[Bugs] #2833 UNSP: add support for PDF export (was: Browse must be save a page to PDF for offline reading.)

[Sugar Labs Bugs]

#2833: add support for PDF export
------------------------------------------+---------------------------------
    Reporter:  godiard                    |          Owner:  lucian                     
        Type:  enhancement                |         Status:  new                        
    Priority:  Unspecified by Maintainer  |      Milestone:  Unspecified by Release Team
   Component:  Browse                     |        Version:  Git as of bugdate          
    Severity:  Unspecified                |       Keywords:                             
Distribution:                             |   Status_field:  New                        
------------------------------------------+---------------------------------
Changes (by sascha_silbe):

  * distribution:  Unspecified =>
  * version:  Unspecified => Git as of bugdate
  * status_field:  Unconfirmed => New


Comment:

 For reading web pages offline there are other, potentially better
 solutions (e.g. Lucians [http://wiki.sugarlabs.org/go/Webified Webified]
 work, wwwoffle). Nevertheless I took a stab at implementing PDF support.

 This is the code I added to {{{browser.Browser}}}:

 {{{
     def export_pdf(self):
         cls = components.classes['@mozilla.org/gfx/printsettings-
 service;1']
         setting_service =
 cls.getService(interfaces.nsIPrintSettingsService)
         req =
 self.get_dom_window().QueryInterface(interfaces.nsIInterfaceRequestor)
         print_iface = req.getInterface(interfaces.nsIWebBrowserPrint)

         temp_dir = os.path.join(activity.get_activity_root(), 'instance')
         pdf_file = tempfile.NamedTemporaryFile(suffix='.pdf',
 dir=temp_dir,
                                                delete=False)

         settings = setting_service.newPrintSettings
         settings.printSilent = True
         settings.printToFile = True
         settings.toFileName = pdf_file.name
         settings.outputFormat =
 interfaces.nsIPrintSettings.kOutputFormatPDF

 #        print_iface.print(printSettings, None)
         getattr(print_iface, 'print')(printSettings, None)
 }}}

 It fails with the following error:

 {{{
 Traceback (most recent call last):
   File "/home/sascha.silbe/sugar-
 jhbuild/install/share/sugar/activities/Browse.activity/webtoolbar.py",
 line 494, in _export_pdf_cb
     browser.export_pdf()
   File "/home/sascha.silbe/sugar-
 jhbuild/install/share/sugar/activities/Browse.activity/browser.py", line
 320, in export_pdf
     logging.debug('print: %r', getattr(print_iface, 'print'))
   File "/usr/lib/pymodules/python2.6/xpcom/client/__init__.py", line 374,
 in __getattr__
     return getattr(interface, attr)
   File "/usr/lib/pymodules/python2.6/xpcom/client/__init__.py", line 466,
 in __getattr__
     unbound_method = BuildMethod(method_info, self._iid_)
   File "/usr/lib/pymodules/python2.6/xpcom/client/__init__.py", line 125,
 in BuildMethod
     codeObject = compile(method_code, "<XPCOMObject method '%s'>" %
 (name,), "exec")
   File "<XPCOMObject method 'print'>", line 2
     def print(self, Param1, Param2):
             ^
 SyntaxError: invalid syntax
 }}}

 The problem is that {{{print}}} is a reserved keyword in Python 2. XPCOM
 would need to rename {{{print}}} to something else, e.g. {{{print_}}}. I'm
 not sure how feasible it is to get that fix rolled out to the
 distributions that still ship a python-xpcom we can use in the first place
 (Ubuntu doesn't ship it at all and recent versions of Fedora are
 [ticket:2772 broken], too).

-- 
Ticket URL: <http://bugs.sugarlabs.org/ticket/2833#comment:4>
Sugar Labs <http://sugarlabs.org/>
Sugar Labs bug tracking system