GtkSourceLanguage @sourcelanguage: the object which received the signal. @arg1: @language: @Returns: @language: @Returns: @language: @Returns: @language: @Returns: @language: @Returns: @language: @mime_types: @language: @Returns: @language: @scheme: @language: @tag_id: @Returns: @language: @tag_id: @style: @language: @tag_id: @Returns: