Cover Browser: Allow any metadata field to be used as the sub-title, not just the rating

src/calibre/db/backend.py

@@ -445,6 +445,7 @@ class DB(object):
         defs['update_all_last_mod_dates_on_start'] = False
         defs['field_under_covers_in_grid'] = 'title'
         defs['cover_browser_title_template'] = '{title}'
+        defs['cover_browser_subtitle_field'] = 'rating'
 
         # Migrate the bool tristate tweak
         defs['bools_are_tristate'] = \

src/calibre/gui2/__init__.py

@@ -140,7 +140,6 @@ 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
 defs['gpm_template_editor_font_size'] = 10
 defs['show_emblems'] = False
 defs['emblem_size'] = 32

src/calibre/gui2/cover_flow.py

@@ -87,6 +87,7 @@ if pictureflow is not None:
             self.model.modelReset.connect(self.reset, type=Qt.QueuedConnection)
             self.ignore_image_requests = True
             self.template_inited = False
+            self.subtitle_error_reported = False
 
         def init_template(self, db):
             self.template_cache = {}
@@ -97,6 +98,11 @@ if pictureflow is not None:
         def count(self):
             return self.model.count()
 
+        def render_template(self, template, index, db):
+            book_id = self.model.id(index)
+            mi = db.get_proxy_metadata(book_id)
+            return mi.formatter.safe_format(template, mi, _('TEMPLATE ERROR'), mi, template_cache=self.template_cache)
+
         def caption(self, index):
             if self.ignore_image_requests:
                 return ''
@@ -108,10 +114,8 @@ if pictureflow is not None:
                 if self.template_is_title:
                     ans = self.model.title(index)
                 else:
-                    book_id = self.model.id(index)
-                    mi = db.get_proxy_metadata(book_id)
                     try:
-                        ans = mi.formatter.safe_format(self.template, mi, _('TEMPLATE ERROR'), mi, template_cache=self.template_cache)
+                        ans = self.render_template(self.template, index, db)
                     except Exception:
                         if not self.template_error_reported:
                             self.template_error_reported = True
@@ -124,11 +128,23 @@ if pictureflow is not None:
             return ans
 
         def subtitle(self, index):
-            if gprefs['show_rating_in_cover_browser']:
             try:
-                    return rating_to_stars(self.model.rating(index) * 2)
+                db = self.model.db.new_api
-                except:
+                field = db.pref('cover_browser_subtitle_field', 'rating')
-                    pass
+                if field and field != 'none':
+                    book_id = self.model.id(index)
+                    fm = db.field_metadata[field]
+                    if fm['datatype'] == 'rating':
+                        val = db.field_for(field, book_id, default_value=0)
+                        if val:
+                            return rating_to_stars(val, allow_half_stars=db.field_metadata[field]['display'].get('allow_half_stars'))
+                    else:
+                        return self.render_template('{%s}' % field, index, db).replace('&', '&&')
+            except Exception:
+                if not self.subtitle_error_reported:
+                    self.subtitle_error_reported = True
+                    import traceback
+                    traceback.print_exc()
             return ''
 
         def reset(self):
@@ -163,10 +179,15 @@ if pictureflow is not None:
             self.context_menu = None
             self.setContextMenuPolicy(Qt.DefaultContextMenu)
             self.setPreserveAspectRatio(gprefs['cb_preserve_aspect_ratio'])
-            self.setSubtitleFont(QFont(rating_font()))
             if not gprefs['cover_browser_reflections']:
                 self.setShowReflections(False)
 
+        def set_subtitle_font(self, for_ratings=True):
+            if for_ratings:
+                self.setSubtitleFont(QFont(rating_font()))
+            else:
+                self.setSubtitleFont(self.font())
+
         def set_context_menu(self, cm):
             self.context_menu = cm
 
@@ -283,6 +304,7 @@ class CoverFlowMixin(object):
             self.db_images = DatabaseImages(self.library_view.model(), self.is_cover_browser_visible)
             self.cover_flow.setImages(self.db_images)
             self.cover_flow.itemActivated.connect(self.iactions['View'].view_specific_book)
+            self.update_cover_flow_subtitle_font()
         else:
             self.cover_flow = QLabel('<p>'+_('Cover browser could not be loaded') +
                                      '<br>'+pictureflowerror)
@@ -302,6 +324,16 @@ class CoverFlowMixin(object):
                 self.cover_flow.stop.connect(self.cb_splitter.hide_side_pane)
         self.cb_splitter.button.toggled.connect(self.cover_browser_toggled, type=Qt.QueuedConnection)
 
+    def update_cover_flow_subtitle_font(self):
+        db = self.current_db.new_api
+        field = db.pref('cover_browser_subtitle_field', 'rating')
+        try:
+            is_rating = db.field_metadata[field]['datatype'] == 'rating'
+        except Exception:
+            is_rating = False
+        if hasattr(self.cover_flow, 'set_subtitle_font'):
+            self.cover_flow.set_subtitle_font(is_rating)
+
     def toggle_cover_browser(self, *args):
         cbd = getattr(self, 'cb_dialog', None)
         if cbd is not None:

src/calibre/gui2/preferences/look_feel.py

@@ -291,8 +291,11 @@ 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('cover_browser_title_template', db.prefs)
+        fm = db.field_metadata
+        r('cover_browser_subtitle_field', db.prefs, choices=[(_('No subtitle'), 'none')] + sorted(
+            (fm[k].get('name'), k) for k in fm.all_field_keys() if fm[k].get('name')
+        ))
         r('emblem_size', gprefs)
         r('emblem_position', gprefs, choices=[
             (_('Left'), 'left'), (_('Top'), 'top'), (_('Right'), 'right'), (_('Bottom'), 'bottom')])
@@ -636,6 +639,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         gui.library_view.refresh_book_details()
         gui.cover_flow.setShowReflections(gprefs['cover_browser_reflections'])
         gui.cover_flow.setPreserveAspectRatio(gprefs['cb_preserve_aspect_ratio'])
+        gui.update_cover_flow_subtitle_font()
         gui.cover_flow.template_inited = False
         gui.library_view.refresh_row_sizing()
         gui.grid_view.refresh_settings()

src/calibre/gui2/preferences/look_feel.ui

@@ -977,7 +977,7 @@ if you never want subcategories</string>
          </property>
         </widget>
        </item>
-       <item row="8" column="0" colspan="2">
+       <item row="9" column="0" colspan="2">
         <spacer name="verticalSpacer_4">
          <property name="orientation">
           <enum>Qt::Vertical</enum>
@@ -990,13 +990,6 @@ if you never want subcategories</string>
          </property>
         </spacer>
        </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>
        <item row="5" column="0">
         <widget class="QLabel" name="label_23">
          <property name="text">
@@ -1017,7 +1010,7 @@ if you never want subcategories</string>
        <item row="1" column="1" colspan="2">
         <widget class="QSpinBox" name="opt_cover_flow_queue_length"/>
        </item>
-       <item row="6" column="0" colspan="3">
+       <item row="7" column="0" colspan="3">
         <widget class="QCheckBox" name="opt_cb_fullscreen">
          <property name="text">
           <string>When showing cover browser in separate window, show it &amp;fullscreen</string>
@@ -1049,7 +1042,7 @@ them to all have the same width and height</string>
          </property>
         </widget>
        </item>
-       <item row="7" column="0" colspan="3">
+       <item row="8" column="0" colspan="3">
         <widget class="QLabel" name="fs_help_msg">
          <property name="styleSheet">
           <string notr="true">margin-left: 1.5em</string>
@@ -1062,6 +1055,19 @@ them to all have the same width and height</string>
          </property>
         </widget>
        </item>
+       <item row="6" column="0">
+        <widget class="QLabel" name="label_24">
+         <property name="text">
+          <string>Fie&amp;ld for sub-title:</string>
+         </property>
+         <property name="buddy">
+          <cstring>opt_cover_browser_subtitle_field</cstring>
+         </property>
+        </widget>
+       </item>
+       <item row="6" column="1" colspan="2">
+        <widget class="QComboBox" name="opt_cover_browser_subtitle_field"/>
+       </item>
       </layout>
      </widget>
     </widget>