Quickview changes:

1) Close the quickview window on library change. Keeping track of what should be shown in the new library wasn't working.
2) Add keyboard shortcuts to move between quickview's controls.
3) Add a checkbox to "lock" quickview's contents, preventing their change when moving around on the main spreadsheet.

src/calibre/gui2/actions/show_quickview.py

@@ -47,4 +47,4 @@ def change_quickview_column(self, idx):
 
     def library_changed(self, db):
         if self.current_instance and not self.current_instance.is_closed:
-            self.current_instance.set_database(db)
+            self.current_instance.reject()

src/calibre/gui2/dialogs/quickview.py

@@ -6,7 +6,7 @@
 
 from PyQt4.Qt import (Qt, QDialog, QAbstractItemView, QTableWidgetItem,
                       QListWidgetItem, QByteArray, QCoreApplication,
-                      QApplication, pyqtSignal)
+                      QApplication, pyqtSignal, QDialogButtonBox)
 
 from calibre.customize.ui import find_plugin
 from calibre.gui2 import gprefs
@@ -112,14 +112,8 @@ def __init__(self, gui, view, row):
         self.search_button.clicked.connect(self.do_search)
         view.model().new_bookdisplay_data.connect(self.book_was_changed)
 
-    def set_database(self, db):
-        self.db = db
-        self.items.blockSignals(True)
-        self.books_table.blockSignals(True)
-        self.items.clear()
-        self.books_table.setRowCount(0)
-        self.books_table.blockSignals(False)
-        self.items.blockSignals(False)
+        close_button = self.buttonBox.button(QDialogButtonBox.Close)
+        close_button.setAutoDefault(False)
 
     # search button
     def do_search(self):
@@ -138,7 +132,7 @@ def book_was_changed(self, mi):
         # view is changed, triggering a book_was_changed signal. Unfortunately
         # this happens before the library_changed actions are run, meaning we
         # still have the old database. To avoid the problem we just ignore the
-        # operation if we get an exception. The set_database will come
+        # operation if we get an exception. The "close" will come
         # eventually.
         try:
             self.refresh(self.view.model().index(self.db.row(mi.id), self.current_column))
@@ -153,6 +147,9 @@ def item_selected(self, txt):
 
     # Given a cell in the library view, display the information
     def refresh(self, idx):
+        if self.lock_qv.isChecked():
+            return
+
         bv_row = idx.row()
         self.current_column = idx.column()
         key = self.view.model().column_map[self.current_column]
@@ -167,7 +164,7 @@ def refresh(self, idx):
                 self.indicate_no_items()
                 return
             key = self.current_key
-        self.items_label.setText('{0} ({1})'.format(
+        self.items_label.setText(_('&Item: {0} ({1})').format(
                                     self.db.field_metadata[key]['name'], key))
 
         self.items.blockSignals(True)
@@ -219,7 +216,7 @@ def fill_in_books_box(self, selected_item):
                                sort_results=False)
 
         self.books_table.setRowCount(len(books))
-        self.books_label.setText(_('Books with selected item "{0}": {1}').
+        self.books_label.setText(_('&Books with selected item "{0}": {1}').
                                  format(selected_item, len(books)))
 
         select_item = None
@@ -296,7 +293,7 @@ def save_state(self):
         gprefs['quickview_dialog_books_table_widths'] = self.books_table_column_widths
         gprefs['quickview_dialog_geometry'] = bytearray(self.saveGeometry())
 
-    def close(self):
+    def _close(self):
         self.save_state()
         # clean up to prevent memory leaks
         self.db = self.view = self.gui = None
@@ -304,10 +301,10 @@ def close(self):
 
     # called by the window system
     def closeEvent(self, *args):
-        self.close()
+        self._close()
         QDialog.closeEvent(self, *args)
 
     # called by the close button
     def reject(self):
-        self.close()
+        self._close()
         QDialog.reject(self)

src/calibre/gui2/dialogs/quickview.ui

@@ -22,8 +22,8 @@
   <layout class="QGridLayout">
    <item row="0" column="0">
     <widget class="QLabel" name="items_label">
-     <property name="text">
-      <string>Items</string>
+     <property name="buddy">
+      <cstring>items</cstring>
      </property>
     </widget>
    </item>
@@ -39,6 +39,9 @@
    </item>
    <item row="0" column="1">
     <widget class="QLabel" name="books_label">
+     <property name="buddy">
+      <cstring>books_table</cstring>
+     </property>
     </widget>
    </item>
    <item row="1" column="1">
@@ -59,14 +62,41 @@
    </item>
    <item row="3" column="0" colspan="2">
     <layout class="QHBoxLayout">
+     <item>
+      <widget class="QCheckBox" name="lock_qv">
+       <property name="text">
+        <string>&amp;Lock Quickview contents</string>
+       </property>
+       <property name="toolTip">
+        <string>Select to prevent Quickview from changing content when the
+        selection on the library view is changed</string>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <spacer>
+       <property name="orientation">
+        <enum>Qt::Horizontal</enum>
+       </property>
+       <property name="sizeHint" stdset="0">
+        <size>
+         <width>0</width>
+         <height>0</height>
+        </size>
+       </property>
+      </spacer>
+     </item>
      <item>
       <widget class="QPushButton" name="search_button">
        <property name="text">
-        <string>Search</string>
+        <string>&amp;Search</string>
        </property>
        <property name="toolTip">
         <string>Search in the library view for the selected item</string>
        </property>
+       <property name="autoDefault">
+        <bool>false</bool>
+       </property>
       </widget>
      </item>
      <item>