Java tutorial
/* * 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. */ import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.Rectangle; import java.awt.datatransfer.DataFlavor; import java.awt.datatransfer.StringSelection; import java.awt.datatransfer.Transferable; import java.awt.datatransfer.UnsupportedFlavorException; import javax.swing.BorderFactory; import javax.swing.BoxLayout; import javax.swing.DefaultListModel; import javax.swing.DropMode; import javax.swing.JComponent; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JList; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.ListSelectionModel; import javax.swing.SwingUtilities; import javax.swing.TransferHandler; import javax.swing.UIManager; public class ChooseDropActionDemo extends JFrame { DefaultListModel from = new DefaultListModel(); DefaultListModel copy = new DefaultListModel(); DefaultListModel move = new DefaultListModel(); JList dragFrom; public ChooseDropActionDemo() { super("ChooseDropActionDemo"); for (int i = 15; i >= 0; i--) { from.add(0, "Source item " + i); } for (int i = 2; i >= 0; i--) { copy.add(0, "Target item " + i); move.add(0, "Target item " + i); } JPanel p = new JPanel(); p.setLayout(new BoxLayout(p, BoxLayout.Y_AXIS)); dragFrom = new JList(from); dragFrom.setTransferHandler(new FromTransferHandler()); dragFrom.setPrototypeCellValue("List Item WWWWWW"); dragFrom.setDragEnabled(true); dragFrom.setSelectionMode(ListSelectionModel.SINGLE_SELECTION); JLabel label = new JLabel("Drag from here:"); label.setAlignmentX(0f); p.add(label); JScrollPane sp = new JScrollPane(dragFrom); sp.setAlignmentX(0f); p.add(sp); add(p, BorderLayout.WEST); JList moveTo = new JList(move); moveTo.setTransferHandler(new ToTransferHandler(TransferHandler.COPY)); moveTo.setDropMode(DropMode.INSERT); JList copyTo = new JList(copy); copyTo.setTransferHandler(new ToTransferHandler(TransferHandler.MOVE)); copyTo.setDropMode(DropMode.INSERT); p = new JPanel(); p.setLayout(new BoxLayout(p, BoxLayout.Y_AXIS)); label = new JLabel("Drop to COPY to here:"); ; label.setAlignmentX(0f); p.add(label); sp = new JScrollPane(moveTo); sp.setAlignmentX(0f); p.add(sp); label = new JLabel("Drop to MOVE to here:"); label.setAlignmentX(0f); p.add(label); sp = new JScrollPane(copyTo); sp.setAlignmentX(0f); p.add(sp); p.setBorder(BorderFactory.createEmptyBorder(0, 2, 0, 0)); add(p, BorderLayout.CENTER); ((JPanel) getContentPane()).setBorder(BorderFactory.createEmptyBorder(2, 2, 2, 2)); getContentPane().setPreferredSize(new Dimension(320, 315)); } private static void createAndShowGUI() { // Create and set up the window. ChooseDropActionDemo test = new ChooseDropActionDemo(); 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(); } }); } class FromTransferHandler extends TransferHandler { public int getSourceActions(JComponent comp) { return COPY_OR_MOVE; } private int index = 0; public Transferable createTransferable(JComponent comp) { index = dragFrom.getSelectedIndex(); if (index < 0 || index >= from.getSize()) { return null; } return new StringSelection((String) dragFrom.getSelectedValue()); } public void exportDone(JComponent comp, Transferable trans, int action) { if (action != MOVE) { return; } from.removeElementAt(index); } } class ToTransferHandler extends TransferHandler { int action; public ToTransferHandler(int action) { this.action = action; } public boolean canImport(TransferHandler.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; } boolean actionSupported = (action & support.getSourceDropActions()) == action; if (actionSupported) { support.setDropAction(action); return true; } return false; } public boolean importData(TransferHandler.TransferSupport support) { // if we can't handle the import, say so if (!canImport(support)) { return false; } // fetch the drop location JList.DropLocation dl = (JList.DropLocation) support.getDropLocation(); int index = dl.getIndex(); // fetch the data and bail if this fails String data; try { data = (String) support.getTransferable().getTransferData(DataFlavor.stringFlavor); } catch (UnsupportedFlavorException e) { return false; } catch (java.io.IOException e) { return false; } JList list = (JList) support.getComponent(); DefaultListModel model = (DefaultListModel) list.getModel(); model.insertElementAt(data, index); Rectangle rect = list.getCellBounds(index, index); list.scrollRectToVisible(rect); list.setSelectedIndex(index); list.requestFocusInWindow(); return true; } } }