Move TTS UI logic into its own module

src/calibre/gui2/viewer/tts.py

@@ -0,0 +1,45 @@
+#!/usr/bin/env python
+# vim:fileencoding=utf-8
+# License: GPL v3 Copyright: 2020, Kovid Goyal <kovid at kovidgoyal.net>
+
+from PyQt5.Qt import QObject, pyqtSignal
+from calibre.gui2 import error_dialog
+
+
+class TTS(QObject):
+
+    dispatch_on_main_thread_signal = pyqtSignal(object)
+
+    def __init__(self, parent=None):
+        QObject.__init__(self, parent)
+        self._tts_client = None
+        self.dispatch_on_main_thread_signal.connect(self.dispatch_on_main_thread)
+
+    def dispatch_on_main_thread(self, func):
+        try:
+            func()
+        except Exception:
+            import traceback
+            traceback.print_exc()
+
+    @property
+    def tts_client(self):
+        if self._tts_client is None:
+            from calibre.gui2.tts.implementation import Client
+            self._tts_client = Client(self.dispatch_on_main_thread_signal.emit)
+        return self._tts_client
+
+    def shutdown(self):
+        if self._tts_client is not None:
+            self._tts_client.shutdown()
+            self._tts_client = None
+
+    def speak_simple_text(self, text):
+        from calibre.gui2.tts.errors import TTSSystemUnavailable
+        try:
+            self.tts_client.speak_simple_text(text)
+        except TTSSystemUnavailable as err:
+            return error_dialog(self.parent(), _('Text-to-Speech unavailable'), str(err), show=True)
+
+    def action(self, action, data):
+        pass

src/calibre/gui2/viewer/web_view.py

@@ -25,6 +25,7 @@ from calibre.ebooks.metadata.book.base import field_metadata
 from calibre.ebooks.oeb.polish.utils import guess_type
 from calibre.gui2 import choose_images, error_dialog, safe_open_url
 from calibre.gui2.viewer.config import viewer_config_dir, vprefs
+from calibre.gui2.viewer.tts import TTS
 from calibre.gui2.webengine import (
     Bridge, RestartingWebEngineView, create_script, from_js, insert_scripts,
     secure_webengine, to_js
@@ -465,18 +466,16 @@ class WebView(RestartingWebEngineView):
     paged_mode_changed = pyqtSignal()
     standalone_misc_settings_changed = pyqtSignal(object)
     view_created = pyqtSignal(object)
-    dispatch_on_main_thread_signal = pyqtSignal(object)
 
     def __init__(self, parent=None):
         self._host_widget = None
-        self._tts_client = None
         self.callback_id_counter = count()
         self.callback_map = {}
         self.current_cfi = self.current_content_file = None
         RestartingWebEngineView.__init__(self, parent)
+        self.tts = TTS(self)
         self.dead_renderer_error_shown = False
         self.render_process_failed.connect(self.render_process_died)
-        self.dispatch_on_main_thread_signal.connect(self.dispatch_on_main_thread)
         w = QApplication.instance().desktop().availableGeometry(self).width()
         QApplication.instance().palette_changed.connect(self.palette_changed)
         self.show_home_page_on_ready = True
@@ -519,8 +518,8 @@ class WebView(RestartingWebEngineView):
         self.bridge.close_prep_finished.connect(self.close_prep_finished)
         self.bridge.highlights_changed.connect(self.highlights_changed)
         self.bridge.open_url.connect(safe_open_url)
-        self.bridge.speak_simple_text.connect(self.speak_simple_text)
+        self.bridge.speak_simple_text.connect(self.tts.speak_simple_text)
-        self.bridge.tts.connect(self.tts_action)
+        self.bridge.tts.connect(self.tts.action)
         self.bridge.export_shortcut_map.connect(self.set_shortcut_map)
         self.shortcut_map = {}
         self.bridge.report_cfi.connect(self.call_callback)
@@ -534,34 +533,8 @@ class WebView(RestartingWebEngineView):
             self.inspector = Inspector(parent.inspector_dock.toggleViewAction(), self)
             parent.inspector_dock.setWidget(self.inspector)
 
-    @property
-    def tts_client(self):
-        if self._tts_client is None:
-            from calibre.gui2.tts.implementation import Client
-            self._tts_client = Client(self.dispatch_on_main_thread_signal.emit)
-        return self._tts_client
-
-    def dispatch_on_main_thread(self, func):
-        try:
-            func()
-        except Exception:
-            import traceback
-            traceback.print_exc()
-
-    def speak_simple_text(self, text):
-        from calibre.gui2.tts.errors import TTSSystemUnavailable
-        try:
-            self.tts_client.speak_simple_text(text)
-        except TTSSystemUnavailable as err:
-            return error_dialog(self, _('Text-to-Speech unavailable'), str(err), show=True)
-
-    def tts_action(self, action, data):
-        pass
-
     def shutdown(self):
-        if self._tts_client is not None:
+        self.tts.shutdown()
-            self._tts_client.shutdown()
-            self._tts_client = None
 
     def set_shortcut_map(self, smap):
         self.shortcut_map = smap