Java example source code file (TableRowSorter.java)

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Java - Java tags/keywords

class, comparable_comparator, comparablecomparator, comparator, defaultrowsorter, gui, integer, object, string, suppresswarnings, swing, tablemodel, tablerowsorter, tablerowsortermodelwrapper, tablestringconverter, text, util

The TableRowSorter.java Java example source code

/*
 * Copyright (c) 2005, 2006, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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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 <code>RowSorter that provides sorting
 * and filtering using a <code>TableModel.
 * The following example shows adding sorting to a <code>JTable:
 * <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'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 <code>myModel
 * you need to convert the indices:
 * <pre>
 *   int[] selection = table.getSelectedRows();
 *   for (int i = 0; i < selection.length; i++) {
 *     selection[i] = table.convertRowIndexToModel(selection[i]);
 *   }
 * </pre>
 * Similarly to select a row in <code>JTable 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 will return
 * -1 for locations that are not visible in the view.
 * <p>
 * <code>TableRowSorter uses Comparators for doing
 * comparisons. The following defines how a <code>Comparator is
 * chosen for a column:
 * <ol>
 * <li>If a Comparator has been specified for the column by the
 *     <code>setComparator method, use it.
 * <li>If the column class as returned by getColumnClass is
 *     <code>String, use the Comparator returned by
 *     <code>Collator.getInstance().
 * <li>If the column class implements Comparable, use a
 *     <code>Comparator that invokes the compareTo
 *     method.
 * <li>If a TableStringConverter has been specified, use it
 *     to convert the values to <code>Strings and then use the
 *     <code>Comparator returned by Collator.getInstance().
 * <li>Otherwise use the Comparator returned by
 *     <code>Collator.getInstance() on the results from
 *     calling <code>toString on the objects.
 * </ol>
 * <p>
 * In addition to sorting <code>TableRowSorter provides the ability
 * to filter.  A filter is specified using the <code>setFilter
 * 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 method is invoked) the following
 * are reset to their default values: <code>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.
 * <p>
 * <code>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 <code>RowFilter for an example
 * of this.
 * <p>
 * <b>WARNING: DefaultTableModel returns a column
 * class of <code>Object.  As such all comparisons will
 * be done using <code>toString.  This may be unnecessarily
 * expensive.  If the column only contains one type of value, such as
 * an <code>Integer, you should override getColumnClass and
 * return the appropriate <code>Class.  This will dramatically
 * increase the performance of this class.
 *
 * @param <M> the type of the model, which must be an implementation of
 *            <code>TableModel
 * @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 {
    /**
     * Comparator that uses compareTo on the contents.
     */
    private static final Comparator COMPARABLE_COMPARATOR =
            new ComparableComparator();

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

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


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

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

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

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

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