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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * accompanied this code).
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 * 2 along with this work; if not, write to the Free Software Foundation,
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package javax.swing.table;

import java.text.Collator;
import java.util.*;
import javax.swing.DefaultRowSorter;
import javax.swing.RowFilter;
import javax.swing.SortOrder;


An implementation of RowSorter that provides sorting
and filtering using a TableModel.
The following example shows adding sorting to a JTable:

  TableModel myModel = createMyTableModel();
  JTable table = new JTable(myModel);
  table.setRowSorter(new TableRowSorter(myModel));


This will do all the wiring such that when the user does the appropriate
gesture, such as clicking on the column header, the table will
visually sort.


JTable's row-based methods and JTable's
selection model refer to the view and not the underlying
model. Therefore, it is necessary to convert between the two.  For
example, to get the selection in terms of myModel
you need to convert the indices:

  int[] selection = table.getSelectedRows();
  for (int i = 0; i < selection.length; i++) {
    selection[i] = table.convertRowIndexToModel(selection[i]);
  }


Similarly to select a row in JTable based on
a coordinate from the underlying model do the inverse:

  table.setRowSelectionInterval(table.convertRowIndexToView(row),
                                table.convertRowIndexToView(row));




The previous example assumes you have not enabled filtering.  If you
have enabled filtering convertRowIndexToView will return
-1 for locations that are not visible in the view.


TableRowSorter uses Comparators for doing
comparisons. The following defines how a Comparator is
chosen for a column:

    

  1. If a Comparator has been specified for the column by the
    setComparator method, use it.

  2. If the column class as returned by getColumnClass is
    String, use the Comparator returned by
    Collator.getInstance().

  3. If the column class implements Comparable, use a
    Comparator that invokes the compareTo
    method.

  4. If a TableStringConverter has been specified, use it
    to convert the values to Strings and then use the
    Comparator returned by Collator.getInstance().

  5. Otherwise use the Comparator returned by
    Collator.getInstance() on the results from
    calling toString on the objects.




In addition to sorting TableRowSorter provides the ability
to filter.  A filter is specified using the setFilter
method. The following example will only show rows containing the string
"foo":

  TableModel myModel = createMyTableModel();
  TableRowSorter sorter = new TableRowSorter(myModel);
  sorter.setRowFilter(RowFilter.regexFilter(".*foo.*"));
  JTable table = new JTable(myModel);
  table.setRowSorter(sorter);




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. The default
sort order is natural (the same as the model), and columns are
sortable by default.


TableRowSorter has one formal type parameter: the type
of the model.  Passing in a type that corresponds exactly to your
model allows you to filter based on your model without casting.
Refer to the documentation of RowFilter for an example
of this.


WARNING: DefaultTableModel returns a column
class of Object.  As such all comparisons will
be done using toString.  This may be unnecessarily
expensive.  If the column only contains one type of value, such as
an Integer, you should override getColumnClass and
return the appropriate Class.  This will dramatically
increase the performance of this class.

Type parameters:
  • <M> – the type of the model, which must be an implementation of
           TableModel
See Also:
Since:1.6
/**
 * An implementation of <code>RowSorter</code> that provides sorting
 * and filtering using a <code>TableModel</code>.
 * The following example shows adding sorting to a <code>JTable</code>:
 * <pre>
 *   TableModel myModel = createMyTableModel();
 *   JTable table = new JTable(myModel);
 *   table.setRowSorter(new TableRowSorter(myModel));
 * </pre>
 * This will do all the wiring such that when the user does the appropriate
 * gesture, such as clicking on the column header, the table will
 * visually sort.
 * <p>
 * <code>JTable</code>'s row-based methods and <code>JTable</code>'s
 * selection model refer to the view and not the underlying
 * model. Therefore, it is necessary to convert between the two.  For
 * example, to get the selection in terms of <code>myModel</code>
 * you need to convert the indices:
 * <pre>
 *   int[] selection = table.getSelectedRows();
 *   for (int i = 0; i &lt; selection.length; i++) {
 *     selection[i] = table.convertRowIndexToModel(selection[i]);
 *   }
 * </pre>
 * Similarly to select a row in <code>JTable</code> based on
 * a coordinate from the underlying model do the inverse:
 * <pre>
 *   table.setRowSelectionInterval(table.convertRowIndexToView(row),
 *                                 table.convertRowIndexToView(row));
 * </pre>
 * <p>
 * The previous example assumes you have not enabled filtering.  If you
 * have enabled filtering <code>convertRowIndexToView</code> will return
 * -1 for locations that are not visible in the view.
 * <p>
 * <code>TableRowSorter</code> uses <code>Comparator</code>s for doing
 * comparisons. The following defines how a <code>Comparator</code> is
 * chosen for a column:
 * <ol>
 * <li>If a <code>Comparator</code> has been specified for the column by the
 *     <code>setComparator</code> method, use it.
 * <li>If the column class as returned by <code>getColumnClass</code> is
 *     <code>String</code>, use the <code>Comparator</code> returned by
 *     <code>Collator.getInstance()</code>.
 * <li>If the column class implements <code>Comparable</code>, use a
 *     <code>Comparator</code> that invokes the <code>compareTo</code>
 *     method.
 * <li>If a <code>TableStringConverter</code> has been specified, use it
 *     to convert the values to <code>String</code>s and then use the
 *     <code>Comparator</code> returned by <code>Collator.getInstance()</code>.
 * <li>Otherwise use the <code>Comparator</code> returned by
 *     <code>Collator.getInstance()</code> on the results from
 *     calling <code>toString</code> on the objects.
 * </ol>
 * <p>
 * In addition to sorting <code>TableRowSorter</code> provides the ability
 * to filter.  A filter is specified using the <code>setFilter</code>
 * method. The following example will only show rows containing the string
 * "foo":
 * <pre>
 *   TableModel myModel = createMyTableModel();
 *   TableRowSorter sorter = new TableRowSorter(myModel);
 *   sorter.setRowFilter(RowFilter.regexFilter(".*foo.*"));
 *   JTable table = new JTable(myModel);
 *   table.setRowSorter(sorter);
 * </pre>
 * <p>
 * If the underlying model structure changes (the
 * <code>modelStructureChanged</code> method is invoked) the following
 * are reset to their default values: <code>Comparator</code>s by
 * column, current sort order, and whether each column is sortable. The default
 * sort order is natural (the same as the model), and columns are
 * sortable by default.
 * <p>
 * <code>TableRowSorter</code> has one formal type parameter: the type
 * of the model.  Passing in a type that corresponds exactly to your
 * model allows you to filter based on your model without casting.
 * Refer to the documentation of <code>RowFilter</code> for an example
 * of this.
 * <p>
 * <b>WARNING:</b> <code>DefaultTableModel</code> returns a column
 * class of <code>Object</code>.  As such all comparisons will
 * be done using <code>toString</code>.  This may be unnecessarily
 * expensive.  If the column only contains one type of value, such as
 * an <code>Integer</code>, you should override <code>getColumnClass</code> and
 * return the appropriate <code>Class</code>.  This will dramatically
 * increase the performance of this class.
 *
 * @param <M> the type of the model, which must be an implementation of
 *            <code>TableModel</code>
 * @see javax.swing.JTable
 * @see javax.swing.RowFilter
 * @see javax.swing.table.DefaultTableModel
 * @see java.text.Collator
 * @see java.util.Comparator
 * @since 1.6
 */
public class TableRowSorter<M extends TableModel> extends DefaultRowSorter<M, Integer> {
    
Comparator that uses compareTo on the contents.

/**
     * Comparator that uses compareTo on the contents.
     */
    private static final Comparator COMPARABLE_COMPARATOR =
            new ComparableComparator();

    
Underlying model.

/**
     * Underlying model.
     */
    private M tableModel;

    
For toString conversions.

/**
     * For toString conversions.
     */
    private TableStringConverter stringConverter;


    
Creates a TableRowSorter with an empty model.

/**
     * Creates a <code>TableRowSorter</code> with an empty model.
     */
    public TableRowSorter() {
        this(null);
    }

    
Creates a TableRowSorter using model
as the underlying TableModel.

Params:
  • model – the underlying TableModel to use,
       null is treated as an empty model
/**
     * Creates a <code>TableRowSorter</code> using <code>model</code>
     * as the underlying <code>TableModel</code>.
     *
     * @param model the underlying <code>TableModel</code> to use,
     *        <code>null</code> is treated as an empty model
     */
    public TableRowSorter(M model) {
        setModel(model);
    }

    
Sets the TableModel to use as the underlying model
for this TableRowSorter.  A value of null
can be used to set an empty model.

Params:
  • model – the underlying model to use, or null
/**
     * Sets the <code>TableModel</code> to use as the underlying model
     * for this <code>TableRowSorter</code>.  A value of <code>null</code>
     * can be used to set an empty model.
     *
     * @param model the underlying model to use, or <code>null</code>
     */
    public void setModel(M model) {
        tableModel = model;
        setModelWrapper(new TableRowSorterModelWrapper());
    }

    
Sets the object responsible for converting values from the
model to strings.  If non-null this
is used to convert any object values, that do not have a
registered Comparator, to strings.

Params:
  • stringConverter – the object responsible for converting values
       from the model to strings
/**
     * Sets the object responsible for converting values from the
     * model to strings.  If non-<code>null</code> this
     * is used to convert any object values, that do not have a
     * registered <code>Comparator</code>, to strings.
     *
     * @param stringConverter the object responsible for converting values
     *        from the model to strings
     */
    public void setStringConverter(TableStringConverter stringConverter) {
        this.stringConverter = stringConverter;
    }

    
Returns the object responsible for converting values from the
model to strings.

Returns:object responsible for converting values to strings.
/**
     * Returns the object responsible for converting values from the
     * model to strings.
     *
     * @return object responsible for converting values to strings.
     */
    public TableStringConverter getStringConverter() {
        return stringConverter;
    }

    
Returns the Comparator for the specified
column.  If a Comparator has not been specified using
the setComparator method a Comparator
will be returned based on the column class
(TableModel.getColumnClass) of the specified column.
If the column class is String,
Collator.getInstance is returned.  If the
column class implements Comparable a private
Comparator is returned that invokes the
compareTo method.  Otherwise
Collator.getInstance is returned.

Throws:
  • IndexOutOfBoundsException – {@inheritDoc}
/**
     * Returns the <code>Comparator</code> for the specified
     * column.  If a <code>Comparator</code> has not been specified using
     * the <code>setComparator</code> method a <code>Comparator</code>
     * will be returned based on the column class
     * (<code>TableModel.getColumnClass</code>) of the specified column.
     * If the column class is <code>String</code>,
     * <code>Collator.getInstance</code> is returned.  If the
     * column class implements <code>Comparable</code> a private
     * <code>Comparator</code> is returned that invokes the
     * <code>compareTo</code> method.  Otherwise
     * <code>Collator.getInstance</code> is returned.
     *
     * @throws IndexOutOfBoundsException {@inheritDoc}
     */
    public Comparator<?> getComparator(int column) {
        Comparator comparator = super.getComparator(column);
        if (comparator != null) {
            return comparator;
        }
        Class columnClass = getModel().getColumnClass(column);
        if (columnClass == String.class) {
            return Collator.getInstance();
        }
        if (Comparable.class.isAssignableFrom(columnClass)) {
            return COMPARABLE_COMPARATOR;
        }
        return Collator.getInstance();
    }

    
{@inheritDoc}

Throws:
/**
     * {@inheritDoc}
     *
     * @throws IndexOutOfBoundsException {@inheritDoc}
     */
    protected boolean useToString(int column) {
        Comparator comparator = super.getComparator(column);
        if (comparator != null) {
            return false;
        }
        Class columnClass = getModel().getColumnClass(column);
        if (columnClass == String.class) {
            return false;
        }
        if (Comparable.class.isAssignableFrom(columnClass)) {
            return false;
        }
        return true;
    }

    
Implementation of DefaultRowSorter.ModelWrapper that delegates to a
TableModel.

/**
     * Implementation of DefaultRowSorter.ModelWrapper that delegates to a
     * TableModel.
     */
    private class TableRowSorterModelWrapper extends ModelWrapper<M,Integer> {
        public M getModel() {
            return tableModel;
        }

        public int getColumnCount() {
            return (tableModel == null) ? 0 : tableModel.getColumnCount();
        }

        public int getRowCount() {
            return (tableModel == null) ? 0 : tableModel.getRowCount();
        }

        public Object getValueAt(int row, int column) {
            return tableModel.getValueAt(row, column);
        }

        public String getStringValueAt(int row, int column) {
            TableStringConverter converter = getStringConverter();
            if (converter != null) {
                // Use the converter
                String value = converter.toString(
                        tableModel, row, column);
                if (value != null) {
                    return value;
                }
                return "";
            }

            // No converter, use getValueAt followed by toString
            Object o = getValueAt(row, column);
            if (o == null) {
                return "";
            }
            String string = o.toString();
            if (string == null) {
                return "";
            }
            return string;
        }

        public Integer getIdentifier(int index) {
            return index;
        }
    }


    private static class ComparableComparator implements Comparator {
        @SuppressWarnings("unchecked")
        public int compare(Object o1, Object o2) {
            return ((Comparable)o1).compareTo(o2);
        }
    }
}