Use a separate process for the ToC Editor from the main GUI

This is needed because the main GUI does not use web engine

src/calibre/constants.py

@@ -44,6 +44,7 @@ VIEWER_APP_UID = 'com.calibre-ebook.viewer'
 EDITOR_APP_UID = 'com.calibre-ebook.edit-book'
 MAIN_APP_UID = 'com.calibre-ebook.main-gui'
 STORE_DIALOG_APP_UID = 'com.calibre-ebook.store-dialog'
+TOC_DIALOG_APP_UID = 'com.calibre-ebook.toc-editor'
 try:
     preferred_encoding = locale.getpreferredencoding()
     codecs.lookup(preferred_encoding)

src/calibre/gui2/actions/toc_edit.py

@@ -6,6 +6,7 @@ __license__   = 'GPL v3'
 __copyright__ = '2013, Kovid Goyal <kovid at kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
+import os
 from collections import OrderedDict
 
 from PyQt5.Qt import (QTimer, QDialog, QGridLayout, QCheckBox, QLabel,
@@ -13,6 +14,7 @@ from PyQt5.Qt import (QTimer, QDialog, QGridLayout, QCheckBox, QLabel,
 
 from calibre.gui2 import error_dialog, gprefs
 from calibre.gui2.actions import InterfaceAction
+from calibre.utils.monotonic import monotonic
 from polyglot.builtins import iteritems, unicode_type
 
 SUPPORTED = {'EPUB', 'AZW3'}
@@ -100,6 +102,7 @@ class ToCEditAction(InterfaceAction):
 
     def genesis(self):
         self.qaction.triggered.connect(self.edit_books)
+        self.jobs = []
 
     def get_supported_books(self, book_ids):
         db = self.gui.library_view.model().db
@@ -138,15 +141,50 @@ class ToCEditAction(InterfaceAction):
                 self.do_one(book_id, fmt)
 
     def do_one(self, book_id, fmt):
-        from calibre.gui2.toc.main import TOCEditor
         db = self.gui.current_db
         path = db.format(book_id, fmt, index_is_id=True, as_path=True)
         title = db.title(book_id, index_is_id=True) + ' [%s]'%fmt
-        d = TOCEditor(path, title=title, parent=self.gui)
-        d.start()
-        if d.exec_() == d.Accepted:
-            with open(path, 'rb') as f:
-                db.add_format(book_id, fmt, f, index_is_id=True)
+        data = {'path': path, 'title': title}
+        self.gui.job_manager.launch_gui_app('toc-dialog', kwargs=data)
+        job = data.copy()
+        job.update({'book_id': book_id, 'fmt': fmt, 'library_id': db.new_api.library_id, 'started': False, 'start_time': monotonic()})
+        self.jobs.append(job)
+        self.check_for_completions()
+
+    def check_for_completions(self):
+        from calibre.utils.lock import lock_file
+        for job in tuple(self.jobs):
+            lock_path = job['path'] + '.lock'
+            if job['started']:
+                if not os.path.exists(lock_path):
+                    self.jobs.remove(job)
+                    continue
+                try:
+                    lf = lock_file(lock_path, timeout=0.01, sleep_time=0.005)
+                except EnvironmentError:
+                    continue
+                else:
+                    self.jobs.remove(job)
+                    ret = int(lf.read().decode('ascii'))
+                    lf.close()
+                    os.remove(lock_path)
+                    if ret == 0:
+                        db = self.gui.current_db
+                        if db.new_api.library_id != job['library_id']:
+                            error_dialog(self.gui, _('Library changed'), _(
+                                'Cannot save changes made to {0} by the ToC editor as'
+                                ' the calibre library has changed.').format(job['title']), show=True)
+                        else:
+                            db.new_api.add_format(job['book_id'], job['fmt'], job['path'], run_hooks=False)
+                    os.remove(job['path'])
+            else:
+                if monotonic() - job['start_time'] > 10:
+                    self.jobs.remove(job)
+                    continue
+                if os.path.exists(lock_path):
+                    job['started'] = True
+        if self.jobs:
+            QTimer.singleShot(100, self.check_for_completions)
 
     def edit_books(self):
         book_id_map = self.get_books_for_editing()

src/calibre/gui2/jobs.py

@@ -281,9 +281,9 @@ class JobManager(QAbstractTableModel, AdaptSQP):  # {{{
         self.add_job(job)
         self.threaded_server.add_job(job)
 
-    def launch_gui_app(self, name, args=[], kwargs={}, description=''):
+    def launch_gui_app(self, name, args=(), kwargs=None, description=''):
         job = ParallelJob(name, description, lambda x: x,
-                args=args, kwargs=kwargs)
+                args=list(args), kwargs=kwargs or {})
         self.server.run_job(job, gui=True, redirect_output=False)
 
     def _kill_job(self, job):

src/calibre/gui2/toc/main.py

@@ -1,29 +1,37 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:fdm=marker:ai
+# License: GPLv3 Copyright: 2013, Kovid Goyal <kovid at kovidgoyal.net>
+
 from __future__ import absolute_import, division, print_function, unicode_literals
 
-__license__   = 'GPL v3'
-__copyright__ = '2013, Kovid Goyal <kovid at kovidgoyal.net>'
-__docformat__ = 'restructuredtext en'
-
-import sys, os, textwrap
-from threading import Thread
+import os
+import sys
+import textwrap
 from functools import partial
+from threading import Thread
 
-from PyQt5.Qt import (QPushButton, QFrame, QMenu, QInputDialog, QCheckBox,
-    QDialog, QVBoxLayout, QDialogButtonBox, QSize, QStackedWidget, QWidget,
-    QLabel, Qt, pyqtSignal, QIcon, QTreeWidget, QGridLayout, QTreeWidgetItem,
-    QToolButton, QItemSelectionModel, QCursor, QKeySequence, QSizePolicy)
+from PyQt5.Qt import (
+    QCheckBox, QCursor, QDialog, QDialogButtonBox, QFrame, QGridLayout, QIcon,
+    QInputDialog, QItemSelectionModel, QKeySequence, QLabel, QMenu, QPushButton,
+    QSize, QSizePolicy, QStackedWidget, Qt, QToolButton, QTreeWidget,
+    QTreeWidgetItem, QVBoxLayout, QWidget, pyqtSignal
+)
 
-from calibre.ebooks.oeb.polish.container import get_container, AZW3Container
+from calibre.constants import TOC_DIALOG_APP_UID, islinux, iswindows
+from calibre.ebooks.oeb.polish.container import AZW3Container, get_container
 from calibre.ebooks.oeb.polish.toc import (
-    get_toc, add_id, TOC, commit_toc, from_xpaths, from_links, from_files)
-from calibre.gui2 import Application, error_dialog, gprefs, info_dialog, question_dialog
+    TOC, add_id, commit_toc, from_files, from_links, from_xpaths, get_toc
+)
+from calibre.gui2 import (
+    Application, error_dialog, gprefs, info_dialog, question_dialog, set_app_uid
+)
+from calibre.gui2.convert.xpath_wizard import XPathEdit
 from calibre.gui2.progress_indicator import ProgressIndicator
 from calibre.gui2.toc.location import ItemEdit
-from calibre.gui2.convert.xpath_wizard import XPathEdit
+from calibre.ptempfile import reset_base_dir
+from calibre.utils.lock import ExclusiveFile
 from calibre.utils.logging import GUILog
-from polyglot.builtins import map, unicode_type, range
+from polyglot.builtins import map, range, unicode_type
 
 ICON_SIZE = 24
 
@@ -1117,10 +1125,30 @@ class TOCEditor(QDialog):  # {{{
 # }}}
 
 
-if __name__ == '__main__':
-    app = Application([], force_calibre_style=True)
-    app
-    d = TOCEditor(sys.argv[-1])
+def main(path=None, title=None):
+    # Ensure we can continue to function if GUI is closed
+    os.environ.pop('CALIBRE_WORKER_TEMP_DIR', None)
+    reset_base_dir()
+    if iswindows:
+        # Ensure that all instances are grouped together in the task bar. This
+        # prevents them from being grouped with viewer/editor process when
+        # launched from within calibre, as both use calibre-parallel.exe
+        set_app_uid(TOC_DIALOG_APP_UID)
+
+    with ExclusiveFile(path + '.lock') as wf:
+        override = 'calibre-gui' if islinux else None
+        app = Application([], override_program_name=override)
+        d = TOCEditor(path, title=title)
         d.start()
-    d.exec_()
-    del d  # Needed to prevent sigsegv in exit cleanup
+        ret = 1
+        if d.exec_() == d.Accepted:
+            ret = 0
+        wf.write('{}'.format(ret).encode('ascii'))
+    del d
+    del app
+    raise SystemExit(ret)
+
+
+if __name__ == '__main__':
+    main(path=sys.argv[-1], title='test')
+    os.remove(sys.argv[-1] + '.lock')

src/calibre/gui_launch.py

@@ -88,6 +88,13 @@ def store_dialog(args=sys.argv):
     main(args)
 
 
+def toc_dialog(**kw):
+    detach_gui()
+    init_dbus()
+    from calibre.gui2.toc.main import main
+    main(**kw)
+
+
 def gui_ebook_edit(path=None, notify=None):
     ' For launching the editor from inside calibre '
     init_dbus()

src/calibre/utils/ipc/worker.py

@@ -32,6 +32,9 @@ PARALLEL_FUNCS = {
     'store-dialog' :
     ('calibre.gui_launch', 'store_dialog', None),
 
+    'toc-dialog' :
+    ('calibre.gui_launch', 'toc_dialog', None),
+
     'render_pages' :
     ('calibre.ebooks.comic.input', 'render_pages', 'notification'),
 

src/calibre/utils/lock.py

@@ -85,6 +85,19 @@ def retry_for_a_time(timeout, sleep_time, func, error_retry, *args):
         time.sleep(sleep_time)
 
 
+def lock_file(path, timeout=15, sleep_time=0.2):
+    if iswindows:
+        return retry_for_a_time(
+            timeout, sleep_time, windows_open, windows_retry, path
+        )
+    f = unix_open(path)
+    retry_for_a_time(
+        timeout, sleep_time, fcntl.flock, unix_retry,
+        f.fileno(), fcntl.LOCK_EX | fcntl.LOCK_NB
+    )
+    return f
+
+
 class ExclusiveFile(object):
 
     def __init__(self, path, timeout=15, sleep_time=0.2):
@@ -95,17 +108,7 @@ class ExclusiveFile(object):
         self.sleep_time = sleep_time
 
     def __enter__(self):
-        if iswindows:
-            self.file = retry_for_a_time(
-                self.timeout, self.sleep_time, windows_open, windows_retry, self.path
-            )
-        else:
-            f = unix_open(self.path)
-            retry_for_a_time(
-                self.timeout, self.sleep_time, fcntl.flock, unix_retry,
-                f.fileno(), fcntl.LOCK_EX | fcntl.LOCK_NB
-            )
-            self.file = f
+        self.file = lock_file(self.path, self.timeout, self.sleep_time)
         return self.file
 
     def __exit__(self, type, value, traceback):