Add an option to hide the book rating in the cover browser (Preferences->Look & Feel->Cover Browser). Fixes #1319476 [Disable Rating in Cover Browser](https://bugs.launchpad.net/calibre/+bug/1319476)

src/calibre/gui2/__init__.py

@@ -126,6 +126,7 @@ defs['show_vl_tabs'] = False
 defs['show_highlight_toggle_button'] = False
 defs['add_comments_to_email'] = False
 defs['cb_preserve_aspect_ratio'] = False
+defs['show_rating_in_cover_browser'] = True
 del defs
 # }}}
 

src/calibre/gui2/cover_flow.py

@@ -97,10 +97,11 @@ if pictureflow is not None:
             return ans
 
         def subtitle(self, index):
-            try:
-                return u'\u2605'*self.model.rating(index)
-            except:
-                pass
+            if gprefs['show_rating_in_cover_browser']:
+                try:
+                    return u'\u2605'*self.model.rating(index)
+                except:
+                    pass
             return ''
 
         def reset(self):

src/calibre/gui2/preferences/look_feel.py

@@ -137,10 +137,8 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
 
         r = self.register
 
-        r('gui_layout', config, restart_required=True, choices=
-                [(_('Wide'), 'wide'), (_('Narrow'), 'narrow')])
-        r('ui_style', gprefs, restart_required=True, choices=
-                [(_('System default'), 'system'), (_('Calibre style'),
+        r('gui_layout', config, restart_required=True, choices=[(_('Wide'), 'wide'), (_('Narrow'), 'narrow')])
+        r('ui_style', gprefs, restart_required=True, choices=[(_('System default'), 'system'), (_('Calibre style'),
                     'calibre')])
         r('book_list_tooltips', gprefs)
         r('tag_browser_old_look', gprefs, restart_required=True)
@@ -155,6 +153,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
 
         r('cover_flow_queue_length', config, restart_required=True)
         r('cover_browser_reflections', gprefs)
+        r('show_rating_in_cover_browser', gprefs)
         r('extra_row_spacing', gprefs)
 
         def get_esc_lang(l):

src/calibre/gui2/preferences/look_feel.ui

@@ -897,7 +897,7 @@ a few top-level elements.</string>
          </property>
         </widget>
        </item>
-       <item row="6" column="0" colspan="2">
+       <item row="7" column="0" colspan="2">
         <spacer name="verticalSpacer_4">
          <property name="orientation">
           <enum>Qt::Vertical</enum>
@@ -913,14 +913,14 @@ a few top-level elements.</string>
        <item row="1" column="1">
         <widget class="QSpinBox" name="opt_cover_flow_queue_length"/>
        </item>
-       <item row="4" column="0" colspan="2">
+       <item row="5" column="0" colspan="2">
         <widget class="QCheckBox" name="opt_cb_fullscreen">
          <property name="text">
           <string>When showing cover browser in separate window, show it &amp;fullscreen</string>
          </property>
         </widget>
        </item>
-       <item row="5" column="0" colspan="2">
+       <item row="6" column="0" colspan="2">
         <widget class="QLabel" name="fs_help_msg">
          <property name="styleSheet">
           <string notr="true">margin-left: 1.5em</string>
@@ -951,6 +951,13 @@ them to all have the same width and height</string>
          </property>
         </widget>
        </item>
+       <item row="4" column="0">
+        <widget class="QCheckBox" name="opt_show_rating_in_cover_browser">
+         <property name="text">
+          <string>Show book &amp;rating in cover browser</string>
+         </property>
+        </widget>
+       </item>
       </layout>
      </widget>
     </widget>