Make setting of app uids on windows more robust

src/calibre/constants.py

@@ -39,9 +39,9 @@ isworker = 'CALIBRE_WORKER' in os.environ or 'CALIBRE_SIMPLE_WORKER' in os.envir
 if isworker:
     os.environ.pop('CALIBRE_FORCE_ANSI', None)
 FAKE_PROTOCOL, FAKE_HOST = 'https', 'calibre-internal.invalid'
-VIEWER_APP_UID = 'com.calibre-ebook.viewer'
-EDITOR_APP_UID = 'com.calibre-ebook.edit-book'
-MAIN_APP_UID = 'com.calibre-ebook.main-gui'
+VIEWER_APP_UID = u'com.calibre-ebook.viewer'
+EDITOR_APP_UID = u'com.calibre-ebook.edit-book'
+MAIN_APP_UID = u'com.calibre-ebook.main-gui'
 try:
     preferred_encoding = locale.getpreferredencoding()
     codecs.lookup(preferred_encoding)

src/calibre/gui2/__init__.py

@@ -11,7 +11,7 @@ from PyQt5.Qt import (
     QDesktopServices, QFileDialog, QFileIconProvider, QSettings, QIcon, QStringListModel,
     QApplication, QDialog, QUrl, QFont, QFontDatabase, QLocale, QFontInfo)
 
-from calibre import prints
+from calibre import prints, as_unicode
 from calibre.constants import (islinux, iswindows, isbsd, isfrozen, isosx, is_running_from_develop,
         plugins, config_dir, filesystem_encoding, isxp, DEBUG, __version__, __appname__ as APP_UID)
 from calibre.ptempfile import base_dir
@@ -1286,3 +1286,39 @@ def secure_web_page(qwebpage_or_qwebsettings):
 
 empty_model = QStringListModel([''])
 empty_index = empty_model.index(0)
+
+
+def get_app_uid():
+    import ctypes
+    from ctypes import wintypes
+    lpBuffer = wintypes.LPWSTR()
+    try:
+        AppUserModelID = ctypes.windll.shell32.GetCurrentProcessExplicitAppUserModelID
+    except Exception:  # Vista has no app uids
+        return
+    AppUserModelID.argtypes = [wintypes.LPWSTR]
+    AppUserModelID.restype = wintypes.HRESULT
+    try:
+        AppUserModelID(ctypes.cast(ctypes.byref(lpBuffer), wintypes.LPWSTR))
+    except Exception:
+        return
+    appid = lpBuffer.value
+    ctypes.windll.ole32.CoTaskMemFree(lpBuffer)
+    return appid
+
+
+def set_app_uid(val):
+    import ctypes
+    from ctypes import wintypes
+    try:
+        AppUserModelID = ctypes.windll.shell32.SetCurrentProcessExplicitAppUserModelID
+    except Exception:  # Vista has no app uids
+        return False
+    AppUserModelID.argtypes = [wintypes.LPCWSTR]
+    AppUserModelID.restype = wintypes.HRESULT
+    try:
+        AppUserModelID(unicode(val))
+    except Exception as err:
+        prints(u'Failed to set app uid with error:', as_unicode(err))
+        return False
+    return True

src/calibre/gui2/main.py

@@ -15,12 +15,12 @@ from PyQt5.Qt import QCoreApplication, QIcon, QObject, QTimer
 
 from calibre import force_unicode, plugins, prints
 from calibre.constants import (
-    DEBUG, __appname__, filesystem_encoding, get_portable_base, islinux, isosx,
-    iswindows, MAIN_APP_UID
+    DEBUG, MAIN_APP_UID, __appname__, filesystem_encoding, get_portable_base,
+    islinux, isosx, iswindows
 )
 from calibre.gui2 import (
     Application, choose_dir, error_dialog, gprefs, initialize_file_icon_provider,
-    question_dialog, setup_gui_option_parser
+    question_dialog, set_app_uid, setup_gui_option_parser
 )
 from calibre.gui2.main_window import option_parser as _option_parser
 from calibre.gui2.splash_screen import SplashScreen
@@ -522,11 +522,7 @@ def main(args=sys.argv):
         # Ensure that all ebook editor instances are grouped together in the task
         # bar. This prevents them from being grouped with viewer process when
         # launched from within calibre, as both use calibre-parallel.exe
-        import ctypes
-        try:
-            ctypes.windll.shell32.SetCurrentProcessExplicitAppUserModelID(MAIN_APP_UID)
-        except Exception:
-            pass  # Only available on windows 7 and newer
+        set_app_uid(MAIN_APP_UID)
 
     try:
         app, opts, args = init_qt(args)

src/calibre/gui2/tweak_book/main.py

@@ -11,7 +11,7 @@ from PyQt5.Qt import QIcon
 
 from calibre.constants import EDITOR_APP_UID, islinux, iswindows
 from calibre.gui2 import (
-    Application, decouple, set_gui_prefs, setup_gui_option_parser
+    Application, decouple, set_app_uid, set_gui_prefs, setup_gui_option_parser
 )
 from calibre.ptempfile import reset_base_dir
 from calibre.utils.config import OptionParser
@@ -57,13 +57,7 @@ def _run(args, notify=None):
         # Ensure that all ebook editor instances are grouped together in the task
         # bar. This prevents them from being grouped with viewer process when
         # launched from within calibre, as both use calibre-parallel.exe
-        import ctypes
-        try:
-            ctypes.windll.shell32.SetCurrentProcessExplicitAppUserModelID(
-                EDITOR_APP_UID
-            )
-        except Exception:
-            pass  # Only available on windows 7 and newer
+        set_app_uid(EDITOR_APP_UID)
 
     # The following two lines are needed to prevent circular imports causing
     # errors during initialization of plugins that use the polish container

src/calibre/gui2/viewer/main.py

@@ -22,7 +22,7 @@ from calibre.customize.ui import available_input_formats
 from calibre.ebooks.oeb.iterator.book import EbookIterator
 from calibre.gui2 import (
     Application, choose_files, error_dialog, info_dialog, open_url,
-    setup_gui_option_parser
+    setup_gui_option_parser, set_app_uid
 )
 from calibre.gui2.viewer.toc import TOC
 from calibre.gui2.viewer.ui import Main as MainWindow
@@ -1262,11 +1262,7 @@ def main(args=sys.argv):
         # Ensure that all ebook editor instances are grouped together in the task
         # bar. This prevents them from being grouped with viewer process when
         # launched from within calibre, as both use calibre-parallel.exe
-        import ctypes
-        try:
-            ctypes.windll.shell32.SetCurrentProcessExplicitAppUserModelID(VIEWER_APP_UID)
-        except Exception:
-            pass  # Only available on windows 7 and newer
+        set_app_uid(VIEWER_APP_UID)
 
     parser = option_parser()
     opts, args = parser.parse_args(args)