+ //! Derived classes need to define this and return true if they have default settings.
+ /** If this method returns true, the "Restore Defaults" button in the SettingsDlg is
+ * enabled. You also need to provide an implementation of defaults() then.
+ *
+ * The default implementation returns false.
+ */
+ virtual bool hasDefaults() const;
+
+ //! Check if there are changes in the page, compared to the state saved in permanent storage.