basicdnd.java

java tutorial.sun公司官方出品。java入门书籍。最新版

/*
 * Copyright (c) 1995 - 2008 Sun Microsystems, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Sun Microsystems nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */ 

package dnd;

/*
 * BasicDnD.java requires no other files.
 */

import java.util.*;
import java.awt.*;
import java.awt.event.*;
import java.text.*;
import java.awt.datatransfer.*;

import javax.swing.*;
import javax.swing.text.*;
import javax.swing.tree.*;
import javax.swing.table.*;

public class BasicDnD extends JPanel implements ActionListener {
    private static JFrame frame;
    private JTextArea textArea;
    private JTextField textField;
    private JList list;
    private JTable table;
    private JTree tree;
    private JColorChooser colorChooser;
    private JCheckBox toggleDnD;
    
    public BasicDnD() {
        super(new BorderLayout());
        JPanel leftPanel = createVerticalBoxPanel();
        JPanel rightPanel = createVerticalBoxPanel();

        //Create a table model.
        DefaultTableModel tm = new DefaultTableModel();
        tm.addColumn("Column 0");
        tm.addColumn("Column 1");
        tm.addColumn("Column 2");
        tm.addColumn("Column 3");
        tm.addRow(new String[]{"Table 00", "Table 01", "Table 02", "Table 03"});
        tm.addRow(new String[]{"Table 10", "Table 11", "Table 12", "Table 13"});
        tm.addRow(new String[]{"Table 20", "Table 21", "Table 22", "Table 23"});
        tm.addRow(new String[]{"Table 30", "Table 31", "Table 32", "Table 33"});

        //LEFT COLUMN
        //Use the table model to create a table.
        table = new JTable(tm);
        leftPanel.add(createPanelForComponent(table, "JTable"));

        //Create a color chooser.
        colorChooser = new JColorChooser();
        leftPanel.add(createPanelForComponent(colorChooser, "JColorChooser"));

        //RIGHT COLUMN
        //Create a textfield.
        textField = new JTextField(30);
        textField.setText("Favorite foods:\nPizza, Moussaka, Pot roast");
        rightPanel.add(createPanelForComponent(textField, "JTextField"));

        //Create a scrolled text area.
        textArea = new JTextArea(5, 30);
        textArea.setText("Favorite shows:\nBuffy, Alias, Angel");
        JScrollPane scrollPane = new JScrollPane(textArea);
        rightPanel.add(createPanelForComponent(scrollPane, "JTextArea"));

        //Create a list model and a list.
        DefaultListModel listModel = new DefaultListModel();
        listModel.addElement("Martha Washington");
        listModel.addElement("Abigail Adams");
        listModel.addElement("Martha Randolph");
        listModel.addElement("Dolley Madison");
        listModel.addElement("Elizabeth Monroe");
        listModel.addElement("Louisa Adams");
        listModel.addElement("Emily Donelson");
        list = new JList(listModel);
        list.setVisibleRowCount(-1);
        list.getSelectionModel().setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
        
        list.setTransferHandler(new TransferHandler() {

            public boolean canImport(TransferHandler.TransferSupport info) {
                // we only import Strings
                if (!info.isDataFlavorSupported(DataFlavor.stringFlavor)) {
                    return false;
                }

                JList.DropLocation dl = (JList.DropLocation)info.getDropLocation();
                if (dl.getIndex() == -1) {
                    return false;
                }
                return true;
            }

            public boolean importData(TransferHandler.TransferSupport info) {
                if (!info.isDrop()) {
                    return false;
                }
                
                // Check for String flavor
                if (!info.isDataFlavorSupported(DataFlavor.stringFlavor)) {
                    displayDropLocation("List doesn't accept a drop of this type.");
                    return false;
                }

                JList.DropLocation dl = (JList.DropLocation)info.getDropLocation();
                DefaultListModel listModel = (DefaultListModel)list.getModel();
                int index = dl.getIndex();
                boolean insert = dl.isInsert();
                // Get the current string under the drop.
                String value = (String)listModel.getElementAt(index);

                // Get the string that is being dropped.
                Transferable t = info.getTransferable();
                String data;
                try {
                    data = (String)t.getTransferData(DataFlavor.stringFlavor);
                } 
                catch (Exception e) { return false; }
                
                // Display a dialog with the drop information.
                String dropValue = "\"" + data + "\" dropped ";
                if (dl.isInsert()) {
                    if (dl.getIndex() == 0) {
                        displayDropLocation(dropValue + "at beginning of list");
                    } else if (dl.getIndex() >= list.getModel().getSize()) {
                        displayDropLocation(dropValue + "at end of list");
                    } else {
                        String value1 = (String)list.getModel().getElementAt(dl.getIndex() - 1);
                        String value2 = (String)list.getModel().getElementAt(dl.getIndex());
                        displayDropLocation(dropValue + "between \"" + value1 + "\" and \"" + value2 + "\"");
                    }
                } else {
                    displayDropLocation(dropValue + "on top of " + "\"" + value + "\"");
                }
                
		/**  This is commented out for the basicdemo.html tutorial page.
                 **  If you add this code snippet back and delete the
                 **  "return false;" line, the list will accept drops
                 **  of type string.
                // Perform the actual import.  
                if (insert) {
                    listModel.add(index, data);
                } else {
                    listModel.set(index, data);
                }
                return true;
		*/
		return false;
            }
            
            public int getSourceActions(JComponent c) {
                return COPY;
            }
            
            protected Transferable createTransferable(JComponent c) {
                JList list = (JList)c;
                Object[] values = list.getSelectedValues();
        
                StringBuffer buff = new StringBuffer();

                for (int i = 0; i < values.length; i++) {
                    Object val = values[i];
                    buff.append(val == null ? "" : val.toString());
                    if (i != values.length - 1) {
                        buff.append("\n");
                    }
                }
                return new StringSelection(buff.toString());
            }
        });
        list.setDropMode(DropMode.ON_OR_INSERT);
        
        JScrollPane listView = new JScrollPane(list);
        listView.setPreferredSize(new Dimension(300, 100));
        rightPanel.add(createPanelForComponent(listView, "JList"));

        //Create a tree.
        DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode("Mia Familia");
        DefaultMutableTreeNode sharon = new DefaultMutableTreeNode("Sharon");
        rootNode.add(sharon);
        DefaultMutableTreeNode maya = new DefaultMutableTreeNode("Maya");
        sharon.add(maya);
        DefaultMutableTreeNode anya = new DefaultMutableTreeNode("Anya");
        sharon.add(anya);
        sharon.add(new DefaultMutableTreeNode("Bongo"));
        maya.add(new DefaultMutableTreeNode("Muffin"));
        anya.add(new DefaultMutableTreeNode("Winky"));
        DefaultTreeModel model = new DefaultTreeModel(rootNode);
        tree = new JTree(model);
        tree.getSelectionModel().setSelectionMode
              (TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION);
        JScrollPane treeView = new JScrollPane(tree);
        treeView.setPreferredSize(new Dimension(300, 100));
        rightPanel.add(createPanelForComponent(treeView, "JTree"));

        //Create the toggle button.
        toggleDnD = new JCheckBox("Turn on Drag and Drop");
        toggleDnD.setActionCommand("toggleDnD");
        toggleDnD.addActionListener(this);

        JSplitPane splitPane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,
                                              leftPanel, rightPanel);
        splitPane.setOneTouchExpandable(true);

        add(splitPane, BorderLayout.CENTER);
        add(toggleDnD, BorderLayout.PAGE_END);
        setBorder(BorderFactory.createEmptyBorder(5,5,5,5));
    }

    protected JPanel createVerticalBoxPanel() {
        JPanel p = new JPanel();
        p.setLayout(new BoxLayout(p, BoxLayout.PAGE_AXIS));
        p.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));
        return p;
    }

    public JPanel createPanelForComponent(JComponent comp,
                                          String title) {
        JPanel panel = new JPanel(new BorderLayout());
        panel.add(comp, BorderLayout.CENTER);
        if (title != null) {
            panel.setBorder(BorderFactory.createTitledBorder(title));
        }
        return panel;
    }

    private void displayDropLocation(final String string) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JOptionPane.showMessageDialog(null, string);
            }
        });
    }

    public void actionPerformed(ActionEvent e) {
        if ("toggleDnD".equals(e.getActionCommand())) {
            boolean toggle = toggleDnD.isSelected();
            textArea.setDragEnabled(toggle);
            textField.setDragEnabled(toggle);
            list.setDragEnabled(toggle);
            table.setDragEnabled(toggle);
            tree.setDragEnabled(toggle);
            colorChooser.setDragEnabled(toggle);
        }
    }

    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Create and set up the window.
        frame = new JFrame("BasicDnD");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Create and set up the content pane.
        JComponent newContentPane = new BasicDnD();
        newContentPane.setOpaque(true); //content panes must be opaque
        frame.setContentPane(newContentPane);

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                //Turn off metal's use of bold fonts
	        UIManager.put("swing.boldMetal", Boolean.FALSE);
                createAndShowGUI();
            }
        });
    }
}