Time for action – filtering items in a viewer

Another common feature of viewers is filtering. This is used both when performing a manual search, as well as for filtering specific aspects from a view. Quite often, the filtering is connected to the view's menu, which is the drop-down triangle on the top right of the view, using a common name such as Filters. The ViewerFilter class provides a filtering method, confusingly called select (there are some filter methods, but these are used to filter the entire array; the select is used to determine if a specific element is shown or not).

1. Create a class TimeZoneViewerFilter in the com.packtpub.e4.clock.ui.internal package, which extends ViewerFilter. It should take a String pattern in the constructor, and return true if the element is a TimeZone with that pattern in its display name:

   public class TimeZoneViewerFilter extends ViewerFilter {
     private String pattern;
     public TimeZoneViewerFilter(String pattern) {
       this.pattern = pattern;
     }
     public...