tablesorter.java

Java的面向对象数据库系统的源代码

// You can redistribute this software and/or modify it under the terms of
// the Ozone Library License version 1 published by ozone-db.org.
//
// The original code and portions created by SMB are
// Copyright (C) 1997-@year@ by SMB GmbH. All rights reserved.
//
// $Id: $
package org.ozoneDB.adminGui.widget;

import java.awt.event.InputEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.Date;
import java.util.Vector;
import javax.swing.*;
import javax.swing.event.TableModelEvent;
import javax.swing.table.JTableHeader;
import javax.swing.table.TableColumnModel;
import javax.swing.table.TableModel;

/**
 * A sorter for TableModels. The sorter has a model (conforming to TableModel)
 * and itself implements TableModel. TableSorter does not store or copy
 * the data in the TableModel, instead it maintains an array of
 * integers which it keeps the same size as the number of rows in its
 * model. When the model changes it notifies the sorter that something
 * has changed eg. "rowsAdded" so that its internal array of integers
 * can be reallocated. As requests are made of the sorter (like
 * getValueAt(row, col) it redirects them to its model via the mapping
 * array. That way the TableSorter appears to hold another copy of the table
 * with the rows in a different order. The sorting algorthm used is stable
 * which means that it does not move around rows when its comparison
 * function returns 0 to denote that they are equivalent.
 */
public class TableSorter extends TableMap {

    protected int indexes[];
    protected Vector sortingColumns = new Vector();
    protected boolean ascending = true;
    protected int compares;

    public TableSorter() {
        indexes = new int[0];
    }

    public TableSorter(TableModel model) {
        setModel(model);
    }

    public void setModel(TableModel model) {
        super.setModel(model);
        reallocateIndexes();
    }

    public int compareRowsByColumn(int row1, int row2, int column) {
        Class type = model.getColumnClass(column);
        TableModel data = model;

        // Check for nulls
        Object o1 = data.getValueAt(row1, column);
        Object o2 = data.getValueAt(row2, column);

        if (o1 == null && o2 == null) { // If both values are null return 0
            return 0;
        } else if (o1 == null) { // Define null less than everything.
            return -1;
        } else if (o2 == null) {
            return 1;
        }

        /* We copy all returned values from the getValue call in case
        an optimised model is reusing one object to return many values.
        The Number subclasses in the JDK are immutable and so will not be used in
        this way but other subclasses of Number might want to do this to save
        space and avoid unnecessary heap allocation.
        */
        if (type.getSuperclass() == java.lang.Number.class) {
            Number n1 = (Number) data.getValueAt(row1, column);
            double d1 = n1.doubleValue();
            Number n2 = (Number) data.getValueAt(row2, column);
            double d2 = n2.doubleValue();

            if (d1 < d2)
                return -1;
            else if (d1 > d2)
                return 1;
            else
                return 0;
        } else if (type == java.util.Date.class) {
            Date d1 = (Date) data.getValueAt(row1, column);
            long n1 = d1.getTime();
            Date d2 = (Date) data.getValueAt(row2, column);
            long n2 = d2.getTime();

            if (n1 < n2)
                return -1;
            else if (n1 > n2)
                return 1;
            else
                return 0;
        } else if (type == String.class) {
            String s1 = (String) data.getValueAt(row1, column);
            String s2 = (String) data.getValueAt(row2, column);
            int result = s1.compareTo(s2);

            if (result < 0)
                return -1;
            else if (result > 0)
                return 1;
            else
                return 0;
        } else if (type == Boolean.class) {
            Boolean bool1 = (Boolean) data.getValueAt(row1, column);
            boolean b1 = bool1.booleanValue();
            Boolean bool2 = (Boolean) data.getValueAt(row2, column);
            boolean b2 = bool2.booleanValue();

            if (b1 == b2)
                return 0;
            else if (b1)
                return 1;
            else
                return -1;
        } else {
            Object v1 = data.getValueAt(row1, column);
            String s1 = v1.toString();
            Object v2 = data.getValueAt(row2, column);
            String s2 = v2.toString();
            int result = s1.compareTo(s2);

            if (result < 0)
                return -1;
            else if (result > 0)
                return 1;
            else
                return 0;
        }
    }

    public int compare(int row1, int row2) {
        compares++;
        for (int level = 0; level < sortingColumns.size(); level++) {
            Integer column = (Integer) sortingColumns.elementAt(level);
            int result = compareRowsByColumn(row1, row2, column.intValue());
            if (result != 0) {
                return ascending ? result : -result;
            }
        }
        return 0;
    }

    public void reallocateIndexes() {
        int rowCount = model.getRowCount();

        // Set up a new array of indexes with the right number of elements
        // for the new data model.
        indexes = new int[rowCount];

        // Initialise with the identity mapping.
        for (int row = 0; row < rowCount; row++) {
            indexes[row] = row;
        }
    }

    public void tableChanged(TableModelEvent e) {
        reallocateIndexes();
        super.tableChanged(e);
    }

    public void checkModel() {
        if (indexes.length != model.getRowCount()) {
            System.err.println("Sorter not informed of a change in model.");
        }
    }

    public void sort(Object sender) {
        checkModel();

        compares = 0;
        shuttleSort((int[]) indexes.clone(), indexes, 0, indexes.length);
    }

    public void shuttleSort(int from[], int to[], int low, int high) {
        if (high - low < 2) {
            return;
        }
        int middle = (low + high) / 2;
        shuttleSort(to, from, low, middle);
        shuttleSort(to, from, middle, high);

        int p = low;
        int q = middle;

        for (int i = low; i < high; i++) {
            if (q >= high || (p < middle && compare(from[p], from[q]) <= 0)) {
                to[i] = from[p++];
            } else {
                to[i] = from[q++];
            }
        }
    }

    public void swap(int i, int j) {
        int tmp = indexes[i];
        indexes[i] = indexes[j];
        indexes[j] = tmp;
    }

    // The mapping only affects the contents of the data rows.
    // Pass all requests to these rows through the mapping array: "indexes".

    public Object getValueAt(int aRow, int aColumn) {
        checkModel();
        return model.getValueAt(indexes[aRow], aColumn);
    }

    public void setValueAt(Object aValue, int aRow, int aColumn) {
        checkModel();
        model.setValueAt(aValue, indexes[aRow], aColumn);
    }

    public int translateIndex(int index) {
        return indexes[index];
    }

    public void sortByColumn(int column) {
        sortByColumn(column, true);
    }

    public void sortByColumn(int column, boolean ascending) {
        this.ascending = ascending;
        sortingColumns.removeAllElements();
        sortingColumns.addElement(new Integer(column));
        sort(this);
        super.tableChanged(new TableModelEvent(this));
    }

    // Add a mouse listener to the Table to trigger a table sort
    // when a column heading is clicked in the JTable.
    public void addMouseListenerToHeaderInTable(JTable table) {
        final TableSorter sorter = this;
        final JTable tableView = table;
        tableView.setColumnSelectionAllowed(false);
        MouseAdapter listMouseListener = new MouseAdapter() {
            public void mouseClicked(MouseEvent e) {
                TableColumnModel columnModel = tableView.getColumnModel();
                int viewColumn = columnModel.getColumnIndexAtX(e.getX());
                int column = tableView.convertColumnIndexToModel(viewColumn);
                if (e.getClickCount() == 1 && column != -1) {
                    int shiftPressed = e.getModifiers() & InputEvent.SHIFT_MASK;
                    boolean ascending = (shiftPressed == 0);
                    sorter.sortByColumn(column, ascending);
                }
            }
        };
        JTableHeader th = tableView.getTableHeader();
        th.addMouseListener(listMouseListener);
    }
}