When switching libraries preserve the position and selected books if you switch back to a previously opened library. Fixes #994514 (New wish: stay on the same line in a library)

src/calibre/gui2/actions/choose_library.py

@@ -10,7 +10,7 @@ from functools import partial
 
 from PyQt4.Qt import (QMenu, Qt, QInputDialog, QToolButton, QDialog,
         QDialogButtonBox, QGridLayout, QLabel, QLineEdit, QIcon, QSize,
-        QCoreApplication)
+        QCoreApplication, pyqtSignal)
 
 from calibre import isbytestring, sanitize_file_name_unicode
 from calibre.constants import filesystem_encoding, iswindows
@@ -142,6 +142,7 @@ class ChooseLibraryAction(InterfaceAction):
     dont_add_to = frozenset(['context-menu-device'])
     action_add_menu = True
     action_menu_clone_qaction = _('Switch/create library...')
+    restore_view_state = pyqtSignal(object)
 
     def genesis(self):
         self.base_text = _('%d books')
@@ -206,6 +207,17 @@ class ChooseLibraryAction(InterfaceAction):
         self.maintenance_menu.addAction(ac)
 
         self.choose_menu.addMenu(self.maintenance_menu)
+        self.view_state_map = {}
+        self.restore_view_state.connect(self._restore_view_state,
+                type=Qt.QueuedConnection)
+
+    @property
+    def preserve_state_on_switch(self):
+        ans = getattr(self, '_preserve_state_on_switch', None)
+        if ans is None:
+            self._preserve_state_on_switch = ans = \
+                self.gui.library_view.preserve_state(require_selected_ids=False)
+        return ans
 
     def pick_random(self, *args):
         self.gui.iactions['Pick Random Book'].pick_random()
@@ -221,6 +233,13 @@ class ChooseLibraryAction(InterfaceAction):
     def library_changed(self, db):
         self.stats.library_used(db)
         self.build_menus()
+        state = self.view_state_map.get(self.stats.canonicalize_path(
+            db.library_path), None)
+        if state is not None:
+            self.restore_view_state.emit(state)
+
+    def _restore_view_state(self, state):
+        self.preserve_state_on_switch.state = state
 
     def initialization_complete(self):
         self.library_changed(self.gui.library_view.model().db)
@@ -401,8 +420,11 @@ class ChooseLibraryAction(InterfaceAction):
     def switch_requested(self, location):
         if not self.change_library_allowed():
             return
+        db = self.gui.library_view.model().db
+        current_lib = self.stats.canonicalize_path(db.library_path)
+        self.view_state_map[current_lib] = self.preserve_state_on_switch.state
         loc = location.replace('/', os.sep)
-        exists = self.gui.library_view.model().db.exists_at(loc)
+        exists = db.exists_at(loc)
         if not exists:
             d = MovedDialog(self.stats, location, self.gui)
             ret = d.exec_()

src/calibre/gui2/library/views.py

@@ -32,8 +32,10 @@ class PreserveViewState(object): # {{{
     and dont affect the scroll position.
     '''
 
-    def __init__(self, view, preserve_hpos=True, preserve_vpos=True):
+    def __init__(self, view, preserve_hpos=True, preserve_vpos=True,
+            require_selected_ids=True):
         self.view = view
+        self.require_selected_ids = require_selected_ids
         self.selected_ids = set()
         self.current_id = None
         self.preserve_hpos = preserve_hpos
@@ -51,15 +53,28 @@ class PreserveViewState(object): # {{{
             traceback.print_exc()
 
     def __exit__(self, *args):
-        if self.selected_ids:
+        if self.selected_ids or not self.require_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.selected_ids:
+                self.view.select_rows(self.selected_ids, using_ids=True,
+                        scroll=False, change_current=self.current_id is None)
             if self.preserve_vpos:
                 self.view.verticalScrollBar().setValue(self.vscroll)
             if self.preserve_hpos:
                 self.view.horizontalScrollBar().setValue(self.hscroll)
+
+    @dynamic_property
+    def state(self):
+        def fget(self):
+            self.__enter__()
+            return {x:getattr(self, x) for x in ('selected_ids', 'current_id',
+                'vscroll', 'hscroll')}
+        def fset(self, state):
+            for k, v in state.iteritems(): setattr(self, k, v)
+            self.__exit__()
+        return property(fget=fget, fset=fset)
+
 # }}}
 
 class BooksView(QTableView): # {{{