Dragging and dropping text between a text area, a list, and a table : Drag Drop « Swing « Java Tutorial






Dragging and dropping text between a text area, a list, and a table
/*
 *
 * Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
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 *
 * This software is not designed or intended for use in on-line control of
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 * the design, construction, operation or maintenance of any nuclear
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 * redistribute the Software for such purposes.
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import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.StringSelection;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.io.IOException;

import javax.swing.BorderFactory;
import javax.swing.DefaultListModel;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextArea;
import javax.swing.ListSelectionModel;
import javax.swing.TransferHandler;
import javax.swing.table.DefaultTableModel;

public class ExtendedDnDDemo extends JPanel {
    
    public ExtendedDnDDemo() {
        super(new GridLayout(3,1));
        add(createArea());
        add(createList());
        add(createTable());
    }
    
    private JPanel createList() {
        DefaultListModel listModel = new DefaultListModel();
        listModel.addElement("List 0");
        listModel.addElement("List 1");
        listModel.addElement("List 2");
        listModel.addElement("List 3");
        listModel.addElement("List 4");
        listModel.addElement("List 5");
        listModel.addElement("List 6");
        listModel.addElement("List 7");
        listModel.addElement("List 8");
        
        JList list = new JList(listModel);
        list.setSelectionMode(ListSelectionModel.SINGLE_INTERVAL_SELECTION);
        JScrollPane scrollPane = new JScrollPane(list);
        scrollPane.setPreferredSize(new Dimension(400,100));
        
        list.setDragEnabled(true);
        list.setTransferHandler(new ListTransferHandler());
        
        JPanel panel = new JPanel(new BorderLayout());
        panel.add(scrollPane, BorderLayout.CENTER);
        panel.setBorder(BorderFactory.createTitledBorder("List"));
        return panel;
    }
    
    private JPanel createArea() {
        String text = "This is the text that I want to show.";
        
        JTextArea area = new JTextArea();
        area.setText(text);
        area.setDragEnabled(true);
        JScrollPane scrollPane = new JScrollPane(area);
        scrollPane.setPreferredSize(new Dimension(400,100));
        JPanel panel = new JPanel(new BorderLayout());
        panel.add(scrollPane, BorderLayout.CENTER);
        panel.setBorder(BorderFactory.createTitledBorder("Text Area"));
        return panel;
    }

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

        JTable table = new JTable(model);
        table.getTableHeader().setReorderingAllowed(false);
        table.setSelectionMode(ListSelectionModel.SINGLE_INTERVAL_SELECTION);

        JScrollPane scrollPane = new JScrollPane(table);
        scrollPane.setPreferredSize(new Dimension(400,100));

        table.setDragEnabled(true);
        table.setTransferHandler(new TableTransferHandler());

        JPanel panel = new JPanel(new BorderLayout());
        panel.add(scrollPane, BorderLayout.CENTER);
        panel.setBorder(BorderFactory.createTitledBorder("Table"));
        return panel;
    }

    /**
     * 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.
        JFrame frame = new JFrame("ExtendedDnDDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Create and set up the content pane.
        JComponent newContentPane = new ExtendedDnDDemo();
        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() {
                createAndShowGUI();
            }
        });
    }
}

abstract class StringTransferHandler extends TransferHandler {
    
    protected abstract String exportString(JComponent c);
    protected abstract void importString(JComponent c, String str);
    protected abstract void cleanup(JComponent c, boolean remove);
    
    protected Transferable createTransferable(JComponent c) {
        return new StringSelection(exportString(c));
    }
    
    public int getSourceActions(JComponent c) {
        return COPY_OR_MOVE;
    }
    
    public boolean importData(JComponent c, Transferable t) {
        if (canImport(c, t.getTransferDataFlavors())) {
            try {
                String str = (String)t.getTransferData(DataFlavor.stringFlavor);
                importString(c, str);
                return true;
            } catch (UnsupportedFlavorException ufe) {
            } catch (IOException ioe) {
            }
        }

        return false;
    }
    
    protected void exportDone(JComponent c, Transferable data, int action) {
        cleanup(c, action == MOVE);
    }
    
    public boolean canImport(JComponent c, DataFlavor[] flavors) {
        for (int i = 0; i < flavors.length; i++) {
            if (DataFlavor.stringFlavor.equals(flavors[i])) {
                return true;
            }
        }
        return false;
    }
}
class ListTransferHandler extends StringTransferHandler {
    private int[] indices = null;
    private int addIndex = -1; //Location where items were added
    private int addCount = 0;  //Number of items added.
            
    //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;
    }
}

class TableTransferHandler extends StringTransferHandler {
    private int[] rows = null;
    private int addIndex = -1; //Location where items were added
    private int addCount = 0;  //Number of items added.

    protected String exportString(JComponent c) {
        JTable table = (JTable)c;
        rows = table.getSelectedRows();
        int colCount = table.getColumnCount();
        
        StringBuffer buff = new StringBuffer();
        
        for (int i = 0; i < rows.length; i++) {
            for (int j = 0; j < colCount; j++) {
                Object val = table.getValueAt(rows[i], j);
                buff.append(val == null ? "" : val.toString());
                if (j != colCount - 1) {
                    buff.append(",");
                }
            }
            if (i != rows.length - 1) {
                buff.append("\n");
            }
        }
        
        return buff.toString();
    }

    protected void importString(JComponent c, String str) {
        JTable target = (JTable)c;
        DefaultTableModel model = (DefaultTableModel)target.getModel();
        int index = target.getSelectedRow();

        //Prevent the user from dropping data back on itself.
        //For example, if the user is moving rows #4,#5,#6 and #7 and
        //attempts to insert the rows after row #5, this would
        //be problematic when removing the original rows.
        //So this is not allowed.
        if (rows != null && index >= rows[0] - 1 &&
              index <= rows[rows.length - 1]) {
            rows = null;
            return;
        }

        int max = model.getRowCount();
        if (index < 0) {
            index = max;
        } else {
            index++;
            if (index > max) {
                index = max;
            }
        }
        addIndex = index;
        String[] values = str.split("\n");
        addCount = values.length;
        int colCount = target.getColumnCount();
        for (int i = 0; i < values.length && i < colCount; i++) {
            model.insertRow(index++, values[i].split(","));
        }
    }
    protected void cleanup(JComponent c, boolean remove) {
        JTable source = (JTable)c;
        if (remove && rows != null) {
            DefaultTableModel model =
                 (DefaultTableModel)source.getModel();

            //If we are moving items around in the same table, we
            //need to adjust the rows accordingly, since those
            //after the insertion point have moved.
            if (addCount > 0) {
                for (int i = 0; i < rows.length; i++) {
                    if (rows[i] > addIndex) {
                        rows[i] += addCount;
                    }
                }
            }
            for (int i = rows.length - 1; i >= 0; i--) {
                model.removeRow(rows[i]);
            }
        }
        rows = null;
        addCount = 0;
        addIndex = -1;
    }
}








14.112.Drag Drop
14.112.1.Basic drag and drop
14.112.2.Dragging Text from a JLabelDragging Text from a JLabel
14.112.3.Drag-and-Drop Support for ImagesDrag-and-Drop Support for Images
14.112.4.Drag and drop icons: use an icon property.
14.112.5.implements DragGestureListener, Transferable
14.112.6.Dragging and dropping text between a text area, a list, and a tableDragging and dropping text between a text area, a list, and a table
14.112.7.Drag and drop between JTextArea and JTextField
14.112.8.Transfer both Text and Color between JTextField and JTextArea
14.112.9.Drag and drop between JList and JTextField
14.112.10.DropMode.ON
14.112.11.DropMode.INSERT
14.112.12.DropMode.ON_OR_INSERT
14.112.13.Set tree DropMode to DropMode.USE_SELECTION
14.112.14.Set tree drag mode to DropMode.ON
14.112.15.Set tree drag mode to DropMode.INSERT
14.112.16.Set tree drag mode to DropMode.ON_OR_INSERT
14.112.17.Choose Drop Action
14.112.18.Various drop actions
14.112.19.JTable drag and drop
14.112.20.Create a drag source a drop target and a transferable object.
14.112.21.Making a Component Draggable
14.112.22.Detect a drag initiating gesture in your application
14.112.23.Illustrates cut, copy, paste and drag and drop using three instances of JList
14.112.24.Location sensitive drag and drop
14.112.25.Demonstration of the top-level TransferHandler support on JFrame
14.112.26.Drag-and-Drop customization: drag the foreground color from the first label and drop it as the background color into the second one
14.112.27.Demonstrates how to add copy and drag support to a Swing component with TransferHandler
14.112.28.ScribblePane allows individual PolyLine lines to be selected, cut, copied, pasted, dragged, and dropped
14.112.29.Built-in drag and drop support: utilize a TransferHandler class
14.112.30.DND Drag and drop List