
 229                 if not hasattr(self.save_to_stream, '_rox_default'):
 230                         return 1        # Have user-provided save_to_stream
 231                 if not hasattr(self.save_to_selection, '_rox_default'):
 232                         return 1        # Have user-provided save_to_file
 233                 return 0
 234
 235         def save_cancelled(self):
 236                 """If you multitask during a save (using a recursive mainloop) then the
 237                 user may click on the Cancel button. This function gets called if so, and
 238                 should cause the recursive mainloop to return."""
 239                 raise Exception("Lazy programmer error: can't abort save!")
 240
 241 class SaveArea(g.VBox):
 242         """A SaveArea contains the widgets used in a save box. You can use
 243         this to put a savebox area in a larger window."""
 244
 245         document = None         # The Saveable with the data
 246         entry = None
 247         initial_uri = None      # The pathname supplied to the constructor
 248
 249         def __init__(self, document, uri, type):
 250                 """'document' must be a subclass of Saveable.
 251                 'uri' is the file's current location, or a simple name (eg 'TextFile')
 252                 if it has never been saved.
 253                 'type' is the MIME-type to use (eg 'text/plain').
 254                 """
 255                 g.VBox.__init__(self, False, 0)
 256
 257                 self.document = document
 258                 self.initial_uri = uri
 259
 260                 drag_area = self._create_drag_area(type)
 261                 self.pack_start(drag_area, True, True, 0)
 262                 drag_area.show_all()
 263
 264                 entry = g.Entry()
 265                 entry.connect('activate', lambda w: self.save_to_file_in_entry())
 266                 self.entry = entry
 267                 self.pack_start(entry, False, True, 4)
 268                 entry.show()
 269
 270                 entry.set_text(uri)
 271
 272         def _set_icon(self, type):
 273                 pixbuf = image_for_type(type)
 274                 if pixbuf:
 275                         self.icon.set_from_pixbuf(pixbuf)
 276                 else:
 277                         self.icon.set_from_stock(g.STOCK_MISSING_IMAGE, g.ICON_SIZE_DND)
 278
 279         def _create_drag_area(self, type):
 280                 align = g.Alignment()
 281                 align.set(.5, .5, 0, 0)
 282
 283                 self.drag_box = g.EventBox()
 284                 self.drag_box.set_border_width(4)
 285                 self.drag_box.add_events(gdk.BUTTON_PRESS_MASK)
 286                 align.add(self.drag_box)
 287
 288                 self.icon = g.Image()
 289                 self._set_icon(type)
 290
 291                 self._set_drag_source(type)
 292                 self.drag_box.connect('drag_begin', self.drag_begin)
 293                 self.drag_box.connect('drag_end', self.drag_end)
 294                 self.drag_box.connect('drag_data_get', self.drag_data_get)
 295                 self.drag_in_progress = 0
 296
 297                 self.drag_box.add(self.icon)
 298
 299                 return align
 300
 301         def set_type(self, type, icon = None):
 302                 """Change the icon and drag target to 'type'.
 303                 If 'icon' is given (as a GtkImage) then that icon is used,
 304                 otherwise an appropriate icon for the type is used."""
 305                 if icon:
 306                         self.icon.set_from_pixbuf(icon.get_pixbuf())
 307                 else:
 308                         self._set_icon(type)
 309                 self._set_drag_source(type)
 310
 311         def _set_drag_source(self, type):
 312                 if self.document.can_save_to_file():
 313                         targets = [('XdndDirectSave0', 0, TARGET_XDS)]
 314                 else:
 315                         targets = []
 316                 if self.document.can_save_to_selection():
 317                         targets = targets + [(type, 0, TARGET_RAW),
 318                                   ('application/octet-stream', 0, TARGET_RAW)]
 319
 320                 if not targets:
 321                         raise Exception("Document %s can't save!" % self.document)
 322                 self.drag_box.drag_source_set(gdk.BUTTON1_MASK | gdk.BUTTON3_MASK,
 323                                               targets,
 324                                               gdk.ACTION_COPY | gdk.ACTION_MOVE)
 325
 326         def save_to_file_in_entry(self):
 327                 """Call this when the user clicks on an OK button you provide."""
 328                 uri = self.entry.get_text()
 329                 path = get_local_path(escape(uri))
 330
 331                 if path:
 332                         if not self.confirm_new_path(path):
 333                                 return
 334                         try:
 335                                 self.set_sensitive(False)
 336                                 try:
 337                                         self.document.save_to_file(path)
 338                                 finally:
 339                                         self.set_sensitive(True)
 340                                 self.set_uri(uri)
 341                                 self.save_done()
 342                         except:
 343                                 _report_save_error()
 344                 else:
 345                         rox.info(_("Drag the icon to a directory viewer\n"
 346                                    "(or enter a full pathname)"))
 347
 348         def drag_begin(self, drag_box, context):
 349                 self.drag_in_progress = 1
 350                 self.destroy_on_drag_end = 0
 351                 self.using_xds = 0
 352                 self.data_sent = 0
 353
 354                 try:
 355                         pixbuf = self.icon.get_pixbuf()
 356                         if pixbuf:
 357                                 drag_box.drag_source_set_icon_pixbuf(pixbuf)
 358                 except:
 359                         # This can happen if we set the broken image...
 360                         import traceback
 361                         traceback.print_exc()
 362
 363                 uri = self.entry.get_text()
 364                 if uri:
 365                         i = uri.rfind('/')
 366                         if (i == -1):
 367                                 leaf = uri
 368                         else:
 369                                 leaf = uri[i + 1:]
 370                 else:
 371                         leaf = _('Unnamed')
 372                 _write_xds_property(context, leaf)
 373
 374         def drag_data_get(self, widget, context, selection_data, info, time):
 375                 if info == TARGET_RAW:
 376                         try:
 377                                 self.set_sensitive(False)
 378                                 try:
 379                                         self.document.save_to_selection(selection_data)
 380                                 finally:
 381                                         self.set_sensitive(True)
 382                         except:
 383                                 _report_save_error()
 384                                 _write_xds_property(context, None)
 385                                 return
 386
 387                         self.data_sent = 1
 388                         _write_xds_property(context, None)
 389
 390                         if self.drag_in_progress:
 391                                 self.destroy_on_drag_end = 1
 392                         else:
 393                                 self.save_done()
 394                         return
 395                 elif info != TARGET_XDS:
 396                         _write_xds_property(context, None)
 397                         alert("Bad target requested!")
 398                         return
 399
 400                 # Using XDS:
 401                 #
 402                 # Get the path that the destination app wants us to save to.
 403                 # If it's local, save and return Success
 404                 #                         (or Error if save fails)
 405                 # If it's remote, return Failure (remote may try another method)
 406                 # If no URI is given, return Error
 407                 to_send = 'E'
 408                 uri = _read_xds_property(context, False)
 409                 if uri:
 410                         path = get_local_path(escape(uri))
 411                         if path:
 412                                 if not self.confirm_new_path(path):
 413                                         to_send = 'E'
 414                                 else:
 415                                         try:
 416                                                 self.set_sensitive(False)
 417                                                 try:
 418                                                         self.document.save_to_file(path)
 419                                                 finally:
 420                                                         self.set_sensitive(True)
 421                                                 self.data_sent = True
 422                                         except:
 423                                                 _report_save_error()
 424                                                 self.data_sent = False
 425                                         if self.data_sent:
 426                                                 to_send = 'S'
 427                                 # (else Error)
 428                         else:
 429                                 to_send = 'F'   # Non-local transfer
 430                 else:
 431                         alert("Remote application wants to use " +
 432                                   "Direct Save, but I can't read the " +
 433                                   "XdndDirectSave0 (type text/plain) " +
 434                                   "property.")
 435
 436                 selection_data.set(selection_data.target, 8, to_send)
 437
 438                 if to_send != 'E':
 439                         _write_xds_property(context, None)
 440                         self.set_uri(uri)
 441                 if self.data_sent:
 442                         self.save_done()
 443
 444         def confirm_new_path(self, path):
 445                 """User wants to save to this path. If it's different to the original path,
 446                 check that it doesn't exist and ask for confirmation if it does.
 447                 If document.save_last_stat is set, compare with os.stat for an existing file
 448                 and warn about changes.
 449                 Returns true to go ahead with the save."""
 450                 if not os.path.exists(path):
 451                         return True
 452                 if os.path.isdir(path):
 453                         rox.alert(_("'%s' already exists as a directory.") % path)
 454                         return False
 455                 if path == self.initial_uri:
 456                         if self.document.save_last_stat is None:
 457                                 return True             # OK. Nothing to compare with.
 458                         last = self.document.save_last_stat
 459                         stat = os.stat(path)
 460                         msg = []
 461                         if stat.st_mode != last.st_mode:
 462                                 msg.append(_("Permissions changed from %o to %o.") % \
 463                                                 (last.st_mode, stat.st_mode))
 464                         if stat.st_size != last.st_size:
 465                                 msg.append(_("Size was %d bytes; now %d bytes.") % \
 466                                                 (last.st_size, stat.st_size))
 467                         if stat.st_mtime != last.st_mtime:
 468                                 msg.append(_("Modification time changed."))
 469                         if not msg:
 470                                 return True             # No change detected
 471                         return rox.confirm("File '%s' edited by another program since last load/save. "
 472                                            "Really save (discarding other changes)?\n\n%s" %
 473                                            (path, '\n'.join(msg)), g.STOCK_DELETE)
 474                 return rox.confirm(_("File '%s' already exists -- overwrite it?") % path,
 475                                    g.STOCK_DELETE, _('_Overwrite'))
 476
 477         def set_uri(self, uri):
 478                 """Data is safely saved somewhere. Update the document's URI and save_last_stat (for local saves).
 479                 URI is not escaped. Internal."""
 480                 path = get_local_path(escape(uri))
 481                 if path is not None:
 482                         self.document.save_last_stat = os.stat(path)    # Record for next time
 483                 self.document.set_uri(path or uri)
 484
 485         def drag_end(self, widget, context):
 486                 self.drag_in_progress = 0
 487                 if self.destroy_on_drag_end:
 488                         self.save_done()
 489
 490         def save_done(self):
 491                 self.document.save_done()
 492
 493 class SaveBox(g.Dialog):
 494         """A SaveBox is a GtkDialog that contains a SaveArea and, optionally, a Discard button.
 495         Calls rox.toplevel_(un)ref automatically.
 496         """
 497         save_area = None
 498
 499         def __init__(self, document, uri, type = 'text/plain', discard = False):
 500                 """See SaveArea.__init__.
 501                 If discard is True then an extra discard button is added to the dialog."""
 502                 g.Dialog.__init__(self)
 503                 self.set_has_separator(False)
 504
 505                 self.add_button(g.STOCK_CANCEL, g.RESPONSE_CANCEL)
 506                 self.add_button(g.STOCK_SAVE, g.RESPONSE_OK)
 507                 self.set_default_response(g.RESPONSE_OK)
 508
 509                 if discard:
 510                         discard_area = g.HButtonBox()
 511
 512                         def discard_clicked(event):
 513                                 document.discard()
 514                                 self.destroy()
 515                         button = rox.ButtonMixed(g.STOCK_DELETE, _('_Discard'))
 516                         discard_area.pack_start(button, False, True, 2)
 517                         button.connect('clicked', discard_clicked)
 518                         button.unset_flags(g.CAN_FOCUS)
 519                         button.set_flags(g.CAN_DEFAULT)
 520                         self.vbox.pack_end(discard_area, False, True, 0)
 521                         self.vbox.reorder_child(discard_area, 0)
 522
 523                         discard_area.show_all()
 524
 525                 self.set_title(_('Save As:'))
 526                 self.set_position(g.WIN_POS_MOUSE)
 527                 self.set_wmclass('savebox', 'Savebox')
 528                 self.set_border_width(1)
 529
 530                 # Might as well make use of the new nested scopes ;-)
 531                 self.set_save_in_progress(0)
 532                 class BoxedArea(SaveArea):
 533                         def set_uri(area, uri):
 534                                 SaveArea.set_uri(area, uri)
 535                                 if discard:
 536                                         document.discard()
 537                         def save_done(area):
 538                                 document.save_done()
 539                                 self.destroy()
 540
 541                         def set_sensitive(area, sensitive):
 542                                 if self.window:
 543                                         # Might have been destroyed by now...
 544                                         self.set_save_in_progress(not sensitive)
 545                                         SaveArea.set_sensitive(area, sensitive)
 546                 save_area = BoxedArea(document, uri, type)
 547                 self.save_area = save_area
 548
 549                 save_area.show_all()
 550                 self.build_main_area()
 551
 552                 i = uri.rfind('/')
 553                 i = i + 1
 554                 # Have to do this here, or the selection gets messed up
 555                 save_area.entry.grab_focus()
 556                 g.Editable.select_region(save_area.entry, i, -1) # PyGtk bug
 557                 #save_area.entry.select_region(i, -1)
 558
 559                 def got_response(widget, response):
 560                         if self.save_in_progress:
 561                                 try:
 562                                         document.save_cancelled()
 563                                 except:
 564                                         rox.report_exception()
 565                                 return
 566                         if response == int(g.RESPONSE_CANCEL):
 567                                 self.destroy()
 568                         elif response == int(g.RESPONSE_OK):
 569                                 self.save_area.save_to_file_in_entry()
 570                         elif response == int(g.RESPONSE_DELETE_EVENT):
 571                                 pass
 572                         else:
 573                                 raise Exception('Unknown response!')
 574                 self.connect('response', got_response)
 575
 576                 rox.toplevel_ref()
 577                 self.connect('destroy', lambda w: rox.toplevel_unref())
 578
 579         def set_type(self, type, icon = None):
 580                 """See SaveArea's method of the same name."""
 581                 self.save_area.set_type(type, icon)
 582
 583         def build_main_area(self):
 584                 """Place self.save_area somewhere in self.vbox. Override this
 585                 for more complicated layouts."""
 586                 self.vbox.add(self.save_area)
 587
 588         def set_save_in_progress(self, in_progress):
 589                 """Called when saving starts and ends. Shade/unshade any widgets as
 590                 required. Make sure you call the default method too!
 591                 Not called if box is destroyed from a recursive mainloop inside
 592                 a save_to_* function."""
 593                 self.set_response_sensitive(g.RESPONSE_OK, not in_progress)
 594                 self.save_in_progress = in_progress
 595
 596 class StringSaver(SaveBox, Saveable):
 597         """A very simple SaveBox which saves the string passed to its constructor."""
 598         def __init__(self, string, name):
 599                 """'string' is the string to save. 'name' is the default filename"""
 600                 SaveBox.__init__(self, self, name, 'text/plain')
 601                 self.string = string
 602
 603         def save_to_stream(self, stream):
 604                 stream.write(self.string)
 605
 606 class SaveFilter(Saveable):
 607         """This Saveable runs a process in the background to generate the
 608         save data. Any python streams can be used as the input to and
 609         output from the process.
 610
 611         The output from the subprocess is saved to the output stream (either
 612         directly, for fileno() streams, or via another temporary file).
 613
 614         If the process returns a non-zero exit status or writes to stderr,
 615         the save fails (messages written to stderr are displayed).
 616         """
 617
 618         command = None
 619         stdin = None
 620
 621         def set_stdin(self, stream):
 622                 """Use 'stream' as stdin for the process. If stream is not a
 623                 seekable fileno() stream then it is copied to a temporary file
 624                 at this point. If None, the child process will get /dev/null on
 625                 stdin."""
 626                 if stream is not None:
 627                         if hasattr(stream, 'fileno') and hasattr(stream, 'seek'):
 628                                 self.stdin = stream
 629                         else:
 630                                 import tempfile
 631                                 import shutil
 632                                 self.stdin = tempfile.TemporaryFile()
 633                                 shutil.copyfileobj(stream, self.stdin)
 634                 else:
 635                         self.stdin = None
 636
 637         def save_to_stream(self, stream):
 638                 from processes import PipeThroughCommand
 639
 640                 assert not hasattr(self, 'child_run')   # No longer supported
 641
 642                 self.process = PipeThroughCommand(self.command, self.stdin, stream)
 643                 self.process.wait()
 644                 self.process = None
 645
 646         def save_cancelled(self):
 647                 """Send SIGTERM to the child processes."""
 648                 if self.process:
 649                         self.killed = 1
 650                         self.process.kill()