/* * 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;/* * ListTransferHandler.java is used by the DropDemo example. */import javax.swing.*;import java.awt.*;import java.awt.datatransfer.*;public class ListTransferHandler extends TransferHandler {    private int[] indices = null;    private int addIndex = -1; //Location where items were added    private int addCount = 0;  //Number of items added.                public boolean canImport(TransferHandler.TransferSupport info) {        // Check for String flavor        if (!info.isDataFlavorSupported(DataFlavor.stringFlavor)) {            return false;        }        return true;   }    protected Transferable createTransferable(JComponent c) {        return new StringSelection(exportString(c));    }        public int getSourceActions(JComponent c) {        return TransferHandler.COPY_OR_MOVE;    }        public boolean importData(TransferHandler.TransferSupport info) {        if (!info.isDrop()) {            return false;        }        JList list = (JList)info.getComponent();        DefaultListModel listModel = (DefaultListModel)list.getModel();        JList.DropLocation dl = (JList.DropLocation)info.getDropLocation();        int index = dl.getIndex();        boolean insert = dl.isInsert();        // 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; }                                        // Perform the actual import.          if (insert) {            listModel.add(index, data);        } else {            listModel.set(index, data);        }        return true;    }    protected void exportDone(JComponent c, Transferable data, int action) {        cleanup(c, action == TransferHandler.MOVE);    }    //Bundle up the selected items in the list    //as a single string, for export.    protected String exportString(JComponent c) {        JList list = (JList)c;        indices = list.getSelectedIndices();        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 buff.toString();    }    //Take the incoming string and wherever there is a    //newline, break it into a separate item in the list.    protected void importString(JComponent c, String str) {        JList target = (JList)c;        DefaultListModel listModel = (DefaultListModel)target.getModel();        int index = target.getSelectedIndex();        //Prevent the user from dropping data back on itself.        //For example, if the user is moving items #4,#5,#6 and #7 and        //attempts to insert the items after item #5, this would        //be problematic when removing the original items.        //So this is not allowed.        if (indices != null && index >= indices[0] - 1 &&              index <= indices[indices.length - 1]) {            indices = null;            return;        }        int max = listModel.getSize();        if (index < 0) {            index = max;        } else {            index++;            if (index > max) {                index = max;            }        }        addIndex = index;        String[] values = str.split("\n");        addCount = values.length;        for (int i = 0; i < values.length; i++) {            listModel.add(index++, values[i]);        }    }        //If the remove argument is true, the drop has been    //successful and it's time to remove the selected items     //from the list. If the remove argument is false, it    //was a Copy operation and the original list is left    //intact.    protected void cleanup(JComponent c, boolean remove) {        if (remove && indices != null) {            JList source = (JList)c;            DefaultListModel model  = (DefaultListModel)source.getModel();            //If we are moving items around in the same list, we            //need to adjust the indices accordingly, since those            //after the insertion point have moved.            if (addCount > 0) {                for (int i = 0; i < indices.length; i++) {                    if (indices[i] > addIndex) {                        indices[i] += addCount;                    }                }            }            for (int i = indices.length - 1; i >= 0; i--) {                model.remove(indices[i]);            }        }        indices = null;        addCount = 0;        addIndex = -1;    }}