MTP: Implement prepare_addable_books and refactor the GUI to run prepare_addable_books in the device thread

src/calibre/devices/mtp/driver.py

@@ -7,13 +7,13 @@ __license__   = 'GPL v3'
 __copyright__ = '2012, Kovid Goyal <kovid at kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-import json, traceback, posixpath, importlib
+import json, traceback, posixpath, importlib, os
 from io import BytesIO
 
 from calibre import prints
 from calibre.constants import iswindows, numeric_version
 from calibre.devices.mtp.base import debug
-from calibre.ptempfile import SpooledTemporaryFile
+from calibre.ptempfile import SpooledTemporaryFile, PersistentTemporaryDirectory
 from calibre.utils.config import from_json, to_json
 from calibre.utils.date import now, isoformat
 
@@ -199,10 +199,32 @@ class MTP_DEVICE(BASE):
 
     # }}}
 
+    # Get files from the device {{{
     def get_file(self, path, outfile, end_session=True):
         f = self.filesystem_cache.resolve_mtp_id_path(path)
         self.get_mtp_file(f, outfile)
 
+    def prepare_addable_books(self, paths):
+        tdir = PersistentTemporaryDirectory('_prepare_mtp')
+        ans = []
+        for path in paths:
+            try:
+                f = self.filesystem_cache.resolve_mtp_id_path(path)
+            except Exception as e:
+                ans.append((path, e, traceback.format_exc()))
+                continue
+            base = os.path.join(tdir, '%s'%f.object_id)
+            os.mkdir(base)
+            with open(os.path.join(base, f.name), 'wb') as out:
+                try:
+                    self.get_mtp_file(f, out)
+                except Exception as e:
+                    ans.append((path, e, traceback.format_exc()))
+                else:
+                    ans.append(out.name)
+        return ans
+    # }}}
+
     def create_upload_path(self, path, mdata, fname):
         from calibre.devices import create_upload_path
         from calibre.utils.filenames import ascii_filename as sanitize

src/calibre/gui2/actions/add.py

@@ -10,9 +10,9 @@ from functools import partial
 
 from PyQt4.Qt import QPixmap, QTimer
 
-
+from calibre import as_unicode
-from calibre.gui2 import error_dialog, choose_files, \
+from calibre.gui2 import (error_dialog, choose_files, choose_dir,
-    choose_dir, warning_dialog, info_dialog
+        warning_dialog, info_dialog)
 from calibre.gui2.dialogs.add_empty_book import AddEmptyBookDialog
 from calibre.gui2.dialogs.progress import ProgressDialog
 from calibre.gui2.widgets import IMAGE_EXTENSIONS
@@ -400,12 +400,45 @@ class AddAction(InterfaceAction):
             d = error_dialog(self.gui, _('Add to library'), _('No book files found'))
             d.exec_()
             return
-        paths = self.gui.device_manager.device.prepare_addable_books(paths)
+
+        self.gui.device_manager.prepare_addable_books(self.Dispatcher(partial(
+            self.books_prepared, view)), paths)
+        self.bpd = ProgressDialog(_('Downloading books'),
+                msg=_('Downloading books from device'), parent=self.gui,
+                cancelable=False)
+        QTimer.singleShot(1000, self.show_bpd)
+
+    def show_bpd(self):
+        if self.bpd is not None:
+            self.bpd.show()
+
+    def books_prepared(self, view, job):
+        self.bpd.hide()
+        self.bpd = None
+        if job.exception is not None:
+            self.gui.device_job_exception(job)
+            return
+        paths = job.result
+        ok_paths = [x for x in paths if isinstance(x, basestring)]
+        failed_paths = [x for x in paths if isinstance(x, tuple)]
+        if failed_paths:
+            if not ok_paths:
+                msg = _('Could not download files from the device')
+                typ = error_dialog
+            else:
+                msg = _('Could not download some files from the device')
+                typ = warning_dialog
+            det_msg = [x[0]+ '\n    ' + as_unicode(x[1]) for x in failed_paths]
+            det_msg = '\n\n'.join(det_msg)
+            typ(self.gui, _('Could not download files'), msg, det_msg=det_msg,
+                    show=True)
+
+        if ok_paths:
             from calibre.gui2.add import Adder
             self.__adder_func = partial(self._add_from_device_adder, on_card=None,
                                                         model=view.model())
             self._adder = Adder(self.gui, self.gui.library_view.model().db,
                     self.Dispatcher(self.__adder_func), spare_server=self.gui.spare_server)
-        self._adder.add(paths)
+            self._adder.add(ok_paths)
 
 

src/calibre/gui2/device.py

@@ -443,6 +443,14 @@ class DeviceManager(Thread): # {{{
         return self.create_job_step(self._books, done,
                 description=_('Get list of books on device'), to_job=add_as_step_to_job)
 
+    def _prepare_addable_books(self, paths):
+        return self.device.prepare_addable_books(paths)
+
+    def prepare_addable_books(self, done, paths, add_as_step_to_job=None):
+        return self.create_job_step(self._prepare_addable_books, done, args=[paths],
+                description=_('Prepare files for transfer from device'),
+                to_job=add_as_step_to_job)
+
     def _annotations(self, path_map):
         return self.device.get_annotations(path_map)