/** \page uiconcept "User Interface Concepts" *
* The OpenFlipper user interface is composed of 4 essential widgets * each accessible and extendable by user plugins:
*
* -\ref viewport_widget * -\ref plugin_widget * -\ref logging_widget * -\ref tool_bar * * \subsection viewport_widget The viewport widget * * * * \subsection plugin_widget The plugin widget * \subsection logging_widget The logging widget * \subsection tool_bar The tool bar
*/