I'm using the web framework to create my own custom search view. However, from http://docs.splunk.com/DocumentationStatic/WebFramework/1.1/compref_eventsviewer.html(EventsViewerVi...
no method about fields mentioned.
| top field1 | appendpipe [| stats sum(count) AS count | eval field1="ALL" | eval percent=100]
will show you for a single field of interest.
The fields panel (include interesting fields) is not exposed through the web framework. The search page is render through set of html partials, templates, and minified javascript. Not to say you could not use the components.
Many of the components can be found under $SPLUNK_HOME/share/splunk/search_mrsparkle. I believe you can find the field picker code under $SPLUNK_HOME/share/splunk/search_mrsparkle/modules/search
Hope that gets you started.