swing 初级学习（五） 拖动

 

 http://www.jgraph.com/jgraph.html   工具

 

package com.zzst.test;
/**
 * jdk  1.6以上的
 * @author ryan
 * @since Jul 1, 2010 3:17:03 PM
 * @version Jul 1, 2010 3:17:03 PM
 */
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Rectangle;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.IOException;

import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.DefaultListModel;
import javax.swing.DropMode;
import javax.swing.JCheckBoxMenuItem;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.ListSelectionModel;
import javax.swing.SwingUtilities;
import javax.swing.TransferHandler;
import javax.swing.UIManager;
import javax.swing.table.DefaultTableModel;

public class FillViewportHeightDemo extends JFrame implements ActionListener {

  private DefaultListModel model = new DefaultListModel();
  private int count = 0;
  private JTable table;
  private JCheckBoxMenuItem fillBox;
  private DefaultTableModel tableModel;

  private static String getNextString(int count) {
    StringBuffer buf = new StringBuffer();
    for (int i = 0; i < 5; i++) {
      buf.append(String.valueOf(count));
      buf.append(",");
    }

    // remove last newline
    buf.deleteCharAt(buf.length() - 1);
    return buf.toString();
  }

  private static DefaultTableModel getDefaultTableModel() {
    String[] cols = { "Foo", "Toto", "Kala", "Pippo", "Boing" };
    return new DefaultTableModel(null, cols);
  }

  public FillViewportHeightDemo() {
    super("Empty Table DnD Demo");

    tableModel = getDefaultTableModel();
    table = new JTable(tableModel);
    table.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
    table.setDropMode(DropMode.INSERT_ROWS);

    //增加表格拖动事件
    table.setTransferHandler(new TransferHandler() {

      //指示一个组件在实际尝试导入给定数据 flavor 的集合之前是否接受导入。
      public boolean canImport(TransferSupport support) {
        // for the demo, we'll only support drops (not clipboard paste)
        if (!support.isDrop()) {
          return false;
        }

        // we only import Strings
        if (!support.isDataFlavorSupported(DataFlavor.stringFlavor)) {
          return false;
        }

        return true;
      }

      //导致从剪贴板或 DND 放置操作向组件的传输。
      public boolean importData(TransferSupport support) {
        // if we can't handle the import, say so
        if (!canImport(support)) {
          return false;
        }

        // fetch the drop location
        JTable.DropLocation dl = (JTable.DropLocation) support
            .getDropLocation();

        int row = dl.getRow();

        // fetch the data and bail if this fails
        String data;
        try {
          //获得拖动数据
          data = (String) support.getTransferable().getTransferData(
              DataFlavor.stringFlavor);
        } catch (UnsupportedFlavorException e) {
          return false;
        } catch (IOException e) {
          return false;
        }

        String[] rowData = data.split(",");
       
        //将数据增加到表格中
        tableModel.insertRow(row, rowData);

        Rectangle rect = table.getCellRect(row, 0, false);
        if (rect != null) {
          table.scrollRectToVisible(rect);
        }

        // demo stuff - remove for blog
        model.removeAllElements();
        model.insertElementAt(getNextString(count++), 0);
        // end demo stuff

        return true;
      }
    });

    JList dragFrom = new JList(model);
    dragFrom.setFocusable(false);
    dragFrom.setPrototypeCellValue(getNextString(100));
    model.insertElementAt(getNextString(count++), 0);
    dragFrom.setDragEnabled(true);
    dragFrom.setBorder(BorderFactory.createLoweredBevelBorder());

    dragFrom.addMouseListener(new MouseAdapter() {
      public void mouseClicked(MouseEvent me) {
        if (SwingUtilities.isLeftMouseButton(me) && me.getClickCount() % 2 == 0) {
          String text = (String) model.getElementAt(0);
          String[] rowData = text.split(",");
          tableModel.insertRow(table.getRowCount(), rowData);
          model.removeAllElements();
          model.insertElementAt(getNextString(count++), 0);
        }
      }
    });

    JPanel p = new JPanel();
    p.setLayout(new BoxLayout(p, BoxLayout.X_AXIS));
    JPanel wrap = new JPanel();
    wrap.add(new JLabel("Drag from here:"));
    wrap.add(dragFrom);
    p.add(Box.createHorizontalStrut(4));
    p.add(Box.createGlue());
    p.add(wrap);
    p.add(Box.createGlue());
    p.add(Box.createHorizontalStrut(4));
    getContentPane().add(p, BorderLayout.NORTH);

    JScrollPane sp = new JScrollPane(table);
    getContentPane().add(sp, BorderLayout.CENTER);
    fillBox = new JCheckBoxMenuItem("Fill Viewport Height");
    fillBox.addActionListener(this);

    JMenuBar mb = new JMenuBar();
    JMenu options = new JMenu("Options");
    mb.add(options);
    setJMenuBar(mb);

    JMenuItem clear = new JMenuItem("Reset");
    clear.addActionListener(this);
    options.add(clear);
    options.add(fillBox);

    getContentPane().setPreferredSize(new Dimension(260, 180));
  }

  public void actionPerformed(ActionEvent ae) {
    if (ae.getSource() == fillBox) {
      table.setFillsViewportHeight(fillBox.isSelected());
    } else {
      tableModel.setRowCount(0);
      count = 0;
      model.removeAllElements();
      model.insertElementAt(getNextString(count++), 0);
    }
  }

  private static void createAndShowGUI() {
    // Create and set up the window.
    FillViewportHeightDemo test = new FillViewportHeightDemo();
    test.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

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

  public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
      public void run() {
        // Turn off metal's use of bold fonts
        UIManager.put("swing.boldMetal", Boolean.FALSE);
        createAndShowGUI();
      }
    });
  }
}