Table 2.

Pedro Ontology Sources

Class/Interface	Function
OntologySource	Implementing classes provide ontology terms to an OntologyViewer.
TreeOntologySource	Extends OntologySource but implementing classes provide ontology terms that can be organised as a tree structure.
DictionaryDescriptionSupport	Implementing classes provide a definition for OntologyTerms.
ImageDescriptionSupport	Implementing classes can provide images based on an identifier.
URLDescriptionSupport	Implementing classes can provide a link to a webpage.
SingleColumnTextSource, OntologySource	An ontology source that reads terms from a text file that contains a single column of ontology terms.
AbstractTreeOntologySource, TreeOntologySource	A class to manage a tree of terms. This is extended in the classes below.
TabIndentedTextSource	Extends AbstractTreeOntologySource. This is an ontology source that reads terms from a tab-indented text file.
XMLOntologySource	Extends AbstractTreeOntologySource. This is an ontology source that reads its terms from a bespoke XML format.