Remove the notify() debug redirection as it greatly slows down startup and also causes hangs in some not fully understood situations

src/calibre/gui2/__init__.py

@@ -882,8 +882,6 @@ class Application(QApplication):
             args = [override_program_name] + args[1:]
         qargs = [i.encode('utf-8') if isinstance(i, unicode) else i for i in args]
         self.pi = plugins['progress_indicator'][0]
-        if DEBUG:
-            self.redirect_notify = True
         self.setup_styles(force_calibre_style)
         QApplication.__init__(self, qargs)
         f = QFont(QApplication.font())
@@ -913,15 +911,6 @@ class Application(QApplication):
         qt_app = self
         self._file_open_paths = []
         self._file_open_lock = RLock()
-    if DEBUG:
-        def notify(self, receiver, event):
-            if self.redirect_notify:
-                self.redirect_notify = False
-                return self.pi.do_notify(receiver, event)
-            else:
-                ret = QApplication.notify(self, receiver, event)
-                self.redirect_notify = True
-                return ret
 
     def load_builtin_fonts(self, scan_for_fonts=False):
         if scan_for_fonts:

src/calibre/gui2/progress_indicator/QProgressIndicator.cpp

@@ -219,18 +219,6 @@ int load_style(QHash<int,QString> icon_map) {
     return 0;
 }
 
-bool do_notify(QObject *receiver, QEvent *event) {
-    try {
-        return QApplication::instance()->notify(receiver, event);
-    } catch (std::exception& e) {
-        qCritical() << "C++ exception thrown in slot: " << e.what();
-    } catch (...) {
-        qCritical() << "Unknown C++ exception thrown in slot";
-    }
-    qCritical() << "Receiver name:" << receiver->objectName() << "Receiver class:" << receiver->metaObject()->className() << "Event type: " << event->type();
-    return false;
-}
-
 class NoActivateStyle: public QProxyStyle { 
  	public: 
         int styleHint(StyleHint hint, const QStyleOption *option = 0, const QWidget *widget = 0, QStyleHintReturn *returnData = 0) const { 

src/calibre/gui2/progress_indicator/QProgressIndicator.h

@@ -92,16 +92,6 @@ private:
     QColor m_color;
 };
 
-/* Utility function that can be used to load a QStyle from a Qt plugin. This is
- * here so that there is no need to create a separate PyQt plugin just for this
- * simple functionality. 
- * \param path The full path to the DLL containing the plugin
- * \param name The name of the style plugin to load
- * \return 1 if succeeds 0 otherwise. The objectName of the loaded style is set to name
- */
 int load_style(QHash<int,QString> icon_map);
-
-bool do_notify(QObject *receiver, QEvent *event);
-
 void set_no_activate_on_click(QWidget *widget);
 void set_touch_menu_style(QWidget *widget, int margin=14);

src/calibre/gui2/progress_indicator/QProgressIndicator.sip

@@ -7,7 +7,6 @@
 
 %ModuleHeaderCode
 int load_style(QHash<int,QString> icon_map);
-bool do_notify(QObject *receiver, QEvent *event);
 void set_no_activate_on_click(QWidget *widget);
 void set_touch_menu_style(QWidget *widget, int margin);
 %End
@@ -58,8 +57,5 @@ protected:
 };
 
 int load_style(QHash<int,QString> icon_map);
-
-bool do_notify(QObject *receiver, QEvent *event);
-
 void set_no_activate_on_click(QWidget *widget);
 void set_touch_menu_style(QWidget *widget, int margin=20);