They automatically generate all the source code for a widget from general descriptions provided by the developer , usually through direct manipulation .
Graphical user interface builders facilitate the authoring of GUIs in a WYSIWYG manner employing a user interface markup language .
user interface builders automatically generate all the source code for a widget from general descriptions provided by the developer , usually through direct manipulation .
Graphical user interface builders facilitate the authoring of GUIs in a WYSIWYG manner employing a user interface markup language .