This function shows self to the user.
The callback will be called when the alert is dismissed. It should call adw.message_dialog.MessageDialog.chooseFinish to obtain the result.
a gio.cancellable.Cancellable to cancel the operation
a callback to call when the operation is complete
This function shows self to the user.
The callback will be called when the alert is dismissed. It should call adw.message_dialog.MessageDialog.chooseFinish to obtain the result.