/* $Id: ActionPaste.java 17881 2010-01-12 21:09:28Z linus $

  *****************************************************************************

  * Copyright (c) 2009 Contributors - see below

  * All rights reserved. This program and the accompanying materials

  * are made available under the terms of the Eclipse Public License v1.0

  * which accompanies this distribution, and is available at

  * http://www.eclipse.org/legal/epl-v10.html

  *

  * Contributors:

  *    tfmorris

  *****************************************************************************

  *

  * Some portions of this file was previously release using the BSD License:

  */

 // Copyright (c) 1996-2006 The Regents of the University of California. All

 // Rights Reserved. Permission to use, copy, modify, and distribute this

 // software and its documentation without fee, and without a written

 // agreement is hereby granted, provided that the above copyright notice

 // and this paragraph appear in all copies.  This software program and

 // documentation are copyrighted by The Regents of the University of

 // California. The software program and documentation are supplied "AS

 // IS", without any accompanying services from The Regents. The Regents

 // does not warrant that the operation of the program will be

 // uninterrupted or error-free. The end-user understands that the program

 // was developed for research purposes and is advised not to rely

 // exclusively on the program for any reason.  IN NO EVENT SHALL THE

 // UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,

 // SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,

 // ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF

 // THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF

 // SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY

 // WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF

 // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE

 // PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF

 // CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,

 // UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 package org.argouml.uml.ui;

 import java.awt.Toolkit;

 import java.awt.datatransfer.DataFlavor;

 import java.awt.datatransfer.UnsupportedFlavorException;

 import java.awt.event.ActionEvent;

 import java.awt.event.FocusEvent;

 import java.awt.event.FocusListener;

 import java.io.IOException;

 import javax.swing.AbstractAction;

 import javax.swing.Action;

 import javax.swing.Icon;

 import javax.swing.event.CaretEvent;

 import javax.swing.event.CaretListener;

 import javax.swing.text.JTextComponent;

 import org.argouml.application.helpers.ResourceLoaderWrapper;

 import org.argouml.i18n.Translator;

 import org.tigris.gef.base.Globals;

 /**

  * Action to paste the content of either the GEF clipboard or the

  * system clipboard.  The action is enabled if there is content on

  * either clipboard AND either the mouse hovers over the JGraph (the

  * diagram) or the caret in a UMLTextField2 or UMLTextArea2 is

  * enabled.

  */

 public class ActionPaste

     extends AbstractAction

     implements CaretListener, FocusListener {

     ////////////////////////////////////////////////////////////////

     // static variables

     /**

      * The singelton.

      */

     private static ActionPaste instance = new ActionPaste();

     /**

      * The key.

      */

     private static final String LOCALIZE_KEY = "action.paste";

     /**

      * Default constructor for action. We cannot use UMLChangeAction

      * as a parent for this class since it works with shouldBeEnabled

      * etc. which doesn't give enough control about enabling/disabling

      * this action.

      *

      */

     public ActionPaste() {

         super(Translator.localize(LOCALIZE_KEY));

         Icon icon = ResourceLoaderWrapper.lookupIcon(LOCALIZE_KEY);

         if (icon != null) {

             putValue(Action.SMALL_ICON, icon);

         }

         putValue(

                  Action.SHORT_DESCRIPTION,

                  Translator.localize(LOCALIZE_KEY) + " ");

         // setEnabled((Globals.clipBoard != null &&

         // !Globals.clipBoard.isEmpty()) ||

         // !isSystemClipBoardEmpty());

         setEnabled(false);

     }

     /**

      * Singleton implementation.

      * @return The singleton

      */

     public static ActionPaste getInstance() {

         return instance;

     }

     /**

      * The source textcomponent where the caret is positioned.

      */

     private JTextComponent textSource;

     /*

      * @see java.awt.event.ActionListener#actionPerformed(java.awt.event.ActionEvent)

      */

     public void actionPerformed(ActionEvent ae) {

         if (Globals.clipBoard != null && !Globals.clipBoard.isEmpty()) {

                  /* Disable pasting as long as issue 594 is not solved:*/

 //            CmdPaste cmd = new CmdPaste();

 //            cmd.doIt();

         } else {

             if (!isSystemClipBoardEmpty() && textSource != null) {

                 textSource.paste();

             }

         }

     }

     /**

      * Check if there is a selection on the clipboard.

      *

      * @return <code>true</code> if there is.

      */

     private boolean isSystemClipBoardEmpty() {

         try {

             Object text =

                 Toolkit.getDefaultToolkit().getSystemClipboard()

                     .getContents(null).getTransferData(DataFlavor.stringFlavor);

             return text == null;

         } catch (IOException ignorable) {

         } catch (UnsupportedFlavorException ignorable) {

         }

         return true;

     }

     /*

      * @see java.awt.event.FocusListener#focusLost(java.awt.event.FocusEvent)

      */

     public void focusLost(FocusEvent e) {

         if (e.getSource() == textSource) {

             textSource = null;

         }

     }

     /*

      * @see javax.swing.event.CaretListener#caretUpdate(javax.swing.event.CaretEvent)

      */

     public void caretUpdate(CaretEvent e) {

         textSource = (JTextComponent) e.getSource();

     }

     /*

      * @see java.awt.event.FocusListener#focusGained(java.awt.event.FocusEvent)

      */

     public void focusGained(FocusEvent e) {

         textSource = (JTextComponent) e.getSource();

     }

 } /* end class ActionPaste */