5.1.4. Viewer filters
A viewer filter (see Figure 5-6 for the ViewerFilter hierarchy) is used to display a subset of the elements provided by the content provider (see Figure 5-1). If a view does not have a viewer filter, all the elements are displayed. A viewer filter is associated with a viewer using the setFilter() method.
Useful APIs defined by ViewFilter are listed next. Simple viewer filters need only to override the select(Viewer, Object, Object) method to determine whether an object should be visible in the viewer.