An implementation of
RowSorter that provides sorting and filtering around a grid-based data model. Beyond creating and installing a
RowSorter, you very rarely need to interact with one directly. Refer to
TableRowSorter for a concrete implementation of
RowSorter for
JTable.
Sorting is done based on the current SortKeys, in order. If two objects are equal (the Comparator for the column returns 0) the next SortKey is used. If no SortKeys remain or the order is UNSORTED, then the order of the rows in the model is used.
Sorting of each column is done by way of a Comparator that you can specify using the setComparator method. If a Comparator has not been specified, the Comparator returned by Collator.getInstance() is used on the results of calling toString on the underlying objects. The Comparator is never passed null. A null value is treated as occurring before a non-null value, and two null values are considered equal.
If you specify a Comparator that casts its argument to a type other than that provided by the model, a ClassCastException will be thrown when the data is sorted.
In addition to sorting, DefaultRowSorter provides the ability to filter rows. Filtering is done by way of a RowFilter that is specified using the setRowFilter method. If no filter has been specified all rows are included.
By default, rows are in unsorted order (the same as the model) and every column is sortable. The default Comparators are documented in the subclasses (for example, TableRowSorter).
If the underlying model structure changes (the modelStructureChanged method is invoked) the following are reset to their default values: Comparators by column, current sort order, and whether each column is sortable. To find the default Comparators, see the concrete implementation (for example, TableRowSorter). The default sort order is unsorted (the same as the model), and columns are sortable by default.
DefaultRowSorter is an abstract class. Concrete subclasses must provide access to the underlying data by invoking setModelWrapper. The setModelWrapper method must be invoked soon after the constructor is called, ideally from within the subclass's constructor. Undefined behavior will result if you use a DefaultRowSorter without specifying a ModelWrapper.
DefaultRowSorter has two formal type parameters. The first type parameter corresponds to the class of the model, for example DefaultTableModel. The second type parameter corresponds to the class of the identifier passed to the RowFilter. Refer to TableRowSorter and RowFilter for more details on the type parameters.