Code for projecting Feature objects and systematically altering their properties.

Feature Projection is the BioJava system whereby a feature hierarchy can be transformed into a similar hierarchy with feature properties systematically modified. For example, projection may translate all features by 120 residues, or add an annotation property to all features.

This package contains the underlying `engine' code for feature projection. ProjectedFeatureHolder uses a ProjectionContext to project a set of features. ProjectionEngine does the actual magic of gluing the projected features through a ProjectionContext to the underlying features.

There are several implementations of ProjectionContext provided here for your convenience. They do standard things like translate or flip features, and graft them into another feature hierarchy.

To develop your own projections, implement ProjectionContext and provide the necessary projection methods. ReparentContext is a really good base-class to use for deriving your custom projections (belive me, getting the basics of an implementation right are not simple) and will handle both the re-rooting of the feature hierarchy and also any event wiring needed.

ProjectionContext does deep voodoo involving introspeciton and class generation. If you don't really want to know the gory details, we strongly suggest that you don't take a peek inside.