Text component support cut, copy, paste, drag and drop actions

Description

Demo Code

/**//from w w  w  .  j a v  a 2  s .c om
 * TextCutPaste.java requires the following file:
 *     TextTransferHandler.java
 */

import java.io.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.datatransfer.*;
import java.awt.dnd.*;
import javax.swing.*;
import javax.swing.text.*;
/**
 * TextTransferHandler.java is used by the TextCutPaste.java example.
 */

import java.io.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.datatransfer.*;
import java.awt.dnd.*;
import javax.swing.*;
import javax.swing.text.*;

/**
 * An implementation of TransferHandler that adds support for the
 * import and export of text using drag and drop and cut/copy/paste.
 */
class TextTransferHandler extends TransferHandler {
    //Start and end position in the source text.
    //We need this information when performing a MOVE
    //in order to remove the dragged text from the source.
    Position p0 = null, p1 = null;

    /**
     * Perform the actual import.  This method supports both drag and
     * drop and cut/copy/paste.
     */
    public boolean importData(TransferHandler.TransferSupport support) {
        //If we can't handle the import, bail now.
        if (!canImport(support)) {
            return false;
        }

        //Fetch the data -- 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;
        }

        JTextField tc = (JTextField) support.getComponent();
        tc.replaceSelection(data);
        return true;
    }

    /**
     * Bundle up the data for export.
     */
    protected Transferable createTransferable(JComponent c) {
        JTextField source = (JTextField) c;
        int start = source.getSelectionStart();
        int end = source.getSelectionEnd();
        Document doc = source.getDocument();
        if (start == end) {
            return null;
        }
        try {
            p0 = doc.createPosition(start);
            p1 = doc.createPosition(end);
        } catch (BadLocationException e) {
            System.out
                    .println("Can't create position - unable to remove text from source.");
        }
        String data = source.getSelectedText();
        return new StringSelection(data);
    }

    /**
     * These text fields handle both copy and move actions.
     */
    public int getSourceActions(JComponent c) {
        return COPY_OR_MOVE;
    }

    /**
     * When the export is complete, remove the old text if the action
     * was a move.
     */
    protected void exportDone(JComponent c, Transferable data, int action) {
        if (action != MOVE) {
            return;
        }

        if ((p0 != null) && (p1 != null)
                && (p0.getOffset() != p1.getOffset())) {
            try {
                JTextComponent tc = (JTextComponent) c;
                tc.getDocument().remove(p0.getOffset(),
                        p1.getOffset() - p0.getOffset());
            } catch (BadLocationException e) {
                System.out.println("Can't remove text from source.");
            }
        }
    }

    /**
     * We only support importing strings.
     */
    public boolean canImport(TransferHandler.TransferSupport support) {
        // we only import Strings
        if (!support.isDataFlavorSupported(DataFlavor.stringFlavor)) {
            return false;
        }
        return true;
    }
}

/**
 * Example code that shows a text component that supports both
 * cut, copy and paste (using the DefaultEditorKit's built-in
 * actions) and drag and drop.
 */
public class TextCutPaste extends JPanel {
    TextTransferHandler th;

    public TextCutPaste() {
        super(new BorderLayout());

        setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));

        //Create the transfer handler.
        TextTransferHandler th = new TextTransferHandler();

        //Create some text fields.
        JPanel buttonPanel = new JPanel(new GridLayout(3, 1));
        JTextField textField = new JTextField("Cut, copy and paste...", 30);
        textField.setTransferHandler(th);
        textField.setDragEnabled(true);
        buttonPanel.add(textField);
        textField = new JTextField("or drag and drop...", 30);
        textField.setTransferHandler(th);
        textField.setDragEnabled(true);
        buttonPanel.add(textField);
        textField = new JTextField("from any of these text fields.", 30);
        textField.setTransferHandler(th);
        textField.setDragEnabled(true);
        buttonPanel.add(textField);
        add(buttonPanel, BorderLayout.CENTER);
    }

    /**
     * Create an Edit menu to support cut/copy/paste.
     */
    public JMenuBar createMenuBar() {
        JMenuItem menuItem = null;
        JMenuBar menuBar = new JMenuBar();
        JMenu mainMenu = new JMenu("Edit");
        mainMenu.setMnemonic(KeyEvent.VK_E);

        menuItem = new JMenuItem(new DefaultEditorKit.CutAction());
        menuItem.setText("Cut");
        menuItem.setMnemonic(KeyEvent.VK_T);
        mainMenu.add(menuItem);

        menuItem = new JMenuItem(new DefaultEditorKit.CopyAction());
        menuItem.setText("Copy");
        menuItem.setMnemonic(KeyEvent.VK_C);
        mainMenu.add(menuItem);

        menuItem = new JMenuItem(new DefaultEditorKit.PasteAction());
        menuItem.setText("Paste");
        menuItem.setMnemonic(KeyEvent.VK_P);
        mainMenu.add(menuItem);

        menuBar.add(mainMenu);
        return menuBar;
    }

    /**
     * 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("TextCutPaste");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Create and set up the menu bar and content pane.
        TextCutPaste demo = new TextCutPaste();
        frame.setJMenuBar(demo.createMenuBar());
        demo.setOpaque(true); //content panes must be opaque
        frame.setContentPane(demo);

        //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();
            }
        });
    }
}

/*
 * Copyright (c) 1995, 2008, Oracle and/or its affiliates. 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 Oracle or 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.
 */
Text component support cut, copy, paste, drag and drop actions - Java Swing

Description

Demo Code

Related Tutorials
