Save single format to disk: Allow choosing the book cover as the format to save. Fixes #2092395 [[Enhancement] Add cover image to 'Save single format' dialog](https://bugs.launchpad.net/calibre/+bug/2092395)

src/calibre/gui2/actions/delete.py

@@ -121,15 +121,17 @@ class DeleteAction(InterfaceActionWithLibraryDrop):
         for action in list(self.delete_menu.actions())[1:]:
             action.setEnabled(enabled)
 
-    def _get_selected_formats(self, msg, ids, exclude=False, single=False):
+    def _get_selected_formats(self, msg, ids, exclude=False, single=False, add_cover=False):
         from calibre.gui2.dialogs.select_formats import SelectFormats
         c = Counter()
         db = self.gui.library_view.model().db
-        for x in ids:
-            fmts_ = db.formats(x, index_is_id=True, verify_formats=False)
+        for book_id in ids:
+            fmts_ = db.formats(book_id, index_is_id=True, verify_formats=False)
             if fmts_:
                 for x in frozenset(x.lower() for x in fmts_.split(',')):
                     c[x] += 1
+            if add_cover and db.new_api.field_for('cover', book_id, default_value=False):
+                c['..cover..'] += 1
         d = SelectFormats(c, msg, parent=self.gui, exclude=exclude,
                 single=single)
         if d.exec() != QDialog.DialogCode.Accepted:

src/calibre/gui2/actions/save_to_disk.py

@@ -63,10 +63,11 @@ class SaveToDiskAction(InterfaceAction):
             return
         fmts = rb._get_selected_formats(
                 _('Choose format to save to disk'), ids,
-                single=True)
+                single=True, add_cover=True)
         if not fmts:
             return
-        self.save_to_disk(False, False, list(fmts)[0])
+        fmt = list(fmts)[0]
+        self.save_to_disk(False, False, fmt)
 
     def save_to_single_dir(self, checked):
         self.save_to_disk(checked, True)
@@ -107,7 +108,10 @@ class SaveToDiskAction(InterfaceAction):
                     opts.to_lowercase = False
                     opts.save_cover = False
                     opts.write_opf = False
+                    opts.save_extra_files = False
                     opts.template = opts.send_template
+                elif single_format == '..cover..':
+                    opts.save_cover = True
             opts.single_dir = single_dir
             if write_opf is not None:
                 opts.write_opf = write_opf

src/calibre/gui2/dialogs/select_formats.py

@@ -27,12 +27,20 @@ class Formats(QAbstractListModel):
         if role == Qt.ItemDataRole.DisplayRole:
             fmt = self.fmts[row]
             count = self.counts[fmt]
-            return ('%s [%d]'%(fmt.upper(), count))
+            if fmt == '..cover..':
+                fmt = _('Book cover')
+            else:
+                fmt = fmt.upper()
+            return f'{fmt} [{count}]'
         if role == Qt.ItemDataRole.DecorationRole:
             return (self.fi.icon_from_ext(self.fmts[row].lower()))
         if role == Qt.ItemDataRole.ToolTipRole:
             fmt = self.fmts[row]
             count = self.counts[fmt]
+            if fmt == '..cover..':
+                if count == 1:
+                    return _('There is only one book with a cover')
+                return _('There are {} books with a cover').format(count)
             return _('There is one book with the {} format').format(fmt.upper()) if count == 1 else _(
                 'There are {count} books with the {fmt} format').format(
                                 count=count, fmt=fmt.upper())

src/calibre/gui2/save.py

@@ -213,11 +213,14 @@ class Saver(QObject):
         base_path = os.path.join(self.root, *components)
         base_dir = os.path.dirname(base_path)
         if self.opts.formats and self.opts.formats != 'all':
-            asked_formats = {x.lower().strip() for x in self.opts.formats.split(',')}
-            fmts = asked_formats.intersection(fmts)
-            if not fmts:
-                self.errors[book_id].append(('critical', _('Requested formats not available')))
-                return
+            if self.opts.formats == '..cover..':
+                fmts = set()
+            else:
+                asked_formats = {x.lower().strip() for x in self.opts.formats.split(',')}
+                fmts = asked_formats.intersection(fmts)
+                if not fmts:
+                    self.errors[book_id].append(('critical', _('Requested formats not available')))
+                    return
 
         extra_files = {}
         if self.opts.save_extra_files: