Make preserving of library view when device is connected/books are sent to device more robust

src/calibre/gui2/device.py

@@ -855,7 +855,7 @@ class DeviceMixin(object): # {{{
         Force the library view to refresh, taking into consideration new
         device books information
         '''
-        with self.library_view.preserve_selected_books:
+        with self.library_view.preserve_state():
             self.book_on_device(None, reset=True)
             if reset_only:
                 return
@@ -1320,7 +1320,7 @@ class DeviceMixin(object): # {{{
         # If it does not, then do it here.
         if not self.set_books_in_library(self.booklists(), reset=True, add_as_step_to_job=job):
             self.upload_booklists(job)
-        with self.library_view.preserve_selected_books:
+        with self.library_view.preserve_state():
             self.book_on_device(None, reset=True)
             self.refresh_ondevice()
 

src/calibre/gui2/library/views.py

@@ -40,7 +40,42 @@ class PreserveSelection(object): # {{{
     def __exit__(self, *args):
         current = self.view.get_selected_ids()
         if not current:
-            self.view.select_rows(self.selected_ids, using_ids=True)
+            self.view.select_rows(self.selected_ids, using_ids=True,
+                    change_current=False, scroll=False)
+# }}}
+
+class PreserveViewState(object): # {{{
+
+    '''
+    Save the set of selected books at enter time. If at exit time there are no
+    selected books, restore the previous selection, the previous current index
+    and dont affect the scroll position.
+    '''
+
+    def __init__(self, view, preserve_hpos=True, preserve_vpos=True):
+        self.view = view
+        self.selected_ids = set()
+        self.current_id = None
+        self.preserve_hpos = preserve_hpos
+        self.preserve_vpos = preserve_vpos
+
+    def __enter__(self):
+        self.selected_ids = self.view.get_selected_ids()
+        self.current_id = self.view.current_id
+        self.vscroll = self.verticalScrollBar().value()
+        self.hscroll = self.horizontalScrollBar().value()
+
+    def __exit__(self, *args):
+        current = self.view.get_selected_ids()
+        if not current and self.selected_ids:
+            if self.current_id is not None:
+                self.view.current_id = self.current_id
+            self.view.select_rows(self.selected_ids, using_ids=True,
+                    scroll=False, change_current=self.current_id is None)
+            if self.preserve_vpos:
+                self.verticalScrollBar().setValue(self.vscroll)
+            if self.preserve_hpos:
+                self.horizontalScrollBar().setValue(self.hscroll)
 # }}}
 
 class BooksView(QTableView): # {{{
@@ -105,6 +140,7 @@ class BooksView(QTableView): # {{{
         self.setSortingEnabled(True)
         self.selectionModel().currentRowChanged.connect(self._model.current_changed)
         self.preserve_selected_books = PreserveSelection(self)
+        self.preserve_state = partial(PreserveViewState, self)
 
         # {{{ Column Header setup
         self.can_add_columns = True
@@ -788,6 +824,23 @@ class BooksView(QTableView): # {{{
                 ans.append(i)
         return ans
 
+    @dynamic_property
+    def current_id(self):
+        def fget(self):
+            try:
+                return self.model().id(self.currentIndex())
+            except:
+                pass
+            return None
+        def fset(self, val):
+            if val is None: return
+            m = self.model()
+            for row in xrange(m.rowCount(QModelIndex())):
+                if m.id(row) == val:
+                    self.set_current_row(row, select=False)
+                    break
+        return property(fget=fget, fset=fset)
+
     def close(self):
         self._model.close()