Allow removal of tags in bulk metadata dialog

src/libprs500/gui2/dialogs/metadata_bulk.py

@@ -65,6 +65,10 @@ class MetadataBulkDialog(QDialog, Ui_MetadataBulkDialog):
             if tags:
                 tags = tags.split(',')
                 self.db.set_tags(id, tags, append=True)
+            remove_tags = qstring_to_unicode(self.remove_tags.text()).strip()
+            if remove_tags:
+                remove_tags = [i.strip() for i in remove_tags.split(',')]
+                self.db.unapply_tags(id, remove_tags)
             if self.write_series:
                 self.db.set_series(id, qstring_to_unicode(self.series.currentText()))
         self.changed = True

src/libprs500/gui2/dialogs/metadata_bulk.ui

@@ -6,7 +6,7 @@
     <x>0</x>
     <y>0</y>
     <width>461</width>
-    <height>342</height>
+    <height>387</height>
    </rect>
   </property>
   <property name="windowTitle" >
@@ -154,6 +154,23 @@
            </widget>
           </item>
           <item row="5" column="0" >
+           <widget class="QLabel" name="label" >
+            <property name="text" >
+             <string>&amp;Remove tags:</string>
+            </property>
+            <property name="buddy" >
+             <cstring>remove_tags</cstring>
+            </property>
+           </widget>
+          </item>
+          <item row="5" column="1" >
+           <widget class="QLineEdit" name="remove_tags" >
+            <property name="toolTip" >
+             <string>Comma separated list of tags to remove from the books. </string>
+            </property>
+           </widget>
+          </item>
+          <item row="6" column="0" >
            <widget class="QLabel" name="label_7" >
             <property name="text" >
              <string>&amp;Series:</string>
@@ -169,7 +186,7 @@
             </property>
            </widget>
           </item>
-          <item row="5" column="1" >
+          <item row="6" column="1" >
            <widget class="QComboBox" name="series" >
             <property name="toolTip" >
              <string>List of known series. You can add new series.</string>

src/libprs500/library/database.py

@@ -1085,6 +1085,13 @@ ALTER TABLE books ADD COLUMN isbn TEXT DEFAULT "" COLLATE NOCASE;
         for tag in tags:
             self.delete_tag(tag)
     
+    def unapply_tags(self, book_id, tags):
+        for tag in tags:
+            id = self.conn.execute('SELECT id FROM tags WHERE name=?', (tag,)).fetchone()
+            if id:
+                self.conn.execute('DELETE FROM books_tags_link WHERE tag=? AND book=?', (id[0], book_id))
+        self.conn.commit()
+    
     def set_tags(self, id, tags, append=False):
         '''
         @param tags: list of strings