Implement save/restore of last read position

src/calibre/gui2/viewer/ui.py

@@ -7,15 +7,22 @@ from __future__ import absolute_import, division, print_function, unicode_litera
 import os
 from threading import Thread
 
-from PyQt5.Qt import QDockWidget, Qt, pyqtSignal
+from PyQt5.Qt import QDockWidget, Qt, QTimer, pyqtSignal
 
 from calibre.gui2 import error_dialog
 from calibre.gui2.main_window import MainWindow
 from calibre.gui2.viewer.convert_book import prepare_book
 from calibre.gui2.viewer.web_view import WebView, set_book_path
+from calibre.utils.config import JSONConfig
 from calibre.utils.ipc.simple_worker import WorkerError
 
 
+def viewer_data():
+    if not hasattr(viewer_data, 'ans'):
+        viewer_data.ans = JSONConfig('viewer-data')
+    return viewer_data.ans
+
+
 class EbookViewer(MainWindow):
 
     msg_from_anotherinstance = pyqtSignal(object)
@@ -23,6 +30,9 @@ class EbookViewer(MainWindow):
 
     def __init__(self):
         MainWindow.__init__(self, None)
+        self.current_book_data = {}
+        self.save_cfi_debounce_timer = t = QTimer(self)
+        t.setInterval(2000), t.timeout.connect(self.save_cfi)
         self.book_prepared.connect(self.load_finished, type=Qt.QueuedConnection)
 
         def create_dock(title, name, area, areas=Qt.LeftDockWidgetArea | Qt.RightDockWidgetArea):
@@ -35,6 +45,7 @@ class EbookViewer(MainWindow):
         self.toc_dock = create_dock(_('Table of Contents'), 'toc-dock', Qt.LeftDockWidgetArea)
         self.inspector_dock = create_dock(_('Inspector'), 'inspector', Qt.RightDockWidgetArea)
         self.web_view = WebView(self)
+        self.web_view.cfi_changed.connect(self.cfi_changed)
         self.setCentralWidget(self.web_view)
 
     def handle_commandline_arg(self, arg):
@@ -51,6 +62,9 @@ class EbookViewer(MainWindow):
 
     def load_ebook(self, pathtoebook, open_at=None):
         # TODO: Implement open_at
+        if self.save_cfi_debounce_timer.isActive():
+            self.save_cfi()
+        self.current_book_data = {}
         t = Thread(name='LoadBook', target=self._load_ebook_worker, args=(pathtoebook, open_at))
         t.daemon = True
         t.start()
@@ -73,4 +87,29 @@ class EbookViewer(MainWindow):
                 det_msg=data['tb'], show=True)
             return
         set_book_path(data['base'])
-        self.web_view.start_book_load()
+        self.current_book_data = data
+        self.web_view.start_book_load(initial_cfi=self.initial_cfi_for_current_book())
+
+    def initial_cfi_for_current_book(self):
+        vd = viewer_data()
+        lrp = vd.get('last-read-positions', {})
+        return lrp.get('path', {}).get(self.current_book_data['pathtoebook'])
+
+    def cfi_changed(self, cfi):
+        if not self.current_book_data:
+            return
+        self.current_book_data['last_known_cfi'] = cfi
+        self.save_cfi_debounce_timer.start()
+
+    def save_cfi(self):
+        self.save_cfi_debounce_timer.stop()
+        vd = viewer_data()
+        lrp = vd.get('last-read-positions', {})
+        path = lrp.setdefault('path', {})
+        path[self.current_book_data['pathtoebook']] = self.current_book_data['last_known_cfi']
+        vd.set('last-read-positions', lrp)
+
+    def closeEvent(self, ev):
+        if self.save_cfi_debounce_timer.isActive():
+            self.save_cfi()
+        return MainWindow.closeEvent(self, ev)

src/calibre/gui2/viewer/web_view.py

@@ -7,7 +7,8 @@ from __future__ import absolute_import, division, print_function, unicode_litera
 import os
 
 from PyQt5.Qt import (
-    QApplication, QBuffer, QByteArray, QHBoxLayout, QSize, QTimer, QUrl, QWidget
+    QApplication, QBuffer, QByteArray, QHBoxLayout, QSize, QTimer, QUrl, QWidget,
+    pyqtSignal
 )
 from PyQt5.QtWebEngineCore import QWebEngineUrlSchemeHandler
 from PyQt5.QtWebEngineWidgets import (
@@ -238,6 +239,8 @@ class Inspector(QWidget):
 
 class WebView(RestartingWebEngineView):
 
+    cfi_changed = pyqtSignal(object)
+
     def __init__(self, parent=None):
         self._host_widget = None
         self.current_cfi = None
@@ -266,6 +269,7 @@ class WebView(RestartingWebEngineView):
                 cfi = frag[len('bookpos='):]
                 if cfi:
                     self.current_cfi = cfi
+                    self.cfi_changed.emit(cfi)
 
     @property
     def host_widget(self):
@@ -305,12 +309,12 @@ class WebView(RestartingWebEngineView):
         for func, args in iteritems(self.pending_bridge_ready_actions):
             getattr(self.bridge, func)(*args)
 
-    def start_book_load(self):
+    def start_book_load(self, initial_cfi=None):
         key = (set_book_path.path,)
         if self.bridge.ready:
-            self.bridge.start_book_load(key, vprefs['session_data'])
+            self.bridge.start_book_load(key, vprefs['session_data'], initial_cfi)
         else:
-            self.pending_bridge_ready_actions['start_book_load'] = key, vprefs['session_data']
+            self.pending_bridge_ready_actions['start_book_load'] = key, vprefs['session_data'], initial_cfi
 
     def set_session_data(self, key, val):
         if key == '*' and val is None:

src/pyj/read_book/view.pyj

@@ -367,7 +367,7 @@ class View:
                 cfi =  '/' + rest
         return name, cfi
 
-    def display_book(self, book):
+    def display_book(self, book, initial_cfi):
         self.hide_overlays()
         self.iframe.focus()
         is_current_book = self.book and self.book.key == book.key
@@ -383,7 +383,7 @@ class View:
         pos = {'replace_history':True}
         unkey = username_key(get_interface_data().username)
         name = book.manifest.spine[0]
-        cfi = None
+        cfi = initial_cfi or None
         q = parse_url_params()
         if q.bookpos and q.bookpos.startswith('epubcfi(/'):
             cfi = q.bookpos

src/pyj/viewer-main.pyj

@@ -126,7 +126,7 @@ def show_error(title, msg, details):
     error_dialog(title, msg, details)
 
 
-def manifest_received(key, end_type, xhr, ev):
+def manifest_received(key, initial_cfi, end_type, xhr, ev):
     nonlocal book
     if end_type is 'load':
         book = new_book(key, {})
@@ -137,7 +137,7 @@ def manifest_received(key, end_type, xhr, ev):
         book.is_complete = True
         v'delete book.manifest["metadata"]'
         v'delete book.manifest["last_read_positions"]'
-        view.display_book(book)
+        view.display_book(book, initial_cfi)
     else:
         error_dialog(_('Could not open book'), _(
             'Failed to load book manifest, click "Show details" for more info'),
@@ -177,12 +177,12 @@ def create_session_data(prefs):
 
 
 @from_python
-def start_book_load(key, prefs):
+def start_book_load(key, prefs, initial_cfi):
     nonlocal view
     if view is None:
         create_session_data(prefs)
         view = View(document.getElementById('view'))
-    xhr = ajax('manifest', manifest_received.bind(None, key), ok_code=0)
+    xhr = ajax('manifest', manifest_received.bind(None, key, initial_cfi), ok_code=0)
     xhr.responseType = 'json'
     xhr.send()