Implement #3515 (Reset the conversion options)

src/calibre/ebooks/conversion/config.py

@@ -51,6 +51,9 @@ def load_specifics(db, book_id):
         r.from_string(raw)
     return r
 
+def delete_specifics(db, book_id):
+    db.delete_conversion_options(book_id, 'PIPE')
+
 class GuiRecommendations(dict):
 
     def __new__(cls, *args):

src/calibre/gui2/convert/single.py

@@ -23,6 +23,7 @@ from calibre.gui2.convert.debug import DebugWidget
 
 
 from calibre.ebooks.conversion.plumber import Plumber, supported_input_formats
+from calibre.ebooks.conversion.config import delete_specifics
 from calibre.customize.ui import available_output_formats
 from calibre.customize.conversion import OptionRecommendation
 from calibre.utils.config import prefs
@@ -115,9 +116,10 @@ class Config(ResizableDialog, Ui_Dialog):
     def __init__(self, parent, db, book_id,
             preferred_input_format=None, preferred_output_format=None):
         ResizableDialog.__init__(self, parent)
-        self.setup_input_output_formats(db, book_id, preferred_input_format,
-                preferred_output_format)
         self.db, self.book_id = db, book_id
+
+        self.setup_input_output_formats(self.db, self.book_id, preferred_input_format,
+                preferred_output_format)
         self.setup_pipeline()
 
         self.connect(self.input_formats, SIGNAL('currentIndexChanged(QString)'),
@@ -130,8 +132,14 @@ class Config(ResizableDialog, Ui_Dialog):
                 self.show_pane)
         self.connect(self.groups, SIGNAL('entered(QModelIndex)'),
                 self.show_group_help)
+        rb = self.buttonBox.button(self.buttonBox.RestoreDefaults)
+        self.connect(rb, SIGNAL('clicked()'), self.restore_defaults)
         self.groups.setMouseTracking(True)
 
+    def restore_defaults(self):
+        delete_specifics(self.db, self.book_id)
+        self.setup_pipeline()
+
     @property
     def input_format(self):
         return unicode(self.input_formats.currentText()).lower()

src/calibre/gui2/convert/single.ui

@@ -108,8 +108,8 @@
        <rect>
         <x>0</x>
         <y>0</y>
-        <width>800</width>
+        <width>810</width>
-        <height>471</height>
+        <height>492</height>
        </rect>
       </property>
       <layout class="QVBoxLayout" name="verticalLayout_3">
@@ -138,7 +138,7 @@
       <enum>Qt::Horizontal</enum>
      </property>
      <property name="standardButtons">
-      <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
+      <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok|QDialogButtonBox::RestoreDefaults</set>
      </property>
     </widget>
    </item>

src/calibre/library/database.py

@@ -1081,6 +1081,10 @@ ALTER TABLE books ADD COLUMN isbn TEXT DEFAULT "" COLLATE NOCASE;
             return cPickle.loads(str(data))
         return None
 
+    def delete_conversion_options(self, id, format):
+        self.conn.execute('DELETE FROM conversion_options WHERE book=? AND format=?',
+                (id, format.upper()))
+
 
     def add_format(self, index, ext, stream, index_is_id=False):
         '''