sortabletableheaderlistener.java

该源代码为一些通用的程序

/* ========================================================================
 * JCommon : a free general purpose class library for the Java(tm) platform
 * ========================================================================
 *
 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
 * 
 * Project Info:  http://www.jfree.org/jcommon/index.html
 *
 * This library is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU Lesser General Public License as published by 
 * the Free Software Foundation; either version 2.1 of the License, or 
 * (at your option) any later version.
 *
 * This library 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 Lesser General Public 
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 * 
 * --------------------------------
 * SortableTableHeaderListener.java
 * --------------------------------
 * (C) Copyright 2000-2004, by Nabuo Tamemasa and Contributors.
 *
 * Original Author:  Nabuo Tamemasa;
 * Contributor(s):   David Gilbert (for Object Refinery Limited);
 *
 * $Id: SortableTableHeaderListener.java,v 1.4 2005/11/16 15:58:41 taqua Exp $
 *
 * Changes (from 26-Oct-2001)
 * --------------------------
 * 26-Oct-2001 : Changed package to com.jrefinery.ui.*;
 * 14-Oct-2002 : Fixed errors reported by Checkstyle (DG);
 *
 */

package org.jfree.ui;

import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

import javax.swing.table.JTableHeader;

/**
 * Captures mouse clicks on a table header, with the intention of triggering a sort.  Adapted from
 * code by Nabuo Tamemasa posted on http://www.codeguru.com.
 *
 * @author Nabuo Tamemasa
 */
public class SortableTableHeaderListener implements MouseListener, MouseMotionListener {

    /** A reference to the table model. */
    private SortableTableModel model;

    /** The header renderer. */
    private SortButtonRenderer renderer;

    /** The index of the column that is sorted - used to determine the state of the renderer. */
    private int sortColumnIndex;

    /**
     * Standard constructor.
     *
     * @param model  the model.
     * @param renderer  the renderer.
     */
    public SortableTableHeaderListener(final SortableTableModel model, 
                                       final SortButtonRenderer renderer) {
        this.model = model;
        this.renderer = renderer;
    }

    /**
     * Sets the table model for the listener.
     *
     * @param model  the model.
     */
    public void setTableModel(final SortableTableModel model) {
        this.model = model;
    }

    /**
     * Handle a mouse press event - if the user is NOT resizing a column and NOT dragging a column
     * then give visual feedback that the column header has been pressed.
     *
     * @param e  the mouse event.
     */
    public void mousePressed(final MouseEvent e) {

        final JTableHeader header = (JTableHeader) e.getComponent();

        if (header.getResizingColumn() == null) {  // resizing takes precedence over sorting
            if (header.getDraggedDistance() < 1) {   // dragging also takes precedence over sorting
                final int columnIndex = header.columnAtPoint(e.getPoint());
                final int modelColumnIndex 
                    = header.getTable().convertColumnIndexToModel(columnIndex);
                if (this.model.isSortable(modelColumnIndex)) {
                    this.sortColumnIndex = header.getTable().convertColumnIndexToModel(columnIndex);
                    this.renderer.setPressedColumn(this.sortColumnIndex);
                    header.repaint();
                    if (header.getTable().isEditing()) {
                        header.getTable().getCellEditor().stopCellEditing();
                    }
                }
                else {
                    this.sortColumnIndex = -1;
                }
            }
        }

    }

    /**
     * If the user is dragging or resizing, then we clear the sort column.
     *
     * @param e  the mouse event.
     */
    public void mouseDragged(final MouseEvent e) {

        final JTableHeader header = (JTableHeader) e.getComponent();

        if ((header.getDraggedDistance() > 0) || (header.getResizingColumn() != null)) {
            this.renderer.setPressedColumn(-1);
            this.sortColumnIndex = -1;
        }
    }

    /**
     * This event is ignored (not required).
     *
     * @param e  the mouse event.
     */
    public void mouseEntered(final MouseEvent e) {
        // not required
    }

    /**
     * This event is ignored (not required).
     *
     * @param e  the mouse event.
     */
    public void mouseClicked(final MouseEvent e) {
        // not required
    }

    /**
     * This event is ignored (not required).
     *
     * @param e  the mouse event.
     */
    public void mouseMoved(final MouseEvent e) {
        // not required
    }

    /**
     * This event is ignored (not required).
     *
     * @param e  the mouse event.
     */
    public void mouseExited(final MouseEvent e) {
        // not required
    }

    /**
     * When the user releases the mouse button, we attempt to sort the table.
     *
     * @param e  the mouse event.
     */
    public void mouseReleased(final MouseEvent e) {

        final JTableHeader header = (JTableHeader) e.getComponent();

        if (header.getResizingColumn() == null) {  // resizing takes precedence over sorting
            if (this.sortColumnIndex != -1) {
                final SortableTableModel model = (SortableTableModel) header.getTable().getModel();
                final boolean ascending = !model.isAscending();
                model.setAscending(ascending);
                model.sortByColumn(this.sortColumnIndex, ascending);

                this.renderer.setPressedColumn(-1);       // clear
                header.repaint();
            }
        }
    }

}