Viewer: Ensure last read position is fully accurate

This is particularly important when quitting while autoscroll is active
as CFI is not updated during autoscroll.

src/calibre/gui2/viewer/ui.py

@@ -14,7 +14,7 @@ from threading import Thread
 
 from PyQt5.Qt import (
     QApplication, QCursor, QDockWidget, QEvent, QMenu, QMimeData, QModelIndex,
-    QPixmap, Qt, QToolBar, QUrl, QVBoxLayout, QWidget, pyqtSignal
+    QPixmap, Qt, QTimer, QToolBar, QUrl, QVBoxLayout, QWidget, pyqtSignal
 )
 
 from calibre import prints
@@ -87,7 +87,7 @@ class EbookViewer(MainWindow):
 
     def __init__(self, open_at=None, continue_reading=None, force_reload=False):
         MainWindow.__init__(self, None)
-        self.shutting_down = False
+        self.shutting_down = self.close_forced = False
         self.force_reload = force_reload
         connect_lambda(self.book_preparation_started, self, lambda self: self.loading_overlay(_(
             'Preparing book for first read, please wait')), type=Qt.QueuedConnection)
@@ -172,6 +172,7 @@ class EbookViewer(MainWindow):
         self.web_view.quit.connect(self.quit, type=Qt.QueuedConnection)
         self.web_view.shortcuts_changed.connect(self.shortcuts_changed)
         self.web_view.scrollbar_context_menu.connect(self.scrollbar_context_menu)
+        self.web_view.close_prep_finished.connect(self.close_prep_finished)
         self.actions_toolbar.initialize(self.web_view, self.search_dock.toggleViewAction())
         self.setCentralWidget(self.web_view)
         self.loading_overlay = LoadingOverlay(self)
@@ -568,7 +569,24 @@ class EbookViewer(MainWindow):
     def quit(self):
         self.close()
 
+    def force_close(self):
+        if not self.close_forced:
+            self.close_forced = True
+            self.quit()
+
+    def close_prep_finished(self, cfi):
+        if cfi:
+            self.cfi_changed(cfi)
+        self.force_close()
+
     def closeEvent(self, ev):
+        if self.current_book_data and self.web_view.view_is_ready and not self.close_forced:
+            ev.ignore()
+            if not self.shutting_down:
+                self.shutting_down = True
+                QTimer.singleShot(2000, self.force_close)
+                self.web_view.prepare_for_close()
+            return
         self.shutting_down = True
         self.search_widget.shutdown()
         try:

src/calibre/gui2/viewer/web_view.py

@@ -273,6 +273,7 @@ class ViewerBridge(Bridge):
     quit = from_js()
     customize_toolbar = from_js()
     scrollbar_context_menu = from_js(object, object, object)
+    close_prep_finished = from_js(object)
 
     create_view = to_js()
     start_book_load = to_js()
@@ -286,6 +287,7 @@ class ViewerBridge(Bridge):
     trigger_shortcut = to_js()
     set_system_palette = to_js()
     show_search_result = to_js()
+    prepare_for_close = to_js()
 
 
 def apply_font_settings(page_or_view):
@@ -445,6 +447,7 @@ class WebView(RestartingWebEngineView):
     quit = pyqtSignal()
     customize_toolbar = pyqtSignal()
     scrollbar_context_menu = pyqtSignal(object, object, object)
+    close_prep_finished = pyqtSignal(object)
     shortcuts_changed = pyqtSignal(object)
     paged_mode_changed = pyqtSignal()
     standalone_misc_settings_changed = pyqtSignal(object)
@@ -463,6 +466,7 @@ class WebView(RestartingWebEngineView):
         self.show_home_page_on_ready = True
         self._size_hint = QSize(int(w/3), int(w/2))
         self._page = WebPage(self)
+        self.view_is_ready = False
         self.bridge.bridge_ready.connect(self.on_bridge_ready)
         self.bridge.view_created.connect(self.on_view_created)
         self.bridge.content_file_changed.connect(self.on_content_file_changed)
@@ -494,6 +498,7 @@ class WebView(RestartingWebEngineView):
         self.bridge.quit.connect(self.quit)
         self.bridge.customize_toolbar.connect(self.customize_toolbar)
         self.bridge.scrollbar_context_menu.connect(self.scrollbar_context_menu)
+        self.bridge.close_prep_finished.connect(self.close_prep_finished)
         self.bridge.export_shortcut_map.connect(self.set_shortcut_map)
         self.shortcut_map = {}
         self.bridge.report_cfi.connect(self.call_callback)
@@ -578,6 +583,7 @@ class WebView(RestartingWebEngineView):
 
     def on_view_created(self, data):
         self.view_created.emit(data)
+        self.view_is_ready = True
 
     def on_content_file_changed(self, data):
         self.current_content_file = data
@@ -669,3 +675,6 @@ class WebView(RestartingWebEngineView):
 
     def palette_changed(self):
         self.execute_when_ready('set_system_palette', system_colors())
+
+    def prepare_for_close(self):
+        self.execute_when_ready('prepare_for_close')

src/pyj/read_book/view.pyj

@@ -172,7 +172,7 @@ class View:
         self.current_progress_frac = self.current_file_progress_frac = 0
         self.current_toc_node = self.current_toc_toplevel_node = None
         self.report_cfi_callbacks = {}
-        self.show_chrome_counter = 0
+        self.get_cfi_counter = 0
         self.show_loading_callback_timer = None
         self.timer_ids = {'clock': 0}
         self.book_scrollbar = BookScrollbar(self)
@@ -521,12 +521,11 @@ class View:
         self.iframe.contentWindow.focus()
 
     def show_chrome(self, data):
-        self.show_chrome_counter += 1
         elements = {}
         if data and data.elements:
             elements = data.elements
         initial_panel = data?.initial_panel or None
-        self.get_current_cfi('show-chrome-' + self.show_chrome_counter, self.do_show_chrome.bind(None, elements, initial_panel))
+        self.get_current_cfi('show-chrome', self.do_show_chrome.bind(None, elements, initial_panel))
 
     def do_show_chrome(self, elements, initial_panel, request_id, cfi_data):
         self.hide_overlays()
@@ -536,6 +535,13 @@ class View:
         else:
             self.overlay.show(elements)
 
+    def prepare_for_close(self):
+
+        def close_prepared(request_id, cfi_data):
+            ui_operations.close_prep_finished(cfi_data.cfi)
+
+        self.get_current_cfi('prepare-close', close_prepared)
+
     def show_search(self):
         self.hide_overlays()
         if runtime.is_standalone_viewer:
@@ -903,6 +909,8 @@ class View:
             self.goto_named_destination(toc_node.dest, toc_node.frag)
 
     def get_current_cfi(self, request_id, callback):
+        self.get_cfi_counter += 1
+        request_id += ':' + self.get_cfi_counter
         self.report_cfi_callbacks[request_id] = callback
         self.iframe_wrapper.send_message('get_current_cfi', request_id=request_id)
 
@@ -923,7 +931,7 @@ class View:
     def on_report_cfi(self, data):
         cb = self.report_cfi_callbacks[data.request_id]
         if cb:
-            cb(data.request_id, {
+            cb(data.request_id.rpartition(':')[0], {
                 'cfi': data.cfi,
                 'progress_frac': data.progress_frac,
                 'file_progress_frac': data.file_progress_frac,

src/pyj/viewer-main.pyj

@@ -293,6 +293,12 @@ def show_search_result(sr):
     if view:
         view.show_search_result(sr)
 
+@from_python
+def prepare_for_close():
+    if view:
+        view.prepare_for_close()
+    else:
+        ui_operations.close_prep_finished(None)
 
 def onerror(msg, script_url, line_number, column_number, error_object):
     if not error_object:
@@ -405,6 +411,8 @@ if window is window.top:
         to_python.search_result_not_found(sr)
     ui_operations.scrollbar_context_menu = def(x, y, frac):
         to_python.scrollbar_context_menu(x, y, frac)
+    ui_operations.close_prep_finished = def(cfi):
+        to_python.close_prep_finished(cfi)
 
     document.body.appendChild(E.div(id='view'))
     window.onerror = onerror