Make decorating custom columns in the GUI a separate 'display' option from subtype. Add the UI to control it to preferences.

src/calibre/gui2/library/models.py

@@ -689,9 +689,8 @@ class BooksModel(QAbstractTableModel): # {{{
             if datatype in ('text', 'comments', 'composite', 'enumeration'):
                 self.dc[col] = functools.partial(text_type, idx=idx,
                                                  mult=self.custom_columns[col]['is_multiple'])
-                if datatype == 'composite':
-                    csort = self.custom_columns[col]['display'].get('composite_sort', 'text')
-                    if csort == 'bool':
+                if datatype in ['text', 'composite', 'enumeration']:
+                    if self.custom_columns[col]['display'].get('use_decorations', False):
                         self.dc_decorator[col] = functools.partial(
                                     bool_type_decorator, idx=idx,
                                     bool_cols_are_tristate=tweaks['bool_custom_columns_are_tristate'] != 'no')

src/calibre/gui2/preferences/create_custom_column.py

@@ -121,6 +121,8 @@ class CreateCustomColumn(QDialog, Ui_QCreateCustomColumn):
         elif ct == 'enumeration':
             self.enum_box.setText(','.join(c['display'].get('enum_values', [])))
         self.datatype_changed()
+        if ct in ['text', '*text', 'composite', 'enumeration']:
+            self.use_decorations.setChecked(c['display'].get('use_decorations', False))
         self.exec_()
 
     def shortcut_activated(self, url):
@@ -161,6 +163,11 @@ class CreateCustomColumn(QDialog, Ui_QCreateCustomColumn):
             getattr(self, 'composite_'+x).setVisible(col_type == 'composite')
         for x in ('box', 'default_label', 'label'):
             getattr(self, 'enum_'+x).setVisible(col_type == 'enumeration')
+        if col_type in ['text', '*text', 'composite', 'enumeration']:
+            self.use_decorations.setVisible(True)
+        else:
+            self.use_decorations.setVisible(False)
+        self.use_decorations.setChecked(False)
 
     def accept(self):
         col = unicode(self.column_name_box.text()).strip()
@@ -233,6 +240,9 @@ class CreateCustomColumn(QDialog, Ui_QCreateCustomColumn):
                     'list more than once').format(l[i]))
             display_dict = {'enum_values': l}
 
+        if col_type in ['text', '*text', 'composite', 'enumeration']:
+            display_dict['use_decorations'] = self.use_decorations.checkState()
+
         if not self.editing_col:
             db.field_metadata
             self.parent.custcols[key] = {

src/calibre/gui2/preferences/create_custom_column.ui

@@ -88,23 +88,58 @@
         </widget>
        </item>
        <item row="2" column="2">
-        <widget class="QComboBox" name="column_type_box">
-         <property name="sizePolicy">
-          <sizepolicy hsizetype="Maximum" vsizetype="Fixed">
-           <horstretch>0</horstretch>
-           <verstretch>0</verstretch>
-          </sizepolicy>
-         </property>
-         <property name="minimumSize">
-          <size>
-           <width>70</width>
-           <height>0</height>
-          </size>
-         </property>
-         <property name="toolTip">
-          <string>What kind of information will be kept in the column.</string>
-         </property>
-        </widget>
+        <layout class="QHBoxLayout" name="horizontalLayout_3">
+         <item>
+          <widget class="QComboBox" name="column_type_box">
+           <property name="sizePolicy">
+            <sizepolicy hsizetype="Maximum" vsizetype="Fixed">
+             <horstretch>0</horstretch>
+             <verstretch>0</verstretch>
+            </sizepolicy>
+           </property>
+           <property name="minimumSize">
+            <size>
+             <width>70</width>
+             <height>0</height>
+            </size>
+           </property>
+           <property name="toolTip">
+            <string>What kind of information will be kept in the column.</string>
+           </property>
+          </widget>
+         </item>
+         <item>
+          <widget class="QCheckBox" name="use_decorations">
+           <property name="text">
+            <string>Show checkmarks</string>
+           </property>
+           <property name="toolTip">
+            <string>Show check marks in the GUI. Values of 'yes', 'checked', and 'true'
+will show a green check. Values of 'no', 'unchecked', and 'false' will show a red X.
+Everything else will show nothing.</string>
+           </property>
+          </widget>
+         </item>
+         <item>
+          <spacer name="horizontalSpacer_27">
+           <property name="orientation">
+            <enum>Qt::Horizontal</enum>
+           </property>
+           <property name="sizePolicy">
+            <sizepolicy hsizetype="Expanding" vsizetype="Fixed">
+             <horstretch>10</horstretch>
+             <verstretch>0</verstretch>
+            </sizepolicy>
+           </property>
+           <property name="sizeHint" stdset="0">
+            <size>
+             <width>20</width>
+             <height>0</height>
+            </size>
+           </property>
+          </spacer>
+         </item>
+        </layout>
        </item>
        <item row="4" column="2">
         <layout class="QHBoxLayout" name="horizontalLayout_3">